This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

This study investigated the relationships between recruitment of Australian salmon (western species Arripis truttaceus) in Barker Inlet, South Australia for the period 1981-1994 and environmental factors such as wind, mean sea level, Southern Oscillation Index (SOI) in spawning grounds Western Australia. Correlations between recruitment numbers in Barker Inlet and mean sea level in Albany, near the spawning grounds, for March, April, May and June for the period 1981-1993 were carried out. All the regressions except May were non-significant for mean level sea level. The correlation between the SOI and mean sea level for May in Albany is significant, while the numbers in Barker Inlet were non-significant. Three hourly wind data for Albany, Western Australia for the period 1981-1995 were resolved into northerly, southerly, easterly and westerly components. A consistent feature of these results was the presence of westerly winds which followed the time of spawning of the salmon (April-May). Duration of continuous westerly component winds ranged between 3 to 7 months during the period 1981-1994. NOAA/AVHRR sea surface temperature (SST) data of cross-shelf gradients in spawning grounds near Albany, Western Australia were examined. Published SST data of the Great Australian Eight (GAB) were examined and used to delineate major current systems of the region. Conductivity-temperature- depth (CTD) surveys were conducted which allowed differentiation of the various water masses present on and off the southern continental shelf. Acoustic Doppler Current Profile (ADCP) measurements along route confirmed the CTD survey results that the easterly limit of the Leeuwin Current was approximately 124 E and confirmed presence of increased shelf edge flow in the eastern portion of the GAB. The temperature of the Leeuwin Current appears as one of several factors which induce spawning. Afterwards the salmon eggs need to be favorably positioned within the mainstream of the Leeuwin Current to be advected to the east. This is affected by favorable winds which transport the larvae into the mainstream of the Leeuwin Current. Larval advection may be adversely affected by offshoots or cold-water intrusions which may transport salmon larvae well off the shelf.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.

The Western Rock Lobster (Panulirus cygnus George) is the most valuable single species fishery in Australia with an annual value in excess of $250 000 000. Consequently, there has been a substantial research effort geared towards gaining a better understanding of the basic biology of this species which has resulted in a comprehensive management programme by the Fisheries Department of Western Australia. This research effort has revealed, amongst other results, a correlation between the relative strength of post-larval recruitment and inter-annual variation in oceanographical processes. More specifically, the strength of puerulus settlement has been shown to correlate positively with the relative strength of flow of the Leeuwin Current as inferred by mean monthly sea level (Pearce & Phillips 1988). There is as yet no strong evidence to suggest a mechanism which might account for this con-elation. This is due largely to the scarcity of information available regarding the pelagic larval phase of the Western Rock Lobster's life cycle.

The bulk of our knowledge concerning the pelagic larval phase of the life cycle emanates from a series of oceanographical surveys conducted by the CSIRO in the 1970's which documented the horiwntal and vertical distribution of phyllosomata off the coast of Western Australia. The results of these surveys suggested that phyllosomata may modify patterns of daily vertical migration in order to take advantage of surface and subsurface circulation features such that horizontal transport conducive to recruitment is achieved (Rimmer & Phillips 1979). Correlational evidence suggests further that light may play an important role in regulating the depth distribution of phyllosomata and also that larval response to light may change with development These investigations did not, however, address the relative role of the Leeuwin Current in larval recruitment dynamics.

There is no laboratory based information available on the relative effect of light and temperature on phyllosoma behaviour and physiology due largely to the difficulties associated with reliable larval culture. Such information is vital to a comprehensive understanding of the possible mechanisms by which inter-annual oceanographic variation may affect larval growth and, ultimately, post-larval recruitment. The purpose of the present study was to investigate the behavioural ressponse to light and the physiological response to temperature of early and mid­stage phyllosomata cultured in the laboratory. The study was made possible because of recent advances in larval culture technology developed at the Marine Biology Laboratory of the Department of Zoology, University of Western Australia.