The lack of a consolidated report on the 1995 pilchard mortality event hampered the Joint Pilchard Scientific Working Group in its investigation of the 1998 mortality event. It remains uncertain that the response to the 1998 mortality was efficient and it poses the risk that should another event occur in the future, it too will be met with a poorly-coordinated response. Such a response may not yield adequate data or appropriate data for researchers and fisheries managers around Australia. There is also a risk that scientific investigations may be duplicated, resulting in an inefficient use of industry and public resources.

The lack of a detailed analysis of the events of both 1995 and 1998 and of similar events in other parts of the world compound the difficulties involved in an evaluation of the implications of the mortalities to commercial fisheries and other species which depend wholly or in part on access to pilchards, eg sea lions and penguins.

Considering the prominence of the NSW prawn resources, it is important that managers be equipped with the information necessary to manage the school prawn resource in a sustainable way that provides equity for all stakeholders. Despite its prominence as one of the two most important contributors to the prawn production in NSW, little is known about the population dynamics of this species.

There is evidence to suggest that the school prawn populations in NSW may be overfished. Available information shows that the size of spawning populations in ocean waters may be declining and that prawns are being caught at sizes far shorter than those that would optimise biological “yield per recruit” under an F0.1 fishing policy.

The data which was used in this population modeling of the species had relatively low levels of precision. Estimates of growth and mortality with acceptable levels of precision are needed so that population models can be used with confidence to predict the outcomes of scenarios aimed at optimising the use of the school prawn resource. Out of a list of ten topics needing research, attendees at the Juvenile Prawn Summit assigned the highest priority for research to the study of growth and mortality of school prawns.

For at least the last 12 years SA growers have noticed unexplained mortality of Pacific Oysters. Tests for Pacific Oyster Mortality Syndrome (OHSV-1uvar) have come up negative each time.

The mortality was first documented in Smokey Bay and is now documented in all the major producing Bays in South Australia, including Coffins Bay, Smoky Bay, Cowell and Ceduna (Denial Bay). Mortality rates have been increasing over time. Losses of between 5-20% each year which equates to between $1.8-$7 million per annum.

Mortalities are generally associated with seasonal temperature related stress in the animals. The timing of the mortalities varies from year to year within specific bays. Mortlaities do not follow a geographical distribution with some sites more affected than others. Anacodatal advice from growers indicates that sites with slower growth rates don’t suffer as badly has highly productivity bays.

In recent years, mortalities have been experienced in the major producing bays. Anacdotal adivce from growers indicates that mortality is particularly in smaller to medium size oysters, but mortality is also occuring in mature stock.

There does seem to be a genetic link to the mortality with anacdotal reports of 100 % mortality of certain “batches”. Given this link the breeding program is breeding for resistance to these unexplained mortality events. Susceptibility varies depending on the family line.

In response some growers are lifting the height of the oysters which reduces the mortlaity rate but slows the growth rate and increases the growout time. There is concerm within the industry that this is not an economically viable solution in the long term.

Research has been proposed to investigate unexpained mortality however industry are supportive of an epidemiological analysis of exisiting data and knowledge to narrow the likely causes so that any future research is focused on likely causes.