411 results
Adoption
PROJECT NUMBER • 2002-641
PROJECT STATUS:
COMPLETED

Aquatic Animal Health Subprogram: crayfish plague disease strategy manual

Crayfish plague is a serious disease of freshwater crayfish in Europe. The infectious agent, Aphanomyces astaci, is an Oomycete that produces hyphae and zoospores and is similar to a fungus. Studies have shown that Australian freshwater crayfish are susceptible to the disease but the disease has...
ORGANISATION:
Aquatilia Healthcare
TAGS
Stakeholder
Reproduction
Invasive Species
Health And Safety
Fisheries Management

Development of acoustic methods to survey orange roughy in the eastern and southern zones

Project number: 1995-031
Project Status:
Completed
Budget expenditure: $144,588.00
Principal Investigator: Tony Koslow
Organisation: CSIRO Oceans and Atmosphere Hobart
Project start/end date: 20 Sep 1995 - 5 May 1999
Contact:
FRDC
TAGS
Survey
Reproduction
Remote Sensing
Life History
Harvest Strategy

Objectives

1. Conduct 2-3 acoustic surveys of orange roughy spawning ground off St Helens, TAS during the peak spawning period 1995
2. Determine the species composition of acoustic marks through trawl sampling of the acoustic marks and the ensonification of targets with several frequencies
3. Determin the relative biomass and spawning condition of orange roughy in the Eastern and Southern zones during the spawining period based upon a survey of selected hills in the Southern Zone that contain the principal concentration of orange roughy
4. Assess the biomass of orange roughy in the area between St. Helens and the Southern Hills through a series of zig-zag transects between 700-1200m and to assess their spawning condition

Final report

ISBN: 0643 06191 6
Author: Tony Koslow
Final Report • 1999-04-09 • 9.30 MB
1995-031-DLD.pdf

Summary

Three acoustic surveys were carried out between 17 and 20 July 1996 on the orange roughy spawning ground off St. Helens, Tasmania. A combination of 22 demersal trawls and ensonification with three frequencies (12, 38 and 120 kHz) was used to assess the species composition around the spawning hill. Both methods showed that orange roughy were aggregated on only the north/northwestern half of the hill. Acoustic marks on the south/southwestern sector of the hill were composed predominantly of macrourids (rattails) and deepwater cods. This was the first successful use of multi-frequency acoustics to discriminate among species groups in a deepwater environment and should greatly enhance the resolution of deepwater acoustic surveys. Acoustic estimates of orange roughy biomass on the spawning hill ranged from 5649 - 9706 tonnes, down from 16,777 tonnes in 1993. A survey of the trawl ground off St. Patrick's Head noted a single moderate-sized aggregation on a single transect.
 
If the school as assumed to be spherical in cross-section, its biomass was 6% the biomass of the largest orange roughy school observed at St. Helens. The biomass at St. Patrick's Head thus appears to have been a small proportion of the biomass around St. Helens Hill during the survey, but the data were insufficient to derive a biomass estimate from this area with confidence. Acoustic surveys were also carried out on a small hill just north of St. Helens and on the seamounts in the Southern Zone but no significant acoustic marks associated with orange roughy were observed in these areas.
 
Several changes were made to the methods of analysis. First, the area of the strata comprising the St. Helens hill were re-calculated based on improved bathymetric and GPS data,. Secondly, we changed the method used to account for targets within the deep scattering layers (DSL) that extend across the survey area. A constant fraction of the ensonified targets were previously assumed to belong to the DSL, but this assumption was no longer tenable considering both the decline in orange roughy abundance on the hill and the ~2-fold variation in the abundance of midwater scatterers between surveys in 1996. Acoustic backscattering from areas outside the survey area were now measured for each survey and subtracted from the backscattering observed around the hill itself. These changes were applied retrospectively to biomass estimate from previous orange roughy surveys.
 
Environment
Industry
Environment
Environment
PROJECT NUMBER • 2016-028
PROJECT STATUS:
COMPLETED

Where do Calamari spawn in Northern Tasmania and how will this information aid the management of the Calamari fishery in Northern Tasmania?

This project has responded directly to management and industry concerns over a rapid increase in catch and effort on the Tasmanian north coast Southern Calamari fishery. The survey methodology applied in this project provided the evidence-base for implementing the first north coast Southern Calamari...
ORGANISATION:
University of Tasmania
TAGS
Yield
Sustainability
Stock Assessment
Reproduction
Recreational Fishing
SPECIES
Southern Calamari
Environment
PROJECT NUMBER • 2016-044
PROJECT STATUS:
COMPLETED

Next-generation Close-kin Mark Recapture: using SNPs to identify half-sibling pairs in Southern Bluefin Tuna and estimate abundance, mortality and selectivity

This report presents the results of the first application of Close-Kin Mark-Recapture (CKMR) using both Parent-Offspring Pairs (POP) and Half-sibling Pairs (HSP). This application to Southern Bluefin Tuna (SBT) has been successful, providing a decadal time series of absolute abundance, total...
ORGANISATION:
CSIRO Oceans and Atmosphere Hobart
TAGS
Stock Assessment
Reproduction
Rac Cmwth
Mortality
Modelling
SPECIES
Southern Bluefin Tuna
Environment
PROJECT NUMBER • 2003-075
PROJECT STATUS:
COMPLETED

Designing, implementing and assessing an integrated monitoring program for the NPF: developing an application to stock assessment

For more than a decade the Northern Prawn Fishery assessments have indicated that the tiger prawn resource is overexploited. Deriso’s1 (2001) review of the tiger prawn assessment supported this conclusion and also drew attention to the high level of uncertainty in the assessment. Deriso...
ORGANISATION:
CSIRO Oceans and Atmosphere Hobart
TAGS
Survey
Stock Assessment
Reproduction
Population Dynamics
Fishing Gear
SPECIES
King Prawns
Banana Prawns
Tiger Prawns
Endeavour Prawns
Industry
PROJECT NUMBER • 2013-221
PROJECT STATUS:
COMPLETED

Stock enhancement of the Western School Prawn (Metapenaeus dalli) in the Swan-Canning Estuary; evaluating recruitment limitation, environment and release strategies

Keywords: Aquaculture-based enhancement, recreational fishing, restocking, post-release survival, larval ecology, larval taxonomy, fish predation Executive Summary: This report provides the first comprehensive investigation into the biology and ecology of the Western School Prawn...
ORGANISATION:
Murdoch University
TAGS
Stock Assessment
Restocking
Reproduction
Recreational Fishing
Rac Wa
SPECIES
School Prawns
Environment
PROJECT NUMBER • 2004-099
PROJECT STATUS:
COMPLETED

An integrated monitoring program for the Northern Prawn Fishery: assessing the design and developing techniques to incorporate survey results into fishery assessment

An international review of the Northern Prawn Fishery tiger prawn assessment was carried out in 2001. The review drew attention to the high level of uncertainty in the assessment and recommended that the logbook data be augmented by fishery-independent survey data. In response to the review,...
ORGANISATION:
CSIRO Oceans and Atmosphere Hobart
TAGS
Survey
Stock Assessment
Reproduction
Population Dynamics
Fishing Gear
SPECIES
King Prawns
Banana Prawns
Tiger Prawns
Endeavour Prawns
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