24 January 2019
The Fisheries Research and Development Corporation (FRDC) welcomes the defence of Australia’s fisheries record in a paper authored by prominent fisheries scientists.
The paper upholds the assessments of fish stock health published bi-yearly in the Status of Australian Fish Stocks Reports (www.fish.gov.au), and contributed to by more than 100 of Australia’s fisheries scientists. Australia’s fisheries are internationally regarded as some of the healthiest and best managed in the world, underpinned by robust and independent science.
The FRDC’s Managing Director, Dr Patrick Hone, said it is pleasing to see the scientific process working. Researchers defending the integrity of Australian fisheries science, by critically analysing research that was clearly deficient.
The paper, published in the Journal of Aquatic Conservations, Marine and Freshwater Ecosystems https://doi.org/10.1002/aqc.2992 refutes the claims made by Edgar et al. in the scientific paper Rapid declines across Australian fishery stocks indicate global sustainability targets will not be achieved without an expanded network of ‘no‐fishing’ reserves.
Initial study lacked scientific rigor
Comments on the evidence for the recent claim on the state of Australian fish stocks by Little LR, Day J, Haddon M, et al., leading researchers from CSIRO, clearly outlines the problems inherent in the methodology used by Edgar et al. These include wrongly extrapolating survey results from shallow inshore areas and applying them to the continental shelf and slope. The analysis also shows the previous study contained numerous analytical deficiencies and factual errors.
It demonstrates how data on commercial catch declines has been used selectively, and catch reporting data should not be used alone to determine biomass. For example, Edgar et al. assume commercial catch level and fish biomass are directly linked (source of data ABARES), which is rarely the case. For example, the Australian fishing fleet has experienced a substantial restructuring over the last 10 years. Likewise catch rates are influenced by many factors other than abundance including, changes in fisher behaviour, management arrangements, costs of fishing and industry profitability.
Valid concerns require further investigation
While the fisheries scientists dispel the above claims, they acknowledge that there are two valid concerns raised in the critiqued study. Firstly, that shallow water inshore survey (downward) trends reported in the original paper are likely valid and should be of concern. Secondly, that a thorough audit and analysis of the reasons for the decline in commercial catch is important, so long as it uses appropriate methods of analysis.
Both articles serve as reminders that fisheries are dynamic systems and require active monitoring and where appropriate management actions need to be taken to ensure the health of populations.
Australia has a justifiably high standard of fisheries science and a corresponding robust standard of fisheries management.
Dr Patrick Hone, said the soon to be released 2018 Edition of the Status of Australian Fish Stocks Reports (www.fish.gov.au) will provide the largest national assessment of the status of Australia’s fisheries undertaken – in total 120 fish species.
