Improve catch rate standardizations to account for changes in targeting
Catch rates are important as the only index of relative abundance in most Australian fisheries. Numerous projects have attempted to improve catch rate standardization in multi-species fisheries but there remains no agreed robust method. Another study of alternative applications of GLMs or GAMs, etc, is unlikely to resolve the issue because the multi-species nature of many of Australia’s fisheries has always overwhelmed attempts at determining targeting behaviour solely from logbook data. There is therefore a need to analyse the problem of targeting and standardization using techniques akin to Management Strategy Evaluation such that standardization strategies can be compared in an environment where the underlying trends in a multi-species fishery being standardized are known.
This is becoming more critical as recent large scale management initiatives (HSP) are beginning to influence how fishers operate and this is changing the character of catch rates. Some species are being actively avoided, which gives a false impression of stock decline; the bias would always be downwards. This obfuscation of catch rates will eventually threaten our ability to assess the stocks appropriately in the absence of a time series of Fishery Independent Surveys. There is a need to understand the extent of this problem and what can be done to mitigate against incorrect assessments of stock status.
There is a need to use available survey information in addition to the use of logbooks to provide a strong test of methods. Additionally, there is a need to simulate catch rate data realistically so that different methods can be subject to stringent testing. This would have wide national and international value.
