Squid differ from fish in more than just short life span. They also have a relatively long juvenile phase, exponential growth, short spawning periods, spatial and temporal variability in population dynmaics and considerable inter-individual variability. Therefore, existing fish management strategies are unlikely to adequately address the spatial and temporal variability evident in squid populations. This project directly addresses the key areas of squid fisheries research, that is the need to clarify the variability in the life history characteristics in space and time. It will only be through the quantification of this information and the application of modelling techniques that we will be able to determine the appropriate management strategy for squid, eg closures vs limited access vs total allowable catch.

A need for research on Southern Calamari has arisen because the fishery targets sexually mature individuals on the spawning grounds while they are mating and laying eggs. This is a short-lived species (6-8 months) and populations are entirely dependent on successful production of young by each generation. Therefore, we need to determine the impacts of fishing upon adult populations and egg production, which may compromise future recruitment.

Fishers and managers in Tasmania have raised questions about the current status of Southern Calamari stocks, with suggestions that increasing exploitation may place the stocks at high risk of collapse. A number of factors such as the short lifespan, low fecundity, non-overlapping generations and high inter-annual recruitment variability of this species exacerbate the risk. Especially since managing a species with these biological characteristics cannot be based on previous catch history. We need to develop numerical models that can use biological indicators to manage stocks that are vulnerable to recruitment failure given that the primary target is spawning individuals.

The current state of biological and ecological knowledge about Southern Calamary does not allow management decisions to be made to allow this fishery to develop at sustainable levels. Consequently, there is an urgent need to quantify the productivity of Southern Calamari populations and determine which components of the population are fished by different gear types.

FRDC have recently allocated $0.5M over 3 years for MAFRI to develop an abalone fishery model (Project 1999/116). Whilst the lack of estimates of illegal catch will not preclude the development of a model it will impede the application of the model for assessing abalone stocks because the true catch is unknown. Recent modelling and risk analysis for the Victorian abalone fishery has demonstrated the high sensitivity of stock reduction models to unknown catch. Although current levels of abalone resource theft are perceived to be high in relation to legal catches, the need to know the quantity of illegally caught abalone persists regardless of such perceptions. Over-estimating the illegal catch can be as serious a problem as assuming it to be negligible. Whilst there is some support for the contemporary view that abalone resource theft is high we also need to know about historical trends in illegal catches to the extent that available data will allow. This is important if we want to draw conclusions regarding the sustainability of the current absolute catch.

Aside from modelling and stock assessment there are other reasons why estimates of illegal catch are required. From a fisheries management perspective the effectiveness of total allowable catch quotas as output controls on Australian abalone fisheries is severely compromised by illegal catches. Even if stock assessments were based solely on fishery independent data that are not compromised by illegal catch levels, management options when deciding whether to adjust catch quotas may be limited if the scale of resource theft is known. For instance, decreases in legal TAC will not reduce the illegal take and may precipitate an increased in unlicensed effort. There will be little ownership by stakeholders of management decisions made under these circumstances. Fisheries enforcement would also benefit from estimating illegal catches, particularly because the underpinning data could be utilised in assessments of compliance rates and evaluation of costs and benefits of alternative enforcement options.

As mentioned in the background to this application, FRDC has already identified the need for projects such as those proposed by MAFRI and NSW FRI (FRDC Wild Abalone Fisheries R & D Needs Review, Project No. 98/170, pp. 69-70).

Resolution of stock structure of toothfish in Australian and other waters is required. Tagging experiments, while important, cannot by themselves give a complete picture of stock structure. If genetic differences between areas are detected, then the amount of gene flow between areas must be minimal and more than one stock can be assumed. However, if differences are not detected, then the hypothesis of a single genetic stock cannot be rejected. This hypothesis may be rejected if there is no evidence from tagging experiments of fish movement between areas. Therefore, resolution of stock structure is better managed by a combination of tagging and genetic approaches than by either approach alone. Tagging experiments are under way; we propose to carry out the required genetic analyses, and then consider both sets of data jointly to define likely stock structures.

Genetic evidence already collected (based on small sample sizes from two areas of Macquarie), suggests that the amount of movement between fishing locations might be very limited. If this preliminary conclusion is substantiated by larger sample sizes, then careful management of the fishery will be needed, as depletion of one area is unlikely to be quickly replaced by immigration from another area.

The work proposed here will resolve this issue for Macquarie island, and will also determine whether there are separable substocks of toothfish around HIMI, and whether the HIMI stock(s) are separable from the Macquarie island stock(s). Importantly, if William's Ridge fish are identified as part of a straddling stock extending into Australia's EEZ (Heard Island), then they can be managed as though wholly part of Australia's EEZ (recent UNIA agreement).

These issues have to be resolved for effective and sustainable management of toothfish fisheries by Australian management (AFMA). The information gathered will also be relevant to the management authorities of other nations controlling toothfish fisheries.

Note: Recent meetings of CCAMLR (1998, 1999) have recognised the urgent requirement of further work on stock structure in D. eleginoides , particularly as initial genetic studies in other laboratories using isolectric focussing and allozyme analysis have reported inconsistent results (see Box 1 below).