David J. Agnew

Current Problems in the Management of Marine Fisheries

The public perception of fisheries is that they are in crisis and have been for some time. Numerous scientific and popular articles have pointed to the failures of fisheries management that have caused this crisis. These are widely accepted to be overcapacity in fishing fleets, a failure to take the ecosystem effects of fishing into account, and a failure to enforce unpalatable but necessary reductions in fishing effort on fishing fleets and communities. However, the claims of some analysts that there is an inevitable decline in the status of fisheries is, we believe, incorrect. There have been successes in fisheries management, and we argue that the tools for appropriate management exist. Unfortunately, they have not been implemented widely. Our analysis suggests that management authorities need to develop legally enforceable and tested harvest strategies, coupled with appropriate rights-based incentives to the fishing community, for the future of fisheries to be better than their past.

Estimating the Worldwide Extent of Illegal Fishing

Illegal and unreported fishing contributes to overexploitation of fish stocks and is a hindrance to the recovery of fish populations and ecosystems. This study is the first to undertake a world-wide analysis of illegal and unreported fishing. Reviewing the situation in 54 countries and on the high seas, we estimate that lower and upper estimates of the total value of current illegal and unreported fishing losses worldwide are between

Review—The CCAMLR Ecosystem Monitoring Programme

10 bn and

Approaches to assessing stocks of Loligo gahi around the Falkland Islands

23.5 bn annually, representing between 11 and 26 million tonnes. Our data are of sufficient resolution to detect regional differences in the level and trend of illegal fishing over the last 20 years, and we can report a significant correlation between governance and the level of illegal fishing. Developing countries are most at risk from illegal fishing, with total estimated catches in West Africa being 40% higher than reported catches. Such levels of exploitation severely hamper the sustainable management of marine ecosystems. Although there have been some successes in reducing the level of illegal fishing in some areas, these developments are relatively recent and follow growing international focus on the problem. This paper provides the baseline against which successful action to curb illegal fishing can be judged.

On the problem of identifying and assessing populations of falkland island squid loligo gahi

The Convention on the Conservation of Antarctic Marine Living Resources states as part of its objective the maintenance of ecological relationships and the prevention of irreversible changes to the ecosystem. The Commission for the conservation of Antarctic Marine Living Resources (CCAMLR) has implemented an Ecosystem Monitoring Programme (CEMP) for the Antarctic marine environment to give effect to this requirement. The design phase of the programme took three years. The programme has been fully implemented since 1987 and involves monitoring selected predator, prey and environmental indicators of ecosystem performance. The central aim of the programme is the detection of changes in these indicators and the interpretation as to whether these changes are due to natural events or the harvesting of marine living resources. The core of the programme is the acquisition, centralised storage and analysis of standardised monitoring data combined with a strong emphasis on empirical and modelling based research. This both modifies the monitoring approach in line with changing requirements and creates a sound scientific background against which to test the effects of management options on components of the Antarctic ecosystem. The development of procedures for translating monitoring results into management advice is a critical part of the programme. Management takes the form of the regulation of fishing activities. Since 1987 CEMP has collected data on six bird and seal species at 15 sites around the Antarctic. Up to 14 parameters of predator performance and 10 parameters of prey and environmental performance are collected at each site. The data sets collected by CEMP form an extremely powerful tool for understanding and managing the Antarctic marine ecosystem.

A revision of the genus Thouarella Gray, 1870 (Octocorallia: Primnoidae), including an illustrated dichotomous key, a new species description, and comments on Plumarella Gray, 1870 and Dasystenella, Versluys, 1906

Management of the Falkland Islands Loligo gahi fishery is by a combination of effort control and in-season assessment of the state of the stock in relation to biological reference points. There are two fishing seasons, from February to May and from August to October inclusive. There appear to be at least two, and sometimes three cohorts that recruit to the fishery over a year, in January, April/May and October. The fishing seasons therefore do not directly coincide with the separate cohorts; the second cohort is caught in both the first and second seasons. Assessments of the cohorts were made using a Delury depletion model. In situations when a Delury could not be fitted satisfactorily, an extension was developed in which annual trends in catchability coefficients were used together with individual vessel CPUE data to estimate stock size. The Delury and its extension enabled both first and second cohorts to be assessed for all years from 1987 to 1996. Results indicated that the cohorts have different dynamics and should be considered as separate stocks. Both cohorts have been declining in size over the last several years. The significance of a transition between two distinct stocks in a single fishing season is discussed in the context of real-time management of this fishery.

Global Estimates of Shark Catches Using Trade Records From Commercial Markets

Patterns of catches of Loligo gahi around the Falkland Islands in the years 1982-1986 initially suggested a simple population structure with one stock peaking in the fishery in autumn and another peaking in spring. Management of two seasons was therefore imposed in 1987. This pattern has proved highly variable, with the result that, for some years, it seems as if up to four cohorts are present in two separated northern and southern fishing areas. In this paper, evidence from fishing vessel and scientific observer data is examined for these different population structures. The conclusion is that the simplest structure that fits the observed data is of two main cohorts recruiting during a year to a single fishing area, albeit with considerable geographic heterogeneity, with a smaller recruitment episode sometimes present at the end of the year. The recruitment of these cohorts to the fishery is not, however, coincident with current management seasons.

Managing fisheries to conserve the Antarctic marine ecosystem: practical implementation of the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR)

A comprehensive revision of the genus Thouarella is presented. Thirty-five holotypes of the 38 nominal Thouarella species, two varieties, and one form were examined. The number of original Thouarella species has been reduced to 25, mostly through synonymy or new genus combinations. In the process several new species have also been identified, one of which is described here as Thouarella parachilensis nov. sp. The genus is split into two groups based on polyp arrangement: Group 1 with isolated polyps and Group 2 with polyps in pairs or whorls. An illustrated dichotomous key and detailed character table of the 25 Thouarella species are presented alongside an up-to-date account of all species described in the 19th and 20th centuries and summaries of the few described from 2000 onwards. We propose that Thouarella longispinosa is synonymous with Dasystenella acanthina, T. versluysi with T. brucei, and, T. tenuisquamis, T. flabellata, and T. carinata are synonymous with T. laxa. Lastly, we propose that T. bayeri and T. undulata be placed in Plumarella and support recent suggestions that T. alternata, T. recta, T. superba, and T. diadema are also Plumarella.