Crustacean Stock Assessment in Namibia

During 1999, Nokome Bentley of Trophia took part in a workshop in Namibia, which aimed to: Review and assess research methods used at present in the lobster and crab research program and recommend alternative methods where necessary. Review and Assess the Namibian lobster and crab database as well as methods of data analysis. Assess the population models presently used in the Namibian crab and lobster stock assessment and test alternative models (also… Read More

Assessment of the trade in live reef fish in the Indian Ocean

In early 1998, the International Marinelife Alliance and the World Resources Institute launched the Destructive Fishing Reform Initiative. The objective of the Initiative is to protect Indo- Pacific coral reefs of outstanding significance from cyanide and other forms of destructive fishing, prevent over-harvesting of live reef fish trade target species, and to establish durable and sustainable reef management policies and practices. The purpose of this project was to provide an overview of… Read More

Stock Assessment of the New Zealand Rock Lobster Fishery

Trophia is contracted by the New Zealand Rock Lobster Industry Council (NZRLIC) to undertake stock assessment research on New Zealand’s rock lobster fishery for the Ministry of Fisheries. Generalised linear models are used to summarise temporal and spatial trends in the catch rates of lobsters. Trophia is assisting in the development of a size structured population dynamics model for rock lobster stocks in New Zealand. This model will enable estimation of population… Read More

New Zealand Rock Lobster Industry Voluntary Logbook Programme

Rock lobster fishers in many parts of New Zealand keep logbooks in which they record the size, sex and stage of maturity for the lobsters they catch. Currently logbook data is used in the stock assessment process and to generate annual summaries to participants. The extensive nature of the logbook sampling provides data that is more representative of the catch than intensive research sampling. As a consequence, the new size-structured model, used… Read More

Use of areas closed to fishing as a diversification strategy to reduce the risk of over-fishing

Along with more traditional regulation of catch and fishing effort, areas closed to harvesting (hereafter closures) have long been used by fisheries managers as tools for the conservation and management of marine habitats. Closures may, broadly, impact on fisheries through two related but different means. Firstly, they may serve as a refuge for animals that grow within the closure and are harvested outside the closure (export of adults). Secondly, and more indirectly,… Read More

New Zealand CRA5MAC Charter Logbook Programme

In New Zealand, commercial catches are accurately recorded through the quota management system. In contrast there are relatively poor estimates of the catch taken by the non-commercial sector, which includes charter boat and own-boat recreational fishers. A logbook scheme for charter boat operators, is currently being implemented in CRA5 quota management area. From this programme an accurate estimate of the charter boat component of the recreational catch will be obtained. The format… Read More

Stock Assessment of the New Zealand Rock Lobster Fishery 2001-02

Trophia is contracted by the New Zealand Rock Lobster Industry Council (NZRLIC) to undertake stock assessment research on New Zealand’s rock lobster fishery for the Ministry of Fisheries. Generalised linear models are used to summarise temporal and spatial trends in the catch rates of lobsters. Trophia is assisting in the development of a size structured population dynamics model for rock lobster stocks in New Zealand. This model will enable estimation of population… Read More

New Zealand Rock Lobster Industry Voluntary Logbook Programme

Rock lobster fishers in many parts of New Zealand keep logbooks in which they record the size, sex and stage of maturity for the lobsters they catch. Currently logbook data is used in the stock assessment process and to generate annual summaries to participants. The extensive nature of the logbook sampling provides data that is more representative of the catch than intensive research sampling. As a consequence, the new size-structured model, used… Read More

Coleraine: A Generalised Stock Assessment Tool

Coleraine is a generalised stock assessment tool developed by the New Zealand Seafood Industry Council (SeaFIC) and the University of Washington. Coleraine is able to assist fisheries scientists and managers using the methods of Bayesian statistical decision analysis. Trophia was contracted by SeaFIC to contribute to this project by: Verifying that the program worked. Producing a simulator for testing precision and accuracy of estimates Proposing bugfixes and improvements Contributing to documentation

New Zealand Rock Lobster Industry Voluntary Logbook Programme

Rock lobster fishers in many parts of New Zealand keep logbooks in which they record the size, sex and stage of maturity for the lobsters they catch. Currently logbook data is used in the stock assessment process and to generate annual summaries to participants. The extensive nature of the logbook sampling provides data that is more representative of the catch than intensive research sampling. As a consequence, the new size-structured model, used… Read More