Understanding and predicting size selectivity and escape mortality in commercial zooplankton fisheries: Case study on Antarctic krill (SILF) (39245)

Project Details

Description

Antarctic krill is an important fisheries resource, regarded as one of the most under-exploited fisheries in the world. Concern is expressed regarding the future sustainability of harvesting and the impact this may have on dependent predators. This is associated with the cumulative pressure from ongoing environmental changes, which modify abundance, distribution and life cycle of krill.

Due to large gaps in knowledge about this marine ecosystem and potential negative effects caused by fishery activities, both the Commission and Scientific Committee of CCAMLR strongly request knowledge about the effects of different fishing gear on krill escape and the indirect mortality on the krill stock. Indirect fishing mortalities include organisms that die after escaping from fishing gear due to injury.

CCAMLR is currently improving their management system, by establishing feedback management procedures and Small Scale management Units. They recommend members to have scientific observers on board to enhance control measures and Marine Protected Areas around the continent is established with various degrees of allowing for exploratory fishing and rational use. It is highly uncertain to establish such a management regime without scientific knowledge about the impact of fishing on the ecosystem. There is an urgent need to address these questions, also for the sake of the development of other new and exploratory fisheries.

A pilot study (NEAT) using both mathematical modeling techniques and practical experiments on size selection of krill shows that escape occurs even from some of the smallest commercial meshes used in the fishery. In this study, we will assess different trawl designs sizes selectivity and establish predictions of sizes selectivity of krill in any given trawl design.

We will also perform experiments to examine the rate of escape mortality of krill in trawls and couple this to full gear sizes selectivity to allow evaluation and optimization of trawls in the commercial krill fishery.

The developed methods are directly transferable to similar fisheries e.g. fisheries targeting species lower in the food chain.

This project is coordinated by the Institute of Marine Research, Norway and funded by the Research Council of Norway.

Research area: Fisheries Technology
StatusFinished
Effective start/end date01/01/201531/12/2017