Spatial Mismatch in Krill Management Approach

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Document Number:

WG-FSA-2023/54

Author(s):

Warwick-Evans, V., M.A. Collins and S. Hill

Submitted By:

Dr Martin Collins (United Kingdom)

Approved By:

Dr Martin Collins (United Kingdom)

Agenda Item(s)

WG-FSA-2023 - 3 - Krill

Abstract

Work towards the development of a revised management approach for the krill fishery in subarea 48.1 has been conducted within several working groups. The objectives of the revised approach include distributing the catches between several management units to ensure that they do not become too spatially concentrated. Here we examine three elements of this work (a set of spatial units developed for calculating krill biomass, and two implementations of a similar spatial overlap analysis) for consistency of approach in representing spatial units. We find several differences including in the projections used to map the units, their shape and area. We identify some potential risks associated with these differences – including the risk of increasing the spatial concentration of catches if a catch limit based on a biomass estimate for the whole of 48.1 is allocated to the smaller area considered in the spatial overlap analysis. We suggest that the Scientific Committee consider whether a standardised set of management units based on a consistent mapping approach is necessary.