Fish distributions reveal discrepancies between zonal attachment and quota allocations

Prof Paul G. Fernandes1, Dr  Niall Fallon1

1University Of Aberdeen, Aberdeen, United Kingdom

The oceans’ fisheries contribute to human wellbeing by providing essential nutrients, employment and income.  The European Union’s (EU) fisheries have improved significantly in the last two decades, with most stocks now sustainably fished; however, some problems remain.  For example, in the EU, the Total Allowable Catch (TAC) for each fish stock is divided into national quotas using a fixed allocation key under the “relative stability” concept, based, largely, on catch records from the 1970s.  These catch records were an indication of fish distributions at the time.  This adherence to 40 year-old information causes significant problems when fish distributions, or management areas, change, due to spatial expansion, climate change, or political changes such as the United Kingdom’s (UK) “Brexit” from the EU.  Changes in distribution jeopardize sustainability because fishers encounter and catch much more than is allocated as quota.  Quotas, or catch shares, should, therefore, correspond to the share of the stock within a country’s Exclusive Economic Zone, a concept known as zonal attachment.  Here, we provide a generic mathematical definition of zonal attachment and assess the zonal attachment of fish stocks present within the United Kingdom’s waters.  In 13 of 14 important fish stocks we examined, estimates of zonal attachment were higher than current quota allocations.  This serves to explain the country’s significant discard problem.  With environmental change, and the recovery of fish stocks under improved stewardship, species are on the move, so scientific evidence should be used not only to set catch limits, but also to re-examine catch shares.


Professor Paul Fernandes holds a Personal Chair in Fisheries Science at the University of Aberdeen in Scotland UK.  His research group focuses on the sustainable management of marine resources.  They use mathematical models to assess the status of fish stocks and to understand the dynamics of marine ecosystems under climate change; they develop advanced survey technologies, notably underwater acoustics, visual surveys and geostatistics, to study the abundance and distribution of marine fauna; and they explore management strategies in support of ecosystem-based fisheries management.

Prior to working at the University, he worked at the Marine Laboratory Aberdeen (now Marine Scotland Science) for over 16 years: initially on fisheries surveys (acoustics and trawl) and, latterly, fish stock assessment, where he was head of the Sea Fisheries Group.  Prior to that he was in Ireland, setting up their fisheries acoustics programme, and in Bolivia working on the artisanal fisheries of Lake Titicaca.

He is a marine biologist, having taken both his BSc and PhD at the wonderful, but sadly now extinct, Port Erin Marine Laboratory of Liverpool University in the UK.  He was born in London, but has Portuguese roots, hence the name. He married a Scot, so is now firmly entrenched in Caledonian customs.

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