Wednesday 21 December 2016

The Manchester giant grouper

The Manchester giant grouper: putting Manchester on the map for the wrong reasons

Dominic A. Andradi-Brown, Clive Hambler, Michelle L. Taylor, Elizabeth Wood

Last week we were greeted with the regrettable news that a grouper, "the third largest fish of its kind on record", an animal that lived out its life around the tropical coral reefs of the Indian Ocean, was flown to a fish market in Manchester, UK. What can be learned - or gained - from its fate?

The grouper was reported to weigh '30 stone' (192 kg) and be over 2 m long (6ft 5in), drawing media coverage in several British newspapers, the BBC and internationally. The market owner was quoted in the Manchester Evening News as saying this was a chance to really 'put Manchester on the map'. As ecologists we understand the excitement of seeing a fish of this size, as did the hundreds of people who visited, curious to see it in the flesh.



[Source: https://twitter.com/directfisherie1/status/808597957318758400]

As conservationists however, we were dismayed at how the story was reported in the media. Revealingly, the capture and transport of this grouper from a deep-water site near the Seychelles to Manchester, thousands of kilometres away, was presented as an impressive feat, with little critical evaluation - except by many of the online commentators on the articles. In an age of supposed interest in 'sustainability' it is remarkable that news outlets typically did not question whether such large predatory fish should be caught for food, or discuss whether flying it into the UK would be creating demand for species not found in UK waters.

We don't know for certain what this fish was (since it was reported variously as giant grouper, brown grouper or goliath grouper). However based on the published photos it's most likely to be the Giant Grouper, Epinephelus lanceolatus, a ‘Vulnerable’ species on the IUCN Red List of threatened species. Fishing is the major threat to this species, and being classified as Vulnerable means it is facing a high risk of extinction - as is more widely appreciated with other Vulnerable species such as Leatherback and Loggerhead Turtles.

[ Source: https://twitter.com/directfisherie1/status/808322703555969024]

There are several reasons why groupers should not be commercially fished for export markets such as the UK and why consumers here should not eat them. They are large predatory fish, and their removal from an ecosystem can have big knock-on effects on many other marine species [1]. The biology of some groupers may also make their populations particularly sensitive to losing large individuals to fishing [2]. Groupers are sequential hermaphrodites, changing sex from female to male as they become larger. We don't know the sex of the 'Manchester grouper', but from its size a guess would be that it was a male and likely to have been decades old. For example, similar sized Goliath Groupers from the Atlantic are estimated to be approximately 37 years old, with projections they can live to be over 50.

The conservation community has been surprisingly slow to condemn the coverage and consumption of this fish - although protest is now building. It may not be too late to expand on the public interest in this unfortunate individual - for the wider benefit of such species. Perhaps the legacy of the 'Manchester grouper' will eventually be to put the city on the map as a turning point in concern for exotic marine species, raising awareness of how to reduce our impacts - and resist temptation for the spectacular.

The Marine Conservation Society Good Fish Guide (printable and pocket-sized) and App suggests sustainable fish to eat, and also, importantly, which fish to avoid. For the reasons outlined above, it rates all grouper species as 'fish to avoid' and places them in the 'least sustainable' category. Brilliantly, this guide also provides a list of alternative, more sustainable choices allowing seafood consumers to easily switch to a similar but more environmentally-friendly option. Whilst we appreciate the Manchester grouper was just one fish, there are other more locally-sourced and more sustainable fish choices available. We hope the media buzz doesn't increase demand for groupers and other exotics in the UK. After all, in the case of Giant Grouper, and contrary to the age-old saying, there aren't plenty more fish in the sea.

References
[1] Dulvy, N.K., Freckleton, R.P. & Polunin, N.V.C., 2004. Coral reef cascades and the indirect effects of predator removal by exploitation. Ecology Letters, 7(5), pp.410–416.
[2] Coleman, F.C., Koenig, C.C. & Collins, L.A., 1996. Reproductive styles of shallow-water groupers (Pisces: Serranidae) in the eastern Gulf of Mexico and the consequences of fishing spawning aggregations. Environmental Biology of Fishes, 47(2), pp.129–141.
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