The Goliath Grouper, a giant under threat
The Goliath grouper undoubtedly needs people in its corner, but it’s not the only family member at risk. The calico grouper, Epinephelus drummondhayi, is another critically endangered relative. It may be smaller, but can still grow to an impressive 1.1m and 30kg. It’s a striking looking fish, adults are dark red and covered in distinctive white spots. It’s clear how it gained its alternative names, the strawberry grouper or speckled hind.
Calico groupers are sequential hermaphrodites, meaning they start life as females and become male after seven to fourteen years. They reach sexual maturity in about five years, and can live for twenty-five. This slow growth makes the population vulnerable even though each female produces many young. They are key predators in their habitat, so population trends certainly have top down impacts on the ecosystem they inhabit.
It is largely resident in American waters, from the Gulf of Mexico up through the Western Atlantic. Although some individuals been recorded in Bermuda, there is not a breeding population there. The calico grouper is a coastal, deep water species, which makes it vulnerable to a number of threats.
A catch of 16 Goliath grouper made on the charter boat Gulfstream in the 1950's. Photo from the Wil-Art Studio, gift of Angie Marine.
It is fished recreationally and commercially. There are protections in place, with a catch restriction of one grouper per vessel per trip, but the sheer extent of fishing activity in its range still makes this a significant impact to such a large, slow maturing fish species.
Fishing restrictions have no impact on the effects bycatch, which is a major threat to the calico grouper. As a deep water species, the change in pressure of being accidentally caught causes severe gas expansion in the swim bladder (barotrauma), meaning even if immediately released, a grouper is highly unlikely to survive the capture experience. As shallow-water fish stocks decline, fishing is moving increasingly into deep ocean habitats, increasing the risk of bycatch for species like the calico grouper.
Perhaps we should accept that we shouldn’t be recreationally fishing such rare and at risk animals, or at the very least that the restrictions should be much tighter.
Bycatch is hard to tackle, and is a major problem for many marine species – fish, whales, dolphins, sharks, and even seabirds.
NOAA scientists gather data on Goliath Grouper
NOAA Fisheries funds a Bycatch Reduction Engineering Program to sup-port the development of new technologies to minimise bycatch. This is an excellent example of how marine conservation as a field is expanding. We need more than just biologists to save species like the calico grouper – it’s time for everyone to get involved however they can.
Coverphoto: http://oceana.org/marine-life/ocean-fishes/atlantic-goliath-grouper http://www.arkive.org/calico-grouper/epinephelus-drummondhayi/ https://www.fisheries.noaa.gov/national/bycatch/bycatch-reduction-engineering-program https://www.fisheries.noaa.gov/national/bycatch/national-bycatch-reduction-strategy#what-is-noaa-fisheries-doing-about-bycatch http://www.iucnredlist.org/details/7854/0