Times of the Islands Winter 2015-16

green pages newsletter of the department of environment & maritime affairs
It is also quite easy to find them on a dinner plate:
many restaurants will offer this locally caught fish, usually
listed simply as “grouper” on the menu. We take this
for granted, but in some other countries Nassau groupers
have become so rare that it is illegal to catch them. In fact,
the species is considered endangered by the International
Union for the Conservation of Nature, the organisation
tasked with assessing species’ risks of extinction.
Nassau grouper is usually considered to be a coral
reef fish, but that is a little misleading. When grouper
spawn, eggs are released high above the substratum;
eggs then hatch into larvae and spend about forty days
in the water column drifting offshore and potentially dispersing
long distances in the currents. Eventually, once
they have grown about an inch long and become capable
swimmers, larvae are ready to swim back to shallow areas
and settle, but typically the habitats they choose are not
reefs, but seagrass or algal areas.
In the TCI, early juvenile Nassau grouper often use
discarded conch shells and “blowout” ledges — the shelter
formed by exposed roots and rhizomes in seagrass
beds. After spending about a year in their early juvenile
habitats, Nassau grouper migrate to shallow patch reefs,
and then to deeper reefs, where they become reproductively
mature at four to eight years of age. While some reef
fishes breed year-round, Nassau grouper has a very short
spawning season of two to three months only, which in
the TCI runs from December to the end of February and
synchronises with a phase of the moon. Nassau grouper
breeding can be spectacular: they form aggregations
of thousands (reportedly up to one hundred thousand)
with individuals capable of migrating over sixty miles to
spawn at the same location year after year.
Unfortunately, the demise of Nassau grouper
throughout the region is directly linked to fishing spawning
aggregations. Large numbers of big fish found at the
same time and place each year are attractive targets for
fishers, but such fishing has rarely been sustainable, and
sometimes an aggregation of tens of thousands can be
“fished out” in a few years. When this happens, the local
population crashes, the fishery is no longer viable, and
your chances of seeing one on a dive are close to zero.
From top right: Nassau grouper are common fare in TCI. Here, they
are shown at the fishing dock in South Caicos.
Renowned local fisherman and free-diver Conrad Kennedy displays
his impressive catch of Nassau grouper in South Caicos.
Early juvenile Nassau groupers commonly shelter in discarded conch
shells.
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