Blue Marlin - First Ever Recorded in Wales
At this time they could see it was a marlin and contacted South
Wales Sea Fisheries Committee Officer Mark Hamblin to check it out.
Mark was able to determine that it was a Blue Marlin (Makaira
nigricans). A fish virtually unknown in British and Irish waters and
the first ever recorded from the Welsh coast. This large fish with a
spear-like snout can grow up to 5 metres long and weigh over 660
kilos. The Welsh fish was 2.75 metres and weighed about 190 kg. It
is not known what caused its death but the large numbers of dolphins
around the area at the moment might have attacked it, but it also
appears slightly emaciated indicating that it may have been unwell,
or simply unable to feed in the cooler British waters. Once stranded
it was attacked by scavengers that opened up its belly. Having been
photographed and measured, the fish was dumped at sea. Marlin are
sometimes confused with Swordfish, which have a longer stouter bill.
Swordfish are also "heavier" more rotund fish with no pelvic fins
and a single keel on the side of the tail base. Marlin have two
keels on the side of the tail base and their pelvic fins are long
and thin ones attached under the "throat".
There are 11 species of marlin and sailfish worldwide, five of which
have been seen in the North East Atlantic, three having turned up
around the British Isles.
Only second UK specimen ever
Records from the UK Marine Fish Recording Scheme managed by the
National Marine Aquarium in Plymouth show that this is the second
Blue Marlin to be recorded from British and Irish waters and only
the fourth billfish (the first in Wales). The first UK Blue Marlin
was a specimen of 3.7 metres found dead on a beach on St Agnes in
the Isles of Scilly in March 1982. A 1.8 metre long White Marlin was
found alive but dying in Morecambe Bay in August 1983, and a
Sailfish of 2.66 metres was washed up at the mouth of the River
Yealm in South Devon back in August 1926.
National Marine Aquarium
Douglas Herdson, Information Officer at the National Marine
Aquarium, said "The billfish are incredible wanderers of the open
oceans of the world, but prefer warmer waters than ours. It is just
the odd vagrant that strays into our seas and comes to grief. They
are very unusual and it is a shame that this fish did not go into a
national collection such as that of the National Museum of Wales."
"This is just a straggler and probably has nothing to do with
climate change, but in years to come if the sea temperatures
continue to increase they may become commoner around our shores, if
the stocks have not been fished down to depletion."
The marlins and sailfish are powerful warm water ocean wanderers,
migrating vast distances each year, often favouring the blue clear
waters. The warmer surface waters above the temperature change of
the thermocline are the normal hunting ground of the marlin, but
they may dive to 350 metres in the search for prey. In the East
Atlantic Blue Marlin normally occurs as far north as southern Bay of
Biscay.
Fastest fish - 100 Kms per hour
Sleek and muscular, they are the fastest of fish reaching 100
kilometres per hour. Visual predators that hunt by day they have
evolved a wonderful anatomy that maintains the eyes and brain at a
warm temperature so increasing their efficiency. The bill is an
elongated toothless upper jaw whose purpose has long been debated,
but recent studies have shown that it is frequently used to slash,
and even spear, fish they feed on. They also target squid and
octopus. They spawn in tropical regions and move out to cooler
latitudes in the hotter periods of the year.
Fishing pressures have reduced their populations to a mere ten
percent or less of their historic levels.
Doug Herdson commented "The seas are a poorly known world of their
own and every so often they reveal some of their wonders. This just
shows how much we should celebrate and protect our marine life."
Wildlife Extra: September 2008
