Blue Marlin found on Welsh beach.
14/08/2008 09:50:38
Blue Marlin found on Welsh beach. Copyright Gareth Davies.
The Billfishes found in North West Europe are:-
- Sailfish Istiophorus albicans
- Blue Marlin Makaira nigricans
- White Marlin Tetrapterus albidus
- Roundscale Marlin Tetrapterus georgei
- Longbill Spearfish Tetrapterus pfluegeri
The relative bulkiness and the depth of the body of the Welsh fish, in comparison to the height of the dorsal (back) fin shows it to be a Makaira, a blue or black marlin, as opposed the more slender sailfish and white marlins. Opinion among experts varies as whether there are one, two or three species of Makaira. Hence it is difficult to distinguish between them from a photograph. The most likely one is the Blue Marlin Makaira nigricans, with an outside possibility of the Black Marlin Makaira indica.
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.
Swordfish found on a Pembrokeshire beach. Copyright Gareth Davies.
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."
