But which way is it going?
The three creatures which have tentacles – squid, octopus and cuttlefish – are known as cephalopods. Squid is significantly more abundant than cuttlefish and octopus. All three types descended from a kind of sea snail with an external shell, with evolution resulting in the shell being internalised, most prominently in the cuttlefish’s cuttlebone; the squid has instead just a thin translucent “quill” (or gladius to icthyologists). Tentacles – eight for the octopus and 10 for the other two types - are not the only feature they have in common. They all have impressive brains, acute vision, eject ink clouds to defend themselves and move by jetting water out of a syphon. Most can change colour to disguise themselves or to make signals.
They are normally social creatures, but not for long: they mature, they mate, they die, usually within three years, sometimes within one (Japanese flying squid). Most squid are pretty prolific – a typical egg count is 100,000 (although that’s nothing compared to a cod).
Cephalopods’ syphons are inside their mantle pointing out past the head. They propel themselves by taking water into the mantle and squirting it through the syphon. Thus they usually travel “backwards”. But their fins can propel them “forwards” if something tasty is in sight.
STUFF OF NIGHTMARES?
Giant squid which attack ships are not entirely creatures of legend. In 1978, a squid attacked the sonar pod under the hull of a naval destroyer, USS Stein. The squid was not seen during the episode, but it was later deduced that it was larger than any squid known to science. The largest squid which has been captured was from a rare species called the colossal squid – it’s in the Te Papa Museum in Wellington, New Zealand. Uncaptured specimens are believed to reach up to 13 metres to the tips of their tentacles or 6 metres for the main body section and weigh over 600 kgs. (Claims about large squid are normally a bit tongue-in-cheek: the big numbers almost always refer to tail to tentacle tip, which is like measuring a human from tippy-toe to the long finger at the top of upstretched arm. Ask ”How long was the mantle?”) The average squid reaches about half a metre and the pygmy squid is doing well at one inch.
The vampire squid is a small very deep sea species with a cloak joining its arms. It’s pretty terrifying to small creatures deep in the sea but harmless to man. The likening of Goldman Sachs to a giant vampire squid rested heavily on the false premise “giant”.
Squid fishing is often carried out at night when lights are used to attract the squid towards the boat. Jigging is a widespread fishing method used for many species but especially popular with squid fishermen. Jigs are hooks attached to a fishing line typically at one metre intervals. A lure may or may not be attached to the jig. The line might be 10 to 50 metres long according to the sea depth. The line is dropped vertically, powered by a weight at its end.
|Artisinal squid fishing off Korea|
The line is then reeled back jerkily to excite the jigs, causing the shoal of squid to attack them. The squid are impaled on the jigs. Jigging is considered a good fishing method because it does not damage the sea bed and the by-catch (unwanted species) is modest. As with all fishing methods, modern technology has resulted in fantastically sophisticated automatic jigging machines with built-in data systems which sense what’s happening to the jigs and improve catch rates dramatically. Other techniques with nets are also used.
How cute is that? (The small bobtail squid - found in all oceans but not a commercial species.)
There are over 300 species of squid, with more identified every year. But only about a dozen constitute the bulk of the world catch. This runs to 3-4m tonnes annually, which makes squid one of the most important food fish (and it’s an even more important feedstock for other marine creatures).
The following catch data was quoted in Reviews in Fisheries Science and Aquaculture 2015, World Squid Fisheries. It is supplemented by sustainability comments from various sources.
|Humboldt or jumbo squid||Dosidicus gigas||200cms||Canada to Tierra del Fuego||Fishsource – good||245||780||816|
|Japanese flying squid||Todarodes pacificus||50cms||Vietnam to Alaska||IUCN - least concern see SFP report||528||411||358|
|European squid||Loligo vulgaris||40cms||North Sea to S Africa||MCS – medium concern||199||209||236|
|Argentine shortfin squid||Illex argentinus||30cms||SW Atlantic||IUCN - least concern (2010)||750||288||190|
|Californian squid|| |
|20cms||Alaska to Mexico||Monterey Bay - best choice||86||56||129|
|Other identified squid (mainly Loligo)||180||364||229|
|Not specifically identified||230||327||430|
|Estimated landings not covered by FAO||600|
* FAO catch statistics in 1,000 tonnes
† Monterey Bay - avoid
IUCN - International Union for the Conservation of Nature
MSC - Marine Conservation Society
Monterey Bay - Conservation focused Aquarium in California
SFP - Sustainable Fisheries Partnership
Individual squid fisheries – eg off Japan, Peru or Scotland – experience huge variations in catch from year to year, but this is believed to be caused more by changes in natural conditions than by overfishing. Squid have been likened to weeds in terms of their capacity to prosper everywhere and to locusts due to their appearance in plague proportions from time to time. Thus the fact that the global squid catch has almost quadrupled from one million tonnes in 1980 has generated relatively little concern over sustainability -there were plenty of unexploited resources. Indeed, often, fishermen turned to squid when they had emptied their seas of other fish. However, the warning bells are beginning to sound.
A 2015 review of squid fisheries by the Sustainable Fisheries Partnership contains catch figures for 2014 which suggest the global catch had risen to 3.7m tonnes. China’s catch (not only in Chinese waters) is around a third of this total, with Peru at one sixth followed by S Korea, Taiwan and Japan, all at around 300,000 tonnes. Another dozen countries including Argentina, the USA and India caught around 100,000 tonnes each in 2014. This report indicates a deeper concern for squid overfishing than the sustainability comments cited in the table.
Tubes, tentacles, rings... and more
Squid meat is a very high quality and convenient protein. Whole squid is marketed widely but most squid is processed into clean meat. The mantle is cleaned of the intestines and is sold as “tubes”, which make ideal pouches for stuffings of every kind. Alternatively, the tube can be sliced into rings, and then often coated in batter to deliver the classic Mediterranean recipe, Calamares a la Romana. Tentacles, possibly thanks to their suckers, have less – but increasing - appeal to northern appetites either stuffed back into the cleaned tubes, or if from larger species, marketed as a solo item. Some Asian markets value various parts of the squid’s innards – in Japan the digestive gland is fermented into “shiokara”, said to be an excellent hangover cure which I suspect most readers will want to miss. The same material is increasingly popular as a raw material for nutraceutical preparations.
Definitely not nutraceutical
The links below all worked as of October 2019 but may have been degraded by subsequent edits at the linked site. In such cases the URL root will normally be worth investigating.
FIRMS page on squid
FAO Species catalogue
BRITISH SEA FISHING page
Wiki page on Humboldt squid
Wiki page on Japanese flying squid
SEAFISH page on Japanese Flying squid
National Geographic video 1
National Geographic video 2
The big squid in Wellington, NZ
WARNING: Do not go to the site squid-world.com