A new study of the mysterious Greenland shark has revealed the likelihood that specimens are born in the deep mid-Atlantic and then move closer to Europe as they enter their teenage years. Their favourite hang-out and feeding spot at this stage appears to be the Skagerrak strait between Denmark, Norway and Sweden.
Greenland sharks (Somniosus microcephalus) are noted for their size (they have been known to grow as long as 6.4m) and longevity of as much as 400 years, and their preferred habitat is in the cold, often deep waters of the North Atlantic.
The species is often caught as bycatch by fisheries, raising concerns for its future, but it has not been widely studied. The new report, carried out by scientific institutions in Canada, Greenland, Iceland, the Faroe Islands and Norway, examined the size, sex and life-stage of 1,610 Greenland sharks from 11 regions.
Sub-adult females were found to dominate in most regions, and while adult females were scarce or absent in, for example, northern Arctic Canada and Svalbard, they dominated in south-west Greenland and Iceland.
In southern Arctic Canada and north-western and south-eastern Greenland, adult females were most often encountered in offshore waters. Depths ranged from 25 to 1,375m and water temperatures from -1.54°C to 10.9°C, with adult females preferring water above 4°C.
Large juveniles were encountered in most regions but dominated in Skagerrak and in offshore southern Arctic Canada.
New-born or small juveniles proved hard to find but, by adding evidence from scientific databases and museum collections, a cluster was identified along the mid-Atlantic Ridge and Irminger Sea. This suggested the possibility of the sharks’ main pupping ground being located there rather than, as had previously been thought, around Baffin Island in Arctic Canada.
The mid-Atlantic area of deep water is less affected by the fishing industry.
The Greenland shark is considered Vulnerable on the IUCN Red List of Threatened Species. In light of their findings the scientists say they want safeguarding for the large and potentially mature females in inshore and offshore waters of south-west Greenland, the offshore waters of southern Arctic Canada, south-east Greenland and Iceland.
The report is published in the journal Ecology & Evolution.
Title is horrible. Pretty sure you meant Study HONES in. Not HOMES in..
No, I meant ‘homes in’, but thanks for the input
What does “homes in” mean?
According to the Oxford English Dictionary, the term “homes in” is the third-person singular present-tense form of the phrasal verb “to home in on”, meaning to aim at and move directly toward something, or to direct your thoughts or attention toward something. For example, a missile “homes in on” its target.