Please select your home edition
Edition
Pantaenius - All Risk

New study casts doubt on Antarctica crab claims

by British Antarctic Survey on 5 Jul 2013
King Crab on yhe sea bed Julian Gutt
A new study has cast doubt on the belief that crabs may have vanished from Antarctica only to return due to warming seas.

The theory surfaced two years ago following the discovery of a major colony of King crabs (Lithodidae) in the Palmer Deep, a basin in the continental shelf off the Antarctic Peninsula. It was thought the species may have left the continent between 40 and 15 million years ago and was returning as seawater temperatures rose. Fears were expressed that its reintroduction would decimate other fauna in the region.

But an extensive study of all known crab records by a team of scientists at British Antarctic Survey (BAS) has led it to conclude the crabs may have been there all along rather than moving in from a different area.

Writing in the online journal PLOS ONE the team, led by marine biologist, Huw Griffiths, claims the 'invasion' hypothesis is fundamentally flawed because it relied upon poor fossil records relating to a completely different group of crabs and that sampling of the extant species is far too limited to draw any firm conclusions.

The fossils of deep water crabs are hard to come by because they are susceptible to decay soon after they die. There is no Antarctic fossil record for King crabs with only two such records existing, neither of which originate from Antarctic waters (south of 60°S). Much of Antarctica is covered with ice restricting access to areas where fossils may be found. This means there is a great deal of uncertainty surrounding the history of crab populations in the continent.


The team assembled a database of more than sixteen thousand records of living and fossil crabs to assess the extent of their populations. Fossil data were compiled from all previously published sources as well as the extensive fossil collection at BAS’ offices in Cambridge. All published data for living specimens were examined as well as records from unpublished fisheries’ and scientific reports.

The first record of a crab in Antarctica is of one from the group Brachyura found on the shores of the South Orkney Islands in 1903. To date, 22 species of crab and lobster have been found in the Southern Ocean, 12 of which are King crabs found in Antarctic waters.

The first record of King crabs dates back to 1967 when an individual was recovered close to Scott Island north of the Ross Sea. The lack of data reflects the fact that very little deep water sampling has been done.

The distribution pattern, with two species being found only in Antarctica (including the one reported as invasive) and no records of them being found elsewhere, implies a long and enduring presence in the region. It would suggest they have had more than a few centuries to develop and evolve.

Lead author, Huw Griffiths, from BAS, said: 'These findings are important because, for the first time, we were able to piece together all available information to get a clearer understanding of the diversity and distribution of crabs in Antarctica. Many of these elusive deep-sea animals, previously thought to be invasive, have turned out to be uniquely Antarctic species.'

Recent studies suggested King crabs would pose a serious risk to native fauna. Invertebrates such as molluscs were thought to be most at risk. But the team says there is strong evidence these crabs are mostly foragers and scavengers attracted to carrion.

The team concludes by recommending that a programme of repeated sampling of King crab distributions in Antarctic waters is British Antarctic Survey website

Sydney Harbour Boat Storage 660x82Absolute MarineHella Marine - July 2016

Related Articles

Coral Bleaching Again - Call to Action
Last week I attended latest Reef 2050 Long Term Sustainability Plan meeting of the Reef Advisory Committee in Brisbane It has become abundantly obvious to CAREFISH that climate change has eventuated and massive scale disruption and or destruction of our environment, particularly the Great Barrier Reef (GBR), is currently being experienced and is escalating. Whilst it is acknowledged that Governments are attending to some aspects and attempting to mitigate effect...
Posted on 22 Mar
Cornish fishing company fined £8,170 for moving vessel
Mark Rowse, who pleaded guilty on behalf of the company, was fined £3,000 by Truro Magistrates Court. Yesterday, Wednesday 15 March, Rowse Fishing Ltd of Newlyn Cornwall was fined a total of £8,170 after being prosecuted by the Maritime and Coastguard Agency (MCA) for moving a new build fishing vessel without the appropriate load-line certificate. Mark Rowse, Director of Rowse Fishing Ltd, who pleaded guilty on behalf of the company, was fined £3,000 by Truro Magistrates Court...
Posted on 16 Mar
There is always something to learn…
Did you know that Marlins have a gland near their eye that secrets oil that is thought to make them even more slippery Did you know that broadbill swordfish have a gland near their eye that secrets a special oil that is thought to make them even more slippery through the water? Until about a year ago, no one did! Also, did you know that the Oceanic White Tip Shark has special sensory structures in its head that act like a natural GPS utilising the earth’s geomagnetic field to locate itself in our vast oceans....
Posted on 9 Mar
Barramundi populations at risk from acid oceans
Wild barramundi populations are likely to be at risk under ocean acidification, a new University of Adelaide study found Wild barramundi populations are likely to be at risk under ocean acidification, a new University of Adelaide study has found. Published in the journal Oecologia, the study is the first to show that even freshwater fish which only spend a small portion of their lifecycle in the ocean are likely to be seriously affected under the higher CO2 levels
Posted on 1 Jan
The Deepwater Horizon aftermath
Researchers analyze 125 compounds from oil spilled in Gulf of Mexico to determine their longevity at different levels. Researchers analyze 125 compounds from oil spilled in the Gulf of Mexico to determine their longevity at different contamination levels. The oil discharged into the Gulf of Mexico following the explosion and sinking of the Deepwater Horizon (DWH) rig in 2010 contaminated more than 1,000 square miles of seafloor.
Posted on 1 Jan
Magnetic force pulls baby reef fish back home
Baby reef fish have an internal magnetic ‘compass’ that directs them home at night, world-first research has revealed. Baby reef fish have an internal magnetic ‘compass’ that directs them home at night, world-first research has revealed. Professor Mike Kingsford from the ARC Centre of Excellence for Coral Reef Studies at James Cook University collaborated with colleagues in Germany to find out how tiny Cardinal fish, the size of a fingernail, are able to swim towards home when there’s no sun or stars to guide them
Posted on 29 Dec 2016
DAERA designates four new MCZs in the Northern Ireland Inshore Region
Following a public consultation, DAERA Marine and Fisheries Division has designated four new Marine Conservation Zones The new MCZs are intended to protect clams in Belfast Lough, the habitat of rare black guillemots on Rathlin Island, one of Ireland’s largest seagrass meadows located off the coast of Waterfoot in Co Antrim, and a community of sea pens – a type of soft coral – in Carlingford Lough.
Posted on 14 Dec 2016
Great Barrier Reef managers and industry prepare for summer
Marine park managers, scientists and experts recently met for the annual pre-summer workshop Marine park managers, scientists and experts recently met for the annual pre-summer workshop to assess climate-related risks to the Great Barrier Reef over the coming months. Current predictions by the Bureau of Meteorology and National Oceanic and Atmospheric Administration are for a summer of average sea temperatures across the Great Barrier Reef.
Posted on 7 Dec 2016
Introducing the Airbnb of the mooring and marina world
Have you ever struggled to find an available mooring, or do you have a mooring that is sitting vacant? Have you ever struggled to find an available mooring, or do you have a mooring that is sitting vacant? makefastmooring.com is aiming to solve this problem by connecting boat owners with those with vacant moorings or berths. With a growing number of moorings and marinas in New Zealand, Australia and around the world, makefastmooring.com allows people to find, rent and share moorings and berths.
Posted on 7 Dec 2016
Radio spectrum changes have been put into place in New Zealand
New Zealand, along with a number of other countries, has been required to change some maritime VHF repeater channels New Zealand, along with a number of other countries, has been required to change some maritime VHF repeater channels to make space for newly allocated international services for ship tracking and data services. On the October 1st, New Zealand moved a few private VHF repeater services, most Coastguard VHF repeater services, and all NowCasting weather services. An updated radio handbook and freq
Posted on 2 Nov 2016