King crab invasion: Antarctic warming?
The Antarctic is a region of constant extremes with “Catabian winds” which have the potential to cause extremely violent snowstorms which can last for days on end. In combination with freezing cold temperatures from between -20°C and -5°C in summer it makes you consider if this habitat is even habitable. The light conditions are also unique in this region with continual darkness or polar winter during Nov to March and continual light or polar summer May to Sept making this region as extreme as it gets and that’s only the surface. In the surrounding waters the temperature can reach around -0.8°C to 2°C providing a stable temperature for any organisms living in this habitat. However ice scoring is a problem for organisms with low mobility as the ice can move causing it to scrape along the sea bed removing all sessile organisms, which is why they have adapted to factor in such a challenge.
As the Antarctic is surrounded by the ACC which originated due to the formation and splitting of the first continent, this current is strong enough to prevent potential predators from entering from the outside whilst also closing of transport of small organisms such as plankton from entering or leaving the Antarctic. With all of the boundaries of extreme temperature and the ACC it makes this region a paradise for any organism which can inhabit it, some speculate that gigantism in the Antarctic is due to the lack of predation others due to the closed circuit of nutrients however it is still largely unknown.
But what would happen if the barriers stopping large predators from entering the Antarctic somehow stopped working or reduced in effectiveness, one could only speculate that some species would possibly invade as this would be easier access to resources. But what would cause the invasion, global warming, ocean acidification and change in current, all are possible results.
New king on the block
King crabs not normally found in the Antarctic are become more commonly found as years progress, the species Neolithodes yaldwyni where originally prominent in the media during 2012 then again during 2015 proving the issue of a potential new resident to the Antarctic is worsening compared to getting better.
It has been theories that the colder waters of the Arctic have kept these predatory king crabs away from the delicate ecosystem, however recent temperature changes have caused a shift in the regions which the king crabs can hunt. In the region of which they are invading known as Palmer Deep, there where know predators which had the capability to crush hard shelled organisms which has the potential to decimate the ecosystem of Antarctica if the population carries on climbing along with the sea temperature.
Evidence of the presence of the king crab was first discovered by crush wounds on the arms of starfish and other organisms, which was estimated to have occurred around 10 to 20 years ago, which will only lead to a further climb in the crab population.
However the rising temperatures doesn’t only have the impact of allowing the king crab to invade it also can cause the habitat for species such as the Antarctic crab and shallow water brittle star to start declining as the temperature could be too much for them to handle.