Navigation Links
Ecological change in the abyss -- the Amperima event
Date:6/24/2010

Even in the dark abyss of the deep ocean animal communities can undergo rapid, widespread and radical changes. Scientists at the National Oceanography Centre are at the forefront of monitoring these changes and understanding the mechanisms responsible. Their latest research is published in a special issue of the journal Deep Sea Research II.

We often think of the deep ocean floor as stable, relatively unvarying environment untroubled by surface climate conditions. But long-term monitoring has shown that animal communities living at great depth on the seafloor can change radically over remarkably short periods, and that these events are ultimately driven by climate.

Such faunal changes are exemplified by the 'Amperima Event' the sudden mass occurrence of the sea cucumber (holothurian) Amperima rosea recorded on the Porcupine Abyssal Plain (PAP) situated off the southwest coast of Ireland in the northeast Atlantic. Communities of animals living on the seabed there at depths of nearly 5000 metres have been monitored from 1989 to the present day.

A major change occurred in the PAP community between 1996 and 1999 involving a number of animal groups, including sea anemones, segmented worms, sea spiders, sea squirts, brittle stars, and sea cucumbers, all of which increased in abundance.

However, the population explosion in the sea cucumber Amperima rosea (hereafter Amperima) was particularly striking thus the 'Amperima Event'. Before 1996 the sea cucumber was found in only ones or twos. They were very rare. But by 1999, the sea cucumber reached such high densities that if you were able to walk on the deep seafloor, you would have difficulty in avoiding squashing them flat.

Dr David Billet and his colleagues showed that the increase abundance and dominance of Amperima occurred over a very wide area, greater than the size of the UK. Changes are also apparent in the abundance of other animals living in the seabed, including the single-celled creatures inhabiting the sediments. The whole deep-sea world had been turned on its head.

"What this strongly suggested," says Dr Billett, "is that the 'Amperima Event' did not simply reflect localised, chance changes in the abundances of one or two species. Instead, changes in the whole deep-sea animal community were driven by environmental factors."

The animals living on the deep seafloor feed on organic matter in the form of phytodetritus the remains of tiny marine plants that once lived in the sunlit surface layer and which fall down through the water column and settle on the seabed. It seemed possible that an increase in the amount of this 'marine snow' might have driven the 'Amperima Event'.

From sediment trap measurements, a team led by Professor Richard Lampitt of the National Oceanography Centre has subsequently shown that variations in the supply of organic matter to the PAP can vary greatly between years. Indeed, a second sudden mass occurrence of Amperima in 2001 a possible second 'Amperima Event' may have been due to increased food availability.

Food quality may also be important. Dr Denise Smythe-Wright, also of the National Oceanography Centre and her colleagues have shown that the composition and potential nutrient quality of organic matter exported from the surface ocean depend on the species composition of the ocean phytoplankton community. This could favour the reproduction, recruitment and competitive ability of particular species.

For example, Amperima has a different requirement for certain carotenoid pigments than other species of sea cucumber. Carotenoids in shallow water are known to improve egg production and improve the chances of larvae in developing into juveniles. Carotenoids are used as feed in aquaculture to improve yields. In the food-limited deep sea, changes in the quantity and quality of the downward flux of carotenoids with season and year may change the egg production in certain species allowing the rapid colonisation of large areas of the seafloor when the conditions are right.

"Whether it is the quality or the quality of the organic matter, or both, that matter," says Dr Billett, "it appears that changes in the density of animals such as Amperima are related to phytoplankton productivity in the overlying surface waters, which is affected by climate change."

"Moreover", he says, "we know from the fossil record that deep-sea animal communities change over geological timescales. Knowing how species density and dominance change in relation to environmental variables in the present will help in interpreting the geological record and will allow predictions of how deep-sea fauna might alter in relation to climate change."


'/>"/>

Contact: Dr. Rory Howlett
r.howlett@noc.soton.ac.uk
44-023-805-98490
National Oceanography Centre, Southampton (UK)
Source:Eurekalert  

Related biology news :

1. DOE, ORNL officially join NSF on massive ecological study
2. Ecological Society of America explores global warming at its 95th Annual Meeting
3. Emergence of fungal plant diseases linked to ecological speciation
4. New research reveals Hurricane Katrinas impact on ecological and human health
5. Emergence of fungal plant diseases linked to ecological speciation
6. Communication trumps penalties in new study of social-ecological systems
7. Return of top predators is key to ecological future
8. New research provides insights into potential ecological costs and cobenefits of REDD
9. Queens scientists on international team discover ecologically unique changes in Arctic lake
10. Arctic lake sediments show warming, unique ecological changes in recent decades
11. Ecological Society of America announces 2009 award recipients
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Ecological change in the abyss -- the Amperima event
(Date:3/14/2016)... , Allemagne, March 14, 2016 ... http://www.apimages.com ) - --> - Renvoi : ... - --> --> ... solutions biométriques, fournit de nouveaux lecteurs d,empreintes digitales ... LF10 de DERMALOG sera utilisé pour produire des ...
(Date:3/10/2016)... 10, 2016 --> ... report "Identity and Access Management Market by Component (Provisioning, ... Governance), by Organization Size, by Deployment, by Vertical, and ... MarketsandMarkets, The market is estimated to grow from USD ... 2020, at a Compound Annual Growth Rate (CAGR) of ...
(Date:3/9/2016)... , March 9, 2016 ... government identified that more than 23,000 public service employees ... had been receiving their salary unlawfully.    --> ... country,s government identified that more than 23,000 public service ... or had been receiving their salary unlawfully.    ...
Breaking Biology News(10 mins):
(Date:5/23/2016)... ... May 23, 2016 , ... PrecisionAg® Media ... in 2017 and Beyond. The paper outlines the key trends that are creating ... , “We’ve witnessed a lot of highs and lows as the precision agriculture ...
(Date:5/23/2016)... Springs, North Carolina (PRWEB) , ... May 23, ... ... process automation and building management solutions and services based in Aurora, Ohio, has ... decade of established business in the Research Triangle Park area, this new location ...
(Date:5/20/2016)... ... ... Kablooe Design, a leading provider of product design and development services to medical ... “We have worked hard to build long-term relationships,” says President and CEO, Tom KraMer. ... serving their product design and development needs through the years.” , Kablooe has earned ...
(Date:5/19/2016)... , May 19, 2016  AdvancedFlow Systems Inc. ... (AGI), based out of Maple Ridge, ... Ltd. to its existing portfolio of contract manufacturing ... AFS along with its sister companies Surround Technologies ... vertically integrated industrial group that specializes in providing ...
Breaking Biology Technology: