[graffis-l] DEEP-SEA SPECIES LOSS COULD LEAD TO OCEANS' COLLAPSE

January 2, 2008

Deep-sea species' loss could lead to oceans'

collapse, study suggest

Posted by: " Mark Graffis "

mgraffis

Tue Jan 1, 2008 8:12 am (PST)

Public release date: 27-Dec-2007

http://www.eurekalert.org/pub_releases/2007-12/cp-dsl122007.php

Contact: Cathleen Genova

cgenova

617-397-2802

Cell Press

Deep-sea species' loss could lead to oceans' collapse, study

suggests

The loss of deep-sea species poses a severe threat to the future of

the oceans, suggests a new report publishing early online on December

27th and in the January 8th issue of Current Biology, a publication of

Cell Press. In a global-scale study, the researchers found some of the

first evidence that the health of the deep sea, as measured by the rate

of critical ecosystem processes, increases exponentially with the

diversity of species living there.

“For the first time, we have demonstrated that deep-sea ecosystem

functioning is closely dependent upon the number of species inhabiting

the ocean floor,” said Roberto Danovaro of the Polytechnic University of

Marche, in Italy. “This shows that we need to preserve biodiversity, and

especially deep-sea biodiversity, because otherwise the negative

consequences could be unprecedented. We must care about species that are

far from us and [essentially] invisible.”

Ecosystem functioning involves several processes, which can be

summarized as the production, consumption, and transfer of organic matter

to higher levels of the food chain, the decomposition of organic matter,

and the regeneration of nutrients, he explained.

Recent investigations on land have suggested that biodiversity loss

might impair the functioning and sustainability of ecosystems, Danovaro

said. However, the data needed to evaluate the consequences of

biodiversity loss on the ocean floor had been completely lacking, despite

the fact that the deep sea covers 65% of the Earth and is “by far the

most important ecosystem for the cycling of carbon, nitrogen, and

phosphorus of the biosphere.” The deep sea also supports the largest

“biomass” of living things, including a large proportion of undiscovered

species.

In the new study, Danovaro’s team examined the biodiversity of

nematode worms and several independent indicators of ecosystem

functioning and efficiency at 116 deep-sea sites. Nematodes are the most

abundant animals on earth and account for more than 90% of all life at

the bottom of the sea. Earlier studies have also suggested that nematode

diversity is a good proxy for the diversity of other deep-sea

species.

They found that sites with a higher diversity of nematodes support

exponentially higher rates of ecosystem processes and an increased

efficiency with which those processes are performed. Efficiency reflects

the ability of an ecosystem to exploit the available energy in the form

of food sources, the researchers said. Overall, they added, “our results

suggest that a higher biodiversity can enhance the ability of deep-sea

benthic systems to perform the key biological and biogeochemical

processes that are crucial for their sustainable functioning.”

The sharp increase in ecosystem functioning as species numbers rise

further suggests that individual species in the deep sea make way for

more species or facilitate one another, Danovaro said. That’s in contrast

to terrestrial-system findings, which have generally shown a linear

relationship between diversity and ecosystem functioning, he noted,

suggesting complementary relationships among species.

“Deep-sea ecosystems provide goods (including biomass, bioactive

molecules, oil, gas, and minerals) and services (climate regulation,

nutrient regeneration and supply to the [upper ocean], and food) and, for

their profound involvement in global biogeochemical and ecological

processes, are essential for the sustainable functioning of our biosphere

and for human wellbeing,” the researchers concluded. “Our results suggest

that the conservation of deep-sea biodiversity can be crucial for the

sustainability of the functions of the largest ecosystem” on the

planet.

###

The researchers include Roberto Danovaro, Department of Marine

Science, Faculty of Science, Polytechnic University of Marche, Via Brecce

Bianche, Ancona, Italy; Cristina Gambi, Department of Marine Science,

Faculty of Science, Polytechnic University of Marche, Via Brecce Bianche,

Ancona, Italy; Antonio Dell’Anno, Department of Marine Science, Faculty

of Science, Polytechnic University of Marche, Via Brecce Bianche, Ancona,

Italy; Cinzia Corinaldesi, Department of Marine Science, Faculty of

Science, Polytechnic University of Marche, Via Brecce Bianche, Ancona,

Italy; Simonetta Fraschetti, Ann Vanreusel, Marine Biology Section,

University of Ghent, Ghent, Belgium; Magda Vincx, Marine Biology Section,

University of Ghent, Ghent, Belgium; and Andrew J. Gooday, National

Oceanography Centre, Southampton, UK.

eAt 08:45 AM 1/2/08, you wrote:

Deep-sea species' loss could lead

to oceans' collapse, study suggest

Posted by: " Mark Graffis " mgraffis

mgraffis

Tue Jan 1, 2008 8:12 am (PST)

Public release date: 27-Dec-2007

http://www.eurekalert.org/pub_releases/2007-12/cp-dsl122007.php

Contact: Cathleen Genova

cgenova

617-397-2802

Cell Press

Deep-sea species' loss could lead to oceans' collapse, study

suggests

The loss of deep-sea species poses a severe threat to the future of the

oceans, suggests a new report publishing early online on December 27th

and in the January 8th issue of Current Biology, a publication of Cell

Press. In a global-scale study, the researchers found some of the first

evidence that the health of the deep sea, as measured by the rate of

critical ecosystem processes, increases exponentially with the diversity

of species living there.

“For the first time, we have demonstrated that deep-sea ecosystem

functioning is closely dependent upon the number of species inhabiting

the ocean floor,” said Roberto Danovaro of the Polytechnic University of

Marche, in Italy. “This shows that we need to preserve biodiversity, and

especially deep-sea biodiversity, because otherwise the negative

consequences could be unprecedented. We must care about species that are

far from us and [essentially] invisible.”

Ecosystem functioning involves several processes, which can be summarized

as the production, consumption, and transfer of organic matter to higher

levels of the food chain, the decomposition of organic matter, and the

regeneration of nutrients, he explained.

Recent investigations on land have suggested that biodiversity loss might

impair the functioning and sustainability of ecosystems, Danovaro said.

However, the data needed to evaluate the consequences of biodiversity

loss on the ocean floor had been completely lacking, despite the fact

that the deep sea covers 65% of the Earth and is “by far the most

important ecosystem for the cycling of carbon, nitrogen, and phosphorus

of the biosphere.” The deep sea also supports the largest “biomass” of

living things, including a large proportion of undiscovered species.

In the new study, Danovaro’s team examined the biodiversity of nematode

worms and several independent indicators of ecosystem functioning and

efficiency at 116 deep-sea sites. Nematodes are the most abundant animals

on earth and account for more than 90% of all life at the bottom of the

sea. Earlier studies have also suggested that nematode diversity is a

good proxy for the diversity of other deep-sea species.