Cascading-driven downslope currents can reverse overexploitation of deep-sea organisms

Washington, Jan 16 : A new study by scientists has described how a climate-driven phenomenon can influence the biological processes of a deep-sea living resource by reversing its overexploitation.

Carried out by Joan B. Company and colleagues at the Institut de Ci¨ncies del Mar (CSIC) in Spain, the study takes the example of a shrimp known as Aristeus antennatus, which is the most valuable deep-sea living resource in the Mediterranean Sea.

Strong downslope currents associated with intense cascading events displace the population of this shrimp species from the fishing grounds, producing a temporary fishery collapse.

However, nutritive particles brought by cascading waters to deep regions cause an enhancement of its recruitment process and an increase of its total landings during the following years.

These new findings resolve the paradox of a long-overexploited fishery that has not collapsed after 70 years of intense deep-sea trawling.

According to the study, the results will have a high socio-economic impact, since this species is the most valuable deep-sea living resource in the Mediterranean Sea.

Also, because the cascading of dense water from continental shelves is a global phenomenon whose effects on biological processes were not considered in the past, it is hypothesized that its influence on deep-sea ecosystems and fisheries worldwide should be more important than previously thought.

Because the progressive depletion of world fisheries is one of the key socio-economical issues of the forthcoming century, the new study hold significance.

Basically, the study demonstrates how a climate-induced phenomenon occurring at a decadal time-scale, such as the formation of dense shelf waters and its subsequent downslope cascading can repeatedly reverse the general trend of overexploitation of a deep-sea living resource.

ANI