Deep-water formation is one of the most fascinating aspects of global thermohaline circulation. Deep-water doesn’t form only at the poles, though, as cold water sinks below warm. Subtropical Underwater, for example, is formed in the central Atlantic where the difference between evaporation and precipitation is highest. Dense, high salinity water sinks down to about 500m before spreading into the bathyl zone of the Caribbean Sea. So, you should ask yourself, where’s my deep water coming from? And, how is it effecting my local shrimp fishery? Read the open-access, full-text article here at Craig’s newest avocation, the PLoS One journal: http://dx.plos.org/10.1371/journal.pone.0001431
Climate Influence on Deep Sea Populations
Dynamics of biological processes on the deep-sea floor are traditionally thought to be controlled by vertical sinking of particles from the euphotic zone at a seasonal scale. However, little is known about the influence of lateral particle transport from continental margins to deep-sea ecosystems. To address this question, we report here how the formation of dense shelf waters and their subsequent downslope cascade, a climate induced phenomenon, affects the population of the deep-sea shrimp Aristeus antennatus. We found evidence that strong currents associated with intense cascading events correlates with the disappearance of this species from its fishing grounds, producing a temporary fishery collapse. Despite this initial negative effect, landings increase between 3 and 5 years after these major events, preceded by an increase of juveniles. The transport of particulate organic matter associated with cascading appears to enhance the recruitment of this deep-sea living resource, apparently mitigating the general trend of overexploitation. Because cascade of dense water from continental shelves is a global phenomenon, we anticipate that its influence on deep-sea ecosystems and fisheries worldwide should be larger than previously thought.
Company JB, Puig P, Sarda F, Palanques A, Latasa M, et al. (2008) Climate Influence on Deep Sea Populations. PLoS ONE 3(1): e1431. doi:10.1371/journal.pone.0001431