The commercial value of
spiny1 lobster2 (Panulirus argus) in the Caribbean reaches $1 billion
annually3, thus making it one of the most valuable fisheries in the region. In a new study of this iconic species, Ph.D. candidate Andrew Kough and Dr. Claire Paris of the Biophysical Interactions Lab at the University of Miami Rosenstiel School of
Marine4 &
Atmospheric5 Science, in
collaboration6 with Dr. Mark Butler from Old
Dominion7 University, studied the
larval(幼虫的) dispersal of this species in the Caribbean. The goal of the study was to describe the sources, sinks, and routes connecting the Caribbean spiny lobster
metapopulation(集合种群). The results led the team to propose marine resource management strategies that incorporate larval connectivity and "larval lobster credits" to sustain and rebuild exploited marine populations. The study, which appears in the June 2013 issue of the journal PLOS ONE, synthesizes empirical data from laboratory studies, mail surveys and published works to parameterize an individual-based model of lobster larval connectivity, the Connectivity Modeling System (CMS), developed by Paris. Results were then verified using two independent studies, separated by over 500 km, giving
validation8 to the model's performance -- something never before achieved for spiny lobster or other
pelagic(浮游的) larvae9 over such large scales.
"Spiny lobster have extraordinary larvae with a prolonged
planktonic11 existence that can last from five months to nearly a year, which confer them with high dispersal potential and complex pelagic pathways. Despite such challenges in documenting their pathways in the open ocean, just like hurricane models that help to reduce the '
cone12 of
uncertainty13', in this case we are improving settlement predictions by simulating large numbers of
spawning14 events and tracking virtual larvae undergoing deep
vertical15 migrations," says Paris.
The
prevailing16 Caribbean current may not be the best path for successful long distance transportation for larvae. Contrary to the established belief, the team's results suggest that powerful currents entrain and push larvae out of the system,
acting17 like a "Highway to Hell." The larvae that ultimately settle in the simulation spend little time within these strong currents. By moving to deeper depths as they age, spiny lobster larvae seem to increase their
odds18 of settlement.
Butler adds, "Despite some expected degree of ocean mixing in the region, we found
relatively19 high levels of larvae settling back to their place of origin. This was surprising for larvae that spend up to 12 months traveling in the
plankton10. But even more surprising was that these simple larval behaviors added to the model also enhanced population connectivity by preventing larvae from being flushed out of the system."
Based on the
dynamics20 of long distance larval exchange uncovered using this computational model, the team proposes potential strategies that may be used to better manage the Caribbean spiny lobster population, and increase the sustainability of this economically important fishery.
"We blended ideas from international trade, terrestrial conservation, and carbon
emission21 protocols22 to suggest 'larval lobster credits' as a
viable23 cooperative management strategy. Predicted larval flow around in the region is dependent on several source regions, which are
optimally24 located for wide ranging dispersal. If the nations receiving the
influx25 of larvae and harvesting the adult
lobsters26 were to invest and help protect these source regions, we believe that the future of the fishery will be more secure and may even improve, which would benefit the entire region ecologically and economically," explains Kough.