North Atlantic Mesoscale Eddy Detection and Marine Species Distribution
Abstract
An eddy detection workflow was developed and applied to reference series of delayed
time maps of sea level anomaly (Ref DT-MSLA) published by Aviso Altimetry, France
in the North Atlantic region between 30-55° N and 30-80° W. The eddy detection parameters,
maximum/minimum Okubo-Weiss parameter to assign to the eddy core/ring, minimum eddy
core area, minimum eddy core area to perimeter ratio, and minimum eddy duration, were
set to -0.2/0.2 standard deviation, 5 cells (6869 km2), 0.4, and 10 images (70 days),
respectively. Using these parameters, 635 anticyclonic eddies and 930 cyclonic eddies
were detected between October 14, 1992 and December 31, 2005. The eddy structure of
the 62103 pelagic longline fishery catch records in The Logbook System maintained
by Southeast Fisheries Science Center was sampled. One-way ANOVA and t-test were conducted
to compare the mean catch-per-unit-effort (CPUE) of bluefin tuna (Thunnus thynnus),
yellowfin tuna (Thunnus albacores), bigeye tuna (Thunnus obesus), and swordfish (Xiphius
gladius) at different eddy structures. For bluefin tuna and bigeye tuna, the mean
CPUE is higher in the eddy area than in the non-eddy area. For yellowfin tuna and
swordfish, the mean CPUE is higher in the non-eddy area than in the eddy area. For
all three species of tuna, the mean CPUE is higher in the anticyclonic eddies than
in the cyclonic eddies. For swordfish, the mean CPUE is higher in the cyclonic eddies
than in the anticyclonic eddies. The results suggest different eddy structures make
different habitats for large marine predators and eddy activities contribute to marine
species distribution.
Type
Master's projectSubject
Eddy detectionNorth Atlantic
Marine species distribution
Catch-per-unit-effort
Sea level anomaly map
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https://hdl.handle.net/10161/2230Citation
Hsu, Ango Chen-Tien (2010). North Atlantic Mesoscale Eddy Detection and Marine Species Distribution. Master's project, Duke University. Retrieved from https://hdl.handle.net/10161/2230.Collections
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