Importance of Mesoscale Features in the Gulf of Mexico on Larval Pelagic Fish Abundance

Sennai Habtes, University of South Florida - College of Marine Science, shabtes@mail.usf.edu (Presenter)
Frank Muller-Karger, University of South Florida, carib@marine.usf.edu
Mitchell Alan Roffer, Roffer's Ocean Fishing Forecasting Service, roffers@bellsouth.net
John T Lamkin, NOAA-Fisheries, john.lamkin@noaa.gov
Barbara A. Muhling, NOAA, barbara.muhling@noaa.gov
David Lindo-Atichati, University of Miami, Cooperative Institute for Marine and Atmospheric Studies, dlindo@rsmas.miami.edu
Matthew A. Upton, Roffer's Ocean Fishing Forecasting Service, matt2@roffs.com
Gregory J. Gawlikowski, Roffer's Ocean Fishing Forecasting Service, greg@roffs.com

The management of fisheries, including the one for internationally important Atlantic bluefin (Thunnus thynnus) tuna, requires accurate and reliable estimates of spawning stock biomass. Adult stock assessments depend on catch per unit effort (CPUE) statistical indices, but often need to include accurate fishery independent indices. Currently the derivation of spawning stock abundance for the Western Atlantic Bluefin uses a fishery independent index of larval abundance in the Gulf of Mexico (GOM) to “tune” the adult stock assessment. This estimate is limited by high coefficients of variation due, in part, to low numbers of larvae and high numbers of zero catches obtained by annual NOAA sampling surveys. There is a desire among fisheries managers to better understand the environmental variables associated with the larvae distribution, and understand the relevant spatial and temporal scales that control the variation in distributions of pelagic fish larvae in the Gulf of Mexico. This research investigates the environmental factors that influence distributions of a variety of larval pelagic fish species (Thunnus thynnus, Auxis spp., Euthynnus alletteratus, Katsuwonus pelamis, Coryphaena spp., Istiophorids, Other thunnus spp., and Xiphias gladius) collected during the NOAA SEAMAP spring ichthyoplankton surveys in the Gulf of Mexico. This study investigates the association between the catch locations of the above species with environmental variables derived from satellites, and the classification of mesoscale oceanographic features in the Gulf of Mexico. In order to determine the importance of the mesoscale features with larval catches, both visual and automated methods of classifying the features were created and compared to determine their respective effectiveness. The variability in larval abundances is defined using cluster analysis to group patterns in important environmental variables and mesoscale features associated with patterns in larval pelagic fish distributions.

Presentation: 2011_Poster_Habtes_163_102.pdf (1190k)

Presentation Type:  Poster

Session:  Science in Support of Decision Making   (Wed 10:00 AM)

Associated Project(s): 

• Roffer, Mitch: Improving The NOAA NMFS and ICCAT Atlantic Bluefin Tuna Fisheries Management Decision Support System ...details

Poster Location ID: 163