For Scientists

Predicting Zooplankton Abundances in the Gulf of Mexico

 

Mesozooplankton (including copepods, krill, appendicularians, and cladocerans) are crucial prey species for many different commercially-important fish in the Gulf of Mexico.  These organisms are particularly important during the larval stages of many open ocean fish.  During these larval stages the fish often experience substantial mortality as a result of predation or starvation.  Access to sufficient prey enables them to grow quickly during this sensitive stage of their life history.  With funding from NASA and NOAA we are developing models to develop real-time predictions of zooplankton abundance that can be incorporated into fisheries assessments to predict the future health of species such as Atlantic Bluefin Tuna.

 

Our research on this project is led by graduate student Taylor Shropshire who has developed an ecosystem model for the Gulf of Mexico that includes three size classes of zooplankton.  Taylor is tuning the model to ensure that it accurately predicts 1) zooplankton abundances measured in the Gulf of Mexico by annual SEAMAP cruises conducted by NOAA fisheries cruises and 2) zooplankton activity measured on our own NOAA RESTORE cruises in the open ocean Gulf of Mexico.  We have many plans to extend Taylors model to understand zooplankton and fisheries dynamics:

 

1) We plan to introduce a larval fish individual-based model that will be coupled to Taylor's model.  This will allow us to simulate the growth (or death) of larval fish as they are moved through the ocean by the ocean currents.

 

2) We plan to run the model using future climate scenarios produced by climate scientists.  The goal is to determine if future warming will have an adverse effect on vulnerable fish species (such as tuna, grouper, and snapper).  In a future, warmer climate we anticipate that there will be greater stratification in the ocean and hence less nutrient input to oligotrophic regions of the Gulf of Mexico, which will decrease phytoplankton and zooplankton production.  At the same time, warmer temperatures will increase the metabolism of larval fish, and hence their need for food.  We hope that our predictions will help fisheries managers engage in proactive steps to protect populations.

 

3) Working with collaborators at Horn Point Laboratory (UMCES) we are introducing an individual-based model of specific zooplankton groups into Taylor's model, to address the impact of fronts and eddies on zooplankton dynamics.  Our goal is to then use statistical analyses to related model zooplankton abundances to satellite observable products - with the ultimate goal of predicting zooplankton from space.