Habitat Trays help researchers monitor exotic crab species. |
As one of the 28 reserves in the National Estuarine Research
Reserve system, the GTM Research Reserve is charged with implementing
national-level long-term research programs, investigating relevant regional and
local-level research questions, and facilitating related research efforts by
visiting scientists and students conducting research in the myriad estuarine
and coastal habitats within the reserve.
A GTM Research Reserve volunteer holds up a blue crab. |
For the past ten years, an Invasive Crab Survey has been a
part of this research. Because it is impossible to predict where and when a
particular species will successfully invade a particular habitat, researchers
at the GTM Research Reserve have been focusing on already established invasive
crabs to predict the likelihood, direction, and rate of spread of the nuisance
species. The researchers are monitoring crab species within the GTM Research Reserve
to determine their diversity, detect new invasions, document seasonality of
both native and invasive populations, and determine trends in species
composition and abundance over time.
Ten different species of crab have been collected over the
course of the survey, but one of the most interesting findings is one that will
cause excitement amongst seafood enthusiasts who enjoy stone crabs (Menippe
mercenaria). Although we have only collected 35 crabs during the survey, our
results over the past two years suggest that stone crab populations in NE
Florida might be increasing, something we will continue to monitor with
interest as the survey continues.
Habitat Trays help researchers monitor populations of exotic crabs. The bars on the graph below illustrates the number of stone crabs per tray out of seven Habitat Trays, while the line illustrates the Florida Fish and Wildlife’s annual commercial landings data for NE Florida in the form of catch per unit effort (lbs of crab/trip).