The Blue Crab:  Callinectes sapidus

 

The blue crab is one of the most well known denizens of the Chesapeake Bay.   It is an economically important creature vital to the success of the Maryland and Virginia seafood market, which employ thousands of workers and generate millions of dollars of revenue.

The blue crab also plays a significant ecological role in the bay.  It is believed by some to be an estuarine keystone species, due to its major role in the food web throughout the bay.  It acts as a predator or as a scavenger feeding on whatever is available, but it also serves as prey to a wide variety of organisms.

Blue crab population numbers have been declining, causing great concern for watermen and scientists.  The drop in population has been attributed to a number of factors including: natural population fluctuations, lack of suitable habitat, i.e. (SAV), over-fishing, as well as a number of other possible causes.  The decline is probably due to a combination of events, however  in order to maintain a sustainable blue crab population, we need to know what can be done  to prevent any further regression of the blue crab population.                     

In order to increase the blue crab population from it’s current level, it is necessary to understand its population dynamics, (The science studying the change in numbers, biomass, and age structure of populations) and identify levels of crab abundance at which exploitation can occur while maintaining a sustainable population.

 

Click on the Blue crab below to explore growth and population dynamics of the blue crab

                                                               

  

   picture courtesy of: Smithsonian Environmental Education Center       

              Life Cycle 

                                                                                                   

                      

   Biochemical methods                                                            Measuring carapace width

 

 

                                                        

Von Bertalanffy Growth Model                                 

 

                        

Crab dissection and how to determine the gender of blue crabs 

Printable lecture note

links  &  references

Taxonomy

Glossary