The Blue Crab in North Carolina
North Carolina State 


Postlarval or 

Megalopal Stage Blue Crab

The Blue Crab in NC HomepageGeneral Information PageLife History of the Blue Crab Fishery Simulations Research Lesson Plans Other Resources, including Library and Internet Resources

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    Ongoing Blue Crab Research by Dr. David Eggleston's Group

    Recruitment   Water Quality   Stock Assessment  Stock enhancement and Pond Grow-out
    Outreach   Current Publications

    Ecological Studies -- Recruitment Dynamics
    Current and recent research has focused on blue crab recruitment in Pamlico Sound, NC. Recruitment can be defined simply as movement of crabs into an area. This research has looked at movement of blue crabs in two different life stages, the megalopal and juvenile stages (see life history). Primary dispersal, or blue crab movement and settlement at the megalopal stage, explains the occurrence of blue crabs at areas near Oregon and Hatteras Inlets (map). Blue crabs are predicted to get to other portions of Pamlico Sound, specifically sites on the western side (map), through secondary dispersal. Secondary dispersal is transport of juvenile crabs by primarily wind-driven water currents.


    Ecological Studies -- Water Quality
    Research in this area has focused on the effects of low oxygen levels on blue crab behavior. Studies have looked at the effects of both hypoxia (low oxygen) and anoxia (no oxygen) effects blue crabs. Field and laboratory work has looked how these conditions effect blue crab movement and feeding behavior.


    Fisheries Stock Assessment Research

    Fishery-dependent and -independent data are being analyzed statistically to determinethe status of the blue crab population in North Carolina. This is useful in determining how the population is responding to intenst fishing pressures. One general goal of this research is to help regulation agencies determine how to make the blue crab fishery a sustainable industry, allowing crabbers to make a living while preserving populations for future generations. For more information, and trends in the fishery, please see the fishery page.

    Megalopa (left), and two stages of Zoea


    Stock Enhancement and Pond Grow-Out
    We are currently testing the feasibility of rearing blue crabs using hatchery technology and stocking these crabs in underutilized nursery habitats to enhance the recruitment limited population of blue crabs in North Carolina. We are also assessing the feasibility of fresh water pond grow-out of hatchery-reared blue crabs to augment the soft-shell industry in North Carolina. This research is conducted in collaboration with colleagues at the University of Maryland Center of Marine Biotechnology, Smithsonian environmental research center, the Virginia Institute of Marine Science, and the University of Southern Mississippi.


    Education and Outreach
    We have given high school students from coastal North Carolina the opportunity to get involved in our research. Every day from August 1 through October 31, the students collect megalopae samples from artificial collectors that are posted at Manns Harbor, Engelhard, Oregon Inlet and Hatteras Inlet. In addition, a fifth grade class along with their parents and teacher are collecting samples at Wrightsville Beach. The data generated from these samples is being used to quantify daily megalopal settlement, in an effort to make predictions about North Carolina's blue crab breeding stock, and determine the importance of physical factors such as wind direction and speed in megalopal transport into estuaries. The students get a unique opportunity to be involved in research in their community, interact with scientists, and get solid scientific field experience. The data they gather is a valuable tool, and is being used as a Master's Thesis for Grant Parkins, one of Dr. Eggleston's students.

    high school students collecting samples
    High school students collecting samples

    In addition, lessons have been developed designed to allow high school teachers to incorporate blue crab and estuarine ecology into their regular science curriculum. The lessons adhere with the North Carolina Science Standard Course of Study, and could be useful to a number of differenty types of science classes. The effectiveness of these lessons is being tested with a pretest/posttest method to determine is student understanding is improved through their participation.

    In terms of education, the research group has constructed a blue crab home page and, in conjunction with UNC-TV, released a video describing the research and outreach efforts of this project.


Current Publications and Theses