IS BLACK SPOT SHELL DISEASE RELATED TO JONAH CRAB HEALTH?

Jonah Crab (<i>Cancer borealis</i>) is a growing fishery in New England. Despite previous studies on the related <i>C. pagurus</i>,  not much information is known about the Jonah crab nor its shell disease, black spot. Due to concerns about the potential severity of black spot, our study aimed to answer the question: Is black spot disease related to Jonah crab health? Black Spot may negatively affect Jonah Crabs health, which could be observed with impaired health metrics with increased disease. Crabs (n = 71) were collected with the Maine Department of Marine Resources through the Ventless Trap Survey near Vinalhaven, Maine. Hemolymph Brix, hepatopancreas % dry weight, septicemia, and hemocyte total counts were assessed in relation to % black spot cover. These health metrics are indicative of energetic resources (Brix and dry weight) and potential secondary infection (septicemia and hemocytes). Although no significant relationship was found between black spot % cover and the health metrics, a significant relationship between Brix and hepatopancreas % dry weight suggests that Brix could serve as a non-lethal proxy for hepatopancreas % dry weight. Our results suggest black spot has no substantial negative effect on Jonah crab health by our assessed metrics, though this may be influenced by our study on mid-summer crab and does not preclude potential disease impacts concurrent with environmental stressors. This information aids fisheries management and understanding the implications of shell disease in crabs.

Presentation Preference: Poster

Primary Presenter: Nyla Thompson, Hampton University (nyla.thompson@my.hamptonu.edu)

Authors:

Nyla Thompson, Hampton University/Bigelow Labs  (nyla.thompson@my.hamptonu.edu)

Reyn Yoshioka, Bigelow Labs  (ryoshioka@bigelow.org)

Maya Groner, Bigelow Labs  (mgroner@bigelow.org)

Melissa Rocker, Bigelow Labs  (mrocker@bigelow.org)

Kirsten Johnson, Bigelow Labs  (kjohnston@bigelow.org)