R/DIS-4

Strategic focus area:

Description:

Rationale: Blue crab harvests and populations are highly variable in Maryland. Viral disease is a possible cause of blue crab mortalities, but  little is known about viruses in crabs. Interstate transport of blue crabs may introduce new viruses into the bay.

• Objective 1. Identify new viruses in blue crab with metagenomic sequencing:   a. viruses in Chesapeake Bay blue crabs that die in soft-shell  production; b. viruses in imported blue crabs that die during transportation.
• Objective 2. Investigate the prevalence of viruses in blue crab populations. a. Conduct a complete survey to investigate the prevalence of known and newly identified virus in Chesapeake Bay blue crabs. b. Conduct a  survey to quantify these virus prevalence and intensity in blue crabs that are being imported into the Chesapeake Bay from states in the Gulf of Mexico or Florida Atlantic coast.
• Objective 3. Test the pathogenicity of newly identified  viruses
• Objective 4. Outreach to managers, scientists, and industry participants:
  • Communicate with scientists and industry at a national conference;
  • Communicate with blue crab modelers and managers;
  • Communicate with fishermen about safe methods of discarding dead crabs.

Methods: Metagenomics of both RNA and DNA will be used to discover virus genomes in collected crabs. PCR-based tools verify and investigate prevalence. Experimental injections will assess pathogenicity of viruses.

Value to constituents: Managers need to understand causes of crab mortality. Biosecurity in transport and aquaculture is not being addressed by managers.
Outreach: The outreach plan is intended to reach managers and industry practitioners using two main strategies: 1) Presentation to the Chesapeake Bay Stock Assessment Committee and other management bodies.
2) Organize a session for the National Shellfisheries Association meeting on biosecurity of crab transportation and discards. 3) Work with Louisiana Sea Grant on printed outreach to discourage in-water discards."