Rising temperatures and changing environmental conditions in our oceans can lead to increased physiological stress upon marine invertebrates and the emergence and spread of infectious diseases. The epizootic shell disease (ESD) in American lobsters H. americanus is characterized by fast spreading cuticle lesions that can invade underlying tissue which can increase mortality and lower reproduction, especially in larger specimen and ovigerous females. Outbreaks of ESD have been associated with warmer summer temperatures and were likely a factor in the collapse of the Southern New England lobster stock in the 1990s. A negative shift in the shell microbial community together with environmental stressors has been proposed to cause ESD proliferation in lobster populations.
Due to current knowledge gaps regarding the shell microbial community associated with H. americanus in Atlantic Canada, this study aims to describe and analyze the shell microbiome of lobsters sampled from several locations in New Brunswick, Nova Scotia and Prince Edward Island.
Long-read, next-generation 16S rDNA amplicon sequencing (PacBio) of cuticle samples followed by bioinformatic analyses will identify the shell associated bacteria to species level. Diversity indices will assess the microbial composition and diversity while network analyses explore bacterial interactions within the microbiome. Furthermore, multivariate analyses will detect any patterns in microbial species’ abundances, composition or distribution based on biotic and abiotic factors.
It is expected that spatial, temporal, and environmental variables as well as lobster characteristics such as sex, size, or molt stage to some extent influence microbial profiles on lobster cuticles. Bacterial taxa that have been associated with ESD are likely present in lobsters from Atlantic Canada as they are ubiquitous in the marine environment but may play a role in ESD proliferation.
This study will help to assess and predict the risk of ESD outbreaks in Atlantic Canada and in turn will encourage the development of suitable fisheries management strategies in the future.