It’s been a few years in the making, but our draft manuscript on lobster shell microbes, epizootic shell disease, and climate change is available online as a preprint (not yet peer reviewed)! You can read the preprint here, and the summary is below.
I joined this project back in the summer of 2020, when I was given a large 16S rRNA gene sequence dataset of bacterial communities from the shells of lobsters by a research group at UMaine who had been studying lobster health for some time. My first point of contact on the project was Jean MacRae, an Associate Professor of Civil and Environmental Engineering at UMaine, who had been working on bacterial community sequencing on other projects which I’ve been involved in, and who has been involved with MSE, and this will be our fourth publication together!
Jean introduced me to the original research team, including Debbie Bouchard, who is the Director of the Aquaculture Research Institute and was researching epizootic shell disease in lobsters for her PhD dissertation; Heather Hamlin, Professor and Director of the School of Marine Sciences; Scarlett Tudor, the Education and Outreach Coordinator at the ARI; and Sarah Turner, Scientific Research Specialist at ARI.
I used the data as a training opportunity for Grace Lee, who at the time was an undergraduate at Bowdoin College participating in the abruptly cancelled summer Research Experience for Undergrads program at UMaine in summer 2020. Instead, Grace joined my lab as a remote research assistant and we worked through the data analysis over the summer and fall. Grace has since graduated with her Bachelor’s of Science in Neuroscience, obtained a Master’s of Science at Bowdoin, and is currently a researcher at Boston Children’s Hospital while she is applying to medical school.
Earlier this year, the research team, along with social science Masters student Joelle Kilchenmann, published a perspective/hypothesis piece which explored unanswered questions about how the movement of microbes, lobsters, and climate could affect the spread of epizootic shell disease in lobsters off the coast of Maine.
“Warmer water temperature and epizootic shell disease reduces diversity but increases cultivability of bacteria on the shells of American Lobster (Homarus americanus).”
Suzanne L. Ishaq1,2,, Sarah M. Turner2,3, Grace Lee4,5,M. Scarlett Tudor2,3, Jean D. MacRae6, Heather Hamlin2,7, Deborah Bouchard2,3
- 1 School of Food and Agriculture; University of Maine; Orono, Maine, 04469; USA.
- 2 Aquaculture Research Institute; University of Maine; Orono, Maine, 04469; USA.
- 3 Cooperative Extension; University of Maine; Orono, Maine, 04469; USA.
- 4 Department of Neuroscience, Bowdoin College, Brunswick, ME 04011; USA.
- 5 Boston Children’s Hospital, Boston, MA 02115; USA.
- 6 Department of Civil and Environmental Engineering; University of Maine; Orono, Maine, 04469; USA.
- 7 School of Marine Sciences; University of Maine; Orono, Maine, 04469; USA.
Summary
The American lobster, Homarus americanus, is an economically valuable and ecologically important crustacean along the North Atlantic coast of North America. Populations in southern locations have declined in recent decades due to increasing ocean temperatures and disease, and these circumstances are progressing northward. We monitored 57 adult female lobsters, healthy and shell-diseased, under three seasonal temperature cycles for a year, to track shell bacterial communities using culturing and 16S rRNA gene sequencing, progression of ESD using visual assessment, and antimicrobial activity of hemolymph. The richness of bacterial taxa present, evenness of abundance, and community similarity between lobsters was affected by water temperature at the time of sampling, water temperature over time based on seasonal temperature regimes, shell disease severity, and molt stage. Several bacteria were prevalent on healthy lobster shells but missing or less abundant on diseased shells, although putative pathogens were found on all shells regardless of health status.