Lobsters are an iconic part of Maine culture, from cuisine to interior decorating to way of life. The Gulf of Maine boasts large lobster landings every year, but as the waters here continue to warm at a faster rate than other nearby coastal regions, there are concerns that this boon might eventually pass us by as lobsters migrate further north in search of colder waters. In addition to rising temperatures along the northeastern coast, we’ve seen an increase in epizootic shell disease (ESD) in the last few decades. ESD causes degradation and pitting of the lobster shell which can leave them susceptible to predation or to harsh weather conditions. There are bacteria living on the shell of healthy lobsters, and it’s not clear how they are involved in ESD in the wild because it is difficult to replicate this disease in an aquaculture facility.
In this perspective piece, we consider how shell microbes might be involved. Marine environments have a thriving microbial community which can change rapidly when currents, storms, filter feeders, or viruses which target microbes roll through. Some of these water or soil microbes end up on lobster shells, and water currents can also lift microbes off and move them elsewhere. The other authors and I wanted to highlight some of these possibilities and what we still don’t know about lobster microbes and health.
This perspective piece is part of a larger, collaborative project on lobster shell disease and warming ocean waters was begun by researchers at the Aquaculture Research Institute: Debbie Bouchard, Heather Hamlin, Jean MacRae, Scarlett Tudor, and later Sarah Turner as a grad student. I was invited to participate in the data analysis aspect two years ago.
At the time, Grace Lee was a rising senior at Bowdoin College, and accepted to my lab for the UMaine REU summer 2020 session, which was canceled. Instead, I hired Grace to perform DNA sequence analysis remotely, by independently learning data analysis following the teaching materials I had generated for my sequencing class. I invited Joelle Kilchenmann to this piece after a series of conversations about microbes and social equity, because her graduate work in Joshua Stoll’s lab focuses on lobster fishing communities in Maine and understanding the challenges they face.
Ishaq, S.L., Turner, S.M., Tudor, M.S., MacRae, J.D., Hamlin, H., Kilchenmann, J., Lee1, G., Bouchard, D. 2022. Many questions remain unanswered about the role of microbial transmission in epizootic shell disease in American lobsters (Homarus americanus). Frontiers in Microbiology 13: 824950.
This was an invited contribution to a special collection: The Role of Dispersal and Transmission in Structuring Microbial Communities
Abstract: Despite decades of research on lobster species’ biology, ecology, and microbiology, there are still unresolved questions about the microbial communities which associate in or on lobsters under healthy or diseased states, microbial acquisition, as well as microbial transmission between lobsters and between lobsters and their environment. There is an untapped opportunity for metagenomics, metatranscriptomics, and metabolomics to be added to the existing wealth of knowledge to more precisely track disease transmission, etiology, and host-microbe dynamics. Moreover, we need to gain this knowledge of wild lobster microbiomes before climate change alters environmental and host-microbial communities more than it likely already has, throwing a socioeconomically critical industry into disarray. As with so many animal species, the effects of climate change often manifests as changes in movement, and in this perspective piece, we consider the movement of the American lobster (Homarus americanus), Atlantic ocean currents, and the microorganisms associated with either.
Ishaq*, S.L., Lee, G., MacRae, J., Hamlin, H., Bouchard, D. “The effect of simulated warming ocean temperatures on the bacterial communities on the shells of healthy and epizootic shell diseased American Lobster (Homarus americanus).” Ecological Society of America 2021. (virtual). Aug 2-6, 2021. (accepted talk)
Ishaq*, S.L., Lee, G., MacRae, J., Hamlin, H., Bouchard, D. The Effect Of Simulated Warming Ocean Temperatures On The Bacterial Communities On The Shells Of Healthy And Epizootic Shell Diseased American Lobster (Homarus americanus). ASM Microbe/ISME World Microbe Forum 2021 (virtual). June 20-24, 2021. (poster)