About This Project

American lobsters are ecologically and economically important to the communities of the Northeast North American coast. Their recent decline in health is a bellwether of a change in water quality in this region. Understanding how their microbiome is changing in the face of this ecological transformation is vital to understanding human effects on the environment, and what can be done to reverse negative impacts.

Ask the Scientists

What is the context of this research?

The primary research question to be answered by this project is as follows: what are the differences in the composition of biofilms on the surface of the American lobster (Homarus americanus H. Milne Edwards 1837)? How do the microbial communities differ in lobsters from different geographic regions? This would be the first phase of an investigation of the lobster surface microbiome that would expand to include an interrogation of epizootic shell disease (ESD)

What is the significance of this project?

The American lobster has served an important ecological and economic role to the New England and Canadian Maritime communities. At the end of the 20th century, lobster populations in the southern portion of the commercial fishery (Rhode Island, southern Massachusetts, and Long Island Sound) were assaulted by mass mortality. Since then, epizootic shell disease (ESD) has emerged as a persistent disease.

My doctoral research has focused on the microbiome of lobsters affected by ESD, and I have surveyed and compared the surface biofilms of lobsters to compare the microbial compositions of apparently healthy and diseased lobsters. I found that while there are subtle differences between lobsters with and without the disease, and while some bacterial genera emerge as correlating--weakly--with ESD, there does not appear to be a statistically significant difference between the microbiomes of lobsters with or without the disease. This lead me to conclude that this disease was probably not caused by a discrete pathogen, but that ESD might be a dysbiosis.

This research represents the first attempt to survey the surface microbiome of the American lobster. As such, it was merely a glimpse into the complexity of the epibiotic community that exists on this crustacean.

The field of microbiomics is relatively new and has emerged with the development of high throughput DNA sequencing technologies such as multitag pyrosequencing, which was employed in my research. The Human Microbiome Project is barely four years old, yet it has already yielded a new understanding of the relationship between microbiomics and human health, particularly as it relates to the digestive system.

The American lobster is not only an economically important marine organism; it occupies an important niche in the coastal and near shore ecosystems that it inhabits, and its health may be an indicator of local water quality. In the process of conducting this research, I have grown to respect the men and women who make their living by harvesting these lobsters. They have made tremendous efforts to maintain a sustainable fishery, often going above and beyond what fish and game laws mandate. I would like to make a positive contribution to lobster biology that would aid these dedicated watermen in preserving not only their way of life, but this magnificent animal.

What are the goals of the project?

Fifty lobsters will be harvested by lobstermen in several locations (Maine, Northeast Massachusetts, Southeast Massachusetts, Rhode Island, Eastern Long Island Sound). The lobsters will be packed alive and shipped to be dissected, and cuticular samples from the cephalothorax will be used to extract microbial DNA from the samples. The DNA will be amplified by PCR, and sequenced using a NextGen sequencing technique such as multitag pyrosequencing or a similar method with ion torrent sequencing.

The funds will enable me to reimburse the lobstermen for the cost of preparing and shipping the lobsters, and for the fair market value of the lobsters themselves. The funds will also be used for dissecting, preparing, storing, and shipping the tissues, and to pay for molecular services. Finally, the funds will allow me to draw a modest salary to cover my living expenses, and to cover travel costs, conference attendances, software purchases, and general operating expenses.