2018 SEANET Student Spotlight: Tyler Van Kirk

Did you catch our most recent SEANET research spotlight? If not, hop on over to our Vimeo page and meet Tyler Van Kirk, a research fellow at the University of Maine who is “Examining the Threat of an Invasive Species on Shellfish Aquaculture.”

Green crabs are the model species for an invasive organism. Green crabs have a major impact on Maine’s ecosystems both economically, predating many aquacultured organisms (such as soft shelled clams), and environmentally, by destroying salt marshes and infrastructure by burrowing under moorings, quays, etc. Green crabs are highly successful in Maine, having been established in the state since the 1800’s. Yet looking at the biology, green crabs should not be this successful due to Maine’s extremely cold winters and water temperatures. In Europe, the green crab’s northern distribution is believed to be limited by temperature. If that were the case, then the green crab would be barely surviving in bioregion I (southern coastal Maine). However, it is thriving and spreading north. The reason for this is unclear, but recent research shows that the impact that parasite predation has on the population is underestimated. It seems possible that the northerly distribution in Europe is limited by a combination of both low temperatures and parasite predation.

In Maine, green crabs only have two known parasites, the spiny head worm Profilicollis botulus, and a parasite identified by Theme 2 in May 2016, Microphallus Spp. By investigating the parasite fauna of green crabs in the three bioregions and the prevalence in the definitive host, herring gulls, it will be possible to investigate the parasite-host relationship with regards to organismal fitness and climate change. This will provide data that can be used to verify models being developed by Theme 1 that look at invasive species distribution in Maine and the likelihood of spread over the next century.

[Watch the video here]