Long-term Research on the Impacts of Rockweed Harvesting at BSS Kent Island

Contributed by Dr. Patricia Jones, Assistant Professor of Biology and Director of the Bowdoin College Scientific Station on Kent Island

The Bay of Fundy is characterized by dramatic 50 foot tides and extraordinary rocky intertidal diversity. One of the most prevalent and defining species in the Fundy intertidal, as well through the Gulf of Maine, is the algae called rockweed or knotted wrack, Ascophyllum nodosum. Rockweed creates a habitat that contains multiple species of snails, crabs, mussels, amphipods and more. In the last decade, harvesting of rockweed has dramatically increased in the northeast as it is used for fertilizer, food-additives, and nutritional supplements. Rockweed harvesting has provided important jobs and stability for many communities across Maine and New Brunswick. The impacts of rockweed harvesting on intertidal communities, however, remain very little studied.

In 2013, when rockweed harvesting was becoming an increasingly contentious issue in the North Atlantic, a Bowdoin student named Christine Walder began a large research project. Christine created 40 2 x 2m research plots at the Schiller Coastal Studies Center on Orr’s Island Maine, and 30 plots at the Bowdoin Scientific Station on Kent Island. In 2014 she returned to Kent Island and established 18 more plots. All of the plots were arranged in pairs in which one plot was unaltered (the control), and in the nearby plot Christine cut the rockweed to the harvest regulation height of 41 cm. Within each plot Christine recorded the area covered by different species of algae, and counted the numbers of marine invertebrates. Christine found that on Orr’s Island rockweed grew 2-5 cm per year, whereas on Kent Island it grew 17-28 cm per year. In the harvested plots on Kent Island there was a higher density of other green algae species both the summer of harvest and the following summer, and in the second summer the density of Fucus sp. (another brown algae like rockweed) tripled. Total invertebrate abundance was reduced by as much as 50% in harvested plots, and harvested plots had a slight decrease in invertebrate species richness. After one year, harvested plots also had fewer of the invasive European green crab, Carcinus maenus, and fewer amphipod and isopod crustaceans. Harvested plots did, however, increase in abundance of the common periwinkle Littorina littorea, in contrast harvesting reduced abundance of another common intertidal snail, Littorina obtusata. Overall, Christine did not observe complete recovery of harvested plots to pre-harvest algal or invertebrate communities over the course of one year.

In order to assess the long-term impacts of rockweed harvesting, this summer another Bowdoin student, Katie Galletta, is re-censusing Christine’s 18 plots from 2014. Sadly the 2013 plots were not marked permanently enough for us to relocate them. But in 2014 Christine used a different method and with the help of GPS Katie has been able to relocate all 18 plots (9 harvested and 9 controls). Katie is exactly replicating Christine’s methods to assess the impacts of rockweed harvesting 4 years later. Katie’s data collection on Fucus algae and invertebrates in still underway, but she has already found that the rockweed in the harvested plots is 10-40 cm shorter than that in the control plots. We are looking forward to more data rolling in over the next few weeks!

Review paper on bivalve pathogens in Maine published

Biology Honors student and BMSS 2015 alumna Madeline Schuldt ’18 and advisor Sarah Kingston contributed to a synthesis of bivalve pathogen history in the state of Maine. Madeline’s honors research builds on this historical base to monitor population dynamics of the oyster pathogen MSX, Haplosporidium nelsoni, in the context of a changing climate. Madeline collaborates with the lab of José Fernandez-Robledo at the Bigelow Laboratory for Ocean Sciences.


Pathogens of marine bivalves in Maine (USA): A historical perspective

José A. Fernández Robledo, Nicholas D. Marquis, Peter D. Countway, Nicholas R. Record, Ellie L. Irish, Madeline M. Schuldt, Sarah E. Kingston, Theodore J. Bishop, d, Nicole A. Messerman, Timothy J. Bowden.

Aquaculture. 2018. Volume 493 (9–17).


Kent Island and DEI field trip

To kick off the official start of the semester, the Bowdoin Marine Science Semester traveled to Bowdoin Scientific Station on Kent Island for four days. Here, the group learned about tides and physical ocean processes, held a benthic ecology journal club, and collected data on two long-term intertidal monitoring sites.

We were also excited that the new Director of the BSS on Kent Island and Assistant Professor of Biology, Dr. Patricia Jones, joined us for the trip.

On the way home, we swung by our friends and collaborators’ at the Downeast Institute in Beal’s, ME, to learn about their research and collect some snails for a class project.

See our Bowdoin Academic Spotlight here: http://community.bowdoin.edu/news/2017/09/marine-science-semester-explores-dramatic-kent-island-environment/

Summer Research Spotlight – hungry, hungry green crabs

Summer 2017, two student research fellows – one Bowdoin student, one Barnard College student – delved into figuring out what invasive green crabs (Carcinus maenas) are eating in Harpswell Sound. Pauline Unietis (’20) and Vanessa Van Deusen (Barnard ’18) set crab traps at four locations around Harpswell sound every week. Crabs caught in these traps offer several types of data: a census of how many (and what sex) crabs are moving into these locations as the season progresses, stomach contents, and tissue. After measuring and counting crabs, Pauline and Vanessa extracted DNA from stomach contents to prepare for a next generation sequencing-based metabarcoding effort to ID different kinds of algae, plants, and animals eaten by the crabs. Future efforts will include compound stable isotope analysis of the crabs’ tissue (from a leg or claw) to figure out the relative proportions of their diet items.

Science Communication with Computational Genomics

This spring semester, Visiting Assistant Professor Sarah Kingston launched a Computational Genomics course. Students learned both statistical theory and practical applications involved with analysis of genome-scale data.

After the long process of independently analyzing and interpreting omic-scale datasets, students tapped their creative, collaborative talents with a final science communication piece.

Students Rob Barron, Eileen Bates, Steve Cho, and Julia Michels created this fantastic stop-motion video to communicate how genomic research can help conserve fish species.

Other creative projects included describing the role of long non-coding RNAs in cancer, microbial metagenomics and type II diabetes, gene expression-related health impacts of performance enhancing drugs, and microevolution in rapidly changing environments.

The final presentation even ended with interactive art (directed by students Nora Cullen, Pilar Giffenig, Sofi Lopez, Alana Luzzio, and Casey Silvernale).

Marine Science Semester Alums attend the 46th Benthic Ecology Meeting in Myrtle Beach, SC

Sam Walkes ’18, Aidan Coyle ’17, Dave, and Alana Luzzio “17 celebrate the success of the meeting.

Bowdoin had a wonderful showing at the Benthic Ecology Meeting/Southeastern Estuarine Research Society meeting hosted in Myrtle Beach, SC over the past week.

Bowdoin Marine Science Semester Alums presented their independent and honors research at the meeting:
Alana Luzzio ’17 spoke on linking genes, environment, and phenotype in Gulf of Maine clam species; Aidan Coyle ’17 talked on physiological and genetic differences between two types of invasive green crabs; and Sam Walkes ’18 presented a poster on adaptive coloration in a species of Gulf of Maine intertidal snail.

Aidan Coyle ’17and Sam Walkes ’18 meet acclaimed coral reef biologist Dr. Howard Lasker.

Director of Coastal Studies Center Dave Carlon presented work on movement of genes between invasive green crab lineages.

Aidan Coyle won the meeting-wide prize for best undergraduate student talk.

Aidan Coyle ’17 wins best undergrad student presentation.

BMSS 2016 Independent Project Symposium 12/16/16

Welcome and Introduction (2:15pm)
Session 1: The Intertidal (2:30pm)

Testing desiccation stresses and visual predation as mechanisms for maintaining a potential color polymorphism cline (Sam Walkes ’18)

Is the European Periwinkle invasion really from Europe? (Caroline Carter ’19)

Saving the snails: how feeding preferences of Carcinus maenas on Littorina littorea may determine the survival of Ilyanassa obsoleta (Meret Beutler ’19)

Predation of the softshell clam Mya arenaria by the nemertean worm Cerebratulus lacteus (Elizabeth Givens ’17)

Session 2: Aquaculture and Fisheries (3:45pm)

Does Mytilus edulis ingest and process the microplastics in Harpswell Sound?                 (Anna Blaustein ’19)

Finding an Easy and Efficient Method of Growing Microalgage for Biofuel: The Effect of Difference in Light and Nitrogen on Phaeodactylum tricornutum Lipid Production         (Maya Morduch-Toubman ’18)

Multiple Species Interactions in Harpswell Sound Lobster Traps (Isaac Schuchat ’19)

Session 3: Ocean Acidification and Environmental Change (4:45pm) 

Fundulus heteroclitus lateralization efficacy in response to rising sea temperatures and ocean acidification (Jonathan Harrison ’19)

The Effects of Climate Change Stressors on the Sea Star, Asterias forbesi, Regeneration (Amber Rock ’19)

The Effects of Ocean Acidification on Shell Resource and Assessment Behavior of Hermit Crab Pagarus longicarpus (Jackie Ricca ’19)

The Effects of Eutrophication and Oxygen Depletion on Bioluminescence in the Tropical Dinoflagellate Pyrocystis lunula (Ripley Mayfield ’19)

Bowdoin Marine Science Semester Concluding Remarks (5:45-6:00pm)

Holiday Reception to Follow (6:00-9:00pm)