New fish on the block: Ecological implications of black sea bass in the Gulf of Maine

Northeastern University
Freeport, Maine
DOI: 10.18258/3480
Raised of $6,000 Goal
Funded on 12/05/14
Successfully Funded
  • $7,553
  • 125%
  • Funded
    on 12/05/14

About This Project

The warming of the world’s oceans has begun to restructure marine communities. One consequence is that species ranges often expand or contract, which may alter interactions such as predation and competition. We will be studying the ecological implications of a northern range expansion of black sea bass into the Gulf of Maine. This project will provide a framework for monitoring emergent species as ocean temperatures continue to warm.

Ask the Scientists

Join The Discussion

What is the context of this research?

Black sea bass traditionally ranged from the Gulf of Mexico to southern Massachusetts, where they were met with a steep temperature gradient that likely deterred them from moving further into the Gulf of Maine (GOM). However, ocean temperatures have significantly increased in the GOM in the past several decades, enabling a northern range expansion.

In their native range, sea bass are an economically important commercial and recreational species and are also an aggressive and territorial predator. Currently, studies and monitoring data on black sea bass in the GOM are limited. Efforts to describe their abundance and distribution shifts in coastal waters of the GOM are a necessary first step in understanding the ecological impacts and economic implications of their range expansion.

What is the significance of this project?

Currently, no commercial or recreational black sea bass fisheries exist north of Massachusetts, and regulations on the species have only recently been implemented. A better understanding of the ecology of sea bass in this newly expanded range may aid in the early management of a potential new fishery.

Furthermore, the emergence of sea bass in the northern GOM could have negative impacts on native species and fisheries. Sea bass have a diet largely comprised of crustaceans in their native range, and the northern GOM is home to a very important crustacean, one that supports the second most valuable fishery in the U.S. – the lobster. Understanding how emergent species impact food web dynamics will be vital to both the ecological and economic resilience of the GOM.

What are the goals of the project?

The goals of this project are:

1.) To quantify the distribution, relative
abundance, and size frequency of black sea bass in its native and newly expanded range.
2.) To determine the impact of sea bass range expansion on benthic communities and native fisheries.
3.) To collect historical and anecdotal information on black sea bass in the Gulf of Maine.

A greater understanding of black sea bass range expansion will lead to more informed stock assessments and management of the northern stock. Overall, this project will provide a framework for future monitoring of emergent species in the GOM.


Please wait...

Achieving the goals of this project will require an immense amount of time and effort. Although I received a Graduate Women in Science Fellowship to help with the cost of materials and travel, I still need to raise money to support my stipend for the spring semester. The required stipend amount is $12k. My initial goal is to raise $6k in this campaign and implement additional fundraising goals should the campaign be successful.

Any donation amount is helpful and appreciated!

If you:
Donate $25
You will be acknowledged in an academic presentation of this research and sent a delicious sea bass recipe.

Donate $50
Everything above, plus an emailed sea bass photo from 2015.

Donate $100
Everything above, plus you will be sent pictures and video footage from the 2015 field season.

Donate $500
Everything above, plus you will be taken lobstering for half a day and you will leave with enough lobster for dinner! *does not include transport to and from home port of Georgetown, Maine

Meet the Team

Marissa McMahan
Marissa McMahan

Team Bio

I grew up on an island along the coast of Maine and come from a family of commercial fishermen. I spent my childhood tagging along with my father and grandfather when they went lobstering. The critters coming up in the lobster traps always fascinated me, and by the end of the day, I would have an impressive assortment of marine life in my 5-gallon bucket ‘aquarium’. Later in life, I worked as a deck hand for my father and uncles. I even tried my hand at lobstering solo from a 12ft skiff!

My background in fisheries is what led me to pursue a master’s degree in Marine Biology at the University of Maine. I studied behavioral interactions between cod and lobsters, two very important fisheries in the Gulf of Maine (GOM). I am now working towards my doctorate and once again studying the ecosystem where I grew up. The health of both GOM ecosystems and fisheries is something that is important to me on a professional and personal level, and I hope that my research will benefit both.

Press and Media

The Times Record: Researcher 'experiments' with crowdfunding to continue study

The Boston Globe: In Maine, scientists see signs of climate change

The Times Record: Georgetown marine biologist leads way on black sea bass study

Northeastern University news : Lobsterwoman turned marine biologist fishes for answers

Portland Press Herald: Maine proposes rules as sea bass fishery grows

The Fisherman: On the move: Black sea bass in the Gulf of Maine

Northeastern University College of Science: Lobsters hide from cod, not the other way around


McMahan, M. D., D. F. Cowan, G. D. Sherwood, J. H.
Grabowski, and Y. Chen. 2012. Evaluation of coded microwire tag retention in juvenile American lobster, Homarus americanus. Journal of Crustacean Biology. 32(3): 497-502.

McMahan, M. D., D. C. Brady, D. F. Cowan, J. H. Grabowski, G. D. Sherwood. 2013. Using acoustic telemetry to observe the effects of a groundfish predator (Atlantic cod, Gadus morhua) on movement of the American lobster (Homarus americanus). Canadian Journal of Fisheries and Aquatic Science. 70(11): 1625-1634.

Additional Information

Link to Northeastern University's Marine Science Center
Link to Grabowski Lab website
View Marissa McMahan's CV here

Happy Halloween! Since this project is launching on Halloween, I wanted to share a rare two-toned (and very festive) lobster that my father caught in October!

Prepping for sea bass surveys.


Tagging Atlantic cod with acoustic tags for an experiment evaluating how large fish predators influence lobster movement behavior.

Lobster outfitted with acoustic tag.

Setting up acoustic receivers in an experimental enclosure.

View video of lobster movement (green, orange, red and yellow dots = lobsters) before and after the addition of cod (blue dots) into a 6-acre enclosure.

Collecting juvenile lobsters for an experiment evaluating the tagging method used in a long term mark-recapture study conducted by The Lobster Conservancy.

Setting up the tagging experiment with Diane Cowan.

Tagging juvenile lobsters with microwire tag (1 mm in length).

A stray cat I recently rescued while collecting juvenile lobsters at a remote field site!

Cover photo of black sea bass by Kevin Bryant, accessed on

Additional photos courtesy of: Webb Chappell

Project Backers

  • 76Backers
  • 125%Funded
  • $7,553Total Donations
  • $99.39Average Donation
Please wait...