HomeResearchPhD Candidate Seeks to Increase Understanding of Lobster Migration

PhD Candidate Seeks to Increase Understanding of Lobster Migration

Emily Blacklock has used a combination of satellite tracking and ocean bathymetry to pinpoint exactly where lobsters are migrating in the Bay of Fundy.

Blacklock, a PhD candidate at the University of New Brunswick, is tracking the migration patterns of American lobster in the Bay of Fundy. Tag and capture methods are routinely used to track the migration of lobsters, but Blacklock said that this system doesn’t paint a complete picture of where lobsters move throughout the year.

“In the winter, lobsters go to deeper water. In the spring and summer, they come to shallower water. But no one knows how they’re getting there or exactly what route they’re taking,” said Blacklock.

To remedy this lack of knowledge, Blacklock has been using pop-off satellite archival tags. These tags have been used with fish and sharks, but never on lobster.

Blacklock tags lobsters around the start of October. Once the tags have been attached to a lobster, its starting position is registered. From there, the tag collects depth and temperature data hourly. The tags remain on the lobsters until early August, when they automatically pop off and float to the surface, giving Blacklock an end location.

“Using a model that we created in our lab, we can use the depth and temperature that they’ve experienced with the start and stop locations to create the most accurate movement paths to date of the lobster,” said Blacklock.

Blacklock and her team have also tagged female lobsters carrying fertilized eggs, better known as a berried female. This gave her the rare opportunity to find out just where these berried lobsters go to hatch their eggs.

What she has found is that the movement of these egg-bearing lobsters can vary greatly. Some, like a lobster tagged near Deer Island, ended up in the same location it was originally caught. Others, like a specimen tagged near Campobello Island, ended up near Advocate Harbour — a distance of nearly 180 kilometres.

“Part of the study was tagging berried females because no one knows exactly where they hatch their eggs, so this way we can predict where they’re hatching them,” said Blacklock.

“We also want to compare that to the females that don’t have eggs to see if that changes their movement at all.”

Blacklock is also inviting fish harvesters to participate in her study by keeping an eye out for her satellite tags. If a tagged lobster is caught, one can text or call in the tag number, and Blacklock will share the lobster’s movement history. If the harvester sends Blacklock a video of the tagged lobster being released back into the ocean, they will be entered for a draw to win $200.

“We do the draw at the end of seasons, usually, but that’s a bit variable,” said Blacklock.

All of the movement, depth and temperature data collected from these tagged lobsters will be made available through both publication and Blacklock’s website, which can be found at eblacklockscience.wixsite.com.