Rehoboth resident helps URI, Conservancy track declining horseshoe crab populations

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KINGSTON, R.I. – January 21, 2011 — University of Rhode Island junior Katherine Hallal spent the last eight months trying to gain new insights into why horseshoe crab populations in southeastern New England have been declining at alarming rates.

A resident of Rehoboth, Mass., Hallal worked with the Watch Hill Conservancy in Westerly to monitor the crabs as they arrived at Napatree Point to spawn last summer.

“It’s very difficult to determine their populations because they spend the majority of the year in deep water and only come to beaches to spawn,” said Hallal, an animal science major. “It’s important to pay attention to them because horseshoe crabs are being seen less and less by folks who have lived along Watch Hill for their whole lives.”

Hallal said that part of the explanation for the horseshoe crab decline could be because they are increasingly being used as bait by commercial fishermen seeking to catch eels and sea snails. Their blood is also harvested for use in the biomedical industry.

Her research project is part of a region-wide effort coordinated by scientists at Sacred Heart University, who are compiling a database of horseshoe crab numbers from Maine to Delaware. During the summer months, Hallal visited beaches at high tides during the new and full moons to count, measure and attach identification tags to the crabs.

“We were trying to see what the population is here, determine if the same horseshoe crabs come to the same beaches every year, and see if we were finding crabs we tagged earlier in the year or even from previous years,” Hallal said.

After spending the last several months analyzing data, the URI student made one interesting discovery: Napatree’s horseshoe crabs don’t seem to like it when the winds blow from the west.

“We saw significantly higher than average numbers of crabs when the wind was coming from the east, but far fewer when it came from the west,” she said. “That’s probably because west winds make it much harder for them to make it into the Napatree Point lagoon, where they prefer to spawn.”

She also found fewer horseshoe crabs in the morning than in the evening, and fewer during full moons compared to those that arrived to spawn during new moons. Due to gaps in data from previous years, these variables need to be monitored closely in the future to scientifically determine trends.

Hallal’s research was funded through the URI Coastal Fellows Program, a unique initiative designed to involve undergraduate students in addressing current environmental problems. Now in its 15th year, it is based at URI’s College of the Environment and Life Sciences. Students are paired with a mentor and research staff to help them gain skills relevant to their academic major and future occupations.

Hallal plans to continue working on the project next summer and fall with the hope of collecting enough data to establish population trends and identify other indicator’s of horseshoe crab health.

But she is also anxious to get additional experience studying and working with animals. While she plans to enroll in graduate school after earning her undergraduate degree at URI in 2012, Hallal says she also wants to keep her options open.

“I’m trying to get an internship at a zoo to decide if I like that working environment. I want to volunteer at an animal hospital or veterinary clinic to see what I do and don’t like about those careers to get a better idea what direction I want to go in. I’m really looking forward to these next steps.”