Science for Everyone

lobster

ROV footage off of Hurricane Island

Back in August the Rozalia Project for a Clean Ocean came out to Hurricane Island to explain their mission for a clean ocean to students in our Marine Ecology ISLE program. The Rozalia Project uses lots of different tools to help them do beach cleanups and extricate marine debris from the ocean. One of the most helpful tools they have is a remotely operated vehicle (ROV), which is outfitted with a robotic arm to be able to grab trash underwater. By using an ROV instead of a diver, they are able to minimize their impact, travel to deeper depths, and also use the camera perspective of the ROV as a great teaching tool. Here is a fun video clip taken off of the main pier at Hurricane Island where "Hector the Collector" surveyed for marine debris. We love collaborating with the Rozalia Project, and seeing new perspectives of our island!

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Gulf of Maine lobster settlement lower than in years past...

Dr. Rick Wahle, one of Hurricane Island's science advisors, and his lab annually quantify the number of newly settled lobsters at 11 sites in the Gulf of Maine from Rhode Island to Lobster Bay, Nova Scotia. This year's results from the American Lobster Settlement Index  show a steady decline in the number of settling lobsters since 2007 which could mean an end to the record high lobster landings we've seen over the last few years to a decade. Based on the 2012 Lobster Settlement Index Update, the southern Gulf of Maine sites typically had lower settlement rates than the northern sites, but that has changed and the regional difference in settlement has since narrowed. A newly settled lobster reaches a harvestable size after approximately 8 years. For the survey, young-of-the-year lobsters are collected via diver-based suction sampling and passive post-larval collectors. In October 2013, Alice went out and helped sort samples.

This is an example of the lobsters being surveyed for the settlement index

This is an example of the lobsters being surveyed for the settlement index

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DMR hearing in Bucksport

A fisherman from Bucksport expresses his concern about the lack of data on mercury levels in crabs. 

A fisherman from Bucksport expresses his concern about the lack of data on mercury levels in crabs. 

On Monday night (March 17, 2014), I attended the Maine Department of Marine Resources (DMR) hearing held in Bucksport regarding the two-year closure to lobster and crab harvesting. The closure is located at the mouth of the Penobscot River and extends approximately 7 square miles. The hearing was an opportunity for the public to voice concerns about or support for the implementation of the closure. 

DMR officials summarized the data they had reviewed and their process for making this decision. DMR believes that an area closure is the appropriate measure to protect the public from the levels of mercury recorded in lobster samples collected at the mouth of the river. Sampling in other areas of Penobscot Bay revealed that high mercury levels seemed contained to a small area, and the closure is estimated to affect approximately 10 lobster and crab harvesters. DMR acknowledged that those harvesters will have to shift some of their gear outside of the closed area and hopes that other fishermen will understand and accommodate the shift. 

Harvesters raised concerns about how lobsters and crabs take up methylmercury. It’s commonly believed that lobsters take up methylmercury from the sediment and from what they eat (more info on bioaccumulation here), but there is a lack of understanding on how quickly lobsters take it up directly from water.... so the question remains: will harvested lobsters stored in the closed area waters take up mercury from the surrounding water while they are waiting to be sold?

Going forward, the DMR will work with the Maine Department of Environmental Protection and the Maine Center for Disease Control and Prevention. These agencies plan to undertake additional data collection year round over the next two years. To ensure their ability to compare data sets, the state agencies will follow the same protocol used to collect data for the independent study carried out in 2006 - 2013. 

The mercury is believed to have come from HoltraChem plant in Orrington which is now closed, but operated from 1967-1982. A 2002 court ruling initiated the study on mercury levels in the area. For more background on the issue, please see the following articles from: The Working Waterfront  and the PenBay Pilot

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DMR Lobster Settlement Survey Dives

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I spent Friday Oct 18 and Monday Oct 21 helping (by sorting samples) DMR scientists Robert Russell and Carl Wilson, who are conducting their annual dive survey of larval lobster settlement rates at 50 sites along the Maine coast. At each site they sampled 12 quadrats via underwater suction sampling. Samples were then sorted and processed on the boat. The suction sampler pulls up all loose sediment and other organisms, so we needed to sift through it and pull out any lobsters and crabs we found. Many of the samples also had shrimp, urchins, seaweed, brittle stars, marine worms, asst. shells, and occasionally rock gunnels and cunner (fish). Once the sample was sifted, we measured the lobsters and crabs carapace length, and we also collected data about the lobster's sex and number of claws.

The boat they used for these dives was the 38' Lady Anne, operated by Sea Ventures Charters, Captained by Dave Sinclair.

Some of the sites we visited during these surveys were Head Harbor at Isle Au Haut, Ragged Island, Allen Island, Matinicus, Hurricane, and Monhegan

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Overall, Carl and Robert said that they were seeing far fewer settler-size lobsters across all of their sites than in previous years (this survey has been going on for 22 years). For example, we only found 6 settlers from the 5 sites that were surveyed on Friday, when in the past Robert and Carl have found 4-5 settlers per site in that area.

The data from these surveys will feed into the American Lobster Settlement Index.

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