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Mytilus edulis

In August 2013, the University of Maine at Machias received a 2-yr, $630,000 grant from the National Science Foundation to conduct applied research on Arctic surfclams, Mactromeris polynyma, and blue mussels, Mytilus edulis.  DEI is a collaborating entity in the project, along with Dr. Sandra Shumway (University of Connecticut), Dr. Christopher Davis (Maine Aquaculture Innovation Center and Pemaquid Oyster), and Dr. Kevin Athearn, University of Maine at Machias.  The project also has two commercial businesses that are participating.  For surfclams, A.C. Inc. (Beals), the largest wholesaler of seafood products in eastern Maine, is working with DEI to examine conditions in lobster impoundments for the nursery and growout phases.  For blue mussels, New DHC, a company related to Cooke Aquaculture (Machiasport), the largest producer of pen-raised salmon in Maine, is working with DEI to grow mussel seed in fallowing salmon pens at sites in Eastport, Machiasport, and Beals.  Recently, NSF produced a 4-minute Science Nation video about our work with blue mussels.

There are nine major questions that are the focus of work in 2014 and 2015.

Question #1:  What is the appropriate type of rope that should be used to maximize mussel settlement? 

Ropes were stretched in a PVC frame that was placed into a 2,000 L settlement tank

Four different rope types were tested to see which one(s) mussels settled on most densely

Here, mussels are settled onto a polypropylene, smooth rope (animals are ca. 1 mm in shell length)

Question #2:  How should ropes that mussel larvae settle onto be configured in culture tanks at DEI?

Question #3:  How large should mussels be upon leaving the MFS to optimize juvenile growth and survival in the field (rafts and salmon pens)?

Removing PVC frames from a 2,000 L tank at DEI for deployment into a salmon pen located in Machiasport, Maine.

PVC frames being deployed in Machiasport, Maine.

Frames with mussel-laden ropes loaded onto a boat that will take them to an unoccupied salmon pen in lower Machias Bay (July 2013)

Question #4:  What is the optimum juvenile mussel density per section of rope needed to maximize growth and survival in the field?

Initial settlement density likely affects subsequent growth and survival

Mussel ropes ready for deployment in April 2014 (Beals, Maine)

Question #5:  Where, within an empty salmon pen (deep, shallow, edge, middle), will juveniles attain fastest growth to sizes approaching 12 mm?

PVC frames containing ropes with settled mussel juveniles are within salmon pens in Machiasport, Maine

Two months after deployment, many mussels have fallen off these ropes (October, 2013; Machiasport, Maine)

Question #6:  Can broodstock be conditioned throughout the year to obtain viable larvae and pediveligers?

A female blue mussel that is spawning.  Broodstock animals are held at seawater temperatures of 13-15° Celsius, then they are placed into seawater that is 22-24° Celsius, and this thermal shock will stimulate them to spawn if they are conditioned properly.

Here, a male mussel is releasing sperm that will be used to fertilize the eggs from one or more females.

Question #7:  Do different combinations of algal diets result in higher quality eggs and/or larvae/ pediveligers?

Question #8:  Does time of year when seeded ropes are transferred to the field (March/May/July) result in different survival and/or growth trajectories?

These mussels are between 1 and 2 mm in length, and are ready for deployment to a salmon pen in Eastern Bay, Beals, Maine.

Mussels from the same ropes after two months.

Mussel seed on 30 July 2014 from an April 2014 deployment (Beals, Maine)

Question #9:  What is the minimum size a seed mussel can be socked, and what time of year should this process be initiated?

Many of the photos on this page were taken by Kyle Pepperman.

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