Off and Running

December 16 2011, Project Update

 A Pilot Project to Stimulate Seaweed Production on Mussel Farms in Maine

Funding: Maine Aquaculture Innovation Center, with lots of match from industry partners, and Maine Sea Grant

We're IMTA active, folks!  A couple of weeks ago, Tollef Olson, Paul Dobbins and Matt Moretti planted seedling lines out on Matt's farm in Casco Bay. That, I believe, made it the first kelp/mussel IMTA farm in the US, and we're pretty stoked about it. 

This week, Sarah and I met up with Tollef, and seeded in rafts on Peter Fischer's site in Walpole, and Joe Larrabee's site in Northport - they are both part of Pemaquid Mussel Farms.  We also met with Evan Young, of Blue Hill Bay Mussels, but it was blowing a gale from the south, and not a good day to be out on that site, given its' exposure. So, we ended up hanging the spools of seed lines off a float temporarily, until Evan can get back out and seed his raft in with them - should be no problem.

L-R: Tollef Olson,  Peter Fischer, Sarah Redmond

Anyway, on Wednesday, we started over at Peter's.  He wanted to hang the lines under one of his rafts, and he'd devised a plan to place one person at the far end of the raft (turned out to be me), and use a 'messenger line' to draw the longline through the seeding tube. Tollef and Peter worked on that end, since Tollef had the technique down for letting the line off the spool. Sarah took all kinds of photos, and helped out with the seeding end of things, and with equipment going back and forth.  Great to hear her talk about seaweeds too; biology and physiology, ecology; the whole nine yards. 

Juvenile kelps on seeding strings, around PVC pipe

The process is simple and effective.  Ocean Approved had done the hatchery work about 40 days ago, to produce the spores and then to set the spores on strings, which are wrapped around a PVC pipe.  Each pipe contains enough string to seed about 200 feet of line.  The horizontal longline is drawn through the PVC pipe, and the string is tied to the longline. As the longline is pulled through the pipe, the string unwinds, and spirals itself around the longline.  It'll take a few weeks for the young plants to 'step off' the string, and grow on to the longline, but once they do, their holdfasts will…well….hold them fast to the longline. 

It was cold to start, but we got into a rhythm,

Seed lines unspooling around longline

hanging lines at depths of either 3 or 7 feet. This is to test growth and quality in relation to sunlight; too much is not good and neither is too little.  About 9am, Pete Smith (Pemaquid Oyster Co) came rowing out to see what we were up to, and brought over some oysters - man, were they good!  Just out of the water, cold and salty…..yum.  After our little morning break, we kept going, and ended up with a total of 17 lines under one raft. 

Pete Smith (right) of Pemaquid Oyster Co - thanks Pete!

Peter's raft, seeded in!

Our water quality data collection includes sampling for nitrate and ammonia, so we gathered samples at the rafts and a short distance away, for baseline information, and then took some info on secchi depth and salinity. We set out an iBcod temp data logger, set to sample every 30 minutes - we can swap that out later, or leave it for the whole 4-6 month growout period.  The hope is to begin to draw some correlations between the growth we observe, and the measurements for these various parameters.  It certainly won't solve any specific puzzle, but might provide the right material for more focused research in the future.

The sun was coming out, and it was getting warm; things shaping up nicely. 

The afternoon was spent up at the Northport site; Joe picked us up in the skiff and out we went - Carter and crew were out there working on the middle raft, and we went to the northern raft and set in our lines there.  Since we'd used essentially the same setup as down in Walpole, it went pretty quickly, and we got the lines settled in with no delay.  More water samples, and a quick chat with the crew, and we headed back to the wharf.  The wharf itself is in the little community of Bayside, a little bit south of Belfast, and it's sort of a secluded little secret - like a summertime beach community, only without the beach.  I had Cape May in mind, for some reason, but anyway, lots of tidy and pretty houses set one close to another, facing a town common just up the shore from the wharf, and a great view across western Pen Bay, to Islesboro.

Joe Larrabee's site in Northport: harvest barge Mumbles and Tim Levesque (also of PMC) with his boat F/V Thunder Bay, working on predator nets, etc.

And that brought us to Thursday morning, and the aforementioned bad weather.  We stood in the parking lot talking about the project, the prospects for seaweeds along the coast, and how we were all looking forward to watching this particular batch of kelp grow.  Even there in the rain and the wind, it was pretty exciting; this is a new venture, with its own set of obstacles and opportunities, but nice to have some of the kelp lines already in and doing their work.  Evan will get a chance to set his lines out, and our next deployments will be on raft sites in Stonington and Lamoine (Pemaquid Mussel), and hopefully on the longline farm that Erick Swanson has for his company, Maine Cultured Mussels, out by Long Island in Blue Hill Bay.

European Oysters at the Downeast Institute, Beals Island, Maine

The European oyster, flat oyster, belon, or mud oyster all refer to the bivalve Ostrea edulis, native to western Europe and introduced into Maine waters near Boothbay Harbor in 1949. Ask a true oyster gourmand and they will call it the best oyster available globally. Ask someone who's got some experience growing them, or working with them in the hatchery, and you'll get a mix of smiles, gritted teeth and a downright Eeyore gloom. In the oyster kingdom, flat oysters have to be most persnickety, mysterious and tantalizing variety out there.

The European industry has fallen (forgive me) flat, and the production from the East Coast of the US and Canada is not going to take the world over, despite tries from very inventive and persistent folks. Ditto for the west coast, and there are two main reasons for this. The first is that a parasite called Bonamia, which affects the hemocytes (blood cells) of the oyster, and is responsible for periodic die-offs of wild and cultured flat oysters: an intimidating enough obstacle. The second – and the reason for this post – is that they are often troublesome in the hatchery.

Some of the juvenile flat oysters produced at DEI. 

Chris Bartlett photo.

Many oyster species are broadcast spawners, meaning that sperm and eggs are released directly into the water, in hopes that the one finds and fertilizes the other. But oh no, that's not good enough for the flat oyster. They have to go and be different, to the point that the female holds on to the eggs, and allows them to be fertilized by sperm in the incoming water. Then, she even goes so far as to allow the embryos to develop for a while attached to her gills, before then ejecting them as free-swimming larvae. Added to this the complexity, is the life-cycle of Ostrea being a “protandric hermaphrodite.” That is, this oyster has the capacity to change its gender twice during a single season – spawning as a female, then changing to a male for a while, then back again! All this causes a lot of difficulty for the hatchery manager, who needs to reliably produce millions of oyster larvae to be financially solvent.

Meanwhile, there is a limited supply of flat oysters to meet the demand, and even though demand is not as large as for say, the Eastern oyster, it's a dedicated following, and there is money to be made for them's that can grow and market the right product.

Which brings me to the Downeast Institute (DEI), on Great Wass Island in the town of Beals, Maine; and the name says it. You come out hear, dear (they say 'heah' and 'deah' of course – music to my Mainer ears), and you have indeed arrived Down East.

Dr. Brian Beal oversees shellfish production and research at DEI; he's a professor at nearby University of Maine at Machias, and he's been working with shellfish for a few decades now. He and his staff, Hatchery Manager George Protopopescu and assistant Kyle Pepperman have been trying to get their flat oysters through full production for a couple of years, and have had decidedly mixed success. In 2009, they had a good run, producing 100,000 juveniles, but since then have had little joy.

The main problem is in the larval phase; that roughly two-week period of time when the larvae have left the female, and are being fed and cared for by the hatchery. Worms and other animals that hitchhike on the shells of the adults end up spawning as well and their tiny offspring compete for food with the small oysters, or eat them, or just change the water quality to a poor state for oyster larvae. While the DEI staff have overcome a large part of this by the novel approach of spreading a marine adhesive over the shells (prevents the hitchhikers from spawning), they still have a bit of a problem to overcome.

Also, there seems to be a bacterium at play in the larval tanks, one that ends up killing small oysters such that they end up clumped up in a pile, dead. Brian, George and Kyle are experimenting with some prophylactic approaches for this, but I can tell you that she ain't solved yet.

So, when I stopped in to talk with George and Kyle on Monday last, George was realistic (not what you'd call giddy) about the chances for the upcoming spawn, while being optimistic about the effectiveness of their new procedures, and chances for success. If they are successful, then oysters will go out to cooperators in industry for nursery culture and growout. Since flat oysters like cooler, more moderate water temperatures than their Eastern cousins, and since we've got a lot of that kind of water around here in Maine, they are a reasonable species to culture, especially for the many fishermen in the state who are beginning to experiment with aquaculture.

Above: Dan Canfield, a shellfish grower out of Tenant's Harbor, Maine and a former commercial fisherman, has a few flat oysters on his farm, and hopes to begin going to market in 2011.

So, for now, my visit was a reinforcement of the promise and the problems with the flat oyster. A couple of years ago, I organized a session on O. edulis at the Northeast Aquaculture Conference and Expo (NACE) in Portland, and one of the titles in the session summed it up accurately. Dr. Andre Mallet, who hails from Shippagan, New Brunswick, and who is himself an accomplished scientist and shellfish producer, called the flat oyster the Beast of Sorrow. Sheesh. Nonetheless, given the allure of a steady supply of belons to the market, I'm sure that Brian and company will persist, and they are every bit as likely as anyone to succeed.

Aquaculture is not for the faint of heart.