Mussels are first line of defense for detecting water toxins
By Laine Welch
October 03, 2007
Mussels provide the first line of defense for detecting toxins in our nation's fresh and salt waters. Since 1986 the abundant bivalves have been at the heart of the Mussel Watch Project , the longest running water monitoring program in the U.S. The Watch monitors chemical and biological contaminants in water and sediment at nearly 300 coastal sites across the U.S. including Prince William Sound and Kachemak Bay near Homer.
Mussels are the fastest filter feeders of all bivalves, and in the process, they pick up whatever toxic material gets in the water.
"Sometimes it's very difficult to try and find very low concentrations of toxics in the water supply. Measuring water requires incredible precision and expense. So if you want to find something in the water, sampling mussels is an extremely good way to do it," said Ray RaLonde, a Sea Grant aquaculture specialist.
Toxicologists have found that mussels are particularly sensitive to copper, ammonia and several pesticides, which can wash into waters from surrounding land. In Alaska, mussels are an important monitoring tool for deadly PSP (Paralytic Shellfish Poison) toxins and RaLonde hopes to expand Mussel Watch sites throughout the state..
Amazingly, the blue bivalves also have been used for toxic clean ups.
"If there's an underwater dump of some sort, you can deposit mussels down there and they will pull those toxicants out of the system. Then you just dispose of the mussels and you have a clean up program," RaLonde said.
There are lots of mussels in Alaska's fresh and salt water systems, but growing them commercially has posed some problems. In some areas the mussels tend to turn filtered silt into tiny hidden pearls that to diners, taste like a mouthful of sand. And healthy batches regularly become stressed by disease and other natural factors.
"For two years it's a healthy mussel bed, and all of a sudden it's gone -- just at the time when they are market size," RaLonde said. In aquaculture, mussels are grown on roaps suspended from rafts and someday they will provide lucrative crops for Alaska growers.
Mussel dredge fisheries still
occur in New England, but most come from farms on both coasts.
The nation's top producer is Washington state where mussels are
valued at $35 million annually. Farmers typically get $2-$2.50
a pound for their mussels, and market watchers say the supply
does not even come close to meeting the enormous demand.
Bering Sea crabbers will enjoy a big boost in their catch quotas for the 2007/08 seasons. Fishery managers on Friday announced a catch of 20.4 million pounds for Bristol Bay red king crab, up 31 percent from last year and the highest harvest level since 1990. For bairdi Tanners, a catch of 5.6 million pounds is nearly double last year's take.
For snow crab - the 'bread
and butter' catch for the Bering Sea fleet the harvest
was boosted by 72 percent to 63 million pounds. The Bering Sea
crab fisheries open on October 15, although the snow crab season
kicks off in earnest in mid-January.
Splits of crab and cod fish will be hot topics for the North Pacific Fishery Management Council as it meets through Oct. 10 in Anchorage.
The council will get its first look at an 18 month review of how the newly 'rationalized' crab plan is working for fisheries in the Bering Sea. Many communities will urge the council to consider broadening a controversial split that requires crabbers to sell 90 percent of their catch to select processors; just ten percent can be sold on the open market.
The council will decide if it will move forward with analyses of different configurations of 80/20, 70/30 and 50/50 splits.
"We have processors in Kodiak, King Cove, even Adak, who would love to be able to put an offer on the board and have fishermen bring them their crab. They are not allowed to do that now. It is my hope the state will take the lead so we can get closer to a 50/50 split that allows more processors and communities to compete actively with Dutch Harbor, and gives fishermen the opportunity to get a more competitive price," said industry consultant Linda Kozak.
The Council will also grapple with how to fairly divide up cod catches in the Gulf of Alaska. A plan gaining favor mirrors one that's worked well in the Bering Sea since the 1990s it splits the cod catch among all gear groups based on their history in the fishery.
Kozak says a sector split gives fishermen more flexibility to fish smarter.
"One of the wonderful
things about doing a sector split in the Gulf is that each gear
group jig fishermen, pot boats, longliners and trawlers
- will all be able to fish at times when they can maximize the
benefit, get the best quality and reduce bycatch. They will all
be secure in the knowledge that their sector is protected from
encroachment by the others. That's what it's all about,"
For more than 30 years National Fisherman magazine has selected top American harvesters for its annual Highliner Awards. The fishermen are recognized not only for their good catches, but also for contributions they've made to the fishing industry.
NF editor Jerry Fraser said
the nod this year goes to two Alaska fishermen - Kaare Ness,
a pioneer in the Bering Sea crab industry among others, and
Eric Jordan, a troll fishermen and industry advocate from Sitka.
The fishermen will receive their awards during the Pacific Marine
Expo in Seattle. www.pacificmarineexpo.com
Contact Laine at msfish[AT]alaska.com
A publication fee is required.
E-mail your news, photos & letters to firstname.lastname@example.org