USA: Studies show geoduck farming hurts intertidal zones of Sound

By Curt Puddicombe
(Gateline).- The expansion of industrial-scale geoduck aquaculture development into pristine and historically residential and recreational tidelands and estuaries of South Puget Sound threatens to permanently alter remaining habitat for salmon and supporting species.

It also threatens to negatively impact near-shore property owners and communities.

According to journalist William Dietrich, 70 percent of Puget Sound’s original wetlands and estuaries are already lost to development. Thirty-three percent of the eel grass beds are gone. Wild salmon is currently at 8 percent of historic values and Puget Sound’s seabirds are down 47 percent just in the past 20 years.

The South Puget Sound Salmon Recovery Group has hypothesized that shellfish aquaculture “reduces productivity, abundance, spatial structure, and diversity of salmon populations.”

The Canadian Science Advisory has suggested that intertidal shellfish aquaculture has an adverse impact on the successful feeding of juvenile salmon, and that farmed shellfish can consume the larvae of commercial fish species.

Intertidal geoduck farming, as now practiced in Puget Sound, is currently banned in British Columbia due to the hypothesis that geoduck farming methods and practices are disruptive to fish habitat.

University of Washington researchers have found that the seeding of geoducks in netted plastic pipes alters the physical and biological conditions of the tidelands, and that farmed shellfish can reduce nutrients important to other species, such as forage fish, an important food source for migrating salmon.

In spite of all this, the shellfish industry continues its attempt to fool the public with claims that the expansion of geoduck aquaculture is actually good for the Sound. This bogus argument centers on the fact that geoducks, as with other bivalves, filter and consume planktonic nutrients.

According to the state Department of Natural Resources, wild subtidal geoducks constitute the single largest biomass in Puget Sound, with between 300 million and 400 million individual geoducks, or about 1 billion pounds, with much more that has yet to be surveyed. The annual farmed geoduck harvest represents less than 0.0009 percent of this biomass.

So the truth is: The filtering benefits of farmed geoducks are not only numerically inconsequential and meaningless, the continuous harvest of farmed geoducks renders the shellfish industry argument of environmental benefit to be almost entirely irrelevant.

The other fact is: natural bivalve shellfish populations are actually better at filtering nutrients from the water column but without the habitat disruption that comes with geoduck farming.

According to the Pacific Coast Shellfish Growers Association, one geoduck can filter 30 gallons of water per day. By contrast, one single clam can filter 50 gallons per day. And according to the Chesapeake Bay Foundation, one oyster can filter as much as 60 gallons per day.

Oysters also are superior at sequestering carbon and, unlike geoducks, provide natural habitat for crab and other filter feeders, such as barnacles. Oysters are intrinsic to the intertidal zone while geoducks are a subtidal species. Not only are farmed geoducks invaders of the intertidal, they are planted in unnaturally high densities, even higher than average subtidal densities.

Thus, the shellfish industry arguments that geoduck farming “improves water quality, enhances the marine environment and mitigates against development” is a public relations fraud that continues to be willfully postulated by the shellfish industry and its proponents. The shellfish industry also makes unsubstantiated claims that geoduck farming is good for the local economy. In reality, very few individuals will benefit from geoduck farming. More people will be negatively impacted.
With the shellfish industry hellbent on moving into quiet residential areas, property values are most likely to go down, according to real estate professionals. Under this likely scenario, the revenue to the county would also be reduced.
Also impacted are sport fishermen, boaters, swimmers and beachcombers.

Right now, Pierce County taxpayers are being forced to defend against multiple appeals by Taylor Shellfish regarding the Foss geoduck farm near Joemma Beach. Also, the state will spend between $18 billion and $27 billion restoring Puget Sound habitat by 2020.

It should also be said that the shellfish industry and the state cannot presently quantify precisely how many acres, public and private, are currently being utilized for geoduck aquaculture.

In terms of relative food value per ounce, salmon has twice the protein, three times the calories and five times the omega 3s as geoducks.

It would make more economic sense to restore wild salmon populations back to near-historic values and levels of sustainability before risking more habitat on the questionable practice of intertidal geoduck farming.

At this point, I would have more respect for the shellfish industry if they openly professed their avidity, rather than continue to hide behind their ridiculous propaganda.

Source: http://www.gateline.com