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Harnessing power from Fundy tides
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Annapolis Tidal Generating Station in Annapolis Royal, Nova Scotia

The powerful tides of the Bay of Fundy have become the focus of several efforts to harness a potential alternative energy source. Six groups of investors already have ambitions to test underwater turbines in the Bay in an effort to turn wave power into electric power.

One of the most recent is Trevor Hughes, president of ATEC Power Inc. of Windsor, Nova Scotia. ATEC, which hopes to test a prototype wave-powered underwater turbine in 2007, is using technology invented by UEK Corp., a company in Annapolis, Maryland. Maritime Tidal Energy Corp. is another Canadian company that plans to generate power from tidal turbines.

Tidal power has been seen by environmentalists and businesspeople as an alternative to oil for producing electricity. ATEC reportedly would like to sell the electricity it may be able to produce to Nova Scotia Power Inc.

Its turbine, which will turn as water passes through it, thereby generating electricity, may be located at Minas Passage between Cape Split and Cape Blomidon because of good tidal conditions. But ATEC will continue to evaluate various sites over the spring and summer.

Impacts on wildlife have been a concern with wave-powered turbines. According to UEK's Web site, http://uekus.com/The_Global_View.html, because the turbines are located underwater, no dam or impoundment is needed. No toxic by-products are produced, and small marine life can pass without harm through slow-turning runners. Larger creatures are diverted by screens. The company also claims the system does not allow the accumulation of silt on the ocean floor or in a river bed.

There currently are three tidal power generators running in the world, one of which is the Annapolis Tidal Generating Station in Nova Scotia (see Gulf Voices, Page 3). It has been operating since 1984, and produces 20 megawatts of energy, enough to power about 3,000 homes. The other two tidal turbines are in France and Russia.

In a related development, draft results from a $425,000 study by the Electric Power Research Institute of California on the feasibility of tidal power were released in May. The report was commissioned by Nova Scotia Power, 12 other North American utility companies and eight provinces and states including Nova Scotia, New Brunswick, Maine and Massachusetts.

Nova Scotia Energy Minister Bill Dooks, told reporters at a news conference in Dartmouth that the province is going to take a go-slow approach to developing its tidal power potential, after the international study found it to be the most promising location in North America for the alternative energy source.

"We need to proceed slowly," Dooks said. "Communities need to be consulted, policies need to be developed and the environment needs to be protected."

The tides in the Bay of Fundy are the strongest in the world, but other areas of Canada and the United States also are exploring using offshore waters to generate electricity and examining the ecological impact of using undersea turbines.

Moving turbines for the birds

The search for alternative sources of energy, including wind farms, often pits human needs against nature. In response to concerns by bird watchers to protect migrating and resident birds, the government of Prince Edward Island has agreed to move more than half of the wind turbines that were to be located at East Point.

The move was prompted by an interim report the government commissioned from Bird Studies Canada, www.bsc-eoc.org, which recommended banning turbines from certain parts of East Point that are a haven for birds and birdwatchers.

The birders were especially worried about a wooded area along the Lighthouse Road, which leads to East Point. The proposed 30 megawatt wind farm at East Point, they argued, also could put thousands of migrating birds in harm's way.

The P.E.I. government has agreed to move six of the 10 planned turbines to the west of East Lake, and will continue to study the birds in the area of concern. However, it still wants the wind farm to move forward on schedule.

In an earlier 2001 study, Bird Studies Canada said bird mortality at wind-powered energy facilities is caused mainly by: 1) birds not detecting the rotating turbine blades and flying into them, 2) migrating birds being attracted to warning lights on the turbines and getting confused, and 3) birds colliding with power lines and wires connected to the power station. (www.bsc-eoc.org/download/PEIwind.pdf). That study also found that the impact of turbine blades appears to be small, but some deaths do occur of migrant and resident birds.

Although the recent survey recommended removal of the turbines from certain areas of concern, it also said there is insufficient data to conclude that wind turbines should be excluded from the entire project site.
For information see: www.gov.pe.ca/photos/original/env_imp_state.pdf.

Alewife loss linked to cod disappearance

The loss of alewife may have been a factor in the collapse of coastal cod populations in the Gulf of Maine in the mid-1980s to 1990s. Ted Ames, a fisherman and researcher at the Penobscot East Resource Center, Stonington, Maine, interviewed cod fishermen who worked back to the 1920s to identify a nearly 600-square-mile spawning area for cod, some parts of which were not previously known to scientists. Further studies showed that some Gulf of Maine cod that appeared to be migrating to spawn also were migrating to feed on alewives, Ames told attendees in April at the Maine Coastal Waters Conference in Rockport, Maine.


There is other evidence for the cod-alewife link. Ames said alewives are now robust in the Penobscot River near Bangor where a dam was removed about seven years ago, and there are five-year classes of cod in a section of Penobscot Bay that hasn't seen cod in 70 years. “The recurrence of cod in the upper bay may be related to the rejuvenation of forage stock of alewife, which is critical to cod reproduction,” Ames said.

Theodore Willis, an adjunct research scientist at the University of Southern Maine, also pointed to the negative impact that dams have had on the numbers of alewife. He and his colleagues have been studying populations of alewife in the St. Croix River that spans Maine and New Brunswick, and have found dramatic drops in the number of fish with the building of a series of dams since the early 1800s.

The conference covered a number of topics including diadromous fish like the cod and alewife, offshore aquaculture, the link between land use and protecting coastal resources, water quality, and coastal energy development.

Diadromous fish, which are fish species that migrate between freshwater and salt or brackish water for reproduction, include the Atlantic salmon, alewife, sea lamprey, striped bass, and American eel, the last of which is on petition now to be listed as a species under the U.S. Endangered Species Act.

“Diadromous fish in Maine are of national significance,” said Stephen Gephard, supervising fisheries biologist with the Connecticut Department of Environmental Protection. “As climate change progresses, Maine could become a refuge for subsequent repopulations of these fish.”

Still, the impact of restoring large populations of diadromous fish on groundfish and other fisheries in the open ocean remains an issue to be studied further.

Better tracking of red tides

While scientists still are not at the point of being able to predict red tides, they did learn a lot from monitoring and studying from the 2005 toxic blooms that devastated New England's fisheries.

“We've made huge strides in the past decade. We knew where to sample these pools and how to sample them,” said Donald Anderson, senior scientist at Woods Hole Oceanographic Institute. “I think we understand this algal bloom better than blooms anywhere else in the world. Our models and tools are better.” He made his comments at a Massachusetts Institute of Technology symposium on the Alexandrium red tide of 2005 held in April in Cambridge, Massachusetts.

“We could figure out where the bloom was, how fast it was moving, and where to deploy resources,” added J. Michael Hickey, chief biologist at the Massachusetts Division of Marine Fisheries. “It the bloom was out of control, we could shut down fisheries. We were confident that what we had open was safe.” He said no one died or got sick from paralytic shellfish poisoning caused by eating contaminated seafood.

Compared to earlier large red tides in the Gulf, such as the 1972 bloom, the researchers could track the bloom in real time and react more quickly. Nonetheless, the 2005 bloom closed shellfish beds in Massachusetts, Maine and New Hampshire, as well as 15,000 square miles of federal waters, for more than a month during the peak of the seafood harvesting season. Economists for the shellfish industry and the state of Massachusetts estimated the bloom cost the seafood industry $2.7 million weekly in lost revenues, and NOAA declared the event a “commercial fisheries failure.”

While much remains to be learned about the Alexandrium algae that cause the red tides, such as the relationship between their cyst and cell stages, researchers are assembling evidence about conditions that precede a red tide, including severe nor'easter storms that stir up Alexandrium cysts in the deep ocean bottom, winds and currents in the Gulf of Maine that help move the algae blooms closer to shore, the presence of nutrients, light and other factors.

“We hope we are heading toward a predictive model such as with new sensors on the GoMOOS buoys that could sense Alexandrium, but that is a number of years away,” said Anderson. “We need to know critical initial conditions to predict a red tide, and we don't have that yet.” Nor do scientists know precisely why a bloom ends.
For more information see: http://web.mit.edu/seagrant/rt06/index.html.

© 2006 The Gulf of Maine Times