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U.S.: Lessons From the Past May Help Puget Sound 'Dead Zones' |
| December 20, 2006 |
By Eve Rickert, AquaNews Correspondent
 | | Visitors to Hood Canal during September's low dissolved oxygen event saw dead lingcod on the beaches—one of more than 30 fish species affected by the dead zone. Photo: Janna Nichols |
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For perhaps thousands of years, the first peoples near Washington State’s Hood Canal have relied upon its abundant supplies of salmon and shellfish—a reliance that continues to this day. A visitor to the canal can normally expect to see beachcombers searching the shores for oysters, and divers seeking a glimpse of places like “Octopus Hole.” But this September, the divers were met with an eerie scene.
Dead fish floated on the water and washed up on the beaches. Octopuses were swimming to the surface, fleeing the deadly waters below, while others lay unmoving on the bottom. Fish were lethargic and disoriented.
In deeper waters, in some places the only life to be seen were thick mats of bacteria. In others the sea floor was completely devoid of life, covered only by a jelly-like substance of dead sea life. The bodies of Dungeness crabs littering the sea floor were blackened, and crumbled when touched.
These divers were experiencing first-hand the dramatic effects of an aquatic “dead zone,” which forms when too many nutrients enter the water, often from sewage or fertilizer runoff. These nutrients feed an explosion of microscopic algae, which in turn support an increase in the tiny animals that feed on the algae.
Together these thick algae and plankton blooms prevent sunlight from reaching deeper waters, killing off the plants that live there. And as the algae and plankton die off and sink to the bottom, the bacteria that decompose their bodies on the sea floor further deprive the water of oxygen. Animals living within these oxygen-poor waters will die if they are too slow to escape or have no place to go.
 |  | | Top: Seasonal algae blooms in the Black Sea can often be seen by satellite. Photo: NASA | | Bottom: This dead lion’s mane jelly was found upside-down in Hood Canal in 30 feet of water. Photo: Janna Nichols |
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Lessons Learned
Because it is not truly a canal but a fjord—an inlet open at only one end and with minimal water exchange—the 72-kilometre-long Hood Canal is particularly susceptible to a buildup of anoxic (oxygen-deprived) waters. But Hood Canal isn’t the only place on the Pacific coast where dead zones are cropping up.
A reef near Cape Perpetua, in Oregon, used to teem with life. In August, researchers described it as a “wasteland”—like the deep waters in Hood Canal; devoid of life and covered in thousands of carcasses. This was the area’s fifth dead zone in as many years, and it lasted four months.
The earliest dead zones to be studied were in the Black Sea—where Soviet-era industrialization of agriculture resulted in massive inflows of nitrogen—and the Chesapeake Bay, on the eastern coast of the United States. And it’s the lessons learned from the Chesapeake that have some worried that Puget Sound may be next.
Several inlets in the Sound have already begun showing lower oxygen levels than usual. Fortunately, with quick action, such a future may be averted. Experience on the other side of the world points the way.
The Black Sea inadvertently became one of the earliest experiments in restoration of dead zones following the collapse of the Soviet Union at the end of the 1980s. This upheaval resulted in the end of centralized economic planning, the closure of many large animal farms, and the drying up of financial resources for the region’s farmers to buy nitrogen fertilizer.
In later years the United Nations, with the participation of the governments in the region, began working on a plan to keep runoff levels at the levels reached during the post-Soviet period. Over the course of a decade, plant and animal communities slowly re-established themselves on the floor of the Black Sea. The dead zones shrank.
 | | A map of the Hood Canal watershed. Map courtesy of Puget Sound Action Team |
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Recovery Plan
It took many years for some animals, such as mussels, to come back, and the ecosystem is still very different than it was in the 1960’s. But the recovery of life on the sea floor offers hope for North America’s waters, and offers lessons for what further steps need to be taken for a full recovery. For example, researchers recommend that fishing be restricted in recovering areas, until predator populations can bounce back.
Action is already being taken in Washington State to try to bring back Hood Canal, and to avert the Chesapeake’s fate for Puget Sound. A coalition of environmental and research groups has formed the Hood Canal Dissolved Oxygen Program, which is working to determine the root causes of the Hood Canal dead zones and propose solutions. A special legislative task force has been meeting for more than a year to review the research and propose a recovery plan for the Canal.
State Governor Christine Gregoire created a commission last year called the Puget Sound Partnership, tasked with making recommendations to the Legislature for rescuing the Sound. The commission recently announced a ten-year, US$12 billion cleanup and restoration plan. Governor Gregoire will be requesting that the state legislature spend US$220 million on the plan over the next two years, and Norm Dicks, one of Washington’s representatives in the U.S. Congress, is expected to ask for federal money for the effort.
Ordinary citizens are doing their part, too. In Thurston County, part of the Puget Sound watershed, eight-grade students are participating in a region-wide survey of the county’s streams. The students are taking water samples from their local Schneider Creek and testing for water quality, including dissolved oxygen.
The program, run by the South Sound Global Rivers Environmental Education Network and Nisqually River Education Project, is providing real data to environmental planners, while teaching students how to care for the state’s water resources—and perhaps, instilling some of the passion that will be needed to fuel the fight to save Hood Canal and Puget Sound.
| Source: Vancouver Aquarium Marine Science Centre |
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