Recreational clam harvesters should take extra caution while preparing and cooking shellfish collected from Shoemaker Bay due to high fecal bacteria levels in those waters, according to Carol Brady of the state Department of Environmental Conservation.
Brian Herman, co-owner of Canoe Lagoon Oysters, began testing the water in the Shoemaker Bay area for fecal bacteria — called fecal coliforms — because he hopes to establish an underwater storage facility to hold oysters that are awaiting meat test results.
The Canoe Lagoon oyster farm is located on the Blashke Islands, 30 miles southwest from Wrangell by boat. The remote location complicates Herman’s harvesting, testing and shipping processes. “We are tide dependent, getting onto our farm,” he said. In winter, “there may be only four or five hours a week that we can actually get (there).” Storing oysters at a Wrangell site would boost the dependability of his oyster sales.
After testing the water near Shoemaker Bay during the summer months, Herman found that between May and August the water’s fecal coliform levels were too high to store oysters.
Shellfish, including oysters and clams, are filter-feeding organisms. They pull water into their gills, capture any microscopic food particles suspended in it, then send the water back out. When shellfish live in contaminated waters, their gills capture the contaminants too. A soft-shelled clam can filter about 10 gallons of water per day and an adult oyster can filter about 50 gallons. If the water contains potentially harmful bacteria like fecal coliforms, these bacteria can quickly build up in a shellfish’s body until its meat becomes dangerous to humans.
“There’s a lot of people who clam on this beach,” Herman said. “The clams do ingest fecal coliforms and it can make people sick.” However, there is hope for recreational clam harvesters, since the dangers of fecal coliforms can be significantly reduced through safe handling practices. Washing hands thoroughly after touching raw shellfish and heating them to 145 degrees Fahrenheit before consumption “should significantly reduce the chance of foodborne illness,” Brady said in a written statement.
Though the Wrangell Cooperative Association performs regular tests for paralytic shellfish toxin, it does not test for fecal coliforms. Paralytic shellfish toxin comes from an algal bloom whose unpredictable growth pattern makes prevention difficult. “(The algal bloom) happens all over the world and it’s always going to happen,” said Herman. “That’s why we do continual meat testing.”
Fecal coliforms levels, however, are influenced by the geography of a location, tidal movement, and human and animal traffic. To develop a wet storage area for oysters, the state Department of Environmental Conservation requires that no more than 10% of samples at a site exceed 28 coliform bacteria per 100 milliliters and that the average sample count not exceed 14 per 100 milliliters.
Herman began testing at three sites near Shoemaker in May. By early August, just over halfway into the testing period, the sites had already exceeded acceptable coliform levels and he stopped testing.
Around Shoemaker, the probable coliform count per 100 milliliters rose as high as 51 in June.
Though Herman will not be able to operate a wet storage area at Shoemaker during the summer, he is hopeful that fecal coliform levels will decrease in the winter as animal and human traffic decreases. “One of the things that can cause it to bump up is just human activity,” said Herman. “If you’ve got dogs walking on the beach … if there are bears upstream … once they hibernate there’s not going to be any of that.”
However, Herman suspects that sewer outfall from City Park could also be contributing to the high bacteria counts. The water treatment plant has a waiver from the U.S. Environmental Protection Agency, which allows it to discharge wastewater that hasn’t received full secondary treatment.
Though Canoe Lagoon’s testing sites are about three miles south of the wastewater discharge point, water flows toward Shoemaker on a strong river current that is not diluted much by the tides, Herman said. He plans to test the direction of the current using a buoy to see if wastewater gets trapped at the north end of Shoemaker harbor.
Public Works Director Tom Wetor called the prospect of sewage contamination “highly unlikely.” Public works regularly tests the water at City Park for fecal coliforms, and bacteria counts at that location are consistently lower than the counts that Herman has gotten three miles south around Shoemaker.
Wetor attributes Herman’s test results to high levels of human and animal activity. “If there was a flock of geese, there’s your fecal coliform right there,” he said. Old septic systems or boats dumping into Shoemaker could also contribute.
Herman will resume coliform testing in December or January.
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