Studies eye potential human health risks
FRISCO — The West Coast isn’t the only place seeing unprecedented algae blooms this summer. Recent water sampling by researchers at William & Mary’s Virginia Institute of Marine Science show some of the densest concentrations of algae recorded in Chesapeake Bay in recent years.
According to the scientists, the current blooms are dominated by an algal species known to release toxins harmful to other marine life, particularly larval shellfish and finfish. Although the recent algae blooms haven’t been directly implicated, there have been some reports of small small numbers of dead fish, oysters, and crabs from the lower York River and adjacent Bay waters associated with nearby blooms.Aerial photography and water sampling by VIMS professor Wolfgang Vogelbein in late August show how far the algae blooms have spread. The researchers outlined their efforts and findings in a press release.
“This is new and important information, as we have never appreciated that Alexandrium extends so far into the mainstem of the Bay or so far up the York River,” Vogelbein said. “The main body of the bloom is several miles off shore,” says Vogelbein, “and thus wasn’t appreciated prior to the recent flyovers.”
It’s not easy to track the scope and the impacts of algal blooms. In places like Chesapeake Bay, tides, winds, currents, and a convoluted shoreline combine to create blooms that are both patchy and ephemeral. Often, the blooms contain a changing mix of algal species, some of which may or may not — depending on environmental conditions — produce the toxins that transform an innocuous algal aggregation into a harmful algal bloom.
“We see high variation among our samples,” said Reece, “even between those that were collected from sites a few hundred yards apart or taken from the same site a few hours apart.”
Researchers with VIMS are also testing to what degree bloom-derived toxins might be moving up the food web to impact marine life and potentially human health. Graduate student Sarah Pease is using funds from Virginia Sea Grant to monitor the health of caged oysters in waters near the Goodwin Islands, and is also working with Smith to conduct toxin analyses on oyster tissues.