Mussels collected from Little Priest Rock in Unalaska this summer tested positive for high levels of toxins that cause paralytic shellfish poisoning, or PSP. That’s according to Melissa Good of the Alaska Sea Grant Marine Advisory Program.

Good said that throughout the summer, she’s been collecting blue mussels from Unalaska for analysis by the Alaska Department of Environmental Conservation. The last of the collection ended on September 30. Once the data is in and analyzed, Good promised to present a community lecture on her findings.

In the meantime, she recommends to those who harvest bivalves such as mussels, clams and scallops from local beaches to become familiar with all the species. Some reach higher levels of toxicity than others.

“PSP levels will likely be different in adjacent beaches during difference times of the year and will change with time,” said Good in an email. “Littleneck clams usually do not reach as high of toxicity levels as butter clams and littleneck clam toxicity levels usually drop off quicker than for butter clams.”

She also recommends taking extreme caution when consuming these foods.

“I recommend not eating dead or sick looking forage fish found on Alaska beaches and report these events to me. Forage fish, such as sand lance (sand eels) can become toxic with PSP too,” Good said.

Good sent out a graph this week illustrating a sharp spike in PSP levels in Unalaska blue mussels this year. A sample collected on June 12 contained roughly ten times the level of PSP toxin as the FDA limit for consumption. The last time local mussels contained such high PSP levels was in 2010.

Data tables for PSP in the Gulf of Alaska and Bering Sea can be found here.