Saving Seafood

How a microscopic coastal creature may become deadlier in our changing climate

June 18, 2024 — Between 2014 and 2015, a “blob” of record-breaking warm water traversed the west coast of the U.S., gaining media attention as the warm temperatures wreaked havoc on the bottom of the food chain, causing fisheries like sockeye, pink, and coho salmon to collapse and thousands of sea lions and sea birds to starve.

However, amid this devastation, one microscopic creature thrived or “bloomed”—a neurotoxin-producing diatom called Pseudo-nitzschia—causing devastating multi-million dollar losses for many West Coast commercial and tribal crab and shellfish fisheries that had to shut down due to the risk of toxin-contaminated seafood.

The toxin produced by Pseudo-nitzschia, domoic acid, can cause amnesic shellfish poisoning in humans, with symptoms like vomiting, diarrhea, headache, loss of short-term memory, motor weakness, seizures, and irregular heart rhythms.

Beyond the clear ecological and economic devastation, this 2015 blob-associated harmful algal bloom also left the scientific community in shock. The prevailing understanding was that toxic Pseudo-nitzschia blooms were associated with nutrient-rich, cold-water pulses of water seasonally brought up or “upwelled” from the depths along the Pacific west coast.

With the massive hot blob of water hovering over the coastline in 2015, there was little to no upwelling. So how did a toxic bloom occur during this massive heat wave?

Read the full article at PHYS.org

Maine: In new cautionary approach, Maine shellfish areas will be closed at first sign of toxins

April 17, 2018 — BOOTHBAY, Maine — Public health officials say they will use extreme caution to manage toxic algae blooms this year to prevent another expensive and potentially dangerous shellfish recall.

In the last two years, sudden toxic algae blooms of a previously unrecorded type of phytoplankton forced the Maine Department of Marine Resources to close huge sections of the Down East coast to shellfish harvesting and to issue rare recalls of tons of clams and mussels from as far away as Utah.

Recalls are bad for public health, business and Maine’s seafood brand, said Kohl Kanwit, head of the department’s public health division, during a workshop Tuesday for harvesters, seafood dealers, regulators and researchers at Bigelow Laboratory for Ocean Sciences in Boothbay.

“The risk is high; you never get 100 percent back” from a recall, Kanwit said. “It is really costly for the industry and bad all around.”

This year, the department isn’t taking any chances as it monitors for pseudo-nitzschia, a single-cell organism that can bloom unexpectedly and make domoic acid, a dangerous biotoxin that may cause amnesic shellfish poisoning, or ASP, in humans and animals. In serious cases, ASP can lead to memory loss, brain damage or even death. The first recorded ASP event, on Prince Edward Island in 1987, killed three people and made at least 100 sick.

Read the full story at the Portland Press Herald

 

Algae bloom forces suspension of shellfishing in parts of Down East Maine

It’s the second straight year that a bloom of Pseudo-nitzschia, a phytoplankton that can carry toxic domoic acid, has forced a closure along large parts of the coast.

September 15, 2017 — A marine algae bloom that can carry a potentially deadly neurotoxin has forced the suspension of shellfish harvesting in parts of Down East Maine.

The state Department of Marine Resources reported Thursday that it was monitoring an active bloom of Pseudo-nitzschia, an ocean phytoplankton that carries domoic acid, a toxin that can cause sickness, memory loss and brain damage in humans. It’s the second year in a row that a toxic Pseudo-nitzschia bloom has halted harvesting of mussels, clams and oysters along large parts of the coast.

Before 2016, there was no record of a toxic bloom of this type in the Gulf of Maine.

The department’s public health section found levels of domoic acid that exceeded health standards in shellfish tested between Mount Desert Island and Gouldsboro. That area has been closed to harvesting and the department enacted a precautionary closure from Deer Isle to Machiasport, almost a third of Maine’s coastline.

Department spokesman Jeff Nichols said officials were monitoring the situation closely. There is no indication that contaminated shellfish have made their way to consumers, he said.

“It is impossible to determine at this point if the concentrations of domoic acid will increase in other areas,” Nichols said. “But we know that the phytoplankton that produces it grows rapidly, so we are carefully monitoring the entire coast and will be able to rapidly detect harmful levels of domoic acid and take action to protect the health of Maine’s shellfish consumers.”

Read the full story at the Portland Press Herald

MASSACHUSETTS: Shellfish, except bay scallops, still off-limits

October 24th, 2016 — Shellfish harvesting — with the exception of bay scallops — continues to be banned in Nantucket waters because of toxic plankton, which first arrived Oct. 7 in Cape Cod waters and made its way to the island a few days later.

“On Tuesday the state Division of Marine Fisheries requested shellfish to sample and we sent them 20 oysters from the harbor for tissue testing,” said Jeff Carlson, Nantucket’s natural resources coordinator.

“Hopefully they can get the testing done quickly and if it comes back clean, we can open things back up.”

Carlson said he did not know how long the state would take to test the samples and added it had sent out similar requests to towns bordering Nantucket Sound that have been included in the harvesting ban.

The reason for the state-mandated closure is plankton called Pseudo-nitzschia that produces a toxin that if consumed leads to amnesic shellfish poisoning. Symptoms of such poisoning include nausea, abdominal cramps, vomiting, dementia, amnesia, permanent loss of short-term memory and, in extreme cases, coma or death.

Read the full story at The Cape Cod Times 

Massachusetts: DMF Expands Shellfish Harvest Closures to All Waters South of Cape Cod

October 12th, 2016 — Effective immediately, the Division of Marine Fisheries (DMF) has expanded its recently announced shellfish harvest closures to include all waters south of Cape Cod due to a substantial bloom of a potentially toxic kind of phytoplankton termed Pseudo-Nitzschia.

As a result of the expanded closure, digging, harvesting, collecting and/or attempting to dig, harvest or collect shellfish, and the possession of shellfish, is prohibited in all waters from the Rhode Island border east to Nantucket Sound, including all of Vineyard and Nantucket Sounds and waters surrounding the islands.

This closure complements the state of Rhode Island’s shellfish harvest closures.

Pseudo-Nitzschia can produce domoic acid, a biotoxin that concentrates in filter feeding shellfish. Shellfish containing high concentrations of domoic acid can cause Amnesic Shellfish Poisoning (ASP) with symptoms that include vomiting, cramps, diarrhea and incapacitating headaches followed by confusion, disorientation, permanent loss of short-term memory, and in severe cases, seizures and coma.

Read the full story at Capecod.com