Thousands of pounds of Maine shellfish are being recalled from the market because of concerns they may be tainted with a potentially deadly marine neurotoxin.

On Friday, the Department of Marine Resources issued a recall of mussels harvested near Mount Desert Island between Sept. 10-14. Five Maine shellfish dealers are being asked to recall product.

This is only the second shellfish recall on record, according Jeff Nichols, a department spokesman. The only other recall was issued during a similar algae bloom last year.

The recall comes a day after the department’s public health agency closed part of the Down East coast to shellfish harvesting after detecting elevated levels of domoic acid, a toxin produced by a large bloom of Pseudo-nitzschia phytoplankton. Shellfish like mussels, clams and oysters eat phytoplankton and store toxin in their flesh. Domoic acid can cause Amnesic Shellfish Poisoning that can cause illness, brain damage and memory loss. Mussel samples collected in Frenchman’s Bay, between Bar Harbor and Gouldsboro, had levels of domoic acid higher than the safety threshold of 20 parts per million, according to the department.

Kirk Loud, a manager at Atlantic Shellfish in Jonesport, said the company only had to recall 10 two-pound bags of mussels sold locally. The remaining product, about 5,000 pounds, is still at the company and will be destroyed, Loud said.

“As far as we are aware, nothing has seen the market,” Loud said.

Maine’s shellfish managers are experts at predicting red tide, a harmful algae bloom carrying a biotoxin that can cause paralysis or death. But where red tide develops gradually and can be carefully monitored, Pseudo-nitzschia blooms are less predictable and intensify rapidly. While Pseudo-nitzschia is common in the Gulf of Maine, the first recorded toxic bloom occurred last fall and caught state officials and the shellfish industry by surprise.

Loud’s impression is the department is unused to Pseudo-nitzschia blooms and is using an abundance of caution.

“This is new to them, they don’t have their thumb on it yet, they want to be safe,” Loud said.

“I am 100 percent with them on this,” Loud said. “Better safe than sorry.”

At Eastern Maine Mussel in Hancock on Friday afternoon, manager Ralph Robertson was still trying to figure out exactly where recalled mussels were and how many would have to be destroyed. The company sells shellfish nationwide, mostly to wholesalers, Robertson said.

“Hopefully it is still all on trucks, that would make it easier,” he said. Every shellfish dealer has a protocol ready in case of a recall, and can find out where the product is, he added.

“Everything is dated, tagged, and triple checked, we have records on everything, when it was towed, packaged, shipped, it is all well documented,” Robertson said.

Fiona de Koning, co-owner of Hollander and de Koning Mussels, did not disclose the precise amount of mussels her company had to recall, but said it was “significant.” de Koning tends five aquaculture leases around Mount Desert Island, at the center of the algae bloom. Most of the company’s recalled mussels were still with distributors and had not reached consumers, de Koning said.

“It really is important that we can move quickly if something like that happens,” de Koning said. “You want to catch it before it goes too far into the supply chain.” This was de Koning’s first recall, and she doesn’t want to repeat the experience, she said.

This is the second year in a row Maine has had to issue a recall because of a biotoxin scare. Last year 5 tons of shellfish were recalled. Some product got as far as Missouri and Utah before it was returned. Approximately 96 percent of the product was recalled, but about 430 pounds were unaccounted for.

Additional shellfish dealers who were notified of the mussel recall and are contacting their customers are Moosabec Mussels Inc. in Jonesport; Pemaquid Oyster Co. in Waldoboro; and Steward GEM LLC in Bar Harbor.

The DMR said based on test results, mussels are the only product affected by the recall at this point. Areas will re-open when there are two consecutive scores from shellfish testing at least one week apart that are deemed safe, and there is a decline in the concentration of phytoplankton in the water.