Parasites, pesticides, sick salmon and dead lobsters.

These four things have become an issue in Passamaquoddy Bay, and no one seems to be happy about it.

Not the salmon aquaculture operators, who are using pesticides to combat a damaging outbreak of sea lice at their fish pens in Passamaquoddy Bay and adjacent Cobscook Bay. Not environmentalists, who are concerned about the effect the pesticides might be having on surrounding marine life. And not lobster fishermen, who fear the use of pesticides has contributed to widespread lobster deaths in the past.

Officials in Canada are looking into the use of pesticides in and near Passamaquoddy Bay as part of separate investigations into the deaths of lobsters off Grand Manan Island in late 2009 and off Deer Island in early 2010. Both islands are located directly across the international border within easy eyesight of Maine.

Lobsters and sea lice, both crustaceans, are highly vulnerable to pesticides that salmon farm operators have been using and then disposing of in coastal waters, according to officials.

As part of the investigation, Environment Canada executed a search warrant in November at eight facilities in New Brunswick owned and operated by Cooke Aquaculture, a salmon aquaculture firm that also operates salmon farms in Maine. Cooke officials have said they are cooperating with the ongoing investigations.