Phytoplankton Early Warning Approaches for Salmon Farmers in Southwestern New Brunswick



When phytoplankton blooms occur in areas where salmon farming is conducted the health of the caged salmon may be compromised. This has happened several times within the past decade, especially within the Passamaquoddy and Bocabec Bay areas. The phytoplankton can cause physical damage to the gills of fish and/or introduce toxins into the fish. In either case the result may be mortality in small S0 and S1 smolts and loss of growth in all sizes of caged salmon. These effects have caused millions of dollars of lost revenue to the affected salmon farmers and insurance companies are interested in knowing what farmers are doing to mitigate potential phytoplankton related losses.

As a result of the economic consequences, the salmon farmers would like to have a monitoring approach that warns them of an upcoming potentially harmful phytoplankton event, a toolbox of mitigation actions and a table of phytoplankton species and cell concentrations that are likely to cause production losses. Warnings of hours to days are useful since farmers could act on the information by adjusting harvesting schedules, delaying the entry of smolts, adjusting feeding schedules and medication treatments.

The purpose of the proposed research is to investigate the feasibility and cost-effectiveness of several potential early warning approaches and to estimate concentration thresholds for production losses in several of the dominant harmful algal species.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)


2004 - 2007


Atlantic: Gulf of Maine, Scotian Shelf

Principal Investigator(s)

Blythe Chang