Nova Scotia, Canada is the close to the northern limit of the striped bass range. On January 3, about 150 miles from Port Morien, Nova Scotia, locals reported a massive fish kill consisting entirely of striped bass. This is the first large-scale die off reported in this region, and officials say it is likely due to significant fluctuation in temperature.
Nova Scotia has a population of striped bass that winter-over, however, residential bass populations of such magnitude had never been recorded. The Port Morien Wildlife Association (PMWA) estimated, conservatively that 2,000-plus striped bass were found washed up along shore of an estuary.
Stripers in Cape Breton
According to reports, an estimated 90-percent of fish discovered on the stretch of beach in Dingwall, were “schoolie” striped bass from 16 to 24 inches in length. Though fish as large as 41 inches and as small as 6 inches were found. These fish are standard size for the typical holdover populations seen in Cape Breton.
Ray Briand of Port Morien Wildlife Association, made the discovery while duck hunting when he noticed birds working an area of beach nearby. Ray has lived and fished in the area for most of his life, and had never seen fish wash up here until this occasion. In a video posted to the internet by his team member Jeff McNeil, the rocky shoreline is visibly littered with dead striped bass. Ray and Jeff both reported the fish looking otherwise healthy, with no signs of physical distress or viral/ bacterial infections such as vibrosis.
Scientists and marine biologists rushed to the site, in order to protect the shoreline for further study. There was immediate concern that the combined impending high tide and lingering waterfowl would deplete much of the evidence. The local community reacted rapidly, and Nova Scotia’s Striped Bass Association (SBA) were quick on the scene to collect samples of DNA. Some of these samples are for genetic tracing purposes, others are for marine pathologists aquatic toxicologists.
The genetic test results will help officials conclude whether or not these fish were holdover fish, or one large body of migratory fish that decided to stick around. From there, further research will be done accordingly; if the fish are migratory, the study will fall into further researching the origins of these fish and why they remained in Nova Scotia rather than migrating. However, if the fish belong to resident bass populations, the study will hone it’s focus on how these local fish died off in such substantial numbers.
Toxicology tests will provide insight into water quality, chemicals, pollutants and nutrients that may have impacted the massive loss of life. Initially, many believed that these fish died in the ocean and the tide brought them into the estuary, but that is highly unlikely. According to Jeff McNeil the waters in this region of Nova Scotia tend to be pristine, leaving little to no chance at a pollutant causing this kill.
Speculation from the Port Morien Wildlife Association, is that significantly fluctuating temperatures and recent heavy rains led to drastic changes in water temperature and pressure. Combined factors of fluctuating water temperatures in a small area of densely populated brackish water could certainly be what led to the demise of this school of fish. The environmental conditions were likely too much to handle for the stripers. Oxygen depletion and excess waste are also concerns when a big school stages up in such a tight space. Still, it’s somewhat surprising that striped bass were the only species affected.
Questions Still Remain
Still unknown: was this the entire body of fish? Did some fish live on, and are they healthy? Are the fish that died resident holdover bass? If not, what brought these fish here to begin with?
Ray Briand investigated in the field on behalf of the Port Morien Wildlife Association; of the samples he took for research, an estimated 30 to 40-percent were spawning females.
For now, this die off seems to be completely contained and specific to one estuary.