St. Andrews Biological Station staff members were witness to some interesting catches during their research survey of the Bay of Fundy and Scotian Shelf this past summer.
According to biologist Don Clark, “We found a large number of species in our nets that we don’t typically see in our waters, as well as large numbers of some species that in previous years we would occasionally catch, but this year were very abundant.”
The reason behind these unusual catches is likely linked to changes in the ocean environment and climate change.
“The survey provides invaluable information on various species and on the ecosystem they call home, as data is also collected on water temperature, salinity, nutrients, oxygen values, microscopic life, and more,” Clark says.
With more than 48 years of survey data, researchers can look at the changes in the species caught and the marine environment to see how they interact.
While the survey proved to be interesting in the unique species that were found, the primary purpose is to collect data on commercial species such as cod, haddock, halibut, and more. Over 20 tonnes of approximately 390 species of groundfish and invertebrates were collected, sorted, weighed and sampled. These data are stored in a departmental database and preliminary analyses have now been conducted.
The resulting information, combined with data collected from the fishery such as landing sizes, the ages of fish caught, and tagging programs, is used to develop scientific assessments that will help the department manage these fisheries.
Here is a snapshot of some of the unusual catches that occurred during the summer survey.
FIRST TIME CATCHES
A Lined Seahorse was captured east of Brown’s Bank. This warm-water species is common in the Caribbean and southern U.S. coastal waters and occasionally is seen all the way to coastal Nova Scotia.
A Black Scabbard fish, a deep-water fish commonly caught in commercial fisheries in the eastern Atlantic, has never been captured in this DFO survey area until this year.
In addition to these first-time catches, some species that more commonly live in warm waters were brought up in the survey nets as well.
American John Dory, which live in waters south of the Scotian Shelf, have been caught in several locations in the past two years during the DFO survey. However, the total catch this past summer was roughly 10 to 20 times as high as in any other year. And short-fin squid were abundant throughout the Bay of Fundy and Scotian Shelf. The total survey catch of these squid was the second highest in the series, 40 times higher than in 2016.
Portuguese shark are stout, black, predatory sharks found in water greater than 1,000 metres. They have small sharp teeth and rough skin, which will easily cut your fingers if they’re handled without gloves.
Lobsters continue to expand their distribution on the Scotian Shelf. This year there were two survey sets along the shelf edge south of Sable Island, which caught several large lobsters, many of which were berried females that were blue in colour.