Impact of Environmental Change on Growth, Reproduction, and Survival, and on Estimation of Productivity/Fishery Reference Points

Description

Ocean modeling incorporating temperature, salinity and other data is useful for many purposes, ranging from weather forecasts and ice breakup information for ships to predicting fisheries productivity. This computer generated snapshot of the ocean surface temperature around Newfoundland on September 1, 2010 showing the cold Labrador current, was generated by the C-NOOFS ocean modeling system.

Understanding how temperature affects the productivity of fish stocks is important as we move into a world of variable climate change that affects ocean temperatures. In turn, certain elements of fish stock recovery plans, such as sustainable fishing levels, are directly linked to stock productivity. This project will use extensive fisheries and oceanographic data collected by Fisheries and Oceans Canada to predict the types of changes in productivity that may occur in cod, haddock, halibut, and plaice as ocean temperatures rise, resulting in better fisheries management advice.

Results: Researchers studied the changes in cod stock productivity that have resulted from rising ocean temperature on the Scotian Shelf. The results indicated that the population has been growing increasingly slowly since the 1980s and remains low. This suggests that there is not good potential for recovery.

The study of changes in cod and plaice productivity during warm and cold periods on the Grand Bank showed that cod were more productive during warm periods, while plaice were less productive. Reference points for sustainable yield are used to inform fisheries management. Because productivity varies, using reference points that were determined during productive periods to inform fisheries management during less productive periods could lead to a rapid collapse of the fish population. This project suggests an approach to setting reference points that may alleviate this problem.

Researchers also studied the spawning of cod exposed to various temperatures. Preliminary results show that above-average winter temperatures lead to an earlier spawning season and potentially lower spawning success. This work will be extended to further study these findings and their impacts on fish productivity.

Detailed results will be published in a journal article currently in preparation.

Program Name

Aquatic Climate Change Adaptation Services Program (ACCASP)

Ecoregion(s)

Atlantic: Newfoundland, Labrador Shelves

Principal Investigator(s)

Edward Trippel
Fisheries and Oceans Canada

Joanne Morgan
Fisheries and Oceans Canada

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