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Data Sources and Methods for the Status of Fish Stocks Indicator

Methods

The indicator is a tabulation of the number of stocks in each status zone: healthy, critical or cautious.

Stocks are subpopulations of a particular species of fish, for which factors such as growth, recruitment, and natural and fishing mortality are the only significant factors in determining population dynamics, while other factors such as immigration and emigration are considered to be insignificant.

Stocks are "healthy" when the spawning biomassFootnote [1] is above the "upper stock reference point," which is determined by DFO productivity objectives for the fisheries. If stocks fall below the "lower stock reference point" (the stock level below which productivity is impaired but well above the level where the risk of extinction becomes a concern), they are in the "critical" zone. Between these two points, the stock is classified as "cautionary." If reference points have not yet been established, zones are based on the best available information on the fish’s biology and historic levels.

Stock assessments are conducted in a variety of ways and use many types of data, including abundance estimates and spawning biomass estimates. Many sources of data contribute to assessments, including data from monitoring fisheries (e.g., catch rates and fish body size distribution), research surveys, community knowledge and directed research.

Stock groups used for reporting on this indicator are marine mammals, salmonids, groundfish, large pelagics, small pelagics, crustaceans, molluscs and others. Each group comprises species with similar life history characteristics. For example, groundfish spend their adult life at or near the bottom of the ocean. These same groupings are used in the Sustainable Fish Harvest indicator.

Since the Fishery Checklist was established in 2007, it has been revised each year to improve its usefulness as a management tool, and the set of stocks addressed has also changed. Since first reported in CESI for 2010 data, Checklist questions have been revised to improve alignment with the Sustainable Fisheries FrameworkFootnote [2] and other policies of Fisheries and Oceans Canada. All stocks meeting the criteria for "major stocks" in 2011 are included, but these are not identical to the set of stocks that met the criteria previously. A standard set of 155 stocks established in 2011 is now part of the Fishery Checklist and will be used until at least 2014 to ensure consistent reporting.

Footnotes

Footnote 1

The spawning biomass is the total weight of all the fish that engage in reproductive activity in a given season. It is affected by both the size and number of mature adult fish.

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Footnote 2

Fisheries and Oceans Canada (2009) Sustainable Fisheries Framework. Retrieved on 10 September, 2012.

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