SCIENCE INDICATORS:
BIG GAPS IN DATA
To track Canada’s progress in improving fish stock health, Oceana Canada uses a set of key science indicators that are consistent with DFO policy guidelines.
Stocks with sufficent data to assign health status
Purpose: Allow scientists to make robust estimates of how many fish are in the water and assign stock heath status.
2017
2018
2019
Stocks with recent biomass estimates
Purpose: Help managers make decisions based on recent estimates5 of how many fish are in the water.
Several stocks haven’t been assessed since 2013 and are therefore considered outdated in this year’s analysis.
2017
2018
2019
An upper stock reference point identifies the boundary above which a fishery can be considered healthy, while a limit reference point identifies the boundary below which it can be considered to be in a critical state. Corrective action should be taken before a stock reaches the limit reference point.
Credit: Jason van Bruggen
Stocks with reference points established
Purpose: Allow managers to assess whether a stock is in healthy, cautious or critical condition, set appropriate harvest levels based on status and gauge the success of management measures.
Limit reference point
2017
2018
2019
Upper stock reference
2017
2018
2019
Stocks with fishing mortality estimates
Purpose: Help determine the rate of fish removal and sustainable fishing limits.
2017
2018
2019
Stocks with natural mortality estimates*
Purpose: Help make better fisheries management decisions by determining the rate at which fish naturally die.
2018
2019
*New indicator in 2018.
5 Within the last five years.
74 stocks don’t have sufficient data to assign them a health status.
Fish are removed from a population in two ways: through fishing (fishing mortality) and through natural causes (natural mortality), including being eaten by other fish. When fisheries managers have reasonable estimates of both, they can more confidently estimate the size of next year’s population and adjust management practices accordingly.
Fishing mortality should include estimates of all the ways that fishing has removed fish from the stock, including commercial and recreational fishing, bycatch, personal consumption, fish taken for bait and fish taken for social and ceremonial purposes.
GOVERNMENT COMMITMENT:
In 2019, DFO made measurable progress toward its commitment to develop limit reference points for all major commercial fish stocks (up 11.3 per cent from 2017). It also made marginal progress in developing upper stock reference points (up 4.1 per cent from 2017). Together, these reference points help DFO to assess stock health and set targets for rebuilding depleted stocks to healthy levels. Under DFO’s precautionary approach framework, fisheries managers must use the best available information to make decisions, but they cannot use a lack of information as an excuse for not taking action.
More than a third of stocks still lack limit reference points and more than half lack upper stock reference points.
Credit: Ian Mcallister