ices how to count fish for management

ICES provides advice on state, exploitation and management targets for fish stocks

How?

Information from fish

• Length

• Weight

• Age

Information on population trends: surveys

• Trawls• Acoustics• Plankton• TV

Research vessels & industry

Information from catch

• Amount• Location• Timing• Bycatch

From ports, log books & observers

How do we use this information?Take a stock of fish:

Every stock has underlying structure

Add fishing…

Mortality rate

Change in thenumbers at age

We also measure the catch

• Observed mortality rates

• Catches recorded

Equations and simulations are used to combine the information.

Also observations of trends in populationsfrom surveys.

This produces a stock assessment

North Sea herring

To provide the advice for next year’s catches

We project forward with our best knowledge(maturity, growth, recruits, impact of fishing gear, natural death etc) across a range of fishing scenarios.

Scenarios set out in management plans

All management plans in the ICES area are tested using simulations

Simulations of Atlantic mackerel multiannual management strategy at different fishing mortalities

Framework for advice

International agreements and policies:• UN Convention on the Law of the Sea (UNCLOS 1982) -MSY• UN Conference on Environment and Development (UNCED, 1992) -precautionary approach• UN Straddling Fish Stocks Agreement of 1995 (UNFSA 1995) - precautionary approach• Convention on Biological Diversity (UN CBD, 1992) - ecosystem approach• Johannesburg Declaration of the World Summit on Sustainable Development (WSSD UN 2002)-

ecosystem approach & MSY

National and regional legislation:including CFP, MSFD, Norwegian Marine Resources Act, Russian Federal Law on Fisheries, Icelandic Fisheries Management Act, Faroe Islands Fisheries Management Act

Reference pointsPrecautionary Approach

Populations need to be maintained within safe biological limits -Certain that reproductive success is not impaired

Reference pointsmaximum sustainable yield (MSY)

ICES interpretation of MSY is maximization of average long-term yield from sustainable stocks

Reference pointsmaximum sustainable yield (MSY)

Ecosystem Approach

Use of reference points: current and future

North Sea herring

State of the stocks North Sea overview