1 Indicators for fisheries management: a French experience Marie-Joëlle Rochet, Verena Trenkel, Jean- Charles Poulard, and Jacques Bertrand Robert Bellail, Olivier Le Pape, Jean-Claude Mahé, Jocelyne Morin, Ivan Schlaich, Arnauld Souplet From: ICES Journal of Marine Science, in press SCMEE Transversal workshop on ecosystem approach to fisheries Salammbo, 7-9 September 2005

2 Outline  Definitions and context  A method to combine indicators for a diagnosis of fishing impacts  A French experience: using survey data to estimate indicators and to inform stakeholders

3 What is an indicator?  Something that can be measured and monitored on an appropriate time-scale  Something related to a management objective: “Something we care about”  Something simple and understandable

4 Ecosystem approach to fisheries management  Focus on marine ecosystems rather than single stocks –bycatch species –habitats –food webs...  Consider several levels of organisation  Consider multiple uses and objectives  Impact of fishing on ecosystems vs consequences of ecosystem state for fisheries

5 Why do we need indicators for fisheries management?  Monitor Status  Support Decision-Making  Inform Dialogue  Evaluate Performance of Management Actions  Provide Understanding Need Reference Points/States/Something!

6 Indicators, reference points and decision criteria  Hall & Mainprize, 2004

7 Reference direction Increasing fishing impact Target RP Limit RP Indicator I 1 Factor A Factor B Factor C Use expected effect of fishing as a “reference direction” for each indicator

8 Reference directions: Several indicators Increasing fishing impact Indicator 2 Indicator 1 Indicator 3 Combine changes in indicators relative to expected effect of fishing

9 Where you want to go depends on where you start from  Retrospective initial state assessment determines undesirable directions –light fishing impact  do not increase fishing impact –severe fishing impact  do not stay here  do not increase fishing impact  Combine indicator trends to assess if system moved towards these directions

10 Combine trends to improve interpretation  More small and large fish: good recruitment and low mortality (F or M)  Shift in spatial distribution: more fish in survey area  More old fish: mortality decreases (F or M) and slower growth  More small fish and faster growth Fishing Environment Fish. x Envir. Abundance Average length

11 Decide which combinations you like Not impacted initial state  do not increase fishing impact p= p= p=0.025p=0.95p=0.025 p=0.95 p=0.025 Test results, a=0.05 H 0 : stationary populations, independent indicators

12 Decide which combinations you like Impacted initial state  do not stay here  do not increase fishing impact p=

13 Matrices can be converted to trees   p=0.025 p=0.95 p=0.975 Deteriorating Not deteriorating  Not impacted initial state    Deteriorating Not improving Improving Impacted initial state

14 More than 2 indicators: community level         p=0.025 p=0.05 p=0.95 p=0.975 Deteriorating Not deteriorating        Not impacted initial state  do not increase fishing impact

15 More than 2 indicators Impacted initial state  do not stay here  do not increase fishing impact                 Deteriorating Not improving Improving    

16 French surveys Vilaine Seine Somme

17 Survey time-series  Initial purpose: target fish species abundance indices / recruitment indices  Consistent information on –target / non-target species –populations / communities  Use for populations / community monitoring  Comparative approach

18 Indicators

19 Results: Bay of Biscay population indicators Anglerfish LOPHBUD LOPHPIS Average weight Monkfish Veined squidEuropean squid

20 Bay of Biscay : slopes in ln(Abundance) = population growth rates

21 Bay of Biscay : slopes in size indicators, population level Average weight Slopes Average length Slopes

22 Results: community indicators Bay of Biscay Total abundance ln(Abondance)

23 Proportion of large fish threshold cm P(stationary)= threshold cm P(stationary)= 0.001

24 Towards a diagnostic: Literature based initial state assessment

25 Results: populations Deteriorating, p= Deteriorating, p= Not improving Stationary 11 pop. 43 pop. 22 pop. 51 pop.

26 Results: initially not impacted communities         Stationary, p(no change)=0.859 Vilaine, East Corsica

27 Results: initially impacted communities Celtic Sea       Deteriorating, p(no change)=0.021 Lions, Somme, Seine, S. North Sea, East. Channel        Not improving, p(no change)=0.815 Bay of Biscay       Not improving, p(no change)=0.021

28 Results: summary

29 Conclusions / Future developments  Separate indicator estimation from diagnosis: desirable trends  management objectives  Importance of initial state assessment: improve methods (in relation to management objectives)  Power and risk can be adjusted through  risks of individual tests  More indicators to refine interpretations  Develop a taxonomy of expected fishing impacts

30 Yearly standardized sampling since 1994 About 1100 stations observed from the Alboran Sea to the Aegean Sea, including Cyprus since 2005 More than 100 species studied More than 15 partners in 9 countries MEDITS SURVEY International bottom trawl survey in the Mediterranean Since 2002, priority action of the European regulation on fishery data collection in the Mediterranean

31 Geographical areas  13 areas based on the GFCM management units GFCM