DEEPFISHMAN Stock assessment (WP 4) and Biological Reference Points (WP 5)

1. DEEPFISHMAN Stock assessment (WP 4) and Biological Reference Points (WP 5) Phil Large

2. Brief background • Deep-water species in NE Atlantic are extremely diverse. • In a data rich situation - biology & life history characteristics (LHCs) pose severe problems for assessments • In data poor situation, where until 2003 fisheries developed without monitoring & management in place.

3. Overview of major assessment problems • Last 10 yrs - greater level of research and biological sampling but still ‘data-poor’. • Stock identity, migration & recruit processes. • Paucity of biological data – where present often short time series & ageing problems • Observer data – sparse • Discards

4. Fisheries-independent surveys:- • Scottish deepwater survey – 1998 to present • Irish deepwater survey - 2006 to present • Iceland autumn survey - 1996 to present • Faroes Autumn survey – 2000 to present. • Azores longline survey – 1995 to present • Spanish Porcupine Bank survey – 2001 to present • Sequential depletion & expansion of effort to new grounds and depths • Need estimates of virgin/current biomass & sustainable catches (MSY – stock reduction)

5. Progress to date • Often only time-series data available are total international landings and fleet CPUE. • Provisional assessment units based on; Theoretical separation of populations in relation to the hydrological and geological structures Distribution of species Comparison of trends in catch rates Consistency with management units. • Exception tusk (genetics studies)

6. Exploratory assessments - surplus production & depletion models, Sep VPA and XSA, Catch Survey Analysis (CSA), stock reduction, catch curves etc. • Fringe methods – software often not very robust & diagnostics are poor. • Increasing stakeholder involvement (French CPUE & blue ling (POORFISH)) • ICES advice based on abundance indices and LHCs.

7. What can DEEPFISHMAN do? • Use case studies as tools to develop and trial methods • Data – review existing monitoring & observer schemes • Data and information – from Stakeholders • Recommendations for surveys (ICES PGNEACS). • Review & make recommendations for research • Existing assessment methods – migrate these to FLR improve diagnostics, user-friendly.

8. Trial alternative assessment methodologies and develop new approaches. • Bayesian models • Multi-species models (linked to conserving current species composition or depleted species) • Life history rule-of-thumb models • Length-based methods • Ecosystem assessment of impact of fisheries on vulnerable/indicator species and VMEs.

9. ICES Benchmark Assessment • Aim – To develop and standardise assessment methodologies • Standardised methodologies should be used in subsequent years for “update” assessments (exploratory assessments?) • Stakeholder participation is encouraged • Includes a 1 day “data compilation” workshop • Provisionally, Feb 2010 at ICES • ICES WGDEEP and DEEPFISHMAN resources will be optimised

10. Biological reference points (BRPs) • WGDEEP in 2005 reviewed BRPs used since 1998. • Proposed for data-poor situations by ICES SGPA and NAFO in 1997 and are as follows:- Ulim = 0.2 * Umax Upa = 0.5 * Umax Where U is the index of exploitable biomass. • Aim is to maintain Ucurrent > Upa

11. WGDEEP proposed BRPs should take into account differences in LHCs between species • ICES concerned that Umax may not represent virgin biomass and BRPs not used

12. DEEPFISHMAN - global review of candidate (biological, ecological and socio-economic) reference points. • Aim to move beyond single target-species approach & test alternative fishery and ecosystem reference points. • Key issue - multi-species nature of many deep-water fisheries & need to capture this in management framework. • Review the potential use of existing and multi-species biological reference points e.g. status of indicator species, biodiversity indicators • Also consider simplistic metrics such as changes in mean length, proportion of large fish in catches etc

13. Interaction with stakeholders • Data – skipper logbooks CPUE series from haul by haul data from French Fishermen’s personal logbooks (source, PROMA IFREMER cooperative work) Data from Skippers private logbooks Ling in Division IIa. Estimates of Norwegian longline cpue (kg/1000 hooks) based on skippers’ logbooks (pre-2000) and from the entire fleet (2000–2006).

14. Qualitative views on abundance and distribution. • Sentinel fishers • What you would see as suitable reference points based on actual catch-rates? Thank you