1,747,382 research outputs found
Report of the ICES-EuroGOOS planning group on the North sea pilot project NORSEPP (PGNSP)
Full text linkContributors: Hein Rune Skjoldal, Are SalthaugThere had been limited intersessional work but members provided updated information on NORSEPP relevant activities and products, including a modelled 50-years time-series (1955–2004) of modelled water fluxes in the North Sea.
NORSEPP agreed to start producing quarterly update reports on the conditions of the North Sea with emphasis on physical conditions and drivers. An attempt will be made to include hydro-graphic data from the IBTS survey this year in the update report for the 1st quarter (January–March). Information related to the seasonal development of phytoplankton will be included in the report for the second quarter. The ICES co-Chair (Hein Rune Skjoldal, IMR) agreed to be editor for the first quarterly update reports for 2005. A process will be initiated to develop practical working relationships between NORSEPP and the various groups in ICES that support the provi-sion of ICES Advice on Fishery Management.
NORSEPP will contribute to the 2006 North Sea Assessment by REGNS by contributing time-series of model data (e.g., on water fluxes) and selected model data for recent years with high spa-tial and temporal resolution. NORSEPP will be represented at the REGNS meeting 9–13 May 2005
Workshop on ICES reference points (WKREF2)
No full textThe ICES Workshop on ICES reference points (WKREF2) was tasked review the WKREF1 report and based on the outcome develop updated guidelines for the ICES reference points system and recommendations for ACOM consideration. The WKREF1 report has suggested 5 key recommendations to simplify and harmonise the ICES reference points framework representing a major change to the current guidelines. At WKREF2, we detailed discussions and four key concerns were raised about the proposed approach. The first related to the simplification of rules to define Blim. Around two thirds of category 1 stocks would end up as WKREF1 “Blim Type 2” where Blim would be set as a fraction of B0. The Allee effect or “depensation” maybe more important than previously thought and should be furthered explored for ICES stocks since it has important consequences for Blim. A number of challenges and issues around defining Blim using the current guidelines were documented. Some suggestions on improvement criteria were discussed including using classifiers to define spasmodic stocks and using change point algorithms to address non-stationary productivity regimes. However, further work is need to make these approaches operational and there was no consensus that the WKREF1 Blim types should replace the current guidelines.WKREF1 recommended that the FMSY proxy should be based on a biological proxies and should be less than the deterministic FMSY. It was pointed out that the stochastic FMSY estimated in EqSim for example, is lower than the deterministic FMSY and that the current guidelines ensure that the FMSY should not pose a more than 5% risk to Blim. A large amount of work described in WD 1 was carried out to develop an MSE framework to consistency and robustness test a candidate reference point system for North East Atlantic stocks. However, WKREF2 recommended that further work needs to be carried out to condition and test the simulation framework before the conclusions could be adopted by ICES and incorporated into the guidelines.A number of considerations for defining MSY related reference points were discussed including using model validation and prediction skill to ensure that ICES provide robust and credible ad-vice. There is evidence that density dependence (DD) is important in the majority of ICES stocks (68% in recruitment and 54% in growth). The correct prediction of the shape and strength of density-dependence in productivity is key to predicting future stock development and providing the best possible long-term fisheries management advice. A suggested approach to use surplus production models (SPMs) to account for DD in FMSY was suggested and discussed but there was no consensus on whether that approach was appropriate. There was consensus that the FECO approach as a means of adapting target fishing mortality to medium-term changes in productivity should be included in the guidelines subject to a benchmark and ACOM approval.While WKREF1 and 2 focused mainly on Category 1 stocks ToR c) called for a “simplified and harmonised set of guidelines for estimating MSY and precautionary reference points applicable in the advice framework across various ICES stock categories.” Ideally the ICES assessment categories should provide equivalent risk across all stocks. This issue was discussed but no recommendations emerged.There was no consensus a revised reference point framework was proposed at WKREF2. However, it was agreed that it should be presented here for further discussion at ACOM and other fora. The key feature of the suggested approach is that the stock status evaluation is treated independent of the Advice Rule (AR). The main feature of the system is that the biomass trigger is not linked to a stock status evaluation, it is linked to the expected biomass when fishing at the target fishing mortality, in contrast to the current ICES approach. It also entailed that FMSY would also become an upper limit of fishing mortality and that the advised fishing mortality would be set at or lower than that level. WKREF2 did not discuss what to do in situations where SSB< Blim or alternative forms of HCR for the advice rule. Building community understanding and consensus around simplified and harmonised guidelines has yet to be achieved. A further workshop WKREF3 will be required to achieve that aim. The report includes 6 recommendations for ACOM consideration
Report of the Study Group on Management of Integrated (SGMID)
Full text linkThe ICES Study Group on Management of Integrated Data met for the third and last time. The group convened at the ICES secretariat at the same time as the annual meeting of the Working Group on Marine Data Management (WGMDM), and half a day was devoted to a joint session on detailed planning of future needs for data groups in the ICES environment, and the organisation of the co-sponsored ASC theme session M on data integration.
SGMID’s main task for this year was to review the implementation of the new ICES data policy. The new policy, drafted at SGMID’s last meeting, was developed further by a number of ICES expert groups and unanimously adopted by the ICES Council in October 2005. The data policy was published in March, and SGMID discussed extensively how to communicate the new approach to data sources and data users. The group also suggested to the ICES Data Centre which technical amendments would be required for a timely implementation. An extension of the ICES in-house databases to hold information on data sources and data quality flags (including “known issues” with historic data) was thought to be of special importance in this context. Another task was the review of the outcome of the ICES data user questionnaire from the ASC 2005.
SGMID concluded that, while the group had reached its end-of-life as a study group, there would still be a need for such a user-oriented group dealing with strategic planning of ICES data issues. After discussion with WGMDM, the group made a number of suggestions on possible approaches. A final resolution requires a meeting between the chairs of the SGMID and WGMDM, the Consultative Committee Chair, and the ICES General Secretary
Report of the Benchmark Workshop on Roundfish (WKROUND)
Full text linkICES. 2010. Report of the Benchmark Workshop on Roundfish (WKROUND), 9–16 February 2010, Copenhagen, Denmark. ICES CM 2010/ACOM:36. 183 pp. Contributors: Åge Fotland, Daniel Howell and Sigbjørn Mehl
Report of Steering Group on Cod and Climate Change
Full text linkContributors: Svein SundbyThis is a report of the ICES Steering Group on Cod and Climate
Change. The report takes note of C.M. 1990/G:50 and C.M. 1991/G:78
and recommends the establishment of a five-year ICES program on Cod
and Climate Change under sponsorship of the ICES Consultative
Committee
Report of the Study Group on Future Requirements for Fisheries Assessment Data and Software [ICES Headquarters, 21 October, 1997]
Full text linkContributor: Knut SunnanåIntroduction: Since the development of IFAP many new analytical methods have been developed which are in
common usage by assessment working groups. It has proved time consuming or impossible to
incorporate these tools into IFAP and as a results most of these new methods are used outside the
IFAP framework. This means there has been a lack of adequate quality control in the implementation
and usage of the software as well as inefficiency in the exchange of data between programs. As a
results there is considerable scope to improve the productivity of assessment working group meetings
and reduce vulnerability to errors by trying to bring software development within an organised
framework. Most of the meeting was devoted to identifying such a framework which would meet
many of the immediate and medium term needs of assessment working groups, ACFM and the
Secretariat. It was also recognised that there was a need also to consider a longer terrn more strategic
view of how ICES assessment needs might develop. This was not discussed in detail at the meeting
but a sub-group has been tasked to produce a policy paper in advance of the May 1998 ACFM
meeting
Report of the International Young Fish Survey in the North Sea, Skagerrak and Kattegat in 1990
Full text linkIntroduction: The results from the International Young Fish survey become
available in successive steps. During the survey the numbers of
1-group fish, based on fish below a certain length, are exchanged
between the participating research vessels. Immediately after the
survey the length compositions of the seven standard species are
sent to ICES (in IYFS exchange format), to be used by the different
assessment working groups, together with all age-length keys
which are available by then. Final data, including length compositions
for all species and age-length data, should be submitted
to ICES before 15 April. These data are then checked and stored
in the ICES IYFS data base, in order to be able to run the final
analysis in time for the May meeting of ACFM. This report is
based on the analysis done in May 1990
Report of the Working Group on Pathology and Diseases of Marine Organisms [Kiel, 5- 8 April, 1989]
No full textContributor: Brit HjeltnesSummary: The Working Group met for 4 days (5-8 April 1989) at the Institut
fur Meereskunde, University of Kiel, FRG, with 20 participants
from 11 countries. National reports on diseases in wild
populations of marine organisms submitted from 7 countries were
discussed with emphasis on data from studies on pollution
effects. Reports on the ICES 2nd Seagoing Workshop on Methodology
of Fish Disease surveys, the German multidisciplinary study on
fish diseases in the Wadden Sea and the Dutch and British
experimental studies on the effects of polluted sediments on fish
health were considered. Attention to disease in mariculture
centred on the national reports, consideration of recent
developments in molluscan disease of economic importance and
preparation of data on problems of medication. Proposals for
further additions to the ICES disease identification leaflets
series and other possible publications to aid fish disease
recognition during stock surveys were discussed. The Working
Group proposed three main recommendations to be put to ICES
Council
Workshop on ICES reference points (WKREF1)
No full textThe ICES Workshop on ICES reference points (WKREF1) was tasked to provide a thorough re-view of the ICES reference points system as a basis to re-evaluate the process for estimating, updating and communicating reference points in the context of the ICES advice. As part of the preparation leading to WKREF1 a large database of the most recent assessment outputs for 78 Category 1 stocks were collated in the form `FLStock` objects, which formed the basis for several components of the presented analyses. The first part of the meeting involved a detailed overview of the history and basis of the ICES references points system, which was aligned with the results of an empirical review of the procedures and choices made to derive ICES reference points for category 1 stocks. The ICES proce-dures were then contrasted with those used in the USA, Canada, New Zealand and across tuna Regional Fishery Management Organizations. A limitation in terms of transparency of the ICES procedures is a lack of complete documentation of the settings used for deriving reference points using, e.g., the EQSIM software. In comparison to other international standards, the main differences identified include the absence of a target biomass reference point and inconsistent estimates of the limit biomass reference point Blim, which is estimated to be below 10% of the un-fished biomass (B0) for a high proportion of analysed stocks (around 50%). In addition, an important difference is that direct estimates of FMSY are used in ICES (which can be unreliable), whereas elsewhere FMSY is often replaced by more conservative biological proxies, such as Fspr% and FB%. The second part focused on the robustness evaluation of the current ICES reference point system. Work presented included examples that demonstrate differences in reference point estimates between standard ICES procedures (EQSIM) and full Management Strategy Evaluation (MSE) simulations, and a study that highlighted the considerable uncertainty in estimating Blim, with guid-ance on how to quantify uncertainty depending on length and contrast in the time-series. A large simulation experiment was conducted by applying a short-cut MSE approach to 68 Category 1 stocks, which revealed that the ICES MSY advice rule is the least robust of all tested generic approaches if assumptions about the typically highly uncertain stock recruitment relationship are violated. This led to poor performance of the ICES MSY advice rule associated with the low-est long-term yields, highest risks to fall below limit reference points and lowest probabilities of attaining biomass levels at MSY. Contributing factors to the poor performance were combina-tions of comparably high FMSY estimates and low Blim ( 10% B0), performance improved notably. Results from a backtest using hindcasting with forecasts of 1-5 years reinforced the need to re-estimate reference points regularly at benchmark assessments, and that short-term forecasts should not exceed a three-year time span to account for time-varying biological traits. Finally, presented work highlighted the advantages (in terms of high consistency and accuracy) of estimating the stock-recruitment relationship or reference points internally in the assessment model, which was illustrated for Stock Synthesis and SAM, and supported by a comprehensive simulation study. The key recommendations of WKREF1 were to: i) revise and simplify how Blim is derived. An absolute Blim should only be specified empirically in cases where there is sufficient contrast in the stock-recruit data to estimate a well-defined break-point. Alternatively, it is suggested that Blim should be determined as a plausible ratio of B0 based on biological principles and the life-history of the stock (e.g. 10-25% B0 depending on the stocks characteristic; Section 7). ; ii) FP.05 should be calculated without Btrigger; iii) to use biological proxies (Fbrp) for deriving FMSY, and the resultant FMSY proxy must not exceed FP.05; iv) to report biomass target (Btrg) that corresponds to the FMSY proxy; and v) to set Btrigger as either a fraction of Btrg or multiplier of Blim. Specifications of setting reference points (e.g. Fbrp) or Btrigger should be informed through further simulation testing to be presented at WKREF2
NAFO/ICES Pandalus Assessment Group Meeting, [22–30 October 2008 ICES Headquarters, Copenhagen, Denmark]
Full text linkContributors: Carsten Hvingel, Guldborg Søvik and Trond Thangsta
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