SEC(2007) 465

COMMISSION STAFF WORKING DOCUMENT

REPORT OF THE SECOND MEETING OF THESUBGROUP ON REVIEW OF STOCKS. (SGRST-05-02)OF THESCIENTIFIC, TECHNICAL AND ECONOMIC COMMITTEE FOR FISHERIES (STECF)MIXED FISHERIESIspra, 17-21 October 2005

This report has been evaluated and endorsed by the Scientific, Technical and Economic Committee for Fisheries (STECF) in its plenary session of 7-11 November 2005

This report does not necessarily reflect the view of the European Commission and in no way anticipates the Commission’s future policy in this area.

Table of Contents

STECF evaluation and endorsement ON MIXED FISHERIES 4

Background 4

STECF Comments and Recommendations 4

1 Summary 5

2 Introduction 6

2.1 Terms of reference 6

2.2 Conduct of the meeting 6

3 Development of Mixed Fisheries Models 6

3.1 Consideration About the Use of MTAC 6

3.2 Working Document 1 on Further Software Development 8

4 Area based analyses 9

4.1 Availability of fleet specific data 9

4.2 Estimation of fleet specific international landings and discards 9

4.3 North Sea and Skagerrak (ICES Division IV and IIIan) 12

4.3.1 Fleet overview and specific data 12

4.3.2 Assessment data overview 17

4.3.3 Mixed fisheries analyses 21

4.4 Eastern Channel (ICES Division VIId) 29

4.4.1 Fleet overview and specific data 29

4.4.2 Assessment data overview 30

4.4.3 Mixed fisheries analyses 30

4.5 Kattegat (ICES Division IIIas) 33

4.5.1 Fleet overview and specific data 33

4.5.3 Mixed fisheries analyses 37

4.6 West of Scotland (ICES Division VIa) 37

4.6.1 Fleet overview and specific data 37

4.6.2 Assessment data overview 41

4.7 Irish Sea (ICES Division VIIa) 42

4.7.1 Fleet overview and specific data 42

4.7.2 Assessment data overview 42

4.7.3 Mixed fisheries analyses 43

4.8 Porcupine Bank, Celtic Sea, Bay of Biscay (ICES Divisions VIIb, e, f, j, k, VIIIa, b, d) 43

4.8.1 Fleet overview and specific data 43

4.8.2 Assessment data overview 51

4.8.3 Mixed fisheries analyses 52

4.9. Iberian Peninsula (ICES Divisions VIIIc-IX) Jose 52

4.9.1 Fleet overview and specific data 53

4.9.2 Assessment data overview 53

4.9.3 Mixed fisheries analyses 54

5 References 55

Appendix 1 List of participants and addresses. 56

European Commission 56

Appendix 2 Exchange data formats 57

Appendix 3 on the terminology of MTAC settings and output 64

STECF EVALUATION AND ENDORSEMENT ON MIXED FISHERIES

STECF was asked the following:

STECF should deliver an opinion based on the work done by subgroup SGRST-05-02 (17-21 October, 2005) which compiled recent data on demersal mixed fisheries, identified stocks, areas and fleets where there are significant mixed catches and estimated catches for 2006.

Background

The Commission convened a STECF-SGRST mixed fisheries meeting in Ispra (Italy) at the JRC premises during 17-21 October 2005 as a follow up of a series of annual meetings, with the following terms of reference:

1. Obtain and compile all available recent data concerning mixed-species demersal fisheries in Community waters and adjacent areas. The data of specific interest are landings and discards by species and by fleet, where possible disaggregated by age and by number of fish.

2. Review the data compiled in (1) and identify those stocks, areas and fleets where significant technical interactions exist and for which adequate data exist to permit those interactions to be evaluated.

3. For each of the area-fleet-stock groupings identified in (2), calculate catch forecasts for 2006 for the stocks concerned, based on:

4. the most recent ICES assessments

5. ACFM advised catches for 2006

6. an appropriate range of assumptions for the factors describing the relative policy weights to be attached to each fish stock, including any particular values that may be requested by the Commission services on receipt of the ICES advice. In support of the above tasks, continue methodological and software development as initiated by this Ad Hoc Working Group since 2002.

7. The main conclusions and STECF comments and recommendations are presented below.

STECF Comments and Recommendations

STECF agrees with the findings presented in the report of October 2005 STECF-SGRST meeting on mixed fisheries and has drawn the following conclusions and recommendations:

8. STECF notes that sampling of catch at sea including discards to quantify technical interactions between mixed demersal fisheries is expensive and difficult. This means that sampling coverage tends to be rather limited, and raised estimates of discards are subject to high uncertainty. This is true of all of the discard estimates, and in some cases the discard estimates presented represent the first attempt to use the discard data from some fisheries in an advisory context. Where the coverage is considered adequate to estimate the overall catch compositions of specific fleets these are presented in the sub-group report. However STECF considers that, they only provide an approximate indication of fleet catch compositions.

9. Technical interactions between mixed demersal fisheries in the North Sea and Skagerrak, Kattegat and West of Scotland only, are indicated in the report based on estimated catch data including discards.

10. Both the lack of stock specific forecast inputs on stock size and exploitation rates and considerable concern regarding incomplete fleet specific catch data including discards prevented meaningful analytical mixed fisheries forecasts for the management areas North Sea and Skagerrak, Eastern Channel, Kattegat, Eastern and Western Baltic, West of Scotland, Irish Sea, Porcupine Bank, Celtic Sea, Bay of Biscay and around the Iberian Peninsula.

11. All mixed fisheries scenarios for the North Sea and Skagerrak that attempt to balance the ICES advice for 2006 of 0-TAC for cod and a 0.68 F-multiplier for plaice, indicate that stringent cuts in fleet-specific fishing mortality are required across the board. Such overall cuts imply that the fishing possibilities as advised under precautionary single species boundaries would have to be severely reduced. STECF considers that the fleet landings and discard information and specific stock parameters are too imprecise to provide MTAC runs that are an acceptable basis for management advice.

1 Summary

- The STECF-SGRST on Mixed Fisheries notes that sampling of catch at sea including discards to quantify technical interactions between mixed demersal fisheries is expensive and difficult. This means that sampling coverage tends to be rather limited, and estimates of discards are subject to high uncertainty. This is true of all the discard data used here, and in some cases the discard estimates presented represent the first attempt to use the discard data from some fisheries in an advisory context. Where the coverage is considered adequate to estimate the overall catch compositions of specific fleets these are presented, but they are intended only to provide an approximate indication of fleet catch compositions.

- Technical interactions between mixed demersal fisheries in the North Sea and Skagerrak, Kattegat and West of Scotland are indicated based on estimated catch data including discards.

- Both the lack of stock specific forecast inputs on stock size and exploitation rates and considerable concern regarding incomplete fleet specific catch data including discards prevented analytical mixed fisheries forecasts for the management areas North Sea and Skagerrak, Eastern Channel, Kattegat, Eastern and Western Baltic, West of Scotland, Irish Sea, Porcupine Bank, Celtic Sea, Bay of Biscay and around the Iberian Peninsula.

- Sensitivity analyses of mixed fisheries scenarios for the North Sea and Skagerrak indicated that attempts to balance the ICES advice for 2006 of 0-TAC for cod and a 0.68 F-multiplier for plaice is unaffected by the uncertainty in the cod assessment and would involve stringent cuts in effort across the board. Such general effort cuts would imply major deviations from the fishing possibilities as advised under precautious single species boundaries. The precise level of cuts is, however, conditional upon the uncertainty in the fleet landings/discards database and the specific stock parameters which are both considered such that the MTAC runs are too imprecise for management purposes. Major fleets, i.e. beam ≥80mm, demersal trawls ≥100mm and demersal trawls 70-99mm and static gears, all contribute significantly to the catch of the reduced cod and plaice stocks and thus appear too poorly defined to generate scope for increased catches of other underexploited species through fleet specific management. The SGRST mixed fisheries stresses that the exploratory analyses are not in any way intended as viable or realistic options for management purposes!

- SGRST mixed fisheries provides further guidelines on how to use the model on mixed fisheries TACs (MTAC, Vinther et al. , 2004).

- Some changes in the data formats are proposed for the south-western ICES divisions to be considered in future data compilations.

2 Introduction

The STECF Sub-group SGRST on Mixed Fisheries met at the European Joint Reseach Centre in Ispra, Italy, during 17-21 October 2005 to deal with terms of reference 1-5 (TOR) listed in the following section 2.1. The list of participants is given in Appendix 1 to this report.

2.1 Terms of reference

STECF Subgroup SGRST on mixed fisheries 2005 has been given the following Terms of Reference:

12. Obtain and compile all available recent data concerning mixed-species demersal fisheries in Community waters and adjacent areas. The data of specific interest are landings and discards by species and by fleet, where possible disaggregated by age and by number of fish.

13. Review the data compiled in (1) and identify those stocks, areas and fleets where significant technical interactions exist and for which adequate data exist to permit those interactions to be evaluated.

14. For each of the area-fleet-stock groupings identified in (2), calculate catch forecasts for 2006 for the stocks concerned, based on:

15. the most recent ICES assessments

16. ACFM advised catches for 2006

17. an appropriate range of assumptions for the factors describing the relative policy weights to be attached to each fish stock, including any particular values that may be requested by the Commission services on receipt of the ICES advice.

18. In support of the above tasks, continue methodological and software development as initiated by this Ad Hoc Working Group since 2002.

2.2 Conduct of the meeting

The meeting started on Monday 17 October at 9.00 hours. The SGRST Mixed Fisheries meeting was attended by 10 participants from Belgium, Denmark, England, France, Germany, Netherlands, Northern Ireland, Scotland and Spain. A full list of the participants and addresses is given in Appendix 1.

There was only one working document (WD) reviewed during the meeting which is summarised in section 3.2.

SGRST was supported by JRC’s excellent secretariat and the provision of an internet site which was used for distribution of information, working papers and data submissions (http://stecf.jrc.cec.eu.int/event.php?id=24

The meeting was adjourned on Friday 21 October 2005 12.00 hours.

3 Development of Mixed Fisheries Models

3.1 Consideration About the Use of MTAC

The MTAC model has not been developed further. The Group reiterates some instructions on the use of MTAC and the interpretation of the results, as well as a minor problem with the program that was discovered last year. Furthermore we communicate a new insight on the use of the optional setting p=1 (for the meaning of optional settings, see Appendix 3).

There are two main ways in which the results of MTAC can be used in a management context.

19. Aggregate MS-TAC advice, using the MS-TACs (mixed species TACs) of the MTAC output.

20. Fleet specific advice, adjusting the effort of the individual fleets through the fleet factors of the MTAC output.

The choice between these two management approaches requires fundamentally different implementations of MTAC and therefore the objectives of management must be stated upfront before mixed fishery analyses. Aggregate MS-TAC advice (approach 1) is obtained by setting p=0, q=0 (i.e. the effort of all fleets is adjusted by the same amount). Fleet specific advice (approach 2) is obtained from the permutations of p=1, p=2 and q=0, q=1. Note that the use of MTAC for the provision of aggregate MS-TAC advice (approach 1) when p≠0 and q≠0 is fundamentally incorrect and will not deliver the expected results.

Another point to emphasize is that where the MS-TAC is higher than the SS-TAC the results are generally not in agreement with the Precautionary Approach and/or any recovery plans.

In the 2003 report of this Group, investigations were made into the use of 0 and very small decision weights, finding that the results of MTAC were potentially quite sensitive to such a choice. It was recommended to use very small decision weights rather than 0 when no priority is given to a stock. However, the 2004 report of this Group states that the stocks with no analytical assessment should receive a decision weight of 0 to ensure that they have absolutely no influence on the MS-TACs. The conclusion, therefore, is: for species included in the MTAC analysis with no analytical assessment always use decision weight 0, and for other species that should receive no priority use a very small non-zero value for the decision weight.

A small problem was found last year when running MTAC as part of the STECF mixed fisheries working group. When the data files are set up so that the following conditions hold the program will crash:

21. In the file ‘species.dat’ there are zero historical catches at a particular age for all species;

22. The file ‘fleet.dat’ is empty.

This is because MTAC reconstructs an age distribution for the population from the historical catches at age. If there is a particular age group with zero catches for all species then this age group seems to be ‘deleted’ by the program. This causes the matrix dimensions of the internal data to be inconsistent and MTAC will crash.

This problem was initially discovered when entering zero historical catches at age 0 for all species. This particular case can be considered as a misspecification of the input data as the age at first capture in ‘species_setup.dat’ was not consistent with the data entered for the historical catch in ‘species.dat’.

However, consider the example of a data set where all species have a high age class with zero historical catches, but higher age classes have non-zero historical catches. The first and last age of capture in ‘species_setup.dat’ would be well defined, but this age class with zero historical catches would be ‘deleted’ and the program will crash.

To avoid this problem, one should make sure that if the file ‘fleet.dat’ is empty, then there should be no age class in the file ‘species.dat’ that has zero entries for all species. A simple solution is to insert a ‘1’ in this age class for one of the species. This makes no difference to the final results but will allow the program to run correctly.

Based on a new insight the Group strongly recommends not to use the optional setting p=1, because results of MTAC runs with this setting are highly dependent on the number of species included in the MTAC analyses. The catch composition data are very far from being complete. This implies that the catch compositions of the fleets (proportions of species’ catches, in weight, within the total catch of the fleet) used in MTAC do not correspond to reality. For example, if only 5 species are considered in the analyses, cod may make up e.g. 30% of a fleet’s catch (of those 5 species), whereas if all species are considered cod perhaps makes up only e.g. 10% of that fleet’s total catch. Or even more extreme, a fleet could target a particular species, e.g. Crangon , and catch a very small by-catch of cod. Whether or not the target species is included in the MTAC analysis has a great influence on the outcome in case MTAC is used with option p=1. Option p=1 leads to a solution where fleets having a large proportion of cod in their catch have to reduce their effort to a greater extent than fleets having a small proportion of cod in their catch. This implies that if the target species is not included in the MTAC analysis and the fleet’s catch thereby consists for e.g. 100% of cod, it has to reduce its effort to a very great extent, whereas if the target species would be included, and the fleet’s catch consists only for e.g. 5% of cod, it has to reduce its effort to a very small extent. This example shows that MTAC results under p=1 depend on the inclusion of other species in the analysis.

The solution to this problem does not lie in acquiring more complete data sets (i.e. containing reliable data on all species in the catch). This will raise the question which species should be considered. Should by-catch of invertebrate benthos be considered? And birds? Such reasoning ad absurdum shows that the option p=1 does not make much sense. In that case a fleet catching a lot of cod, but catching even more of other species would have to reduce its effort to a lesser extent than a very small fleet that catches cod only (but a very small proportion of the total international cod catch). Using the optional setting p=2 makes more sense. With this option a fleet has to reduce its effort according to the proportion of its catch of an endangered species relative to the total international catch of that species. Thus, fleets with high impact on an endangered species should reduce their effort most.

3.2 Working Document 1 on Further Software Development

The SGRST reviewed a working document (WD) describing further software development to analyse and describe mixed fisheries and their effects on exploited stocks. The working document by Rätz et al. (2005) is accepted and in press. A summary of the main conclusions is given below:

Based on a case study of North Sea fisheries in 2004 the WD concludes that the geographical distribution patterns of the commercial landings of the 6 main target fish species cod, haddock, saithe, whiting, pliace and sole and Norway lobster ( Nephrops ) and the catch compositions of the different fleets (gear types) are inhomogeneous. Gadoids and Nephrops are mainly caught by demerals trawls in the northern North Sea while the flat fish fishery operates mainly in the southern North Sea. All demersal gears appear to be less frequently used in the central North Sea.

TAC regulations alone appear insufficient for a sustainable management of mixed fisheries, mainly because discards remain unregulated within the Common Fishery Policy (CFP) but affect negatively future catch potentials. Such discards occur in cases of ecological and economical conflicts in the short term fishing strategies of jointly caught stocks, which naturally do develop differently. Catches in excess of TACs, discarded or illegally landed contributed significantly to the failure of conservation measures in the recent past for cod and plaice.

Fleet based management is considered an effective and easily controllable tool to control fishing mortality through fleet specific effort in the case of mixed fisheries. Especially high discard rates and black market landings in excess of TACs can be avoided.

The fleet specific effects on the main commercially exploited demersal fish stocks in the North Sea in 2003 could be quantified on the basis of extensive data collations on board of fishing vessels. According to the sampling data, demersal trawls ≥100mm and beam trawls ≥80mm had the highest effect on the demersal fish stocks considered, especially on cod and plaice. Such results support the decisions of the Fishery Council regarding fishing possibilities since 2003, which limit the effort of such gear types most.

Fleet definitions are critical and should consider the technical properties (area, season, gear type and mesh size). The assessment of the fleet specific effects on the stocks should be based on the qualitative and quantitative catch composition including discards, due to the fact that discards have the same effect on the stock dynamics like landings.

A variety of numerical variations for fleet based management is conceivable. The catch of the fleets and the status of the stocks with regard to precautionary reference values of SSB and fishing mortality should be the main criteria when assessing fleet specific effects.

Given an appropriate fleet based management a substantial yield increase is attainable in short term in the case of the demersal mixed fisheries in the North Sea under the condition of compliance with precautionary management and recovery plans.

4 Area based analyses

4.1 Availability of fleet specific data

Data were called in the format as designed by the ICES Study Group on Fishery Based Forecasts (ICES 2004a) for 2003 and 2004. The exchange data formats are given in Appendix 2. Identical data calls were issued in preparation of the STECF-SGRST cod recovery meetings in 2005. Such data bases were corrected for data reports from UK-England and updated for data reports from Portugal and Spain.

Table 4.1 lists an overview on data submissions covering the various management areas North Sea and Skagerrak, Eastern Channel, Kattegat, Eastern and Western Baltic, West of Scotland, Irish Sea, Porcupine Bank, Celtic Sea, Bay of Biscay and around the Iberian Peninsula by country. Fleet specific discard data for cod were reported only by UK-Scotland, UK-England, Germany, Sweden, Latvia, and Denmark. Danish discard data, however, was provided in an inconsistent format but included in the analyses regarding the Kattegat. Dutch discard information covered sole and plaice but cod discards recorded were considered non-representative to allow raising to the landings of the fleets.

The reported catch compositions of the regulated gears or fishing metièrs including estimates of discards for the years 2003 and 2004 do not include unallocated catches.

4.2 Estimation of fleet specific international landings and discards

The estimation of fleet specific international landings and discards is based on linking the information about fleet specific discards and catch and discards at age among countries and replacing poor or lacking values with aggregated information from other countries.

Reported data by country are aggregated by fleet properties and raised to the officially reported landings or discards in the SGDFF 2004 format (ICES 2004a). Fleet definitions are based on area, year, quarter, gear and mesh size groups and national fisheries (metier) definitions.

The data management and estimation procedures follow the simple raising strategies outlined below :

- Data management:

The fleets are classified to their management areas, years, quarters and effort regulated gear groups disregarding the countries and fisheries (metiers).

- Estimation of discard rates by fleet ([pic]):

Let the following notation be : D=discards, L= landings, snf = sampled national fleet, unf = unsampled or poorly sampled national fleet.

A poorly sampled fleet is defined as such when [pic]or [pic]

The available landings and discards are aggregated (summed) by fleets and mean discard rates are calculated:

[pic] with [pic]and with [pic] otherwise 0 (means no catch)

Fleet specific discard amounts are calculated when no discard information is available by

[pic] when [pic] is null (empty)

Fleets without any discards information remain as such.

Table 4.1 Data basis on fleets’ specific landings and discard data, also at age by nation, 2003-2004 for the various management areas North Sea and Skagerrak, Eastern Channel, Kattegat, Eastern and Western Baltic, West of Scotland, Irish Sea, Porcupine Bank, Celtic Sea, Bay of Biscay and around the Iberian Peninsula.

Cod 4, 7d and 3a | Reduced reproductive capacity | Uncertain | Overexploited | no |

Haddock 4 and 3a | Full reproductive capacity | Harvested sustainably | Close to target | yes |

Whiting 4 and 7d | unknown | unknown | unknown | no |

Saithe 4, 3a and 6 | Full reproductive capacity | Harvested sustainably | Appropriate | yes |

Plaice 4 | At risk of reduced reproductive capacity | Harvested sustainably | Overexploited | yes |

Sole 4 | Full reproductive capacity | Harvested unsustainably | Overexploited | yes |

Nephrops 3a and 4 | Unknown | Unknown | Unknown | no |

- [pic]

Fig. 4.3.1 Landings and discards by regulated gears and by species in the North Sea and Skagerrak in 2003 and 2004.

[pic]

Fig. 4.3.1 continued. Landings and discards by regulated gears and by species in the North Sea and Skagerrak in 2003 and 2004.

[pic]

Fig. 4.3.2 Cod landings and discards at age caught by demersal trawls ≥100mm and 70-99mm in the North Sea and Skagerrak in 2004.

[pic]

Fig. 4.3.3 Haddock landings and discards at age caught by demersal trawls ≥100mm and 70-99mm in the North Sea and Skagerrak in 2004.

[pic]

Fig. 4.3.4 Whiting landings and discards at age caught by demersal trawls ≥100mm and 70-99mm in the North Sea and Skagerrak in 2004.

[pic]

Fig. 4.3.5 Plaice landings and discards at age caught by demersal trawls ≥100mm and 70-99mm and beam trawls ≥80mm in the North Sea and Skagerrak in 2004.

[pic]

Fig. 4.3.6 Sole landings and discards at age caught by beam trawls ≥80mm in the North Sea and Skagerrak in 2004.

4.3.3 Mixed fisheries analyses

Owing to the lack of accepted assessments and concerns that the mixed fishery database is considered to have inadequate coverage of discards, the following analyses are presented in terms of sensitivity analyses to investigate the effect of some aspects of uncertainty in the input data. They are not in any way intended as viable or realistic options for management purposes.

4.3.3.1 Exploratory MTAC runs

4.3.3.1.1 MTAC settings and analyses

The group received no requests from the Commission specifying the settings for the MTAC runs. The Group decided on the settings according to ToRs 3 and 4. The p- and q-options were set at p=2 and q=1 (see Appendix 3), as was requested by the Commission last year; also note in section 2.1 that the optional setting p=1 is inappropriate.

The MTAC analyses include cod, plaice, sole, haddock, saithe and Nephrops . With p=2 it is not necessary to include data on species that are not targeted and for which no analytical assessment exists, such as Norway pout, sandeel, and whiting. The targeted Nephrops fishery should be included in order to influence the fleet factors and the MS-TACs of the main species. However, since no analytical assessment of Nephrops exists, MTAC will not provide advice on the MS-TAC of Nephrops .

The F-multipliers were set with regards to ToR 3 according to the ACFM advice; the rationale for their choice is presented in Table 4.3.3.1.1.

With regards to ToR 3, the Group decided to set a high decision weight on cod (80), a four times lower one on plaice (20), and very low decision weights (0.1) on the other species, thus reflecting the high importance given to cod recovery and to keeping plaice within safe biological limits.

Table 4.3.3.1.1 Rationale for the choice of F-multipliers, and decision weights.

Species | Target F-multiplier | Rationale (based on ACFM advice) | Decision weight |

Cod | See Table 4.3.3.1.2 | See Table 4.3.3.1.2. | 80 |

Plaice | 0.68 | F expected to rebuild SSB to the proposed Bpa in 2007 | 20 |

Haddock | 0.95 | Agreed management plan setting F in 2006 to 0.3 | 0.1 |

Saithe | 1.48 | F < Fpa | 0.1 |

Sole | 0.86 | F expected to lead to SSB of Bpa in 2007 | 0.1 |

Nephrops | 1 | No increase in effort | 0.1 |

With regards to ToR 3, the input data for the MTAC analyses (population numbers and fishing mortalities) were taken from the respective assessments and short term forecasts accepted by ICES as far as they exist. For Nephrops dummy data were used to ensure that the relative catch compositions for Nephrops were included in the calculations. A range of dummy population data were tested for Nephrops and as expected, the exact values used have no bearing on the outcome of the model.

ACFM considered the exploitation rate of the North Sea cod stock to be highly uncertain due to concerns regarding the catch data and inconsistencies in the surveys in 2005. The relative size of the stock (i.e. close to the lowest observed) was fairly consistent between various model runs. ACFM was therefore unable to accept any one analytical assessment and consequently did not perform the short term forecasts required as input to the MTAC model.

In order to evaluate this uncertainty in terms of potential mixed fishery advice the Group used the results of one of the assessments presented to ACFM, however THIS DECISION SHOULD NOT BE TAKEN AS AN ENDORSEMENT OF THIS PARTICULAR ASSESSMENT AND THE INPUT VALUES AND RESULTS MUST BE VIEWED AS PURELY ARBITRARY .

The B-ADAPT model (Darby, 2004) uses survey data to project removals from the stock over the terminal years, thus the resulting F actually represents the reported landings and discards plus any additional unallocated mortality. This additional mortality could come from a variety of sources including natural mortality (predation, disease and senescence), fishing activity (missing discard estimates, misreporting of landings, mortality induced by escape from fishing gear) or other sources such as ghost fishing from discarded/lost gear. There are no data to elucidate which additional mortality source is the more likely and therefore two scenarios are presented, one assuming that the unallocated mortality is independent from fishery management decisions and the other assuming that adjustments to the fishing effort has a direct effect upon unallocated mortality. In this case the unallocated mortality is distributed amongst the fleets in proportional to the cod catch of each fleet.

In order to get from the terminal population and mortality estimates to input values for MTAC (stock numbers at age 1st Jan 2006), an intermediate year forecast was performed on the terminal population (2005) numbers. The selection pattern for projection was the average of the previous 3 years of mortality. The exception to this was fishing mortality at age 4 which was determined as the mean value for 2002 & 2003 because of the concerns regarding the exceptionally high value for 2004. Two values of F were considered, the unscaled 3-year mean and a 40% reduction from the 2001 estimate. This second value investigated the assumption that the reduction in effort of the main whitefish fleets (working paper to cod recovery meeting) has lead to a reduction in F. Recruitment at age 1 in 2005 was assumed to be the short term geometric mean (1998-2002). Due to the truncated age structure of North Sea cod, the relatively high total mortality and early maturation, the recruitment at age 1 in 2006 will be influential upon the level of SSB in 2007. Three recruitment values for 2006 were investigated,

1. the continuation of the current run of low recruitments – geometric mean (1998-2002).

2. long term geometric mean (1983-2002)

3. a relatively strong recruitment at the level of that seen in 1997.

MTAC also requires either a TAC or an F-multiplier as indicated by single species advice. The joint EU-Norway management plan states that fishing mortality should be adjusted such that SSB will rise by 30% per year. To this end F-multipliers were determined for each recruitment scenario that permitted a 30% increase in SSB from 2006 to 2007. ICES advice for North Sea cod in 2006 is for a TAC of 0, hence an F-multiplier of 0 was imposed using the long term geometric mean recruitment at age 1 in 2006 (arbitrarily chosen).

For each scenario governing recruitment, intermediate year F and the 0 TAC scenario we investigated the effect of assumptions for the source of unallocated mortality. For those scenarios assuming that the unallocated mortality is independent of fishery management, the unallocated portion of mortality was added to M (natural mortality) instead of being part of fishing mortality.

In total there were 16 scenarios defined in the following table (Table 4.3.3.1.2).

Table 4.3.3.1.2. Definition of scenarios and according variations of cod stock parameters used for the North Sea MTAC exploratory runs.

Run | Location of unallocated mortality | Recruitment in 2006 | F-multiplier for 2006 and rationale | F 2005 |

1 | F | Short term GM (“low”) | 0.66 (EU-Norway) | Fsq |

2 | F | Long term GM (“medium”) | 0.75 (EU-Norway) | Fsq |

3 | F | 1996 yearclass (“high”) | 0.85 (EU-Norway) | Fsq |

4 | M | Short term GM (“low”) | 0.54 (EU-Norway) | Fsq |

5 | M | Long term GM (“medium”) | 0.68 (EU-Norway) | Fsq |

6 | M | 1996 yearclass (“high”) | 0.83 (EU-Norway) | Fsq |

7 | F | Long term GM (“medium”) | 0 (ICES ADVICE) | Fsq |

8 | M | Long term GM (“medium”) | 0 (ICES ADVICE) | Fsq |

9 | F | Short term GM (“low”) | 0.66 (EU-Norway) | 0.6* F2001 |

10 | F | Long term GM (“medium”) | 0.75 (EU-Norway) | 0.6* F2001 |

11 | F | 1996 yearclass (“high”) | 0.85 (EU-Norway) | 0.6* F2001 |

12 | M | Short term GM (“low”) | 0.54 (EU-Norway) | 0.6* F2001 |

13 | M | Long term GM (“medium”) | 0.68 (EU-Norway) | 0.6* F2001 |

14 | M | 1996 yearclass (“high”) | 0.83 (EU-Norway) | 0.6* F2001 |

15 | F | Long term GM (“medium”) | 0 (ICES ADVICE) | 0.6* F2001 |

16 | M | Long term GM (“medium”) | 0 (ICES ADVICE) | 0.6* F2001 |

The catch compositions of the fleets are based on data from 2003 and 2004 (see section 4.3.1).

The results for the MTAC runs from scenarios 1-8 are displayed in Figures 4.3.3.1.1 and 4.3.3.1.3. Scenarios 9-16 are shown in Figures 4.3.3.1.2 and 4.3.3.1.4. A summary plot of the fleet effort factors for all 16 scenarios is given in Figure 4.3.3.1.5.

In all scenarios with a non-zero F-multiplier for cod (scenarios 1-6 & 9-14), the DemTrawl_16-31 fleet can continue fishing with status quo effort. For this fleet the database contained almost no cod catches. The Longline fleet and the fleets categorized under “Others” have only minor adjustments to their effort. The DemTrawl_70-99 and static fleets have to reduce effort to 80-95% of its current level. Greater reductions, to 45-95% of the current level, are required from the Beam≥80 and DemTrawl≥100 fleets; these fleets catch plaice and cod respectively, the species that need restriction and had received high decision weight. With the F-multiplier for cod = 0 (scenarios 7 and 8), only the Longline fishery has to be closed completely and all other fleets have to reduce to less than 50% of the current level.

Under the assumption of lower cod recruitment, effort restrictions needs to be greater than when at recruitment is at higher levels. When fewer recruits come in at the start of 2006, fishing needs to be restricted more in order to reach the goal of a 30% increase in SSB over the TAC-year, that is from 2006 to 2007. Some of the recruits of 2006 will be mature and contribute to SSB in 2007.

Under the assumption that the unaccounted mortality is independent of fishery management (scenarios 4-6, 8, 12-14 & 16), greater effort reductions are needed than under the assumption that the unaccounted mortality is associated with fishing (scenarios 1-3 and 7). The assumption about the unaccounted mortality has no observable influence when the cod F-multiplier = 0.

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Figure 4.3.3.1.1. The fleet factors from scenarios 1-8.

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Figure 4.3.3.1.2. The fleet factors from scenarios 9-16.

In all scenarios with a non-zero F-multiplier on cod (scenarios 1-6 & 9-14), the targets for cod and plaice are approached quite closely, and this is due to the high decision weights given to these species. The targets for sole and haddock are undershot in all scenarios. The target of the only species with an F-multiplier > 1, implying that fishing for this species is allowed to increase, saithe, is heavily undershot; the severe effort restrictions needed for cod and plaice leads to missed fishing opportunities for saithe. With the cod F-multiplier = 0 (scenarios 7, 8, 15 & 16), the targets of all other species are severely undershot whilst the ratio MS_TAC/SS_TAC cannot be calculated for cod in this scenario because the SS_TAC = 0.

For all species except cod, the assumption of lower cod recruitment results in lower MS_TAC/SS_TAC ratios – i.e. the implied SS TAC is undershot. For cod the MS_TAC/SS_TAC ratio is close to one although the exact pattern requires further explanation. Under the assumption of low recruitment the SS target F-multiplier is lower and therefore the resulting MS F-multiplier is more likely to be slightly higher. Conversely, when the SS target is not so stringent (i.e. higher cod recruitment), under-shooting the SS target is more likely given the stringent effort restriction required for plaice.

For all species except cod, the assumption that the unallocated mortality is independent of fisheries management (scenarios 4-6, 8, 12-14 and 16) leads to lower MS_TAC/SS_TAC ratios. As was explained above, under the assumption that this mortality is independent of fishery management, more severe restrictions are necessary, leading to lower exploitation of the other species. For cod, it is more difficult to reach these lower targets when the other species are pulling the compromise towards higher effort.

The effect of a lower intermediate year F (scenarios 9-16) implies less restrictive fleet effort factors for the demersal trawls, particularly when recruitment in 2006 is assumed to be high. There is less influence of the intermediate year F on the fleet effort factors for beam trawling, and no effect when the desired F-multiplier is zero (scenarios 15 & 16).

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Figure 4.3.3.1.3. The ratios MS_TAC/SS_TAC (reflecting how well the target is approached, see Annex 3) under scenarios 1-8. Where F-mult cod=0, not ratio can be displayed because the SS_TAC = 0.

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Figure 4.3.3.1.4. The ratios MS_TAC/SS_TAC (reflecting how well the target is approached, see Annex 3) under scenarios 9-16. Where F-mult cod=0, not ratio can be displayed because the SS_TAC = 0.

From Figure 4.3.3.1.5 it can be seen that even the limited uncertainty explored in this years MTAC runs, namely uncertainty in the intermediate year F and the nature of unallocated mortality, gives rise to a huge variation in fleet effort factors for the demersal trawl >=100mm.

The scenario of medium cod recruitment and unallocated mortality in F (scenario 2) was run also with 0 decision weight on Nephrops (instead of 0.1). Only the fleet factor of the fleet that targets Nephrops changed and then to a hardly discernible extent; all others stayed the same. The lack of effect can be explained because the target for Nephrops is quite neutral: the F-multiplier was set to 1, so no change is required. Also, the decision weight on Nephrops was already low in the first place.

4.3.3.1.2 Conclusions on the MTAC simulations

As stated before, there is considerable concern regarding incomplete discard data going into the fleet catch composition database, changes to this would undoubtedly affect the fleet effort multipliers. The limited range of uncertainties investigated surrounding the state of the cod stock demonstrates that the management implications are diverse. The management action required to abide with the EU-Norway agreement is therefore highly uncertain.

Attempting to balance the ICES advice of 0-TAC for cod and a 0.68 F-multiplier for plaice is unaffected by the uncertainty in the cod assessment and would involve stringent cuts in effort across the board. Such general effort cuts would imply major deviations from the maximum fishing possibilities as advised by ICES for the other species. The precise level of the fleet effort factors will be conditional upon the input database and are therefore subject to the uncertainty. The MTAC output for the 0-cod catch scenarios are therefore only qualitative and must not be used as justification for exact advice.

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Figure 4.3.3.1.5. The range of MTAC fleet factors, by fleet for the 16 scenarios. Filled points are for those scenarios where North Sea cod SSB in 2007 was constrained to be 30% higher than in 2006. Open circles are those scenarios where the input F multiplier for North Sea cod was 0 (ICES advice for 2006).

4.3.3.2 Exploratory SMP mixed fisheries simulations for the North Sea

Exploratory runs of the further developed SMP model (section 2.2, WD 1) were run in order to evaluate appropriate fleet effort changes taking into account the precautionary management references in minimum SSB and maximum fishing mortality for the 5 main demersal species, cod, haddock, saithe, plaice and sole.

4.3.3.2.1 SMP settings and analyses

The SMP model formulations are based on the estimated catch including discards for the 7 fleets described in section 4.3.1 and the most recent analytical forecast inputs as used by ICES for haddock, saithe, plaice and sole. For cod, the inputs of starting populations are those adopted in the MTAC scenarios (Darby, 2004) and described in section 4.3.3.1.1. Natural mortality M is raised in order to account for unallocated removals resulting in rather low fishing mortality F and the short term geometric mean represents rather low recruitment. Fishing in 2005 is assumed at status quo level. The Bpa and Fpa used as constraining management boundaries until 2007 correspond to management references for haddock and saithe as stipulated in the EU-Norway agreement in 2004. For plaice and cod ICES PA references or the recovery plan were applied, respectively. As the model allows a choice to which degree the fleet management is implemented, 2 scenarios were estimated to simulate no versus full fleet based management.

The results confirm that both managements scenarios of no and full implemented fleet management could achieve the management goals being constrained by the maximum allowed fishing mortalities and minimum SSB by species. The differences in the scenarios indicate that all fleets would have to reduce their effort to about 60 % under the assumption of no fleet specific management (Fig. 4.3.3.2.1-3). The fleet specific calculations resulted in reductions to about 40-60% of the main catching gears, i.e. beam ≥80mm, demersal trawls ≥100mm and demersal trawls 70-99mm and static gears (Fig.4.3.3.2.1-3). All these gears are indicated to contribute significantly to the catch of the reduced cod and plaice stocks. Only the highly selective gears of demersal trawls 16-31mm, longlines and the category of others, which are indicated having only a little effect on cod and plaice, can increase their efforts. However, such general effort cuts of the main catching gears under both scenarios would imply major deviations from the fishing possibilities advised under precautious single species boundaries (Fig. 4.3.3.2.4). The fleet definitions thus appear too poorly defined to generate scope for increased catches of other underexploited species through fleet specific management.

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Fig. 4.3.3.2.1 Change in fleet specific effort in 2005 relative to 2005 for 7 fleets under no and full fleet specific management scenarios.

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Fig. 4.3.3.2.2 Trends in SSBs by species in 2005-2007 by species under no and full fleet specific management scenarios.

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Fig. 4.3.3.2.3 Trends in reference Fs by species in 2005-2006 under no and full fleet specific management scenarios.

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Fig. 4.3.3.2.4 Trends in catches including discards by species in 2005-2006 under no and full fleet specific management scenarios.

4.3.3.2.2 Conclusions on SMP simulations

The fleet specific calculations resulted in general reductions to about 40-60% of the main catching gears, i.e. beam ≥80mm, demersal trawls ≥100mm and demersal trawls 70-99mm and static gears, regardless of the fleet specific management being implemented or not. Such general effort cuts of the main catching gears would imply major deviations from the fishing possibilities advised under precautious single species boundaries. The fleets thus appear too poorly defined to generate scope for increased catches of other species through fleet specific management. The results of the SMP model runs are quite consistent with results from the MTAC runs.

4.4 Eastern Channel (ICES Division VIId)

4.4.1 Fleet overview and specific data

Total landings by fleet were made available for cod, haddock, whiting, saithe, sole and plaice in 2003 and 2004. Regarding discards, data were collected in 2003 and 2004 on board vessels belonging to the two most important French fleets (demersal trawlers 70-99 mm and netters). However, figures could not be raised to the overall fishery, and discard information could not be used by the Group.

Demersal trawlers 70-99 mm

This fleet segment is the most important in the Eastern Channel. Demersal trawlers operate both in the Eastern Channel and the Southern part of the North Sea. In the Eastern Channel, this fleet may use a minimal mesh size of 80 mm when fishing for whiting (Council Reg. (EC) 850/98). Whiting is the main target species of that fleet in landings weight. However, valuable species are targeted in specific seasons (cephalopods in the third quarter, red mullet in the fourth quarter), while sea bass landings appear to have increased in recent years. Other by-catches include red gurnard, common pout and cod. Figure 4.4.1 shows a decrease in cod landings between 2003 and 2004. In 2004, cod landings represented less than 6% of the total landings.

Netters

Trammel nets and similar bottom nets are the main fixed gears used to catch flatfish, with sole being the target. Other fixed gears are gill nets made up of one single panel (as opposed to three for trammel nets). These nets may have different mesh sizes and heights depending on their target species (e.g. 90 mm mesh and 1 m height for sole, 100 mm mesh and 3 m height for cod). Figure 4.4.2 shows the landings composition in two types of French gillnet fisheries in the Eastern Channel. One gillnet fishery is directed at sole, plaice and cod, although cod contributed less than 7% in weight. In this fishery, total landings have slightly increased between 2000 and 2003 and decreased in 2004. On average, 90 t of cod were landed from this fishery over 2000-2003, while only 28 t were landed in 2004. For the other gillnet fishery the proportion of cod in landings was on average 30% over the period 2000-2003, and then decreased down to 8% in 2004.

Other commercial fleets and fisheries

The other commercial fisheries have a more limited activity in the Eastern Channel. Of particular interest are the dredgers targeting valuable scallops in the middle and Southern Eastern Channel from October to May. Beam trawlers using a mesh size above 80 mm mainly target sole, plaice and turbot. Large Dutch and Belgian twin trawlers fish mainly in the North Sea. They are fishing in the Eastern Channel occasionally (January/February) to catch sole. Smaller French boats (mean length of 14 m) work with a single beam to target sole and plaice in spring and winter. As described in Figure 4.4.1 landings are mainly composed of sole and plaice. In 2003 and 2004, cod catches represented less than 2% of the total catch. Demersal trawlers using a mesh size of 16-31mm target predominantly shrimps and only a small number of boats are involved in this fishery. In order to reduce by-catches of juvenile flatfish, a selective gear (Asselin type) has been used since 2002. By-catches of cod and flatfish are small.

Recreational fishery

This fishery is considered important in the Eastern Channel. A survey has been conducted in 2003 and 2004 to evaluate the quantities of sea bass landed by French sports fishermen. The results of that survey indicated that recreational landings of bass were around 4,000 t for the Atlantic and Channel. A similar survey will be conducted in 2006 to evaluate the impact of recreational fishing on cod landings in the Channel and the Celtic Sea.

Conclusions

The landings figures presented are inappropriate to describe recent gear specific catch at age compositions. No age compositions of the landings or discards were made available. The majority of cod landings is taken by the demersal trawls 70-99mm. A decrease of the cod proportion in landings is observed for all fleets between 2003 and 2004, the fleets appear to have redirected their activity towards other species (e.g. red mullet, bass, cephalopods for trawlers, sole for netters). The impact of the recreational fishery on cod landings is to be investigated.

4.4.2 Assessment data overview

Most of the stocks in the Eastern Channel are defined and assessed together with other ICES divisions.

4.4.3 Mixed fisheries analyses

Both the lack of stock specific forecast inputs on stock size and exploitation rates and considerable concern regarding incomplete fleet specific catch data including discards prevented analytical mixed fisheries forecasts.

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Fig. 4.4.1. Landings by fleet and by species in the Eastern Channel in 2003 and 2004.

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Fig. 4.4.1 continued. Landings by fleet and by species in the Eastern Channel in 2003 and 2004.

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Fig. 4.4.2. Landings composition by 2 different French gill net fisheries in the Eastern Channel over 2000-2004.

4.5 Kattegat (ICES Division IIIas)

4.5.1 Fleet overview and specific data

The four main demersal species in Kattegat are Cod, Plaice, Sole and Nephrops . These species were evaluated as candidates for the MTAC analysis.

Catch data were submitted for Kattegat and for Skagerak separately for all four species. Denmark submitted data for all 4 species whereas Sweden submitted data for cod and plaice. In addition Denmark delivered data for monkfish, herring, hake, mackerel, and whiting.

Discard data by fleet and age were delivered by Sweden only, whereas Denmark could deliver only the total weight of discards for all fleets combined. Only Sweden delivered discard data in SGDFF-format.

Gear category beam ≥80 mm

This fleet category is not present in the Kattegat.

Gear category demersal trawl ≥100mm

The demersal trawl ≥100mm is not an important fleet category in the Kattegat. The main fleet segment targeting roundfish and flatfish is the >=90 mm and hence, the majority of fish was caught in the 70-99mm category (see below). The small fleet using demersal trawl ≥100mm mainly target cod and plaice (Fig. 4.5.1)

Gear category demersal trawl 16-31mm

Catches of demersal species by this fleet constitute bycatch in the industrial fisheries. These are small, and discarding is negligible as all catches go for reduction.

Gear category demersal trawl 70-99 mm

The demersal trawl segment 70-99mm was the main fishing segment in a mixed fish and Nephrops fishery. Trawls with a mesh size>90mm has no minimum target species composition and trawls larger than 90mm are considered as fish trawls. The 70-89 mm fishery can operate with only 30% Nephrops on board. The main target species for this fleet segment are Nephrops , cod, plaice and sole. The gear category as a whole is effectively a mixed Nephrops /fish fishery, though individual fishing operations can target particular species quite effectively. In addition to the more specialized Nephrops vessels, the segment also includes vessels fishing with a mesh size of 90mm or more for plaice and cod. The latest scientific advice on the Nephrops stocks suggests that the stocks were exploited at sustainable levels. Unofficial information indicates substantial landings in excess of those officially reported in recent years. No demersal fish stock in this area allows a potential increase in catches. It is noteworthy that since 2005 the 70-89mm fishery must use a species selective grid in order to minimize cod catches when targeting Nephrops . This segment is allowed 21 days at sea while the 90 mm fishery is allowed 9 days at sea (the same rules applies for Skagerrak). The sampling programmes of commercial catches reveal that these small meshed trawl fisheries have a diverse catch composition with large proportions of Nephrops , cod and plaice. Substantial discard rates in weight (Tab. 4.5.1 and Fig. 4.5.1) are indicated for cod (~40%), plaice (~70%), and Nephrops (35-50%). The minimum landing size for Nephrops in Kattegat and Skagerrak is 40mm carapace length in comparison with 25mm carapace length in North Sea, which explains the higher discard proportions of Nephrops in this area. Observations of discarding of sole indicate discard rates of between 15 and 20%. High discard rates of haddock, whiting and saithe were observed during some sampling trips, often with 95-100% of the catch being discarded. However, the quantities involved were small, and landings of these species from the area are very low (Fig. 4.5.1). No attempt has been made to estimate discards of these species as this would require a different approach to raising the samples than using total landings of the species. Discards of cod are mainly 1 and 2 year olds while for plaice 1-3 year old are discarded. Discard estimates are only available for this fishery (Fig. 4.5.2).

Gear category demersal longline

This gear could target almost all species in a highly selective pattern, but is used mainly to catch round fish. The database on catches including discards indicates this gear category as targeting the round fish species, but with insignificant landings and there is no effort information available.

Gear category static including gill nets, trammel nets and tangle nets

This group covers a variety of fisheries, including cod and plaice-directed gill net fisheries and smaller-meshed trammel nets directed at sole. The compilation of national landings data reveals that static gears catch cod, sole, and plaice with very low discard rates (Table 4.5.1 and Fig. 4.5.1). Discard sampling of Danish gillnetters was stopped in 2001 as observed discard rates for this fleet were consistently very low.

Gear category other

The gear category “other” is not effort regulated and data is probably not provided in a consistent way to be linked to the regulated gear types (mesh size information missing). It covers a variety of gears, mainly demersal trawls. Pelagic trawls are not considered at all. The main demersal target species are cod, plaice, sole and Nephrops. However, no information is available on discards (Table 4.5.1 and Fig. 4.5.1).

Conclusions

Recent discard sampling in the Kattegat has mainly been confined to the principle demersal gear, which is demersal trawls using 70-99mm mesh size. The catch compositions of this gear, including discards, appears fairly consistent over the years 2003 and 2004. The majority of cod and plaice in the Kattegat were caught in the 70-99mm category, even though the small fleet using demersal trawl ≥100mm also target cod and plaice. The discard rates for cod, plaice and Nephrops were relatively high compared to other areas. The discard rates presented here represent the first attempt to use discard data from the Kattegat in an advisory context. As such the results should be treated with great caution.

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Fig. 4.5.1 Landings and discards by regulated gears and by species in the Kattegat in 2003 and 2004.

Table 4.5.1 Landings (t) and discard rates in the Kattegat by species and gears (no pelagic trawls) in 2003 and 2004.

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Fig. 4.5.2 Kattegatt in 2004. Landings and discards for cod and plaice at age for whiting by the regulated gear demersal trawl 70-99mm.

4.5.2 Assessment data overview

The two flatfish species are not assessed for Kattegat separately, but only for the total area IIIa. The Nephrops has not been assessed. Thus only the cod has been assessed for Kategat in isolation. Table 4.5.2 summarises the assessments made in 2004-5 of cod, plaice, sole, Nephrops in Kattegat.

Table 4.5.2 State of the stocks and availability of analytical forecasts as estimated by ICES (2006b).

Stock | Spawning biomass in relation to precautionary limits | Fishing mortality in relation to precautionary limits | Fishing mortality in relation to target reference points | Analytical forecast available |

Cod in Kattegat | Reduced reproductive capacity | Harvested unsustainably | Over-exploited | yes |

Plaice in IIIa | Full reproductive capacity | At risk of being harvested unsustainably | Over-fished | yes |

Sole in IIIa | Full reproductive capacity | Harvested sustainbly | Over-fished | yes |

Nephrops in Kattegat (FU 4) | exploited at sustainable levels. | no |

4.5.3 Mixed fisheries analyses

SGRST considers the MTAC analysis problematic in the case of Kattegat for the following 2 reasons:

1) Plaice and sole are assessed for the IIIa (Skagerak + Kattegat) management area.

2) Nephrops is not analytically assessed.

The group concluded that an analysis of Kattegat by MTAC would be inappropriate due to the mismatch between the areas within the main target stocks are defined and assessed.

4.6 West of Scotland (ICES Division VIa)

4.6.1 Fleet overview and specific data

The demersal fisheries in the waters to the west of Scotland are dominated by otter trawl fisheries exploiting cod, haddock, whiting, saithe, Nephrops , anglerfish, megrim, hake and deepwater species.

The majority of the vessels in the demersal fishery are locally-based Scottish trawlers using ‘light-trawls’ (otter trawlers >27.4m, 90 feet), but trawlers from Ireland, Northern Ireland, England, France, and Germany also participate in this fishery. Scottish trawlers also take part in fisheries for Nephrops on inshore grounds, and in recent years Irish vessels have also been targeting Nephrops , mainly on offshore grounds.

A brief description of the catch composition for each of the regulated gears is provided for 2004, as complied by SGRST. The sampling includes coverage of Scottish vessels. Of the regulated gears, only demersal trawls in the ≥100mm and 70-99mm gear categories are sampled regularly. It should be noted that for the main demersal species the procedures applied by the SGRST produce generally higher estimates of discards (% of catch by weight) for Division VIa than those reported by the ICES working group for the Northern Shelf Demersal Stocks (ICES, 2005a).

Beam trawl ≥80mm

A small number of beam trawlers, including UK registered and Irish vessels, fish in shelf waters west of Scotland. Landings in 2004, comprising plaice, cod, haddock and saithe, were small relative to those reported for other gear categories (Tab. 4.6.1 and Fig. 4.6.1). No information on discards is available.

Demersal trawl ≥100mm

Vessels in this category include otter trawlers fishing on the shelf to the west of Scotland for roundfish (cod, haddock and whiting) with bycatches of anglerfish, saithe and flatfish and otter trawlers which fish further offshore targeting mainly saithe, anglerfish and / or deep water species.

The catch of this gear category comprises predominantly haddock and saithe with whiting and cod being caught in lesser amounts (Tab. 4.6.1 and Fig. 4.6.1). Although relatively small amounts of cod are caught in this fishery, compared to other species, this gear category appears to account for the majority of the cod catch in Division VIa. discarding mainly at cod at age 1 (Fig. 4.6.2).

A Spanish Bottom Otter Trawl fleet operating in Subarea VI targets Blue Ling, Witch Hake and Anglerfish. Discard data is available and catch are composied of blue ling (23%), witch (20%) and Scorpion fishes (12%). The rest of the catch is made of anglerfish (11%), Great Fork beard (9%), Hake (8%), Megrim (7%) and Ling (4%). Around 20 commercial species are caught in this fishery.

Demersal trawl 16-31mm

No landings were reported in 2004 for this gear category.

Demersal trawl 70-99mm

This gear category includes Scottish trawlers fishing for Nephrops on inshore grounds and also Scottish and Irish trawlers targeting Nephrops further offshore at the Stanton Bank. Landings are predominantly Nephrops (discard data not available in appropriate format) but small quantities of haddock, whiting and cod are also caught (Tab. 4.6.1 and Fig. 4.6.1). The gear category appears to discard cod at age 1 in a similar magnitude as the demersal trawl ≥100mm (Fig. 4.6.2). Haddock and whiting are also discarded at young ages in high numbers but at a lesser extent compared to the demersal trawl ≥100mm (Fig. 4.6.3-4).

Demersal longline

A small demersal longline fishery is located offshore, probably associated with the shelf edge. Landings of the main demersal species for this gear are very low, less than 10 tonnes in total for cod, haddock and saithe combined (Tab. 4.6.1 and Fig. 4.6.1). No information on discards is available. A Spanish longline fishery also exists in this area, targeting hake (around 85% of landings), but also taking ling, blueling, monkfish and congers.

Static gears

Gears in this category will include gillnets on the continental slopes to the west of Scotland and other fixed and trammel nets. Landings reported by species for this gear in 2004 comprised cod (<1 t) and anglerfish (ca. 40 t). No information on discards is available.

Other

This gear category ‘other’ represents landings for gears which are not effort regulated or landings which were reported to SGRST but not disaggregated according to regulated gear category. For west of Scotland most of the landings in the ‘other’ category fall into the later group. The catch composition, comprising a mixture of Nephrops and haddock is consistent with those of demersal trawlers in the ≥ 100mm and the 70-99mm category (Tab. 4.6.1 and Fig. 4.6.1).

Conclusion

The fisheries on the West of Scotland are dominated by the 70-99 and ≥ 100mm demersal trawler gear categories, targeting Nephrops and roundfish, respectively. Observed discard rates vary considerably, but data are not available for all fleets or fisheries.

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Fig. 4.6.1 Landings and discards West of Scotland by regulated gears and by species in 2004.

Tab. 4.6.1 Landings and discards (t) and discard rates West of Scotland by species and gears (no pelagic trawls) in 2003 and 2004.

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Fig. 4.6.2 West of Scotland. 2004 landings and discards at age for cod by the regulated gears demersal trawl≥100mm and 70-99mm and other gears.

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Fig. 4.6.3 West of Scotland. 2004 landings and discards at age for cod by the regulated gears demersal trawl≥100mm and 70-99mm and other gears.

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Fig. 4.6.4 West of Scotland. Landings and discards (D) at age for whiting by the regulated gears demersal trawl≥100mm, 16-31mm and 70-99mm and other gears.

4.6.2 Assessment data overview

The October 2005 ICES advice with regard to single-species exploitation boundaries for the principle demersal stocks in ICES Division VIa is summarised in the Table 4.6.2 below.

Table 4.6.2 State of the stocks and availability of analytical forecasts as estimated by ICES (2006b).

Stock | Spawning biomass in relation to precautionary limits | Fishing mortality in relation to precautionary limits | Fishing mortality in relation to target reference points | Analytical forecast available |

Cod Via | Reduced reproductive capacity | Unknown | Unknown | no |

Haddock Via | Harvested sustainably | Overexploited | Not defined | yes |

Whiting Via | Unknown | Unknown | Not defined | no |

Nephrops in Division Via | Unknown | Unknown | Unknown | no |

4.6.3 Mixed fisheries analyses

ICES is not in a position to give quantitative forecasts for many of the above stocks, and it is therefore not appropriate to undertake mixed species analysis.

4.7 Irish Sea (ICES Division VIIa)

4.7.1 Fleet overview and specific data

No fleet specific catch data including discards were available.

Demersal stocks in the Irish Sea are fished mainly by fleets from Northern Ireland, England & Wales, Ireland and Belgium. Some vessels from Scotland fish in the northern Irish Sea whilst some French vessels fish in the southern Irish Sea. The main fleet sectors are the Nephrops fleets using 70-80mm single or twin otter trawls, whitefish trawlers using 100-120mm mesh otter and mid-water trawls and seine nets, and beam trawlers using 80mm mesh. Small landings are recorded for pair-trawlers and fixed gears such as gill nets, tangle nets and long-lines. A more detailed description is given in the ACFM report (ICES, 2006b), ICES (2005a) and also STECF (2003 and 2004).

Fisheries interactions in the Irish Sea have been described by ACFM (ICES, 2006b) as follows:

“Demersal fisheries in the area are mixed fisheries, with many stocks exploited together in various combinations in different fisheries. Four main fishery units can be described in the Irish Sea: these are Nephrops otter trawlers, roundfish otter trawlers, semi-pelagic trawlers, and beam trawlers.

Possibly the strongest mixed fishery interaction in the Irish Sea is between the Nephrops fishery and the whiting stock, although discard estimates for fleets targeting Nephrops are incomplete and are considered imprecise. The use of square mesh panels for vessels targeting Nephrops with 70-mm cod-end mesh have been obligatory since 1994. Despite this technical conservation measure the proportion of small whiting caught and discarded in this fishery has continued to increase. ICES points out that in addition to effort restrictions further technical measures (e.g. increased cod-end and square mesh panel mesh sizes, separator panels, and fixed grids) should be investigated and may substantially reduce bycatch and discarding of whiting in this Nephrops fishery. The measures implemented do not seem to have improved the selection pattern in the fishery or the overall status of the stock. This implies that a more radical re-design of Nephrops trawls or the introduction of other fishing technologies (e.g. pot fisheries) to reduce whiting bycatch to the lowest possible level is required.

The cod fishery was traditionally carried out by otter trawlers targeting spawning cod in spring and juvenile cod in autumn and winter. Activities of these vessels have decreased, whilst a fishery for cod and haddock using large pelagic trawls increased substantially during the 1990s. Cod are also taken as a bycatch in the Nephrops -directed fishery. Although discard estimates for cod in the Irish Sea are not available discard rates are not thought to be substantial. However, misreporting and under-reporting of cod is thought to occur in some VIIa fisheries. Estimates of mis-reporting for some nations are included in the assessment, but the scientific advice for zero catch of the cod stock requires that the practice be terminated.”

The extent to which the stocks are taken in the same fisheries cannot be quantified on basis of the available data. A table summarising the level of stock and fisheries interactions based on existing information is given in ICES (2006b). There is, however, no basis to quantify the interactions.

4.7.2 Assessment data overview

The October 2005 ICES advice with regard to single-species exploitation boundaries for the principle demersal stocks in ICES Division VIIa is summarised in the Table 4.7.1.

The stock status of Irish Sea demersal fish stocks (cod, haddock, whiting and sole) are relatively uncertain, except for plaice. ICES presented no analytical catch-based assessments for these stocks in 2005 that can form the basis for sufficiently precise forecasts, due to various attributing factors. The major deficiency for the cod, haddock and whiting assessments is poor quality of the input data due, in part, to sampling problems due to a lack of access to ports for sampling in some years. Some discarding information is available for these stocks, which indicates that discarding is substantial for younger age-classes. Recent discard data are limited and discard estimates may be imprecise due to problematic estimation and raising procedures. Consequently, discards are not currently incorporated into the assessments. The reported catches are also considered too biased to form the basis of an analytical catch-based assessment (ICES 2005a). Whilst methods can be applied in order to estimate total unallocated catches there are no data available that can reliably describe the landings and discards disaggregated by regulated gear category.

There is also uncertainty in the stock estimates of sole due to substantial problems with the input data (anomalously low weights-at-age and exploitation pattern) in 2002 and 2003, which did not allow for an analytical assessment. The status of the Nephrops stocks in this Management Area is unknown. Previously advice for Nephrops has been based largely on historical landings but there are now concerns over the accuracy of official landings and effort statistics.

Table 4.7.1 State of the stocks and availability of analytical forecasts as estimated by ICES (2006b).

Stock | Spawning biomass in relation to precautionary limits | Fishing mortality in relation to precautionary limits | Fishing mortality in relation to target reference points | Analytical forecast available |

Cod VIIa | Reduced reproductive capacity | Harvested unsustainably | Overexploited | no |

Haddock VIIa | Undefined | Unknown | Unknown | no |

Nephrops FU 15 & FU 14 (Management area J) | Unknown | no |

Whiting VIIa | Unknown, low SSB | Unknown | Unknown | no |

Plaice VIIa | Full reproductive capacity | Harvested sustainably | Harvested sustainably | yes |

Sole in VIIa | Unknown | Unknown | Unknown | no |

4.7.3 Mixed fisheries analyses

Given that no single stock analytical catch-based assessments were presented for the majority of the Irish Sea stocks, the inability to reliably forecast catches, the lack of discard data and no well-defined fisheries, no analytical mixed fisheries forecasts were performed.

4.8 Porcupine Bank, Celtic Sea, Bay of Biscay (ICES Divisions VIIb, e, f, j, k, VIIIa, b, d)

4.8.1 Fleet overview and specific data

French landings for 2004 were provided by age and FU for hake.

Spanish catch data from 2004 were provided by age and fishery, as defined in Prellezo et al. (2005) for hake, anglerfish (both species), and megrim ( Lepidorhombus whiffiagonis ). Length distributions of Spanish catches (landings and discards) of Nephrops from Functional Unit 16 were also provided. Catch (landings and discards) composition is provided by Spain for hake, monkfish and megrim. Landings at age by fishing unit were made available by France for hake. Spanish catch and available French landings compositions are shown in Table 4.8.3 and Figure 4.8.1.

Total landings by fleet were available for the other countries involved in the fishery (Belgium, UK, Ireland).

As no data for all countries and species involved in the fisheries were available it was therefore decided that no MTAC analysis will be carried out. Discard data were only available for hake, megrim and both anglerfish, although in the hake and anglerfish assessment, these are not used. For the Nephrops Functional Unit 16 discards data were not available by age.

In the present Subgroup, no attempt to compile 2004 international landings data by traditional Fishing Units (FU) was tried as this exercise was already carried out during last year. 2003 data were aggregated over traditional FUs and countries but no useful analysis was obtained from the MTAC (STECF 2004).

An attempt was also made to extend the number of species including the Nephrops Functional Units. Thus, in relation to Nephrops data, for the functional Units: FU16 (Porcupine Bank), FU 17 (Aran Ground), FU 18-19 (Ireland W) and FU 23-24 (Bay of Biscay), just the FU 23-24 was assessed during the last (ICES 2005b).

So, in relation to data compilation, problems identified were as listed below:

- No common definition of fisheries was agreed among countries

- No discards were included in the single stocks assessments

- Fleet-disaggregated landings at age data were not provided for all species by some of the major contributing fishing units

- Not all species were taken into account

- The species concerned have different management/assessment areas (Northern hake distribution includes Northern Shelf, while the Northern Stocks of megrim and anglerfish are properly delimited to the Porcupine bank, Celtic Sea and Bay of Biscay)

- Stock assessments were not accepted by ICES for some of the major species in the area (e.g. Celtic Sea cod and haddock)

The Group recommends the following amendments to the formats of the mixed fisheries data:

Appendix 2, Annex 3 Gear coding, the introduction of another category to be discussed:

Pair trawls operated with bottom high vertical opening nets.

Appendix 2, Annex 5 Area coding:

Divisions 8abd should be added together

Iberian Peninsula: 8c and 9a should be added

Appendix 2, Annex 6 Species coding, the following species to be included:

EG: Lepidorhombus whiffiagonis

LDB: Lepidorhombus boscii

MON: Lophius piscatorius

ANK: Lophius budegassa

The SGRST notes that the recommended changes are not yet included in the appendixes specifying the data collection for mixed fisheries analyses nor have they been considered in the data base itself. The management areas off the Iberian Peninsula an in the Bay of Biscay as well as the landings and discards of the listed species taken by the Spanish and Portuguese fleets are thus inconsistently grouped.

4.8.1.1 Introduction

No fleet specific catch data including discards were available.

The main demersal species (assessed and) exploited in the Southern Shelf area are hake, sole, cod, plaice, megrim, anglerfish and Nephrops . They are caught by a large variety of gears either as target species or as by-catch. This includes trawls (otter or beam trawl), gillnets and longline. Other demersal and pelagic species are also caught by those gears in this area. As many of them are not under the TACs and Quotas system or are not assessed, they will not be taken into consideration in the present study. However, some of these “other species” may represent for some fleets the bulk of their catches.

Historically, in relation to Hake, Anglerfish, Megrim and Nephrops, a set of several Fishery/Fishing Units (FU) was defined by the ICES Working Group on Fisheries Units in Sub-areas VII and VIII in 1985 in order to study the interaction of the fishing activity related to these demersal species in Divisions VIIe-k and VIIIa,b,d (ICES, 1991). The FUs then selected and defined are presented below in Table 4.8.1.

Tab. 4.8.1 Fishery/Fishing Units (FU) was defined by the ICES Working Group on Fisheries Units in Sub-areas VII and VIII in 1985.

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As the fleets fishing in the more northern sea areas of distribution of the northern Hake (that is assessed as only one stock) were not considered by the 1985 ICES Working Group on Fisheries Units in Sub-areas VII and VIII, later a new FU was introduced for the case of the Northern Hake and was denominated “Outsiders” (FU 16). This new FU does not have a so precise definition as most of the other ones because it comprises four sea areas (Divisions IIIa, IVa,b, VIa,b and VIIa) and four main metiers (trawl, long line, gillnet and Danish purse seine).

During the Hake Technical Measures Meeting in October 2003 in Lisbon (STECF 2003b), in order to reflect a more recent description of the Spanish fleets, it was decided to revise the old FUs assignation, as it was found that for FUs 4 and 14 (trawlers in sub-area VII and VIII, respectively) was better to split them between Bottom Trawl and Pair Trawl components for both areas. During the period 1994-1999 very important changes have taken place in the relative composition of Spanish trawler fleets. Thus four different components have been included in the same Fishing Unit along the 80s and 90s: the “baka”-trawl, the “bou”-trawl (which disappeared in 2000, but was very important in the 70s, 80s and 90s), the new pairs-trawl (operating with “Naberan” nets) since 1993, and the experimental metier of boats operating with twin nets, implemented in 1999-2000, but disappeared in 2001 and appearing again in 2004.

Thus, new métier definitions for Spanish trawl fishery operating in the Porcupine Bank , Celtic Sea and Bay of Biscay were carried out and presented during the SGDFF 2004 by institute (Castro and Punzón , 2005). A jointly analysis and posterior catch profile comparisons was carried out between both institutes, IEO & AZTI, in order to reflect a more summarised description of the different fisheries (Prellezo et al. , 2005). Finally, taking into account passive gears, Spanish fleets are being segmented in 11 fisheries:

1. SP-LLS-VI: Long line VI

2. SP-OTB-VI: Bottom Otter Trawl VI targeting BLI-WIT-HKE-ANF

3. SP-LLS-VII: Long line VII

4. SP-GNS-VII Gillnet VII

5. SP-OTB-VII-HKE: Bottom Otter Trawl VII target HKE

6. SP-OTB-VII-MEG/ANF: Bottom Otter Trawl VII target MEG & ANF

7. SP-PTB-VII: Bottom Pair Trawl VII target HKE

8. SP-LLS-VIII: Long line VIIIabd

9. SP-GNS-VIII: Gillnet VIIIabd

10. SP-OTB-VIII-mixed: Baca trawl VIIIabd mixed

11. SP-PTB-VIII: VHVO Pair trawl VIIIabd target HKE

A proposal has also been made to further segment the traditional French fishing units in the Celtic Sea and the Bay of Biscay (ICES, 2004a), and this is presented in the Table 4.8.2 below.

4.8.2 Traditional French fishing units FU in the Celtic Sea and the Bay of Biscay (ICES, 2004a)

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Most of the demersal fisheries in this area have a mixed catch. However, it is currently possible to associate specific target species with particular fleets and sea areas. Thus, various quantities of hake, anglerfish, megrim and Nephrops are taken together, depending on gear type and area where these operates. Some fleets have also a large part of valuable non-TAC species in their catch (squids, cuttlefish, red mullet, etc.). This is particularly the case for purely mixed fisheries deployed in the Bay of Biscay.

The main interactions between the stocks in the Porcupine Bank, Celtic Sea and Bay of Biscay are between:

- Hake, anglerfish and megrim in the otter trawl fishery in the Celtic Sea and the Bay of Biscay;

- Gadoids (cod, haddock, and whiting) within the trawl fishery for roundfish, mainly within Divisions VIIf,g;

- Nephrops and cod in the Celtic Sea, Nephrops and hake in the Porcupine Bank and the Bay of Biscay;

- Deep-water fish in the otter trawl fishery in the Celtic Sea;

- Sole and plaice in the beam trawl fishery in Divisions VIIf,g and VIIe, and sole and anglerfish in VIIIa,b;

- Mixed species within undirected demersal trawl fisheries.

The directed fisheries for hake (pair trawl, longlines, and gillnets), anglerfish (gillnets) and Bay of Biscay sole (trammel nets) have few interactions with other stocks.

4.8.1.2 The mixed-species fisheries

Otter trawl fishery directed at hake, monkfish and megrim in the Celtic Sea and the Bay of Biscay

Since the 1930s, hake has been the main demersal species supporting trawl fleets on the Atlantic coasts of France and Spain. A trawl fishery for anglerfish by Spanish and French vessels developed in the Celtic Sea and Bay of Biscay, on the shelf edge around the 200-m contour to the south and west of Ireland and Bay of Biscay in the 1970s and expanded until 1990. This fishery used single and twin rig otter trawls in medium and deep water in Subarea VII and Div. VIIIabd. By-catch species include hake, megrim and demersal elasmobranches ( Leucoraja fullonica , L. circularis , and Dipturus spp. ). Although effort in most fleets appears to have declined since the early 1990s the increasing use of twin trawls may have increased the overall efficiency.

The Spanish otter-trawl fishery may be further fragmented into 2 components:

- Bottom Otter Trawl operating in Subarea VII targeting Hake (SP-OTB-VII-HKE). Catches of Hake deployed by single Otter trawlers operating in Subarea VII ranges, in the last 3 years 2002 to 2005 , from 22 to 27 % of the total Hake Spanish catches. In general, Hake comprises close to 75 % of the catches of this fishery.

- Bottom Otter Trawl operating in Subarea VII targeting Megrim and Anglerfish (SP-OTB-VII-MEG/ANF). This fishery mostly directed to Megrim and Anglerfish is deployed in depths larger than Otter trawlers targeting Hake. Thus the first one is considered mostly as a more benthic fishery while the one targeting Hake is considered a demersal fishery.

Otter trawl fishery directed at gadoids in the Celtic Sea

Fisheries for demersal gadoids target mainly cod, whiting, haddock, and take by-catches of flatfish, rays and skates. These fisheries are mainly operated by French otter trawlers, which prior to 1980 were mainly fishing for hake in the Celtic Sea. The other countries contributing to that fishery are UK, Ireland, Spain, and Belgium. Cod is mainly landed by French gadoid trawlers. UK (England and Wales) accounts for about 10% and Ireland for 15%, while Belgian vessels take about 5%. In Ireland in recent years, cod has increasingly been targeted using gillnet, rather than trawl. Landings are made throughout the year, but mainly in the winter months during November to April. French trawlers contribute to about 60% of the whiting landings. Ireland takes about a third of the landings and the UK and Belgium each take under 10% of the landings. Irish demersal trawlers from south-west Ireland have traditionally targeted Celtic Sea whiting in a mixed trawl fishery. In response to poor catches in other areas vessels have been attracted into this fishery in recent years from other part of Ireland, County Donegal. French trawlers contribute to about 50-60% of the haddock landings. Ireland has usually taken about 25-40% of the landings. Irish demersal trawlers from Dunmore East and Castletownbere and other ports in south-west Ireland have traditionally targeted haddock in a mixed trawl fishery. In Divisions VIIb and c the Irish fleet operates mainly from the ports of Rossaveal and the Aran Islands. Fleets from Belgium, Norway, the Netherlands, Spain, and the UK take the remainder of the haddock landings.

Otter trawl fishery directed at Nephrops

The Nephrops fishery developed in the 1970s and 1980s. Fishing effort has decreased continuously since the early 1990s. However, gear efficiency has increased in recent years and this may have helped maintaining LPUE at relatively high levels. In the Bay of Biscay, since 1st January 2000, the mesh size used when fishing for Nephrops has increased and is now similar to the one used for other demersal fish (70 mm). Management of these fisheries needs to be sensitive to bycatches of other stocks.

This fishery is mostly operated by French otter trawlers in the Celtic Sea and the Bay of Biscay. Twin trawls began to be used in the nineties for that fishery. In 2004, 70% of the vessels targeting Nephrops were equipped with twin trawls, resulting in a substantial increase of efficiency for that species. In the Celtic Sea, vessels targeting Nephrops catch a substantial amount of cod and whiting. In the Bay of Biscay Nephrops fishing results in by-catches of juvenile hake. Square-meshed panels have been introduced recently to improve the selectivity of the trawls.

Otter trawl fishery directed at deep-water species in the Celtic Sea

A deep-water fishery, mainly operated by French vessels, targets roundnose grenadier, with by-catches of black scabbard and deep-water squalids. Orange roughy is targeted by Irish vessels, but technical interactions with the other commercial deep-water species are estimated to be at low levels.

Undirected otter trawl fisheries

Some fisheries are not targeting particular assemblages of species. For example, some Spanish bottom otter trawlers operating in Division VIIIabd target a variety of species (SP-OTB-VIII-mixed) including hake, anglerfish, megrim, but also flatfish, squids, elasmobranches. The single trawling in deep and medium depth of the Bay of Biscay shelf, that traditionally represented the first position of the Hake landings in this area, have presented very important changes. In 1990’s, it accounted close to 25% of the Spanish landings of Northern hake, however hake has comprised around 2 % in 2004.

Beam trawl fishery directed at flatfish

The targeting of sole and plaice in the Celtic Sea using beam trawls became prevalent during the mid-1970s, leading to an increase in the landings of these two species. More recently, cuttlefish have become an important component of beam trawl landings, particularly during the winter months. The gradual replacement of otter trawls by beam trawls has occurred in the Belgian and UK fleets. In the Bay of Biscay there has been a substantial replacement of inshore trawling by gillnet fisheries targeting sole since the 1980s.

In the Western Channel, UK vessels have in recent years accounted for around 70% of the total international landings, with France taking approximately a quarter and Belgian vessels the remainder. Sole is the target species of an offshore beam-trawl fleet, which is concentrated off the south Devon & Cornish coasts, and also catches plaice and anglerfish. In recent years a winter beam trawl fishery targeting cuttlefish has developed in the Western Channel.

The beam-trawl fishery in VIIf,g involves vessels from Belgium, taking approx. 3/4, the UK taking approx. 1/4, and France and Ireland taking minimal amounts of the total landings. Sole are mainly targeted by beam trawlers and the fishery is concentrated on the north Cornish coast off Trevose Head and around Lands End.

The beam trawl fishery in the Bay of Biscay is mainly operated by Belgian vessels from June to August. However a noticeable Dutch contribution occurred in 2001.

4.8.1.3 Fisheries with limited technical interactions

Pair trawl fishery directed at hake

This fishery is operated by Spanish vessels. This fishery may be further fragmented into 2 components:

- Bottom Pair Trawl with Very High Vertical Opening nets (VHVO) operating in Subarea VII targeting Hake (SP-PTB-VII). VHVO Bottom pair trawl in Subarea VII is a clean fishery which landing profiles shows more than 90% of hake. This fleet catch landed around 22% of the Spanish landings of Northern hake in 2004.

- Bottom Pair Trawl with VHVO nets operating in Division VIIIabd targeting Hake (SP-PTB-VIII). Pair trawling towing Very High Vertical Opening Bottom nets in deep and medium depth continues representing the first position of the Hake landings in the Bay of Biscay. In 2004, landings deployed by this fishery were around 20% of the total Spanish landings. Catch composition of this fishery is mostly composed by Hake in more than 80%.

Gill net fishery directed at hake

Gill-nets have traditionally been one of the main gears used to target hake in the Celtic Sea and the Bay of Biscay, along with otter trawls and long-lines. This fishery is mainly operated by French and Spanish vessels. The Spanish fishery is segmented into two components:

- Gillnet operating in Sub area VII (SP-GNS-VII). The gill net fishery for Northern Hake in Celtic Sea appears to be, together with gillnet in Bay of Biscay, the fishery that experimented recently a larger decrease in the proportional landings from all the Spanish Northern hake landings since 1999. In 2004 Gillnets operating in Subarea VII comprised just the 6% of the total hake Spanish landings. Landing composition of this fishery is mostly composed by Hake and in much more smaller amounts anglerfish and megrim.

- Gillnet operating in Division VIIIabd (SP-GNS-VIII). This gill net fishery occupied in 1999 the second position of the Hake landings in the Bay of Biscay. This fishery has remained relatively stable during the last ten years, accounting for around 10% of the Spanish landings of Northern hake.

Gill net fishery directed at anglerfish

A gillnet fishery targeting anglerfish developed in the Celtic Sea on the shelf edge around the 200-m contour to the south and west of Ireland in the 1990s. There has been an expansion of the French gillnet fishery in the last decade in the Celtic Sea and in the north of the Bay of Biscay, mainly by vessels based in Spain and fishing in medium to deep waters.

Gill net fishery directed at sole

This fishery is operated by French vessels using trammel nets in the Bay of Biscay, and it has contributed to the majority of the total official international landings of Bay of Biscay sole in the last ten years. A part of the boats operate in coastal areas, being generally less than 12 m long and using often several gears. The boat length of the offshore fleet is mainly between 12 and 25 m. Although sole is taken throughout the year, the catch of coastal boats is less important in autumn and winter, while those of offshore boats are highest in the first quarter. Sole is a major resource for all these boats, given the price of this species on the market. Gill-netters were a minor component of the French fleet operating in the Bay of Biscay up to the middle of the 80’s. However, the proportion of gill-netters increased steadily from 25% in 1985-88 to more than 75% in recent years.

Longline fishery directed at hake

Longlines have traditionally been one of the main gears used to target hake in the Celtic Sea and the Bay of Biscay, along with otter trawls and gill nets. This fishery is mainly operated by Spanish vessels. The Spanish fishery is segmented into three components:

- Long line operating in Sub area VI (SP-LLS-VI): Although the sea area where this fishery operates is out of this report section, the fishery is here included because hake, the main species exploited, stock range goes from Subarea III to the Bay of Biscay (Div. VIIIabd). The landing composition of Spanish longliners operating in Subarea VI is composed mostly by Hake (around 85%) the rest of the catch is made up of ling, blue ling, monkfish, congers...

- Long line operating in Sub area VII (SP-LLS-VII). The long line in medium to deep water fishery consist on an almost monospecific one directed to hake. This fishery represented the first position of total Northern hake landings in 1994, but its importance has gradually decreased comprising around 30% of the total hake Spanish landings in 2004. Spain continues to be the only country mainly involved in it.

- Long line operating in Division VIIIabd (SP-LLS-VIII). The long line fishery in deep to medium water that had in the 80s and beginning of the 90s a relatively high importance of the hake fisheries in the Bay of Biscay, has decreased markedly since 1994. In 2005 3% of the Northern hake Spanish catches were landed by this fishery.

Table 4.8.3 Spanish landings and discards (t) and discard rates in the Porcupine Bank, Celtic Sea and Bay of Biscay by species and gears in 2004.

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Fig. 4.8.1 Spanish landings and discards by trawling gears and by species in the Porcupine Bank, Celtic Sea and Bay of Biscay in 2004. No static gears are presented as catch composition is mostly hake.

4.8.2 Assessment data overview

State of the main demersal target species and the availability of short term forecasts are listed in Table 4.8.4.

Table 4.8.4 State of the stocks and availability of analytical forecasts as estimated by ICES (2006a).

Stock | Spawning biomass in relation to precautionary limits | Fishing mortality in relation to precautionary limits | Fishing mortality in relation to target reference points | Analytical forecast available |

Anglerfish in VIIb-k and VIIIa,b (L. piscatorius and L. budegassa) | Full reproductive capacity | Increased risk (L. piscatorius) Harvested sustainably (L. budegassa) | Overexploited | yes |

Cod in VIIe-k | Unknown | Unknown | Unknown | No |

Haddock in VIIb-k | Unknown | Unknown | Unknown | No |

Hake - Northern stock ( IIIa, Subareas IV, VI and VII, and VIIIa, b, d) | Increased risk | Harvested sustainable | Overexploited | yes |

Megrim in VIIb,c,e-k and VIIIa,b,d (L. whiffiagonis and L. boscii) | Full reproductive capacity | Increased risk | Overexploited | yes |

Nephrops in VIIb,c,j,k (Management Area L) | Unknown | Unknown | Unknown | No |

Nephrops in VIIf,g,h, FU20-22 (Management Area M) | Unknown | Unknown | Unknown | No |

Nephrops in VIIIa,b (Management Area N) | Reference points not defined | Reference points not defined | Unknown | No |

Plaice in the Celtic Sea (VIIf and g) | Increased risk | Unknown | Overexploited | yes |

Plaice in VIIe (Western Channel) | Increased risk | Increased risk | Overexploited | No |

Plaice Southwest of Ireland ( VIIh-k) | Unknown | Unknown | Unknown | No |

Plaice West of Ireland ( VIIb,c) | Unknown | Unknown | Unknown | No |

Sole in the Celtic Sea (VIIf and g) | Full reproductive capacity | Harvested unsustainably | Overexploited | yes |

Sole in VIIe (Western Channel) | Increased risk | Harvested unsustainably | Overexploited | yes |

Sole in VIIIa,b (Bay of Biscay) | Increased risk | Increased risk | Overexploited | yes |

Sole Southwest of Ireland ( VIIh-k) | Unknown | Unknown | Unknown | No |

Sole West of Ireland (VIIb,c) | Unknown | Unknown | Unknown | No |

Whiting in VIIe-k | Full reproductive capacity | Unknown | Overexploited | yes |

4.8.3 Mixed fisheries analyses

Given the concerns expressed in section 4.8.1 on data availability, no attempt was made this year to run an MTAC analysis for this area. However, the Group considered that progress has been made in the process of integrating the definition of fisheries in the Celtic Sea, the Porcupine Bank and the Bay of Biscay. The Group suggests that fleets and fisheries definitions be consolidated by the ad hoc Group of EU experts that will meet in January 2005 to discuss fleets and fisheries segmentation in the context of the forthcoming DCR programme.

4.9. Iberian Peninsula (ICES Divisions VIIIc-IX) Jose

The Atlantic Iberian Peninsula waters (ICES Divisions VIIIc and IXa) include the Portuguese and the Atlantic Spanish coasts. The fleets operating in that area are composed by large number of small vessels using a variety of gears and targeting a variety of species, doing specially complicated to get a suitable fleet segmentation. Moreover, both the artisanal and the trawl fleet have greatly changed during last years, making specially needed a review of the fleet components. A research project has been recently aproved by the European Commission DGFISH for supporting the extra effort needed to get over those difficulties, with the participation of the three laboratories covering the area: AZTI, IEO, and IPIMAR. Unfortunately, only some preliminary results regarding fleet segmentation have been obtained, and they are not still enough for permitting a data compilation disaggregated by métiers, which would permit to calculate a mixed-fisheries forecast.

4.9.1 Fleet overview and specific data

The traditional fleets operating in the Atlantic Iberian Peninsula waters have been widely described in previous “STECF: Mixed Fisheries” reports (STECF, 2002; STECF, 2004). In relation to new segmentations some improvements have been made by both countries involved, Spain and Portugal.

Spain

Preliminary results were obtained classifying the Spanish bottom trawl fleet operating in the ICES Divisions VIIIc (Cantabrian Sea and Northern Galician waters) and IXa-North (Southern Galician waters) by using multivariate analysis (Punzón et al. , 2001; Bellido et al. , 2003). A more recent analysis of individual trips based on the species composition of landings was made separately for the bottom otter trawl (OTB) and the bottom pair trawl (PTB) fleets, obtaining five and two catch profiles from each one, respectively (Castro and Punzón, 2005):

- OTB-jax (bottom otter trawl targeting horse mackerel)

- OTB-mac (bottom otter trawl targeting mackerel)

- OTB-whb (bottom otter trawl targeting blue whiting)

- OTB-hmmn (bottom otter trawl targeting hake, megrim, monk and Nephrops )

- OTB-mixed (bottom otter trawl targeting a variety of species)

- PTB-whb (bottom pair trawl targeting blue whiting)

- PTB-hke (bottom pair trawl targeting hake)

These results show that most of the bottom otter and pair trawl métiers are surprisingly targeting pelagic species. Further investigations are needed to establish a definitive number of trawl fleet components and to put into practice similar analysis with the artisanal fleet.

Similar multivariate analysis were carried out for the trawl and artisanal Spanish fleet operating in the Gulf of Cadiz (ICES Division IXa-South) (Silva et al. , 2002; Jiménez et al. , 2004). However, the high number of métiers obtained is still being a difficulty to decide a suitable and workable number of groups for effective sampling.

Portugal

A multivariate analysis of the coastal Portuguese bottom trawl fleet was carried out using the 2002-2004 monthly landings per vessel, i.e. fishing trips (Campos et al. , 2005). A correspondence between some of the “fishing trip types” obtained, each defined by the relative importance of their target and by-catch species, and fleet components could be established. These patterns indicate the existence of groups of trawlers developing the same fishing pattern over time:

Trawlers for invertebrates:

- Crustacean trawlers (targeting Nephrops and/or rose shrimp).

- Cephalopods trawlers (targeting Octopus ).

Fish trawlers:

- targeting small pelagic species (horse mackerel, mackerel and blue whiting).

- targeting a combination of Octopus with demersal fish species (hake).

Due to the preliminary stage of the analyses described above, a suitable compilation of catch data segmented by metier was not carried out.

4.9.2 Assessment data overview

State of the main demersal target species and the availability of short term forecasts are listed in Table 4.9.1.

Table 4.9.1 State of the stocks and availability of analytical forecasts as estimated by ICES (2006b).

Stock | Spawning biomass in relation to precautionary limits | Fishing mortality in relation to precautionary limits | Fishing mortality in relation to target reference points | Analytical forecast available |

Southern stock of hake (VIIIc and IXa) | Reduced reproductive capacity | Harvested unsustainably | Overexploited | yes |

Megrim (L. boscii and L. whiffiagonis) in VIIIc and IXa | Not defined | Not defined | Appropriate (L. boscii), Appropriate (L. whiffiagonis) | yes |

Anglerfish (L. piscatorius and L. budegassa) in VIIIc and IXa | Not defined | Not defined | Overexploited | yes |

Nephrops in VIIIc North Galicia (FU25) (Management Area O) | Reference Points not defined | Reference Points not defined | Unknown | yes |

Nephrops in VIIIc Cantabrian Sea (FU31) (Management Area O) | Reference Points not defined | Reference Points not defined | Unknown | no |

Nephrops in IXa Galician West and North of Portugal (FU26-27) (Management Area Q) | Reference points not defined | Reference points not defined | Cannot be defined | no |

Nephrops in IXa - SW and South of Portugal (FU28-29) (Management Area Q) | Reference points not defined | Reference points not defined | Cannot be defined | yes |

Nephrops in IXa - Cadiz (FU 30) - (Management Area Q) | Reference points not defined | Reference points not defined | Cannot be defined | no |

4.9.3 Mixed fisheries analyses

During the 2004 STECF Mixed Fisheries meeting (STECF 2004), a MTAC for the Atlantic Iberian Peninsula stocks was carried out using the traditional fleet segmentation. However, the traditional segmentation does not represent the reality of the fishery and so it was recommended not to use these preliminary results for advice purposes. Some advances have been made regarding new definitions. However, the second step, the compilation of the data under that new segmentation, needs further investigations. Thus, the possible consequences in the respective National Sampling Programmes would need to be analyzed. As a result of this lack of appropriate data, a