The Welsh Assembly Government has announced its intention to consult all stakeholders on a proposal to increase the minimum landing size of bass and the minimum net mesh size in relation to Welsh territorial waters. This consultation is similar to that currently being undertaken by Defra.
The Welsh Assembly Government are keen to promote and improve bass fishing in Wales for both commercial fishermen and recreational anglers. Carwyn Jones AM, Minister for the Environment Planning & Countryside, WAG is encouraging all those with a passion for fishing and conservation, to participate in this consultation, as reported in the news item, Plans to boost bass numbers in Welsh waters, which appears on the Welsh Assembly Government web site.
We reproduce below, the consultation letter from the Welsh Assembly Government, together with a copy of the partial regulatory assessment document, which includes, annex A – CEFAS scientific paper.
Copies of the consultation package can also be found at http://www.countryside.wales.gov.uk.
May we suggest you read the web page ‘how you can help’ before submitting your response to the proposals outlined in the consultation document.
BASS are recommending the proposal to increase the minimum landing size (MLS) of bass to 45 cms (option 2) and an increase in the mesh net size to 110mm as we believe these are the best and most workable options available at this time.
The closing date for submissions to the Department for Environment Planning & Countryside, Welsh Assembly Government in respect of the proposal to increase the bass mls is, 14 february 2006.
The consultation letter from the Welsh Assembly Government
Consultation on measures to increase the number and size of bass available to commercial and recreational fishermen
The Westminster Fisheries Minister Ben Bradshaw has announced his intention to increase the minimum landing size of bass and the minimum mesh size to target bass in English territorial waters.
We are now seeking your views on similar proposals in relation to Welsh territorial waters to increase from 36cm to 45cm the minimum landing size (MLS) of bass that may be caught in UK fishery limits by Welsh registered fishing vessels wherever they may be, and Scottish, Northern Irish and English registered fishing vessels when in the Welsh zone. These proposals also include measures to restrict the carriage and sale of bass below the increased MLS and a complementary proposal to increase the mesh size in enmeshing nets targeting bass. In proposing these measures, the Welsh Assembly Government is looking to increase the value of commercial bass landings, to enable more fish to spawn and to increase the number of larger fish available to anglers.
The proposed increase in MLS and minimum mesh size are the first part of a wider package of measures under consideration for the bass fisheries. These may include bag limits for recreational sea anglers, near shore netting restrictions, closed areas and/or seasons and further gear restrictions. All stakeholders will be given the opportunity to comment in a full consultation on further measures at a later date.
At present I would like to seek your views on an increase in the MLS and minimum mesh size, as follows:
Increase in minimum landing size
We propose that the legislation, in the form of a Statutory Instrument (SI), should prohibit the landing of any bass less than 45cm. This would apply to all UK registered vessels landing into Welsh ports.
The legislation would also prohibit the sale , exposure or offer for sale, or possession for the purpose of sale of bass which is less that 45cm. This would apply throughout Wales.
The proposed SI would not apply to bass taken from a commercial fish farm, as this is covered by separate legislation.
The carriage of bass smaller than the proposed MLS would also be prohibited to Welsh vessels throughout British Fisheries Limits (BFLs) taking into account devolution settlements and, on all British vessels when in BFLs. The Regulatory Impact Assessment (RIA) also explores other options such as a staged increase in the MLS, a regional approach and an increase in the MLS to 55cm.
Increase in minimum mesh size
In order to reduce discards that an increase in the MLS will lead to, we are proposing an increase to 105mm in the minimum mesh size for fisheries using enmeshing gear to catch bass. We are defining a bass fishery as that in which bass comprises more than 10% of the catch, and enmeshing nets as any enmeshing gill nets, drift nets, tangle nets or trammel nets.
Because catches in set net fisheries are sometimes landed when the nets in which they were caught are not being carried on board the fishing vessels, it is not always possible to confirm which mesh size has been used. For this reason we are considering introducing a requirement that during any voyage where enmeshing nets of mesh size less than 105mm are carried or deployed, or on any voyage where the fishing vessels has any specified nets deployed by it in the water, the catch retained or landed may consist of no more than 10% bass.
We are not proposing a corresponding increase in the mesh size for towed gears because of the different selectivity properties of such nets. Nonetheless, in response to concerns over the possible increase in discards that might arise when using towed gears for bass, we would like your views on whether a permitted 10% bycatch of bass between 36cm and 45cm during the early implementation of the measures would reduce the level of discarding.
If it is decided to proceed with these proposals to increase the MLS and the minimum mesh size, we would aim for an implementation in Autumn 2006.
I have attached a paper by CEFAS setting out the scientific considerations for this increase in MLS and an increase in mesh sizes for all enmeshing nets.
Regulatory Impact Assessment
I also attach a partial Regulatory Impact Assessment (RIA) which sets out our understanding of the costs and benefits of this proposal and other options. We accept that fuller statistics are held by Defra on the commercial fishing sector than the recreational angling sector, and the partial RIA reflects this. I would therefore welcome any comments, corrections or further information on any part of the RIA. You will note that there are some questions posed in the RIA where information is lacking in a specific area or where we would like to explore alternative approaches; we particularly welcome comments on these points.
The Welsh Assembly Government would welcome your views on these proposals, including on the options set out in the RIA and the costs and benefits associated with them. Practical examples of the impact of the proposals on you and your business can help us get a fuller and more accurate understanding of the overall impact of the proposals.
If you would like to comment, could you please respond by 14 February 2006 to:-
Mrs Hannah Hess
Welsh Assembly Government
Government Buildings CP2
Copies of the consultation package can also be found at http://www.countryside.wales.gov.uk.
At the end of the consultation period copies of the responses we receive may be made public, the information contained may also be published in a summary of responses. If you do not consent to this, you must clearly request that your response be treated confidentially. Any confidentiality disclaimer generated by your IT system in e-mail responses will not be treated as such a request. You should also be aware that there may be circumstances in which the Welsh Assembly Government will be required to communicate information to third parties on request, in order to comply with its obligations under the Freedom of Information Act 2000 and the Environmental Information Regulations.
Fisheries Policy Branch
Environment, Conservation and Management Division
Department for Environment, Planning and Countryside
PARTIAL REGULATORY IMPACT ASSESSMENT
TITLE OF PROPOSAL: THE UNDERSIZED BASS ORDER
Purpose and intended effect of the proposals
I. To increase the number of larger bass around the coast of Wales.
I. The Prime Minister’s Strategy Unit’s Report “Net Benefits” recommended that the four fisheries departments consider the evidence for the re-designation of bass as a sport fish, as in some circumstances the economic and social benefits of sea angling for specific species may provide a greater contribution to society than if they are commercially caught. Following consultation and discussion with Welsh Inshore Fisheries Stakeholder Group and in line with the decisions of the Westminster Government and other devolved administrations, this recommendation was not accepted.
I. Instead the Welsh Assembly Government is looking to increase the size of bass, to increase the values of such landings, and to enable more fish to spawn. The biological parameters of bass are consistent around the UK; male bass mature at length 31-35 cm (aged 3-6 years) and females at 40-45 cm (aged 5-8) years. Fishing effort on bass is not subject to quota limits; effort is controlled through minimum landing size limits and net mesh sizes.
I. To increase the value of the bass stock the Welsh Assembly Government is considering a range of measures. The first is to increase the MLS from 36 cm to 45 cm of bass that may be caught in UK fishery limits. This would apply to Welsh fishing vessels wherever they may be (except when in the English territorial sea, where vessels would be subject to English MLSs), and Scottish, Northern Irish and English fishing vessels when in the Welsh part of UK fishery limits. Accompanying the proposal to increase the MLS, is a complementary proposal to increase the mesh size in enmeshing nets (such as gill, tangle, drift, trammel and seine nets) targeting bass. In effect only those vessels landing catches composing over 10% bass will be affected. Similar proposals are to be put forward by the Westminster Government in respect of English territorial waters.
II. The subsequent package, on which further consultation will be conducted, may include measures such as bag limits for recreational sea anglers, near shore netting restrictions, closed areas and/or seasons and other gear restrictions.
I. This proposal would apply to all UK registered vessels (with the exemptions given in para. 4).
I. The Drew Report(note 1) into the economic impact of recreational sea angling reported that in 2002 around 2 million people went sea angling at least once in England and Wales. The total expenditure by sea anglers in the UK on their sport (e.g. on fishing equipment, travel, food and accommodation is estimated to be at least £1 billion annually. According to the BASS Management Plan(note 2) there are an estimated 400,000 anglers who fish primarily for bass.
II. UK Sea Fisheries Statistics show that in 2004 the commercial fishing industry in the UK comprised around 6,700 fishing vessels and some 650 thousand tonnes of sea fish were landed into the UK and abroad by the UK fleet with a total value of £513 million.
III. Approximately 1500 UK vessels are involved in catching bass, either by enmeshing nets, lining or trawling. In 2003, the UK commercial bass fishery was valued at £7.5 million. Within Wales commercial activity is mainly confined to the under 10m fleet and it is estimated that some 120 vessels are engaged in this activity, full or part time with an estimated legally landed catch of some 56 tonnes with a value of around £350,000.
IV. The ICES report for 2004 states that bass stocks in ICES Sub-areas IV and VII appear to be fished sustainably. A succession of strong year classes since 1989 and relatively modest fishing mortality has enabled stock biomass to be sustained or increased in UK coastal waters since the mid-1990s.
Option 1; do nothing.
Option 2; increase the minimum landing size (MLS) for bass in UK fisheries from 36cm to 45 cm and the mesh size for enmeshing nets to 105mm.
Option 3; increase the MLS for bass by stages over a three year period, or a different period and the mesh size for enmeshing nets to 105mm
Option 4; increase the MLS for bass regionally, based on average landing sizes for each defined geographic area and apply a corresponding increase in the mesh size for enmeshing nets to 105mm
Option 5;a staged increase in the MLS for bass to 55 cm and corresponding increases in the mesh size for enmeshing nets.
I. Option 1 Bass stocks are currently being fished sustainably, but this option presents no benefits in terms of realising any potential increase in the economic return from the stock other than as commercial and recreational fishermen’s catches increase as the stocks continue to develop. However, it is unlikely to give an increased number of bigger fish.
I. Option 2 Simulations imposing a MLS of 45 cm on the English west coast bass fishery indicate how the numbers of bigger bass in the population and yields to the fishery might develop over the next 10 years. An effective MLS of 45 cm is approximated by removing all bass of 6 years and younger from the fishery’s catch, and leaves many more fish to survive to be bigger than 45 cm. A measurable increase in the numbers of bass above 45 cm should be apparent by 2008/9. (Annex A sets out in detail the scientific advice underpinning this option and other elements of the RIA.)
I. The availability of larger bass to the recreational sector is expected to increase further the anglers’ interest in this stock, leading to increases in tackle, bait, travel and accommodation expenditure and thus increasing the economic contribution of recreational sea angling to the Welsh economy. Recent Welsh Tourist Board (WTB) statistics for the period May 2004-April 2005 indicate that in excess of £69million was contributed to the Welsh economy by angling tourism, with 45% of this being spent on sea fishing. These figures do not include either the financial contribution made by local anglers or anglers who have not requested information from the WTB. The availability of larger bass would further stimulate this market.
II. Landings for trawls, nets and lines would show initial declines following the introduction of an increased MLS, but these should recover and be close to or above the current level after 5 years. This analysis assumes that the larger bass will not be targeted as effectively as smaller fish, but the fishery is expected to adapt to any new management measures, and the recovery in landings to occur that much faster. However, any increase in the ability of the commercial fishery to catch bigger bass will have the effect of reducing the availability of larger fish to anglers. The main benefits of an increase in average fish size will accrue with fish selling for in excess of £9 per kg (decreasing to approximately £1 per kg for poor quality bass caught during the spawning season). An increase in size will attract a higher value; approximately £4-£6 per fish at current prices (based on average weight of bass at 36cm and 45cm).
1: We would be grateful for any comments, in particular from merchants on these assumptions. Also, would any demand for plate-sized bass be effected by this proposal? If so, to what extent?
I. Extensive trials to determine mesh selection characteristics for bass in enmeshing gears (drift and fixed nets) have shown that a minimum gill net mesh size of between 105 and 110 mm best complements an MLS of 45 cm for bass. This would ensure that the majority of bass caught in enmeshing nets are at or above 45 cm.
II. Introducing a 105-110mm minimum mesh size for all enmeshing nets would have consequences for fisheries where bass are not the target species. For this reason, the minimum mesh size is linked to bass fisheries where bass makes up at least 10% by weight of the catch.
Question 2: there is a possibility that increasing the mesh size to 105mm may increase catches of salmonids. Would this represent a significant problem or is legislation around the coast relating to fixed engines effective in reducing this impact? Are there any other means of mitigating this?
I. An equivalent increase in the mesh size for trawls has not been considered at this time because the chances of fish becoming enmeshed in the net (as opposed to being contained within the bag of the net) increases. Also, there is more chance that fish caught inside a relatively small-meshed net will survive being returned to the sea. The two main trawl fisheries taking bass as a target species are not within Welsh jurisdiction (the offshore winter fishery and the pair-trawl fishery along the Sussex coast). The Welsh Assembly Government is not aware of any Bass trawling fisheries within Welsh waters. If there are there would, however, be an additional though unquantifiable mortality of bass under 45 cm due to discarding.
Question 3: Are Bass Trawl fisheries within Welsh Jurisdiction an issue for Wales?
Question 4: To reduce discard levels in the trawl fishery and limit any short term losses to other commercial fishing sectors, would a temporary bycatch limit allowing 10% of the catch to comprise fish between 36cm-45 cm for, say, 2 years after implementation be appropriate?
I. An increase in the minimum landing size for bass to 45 cm would protect most bass to maturity and enable most female bass to spawn at least once (female bass in NW Europe first spawn at 42-45cm) before recruitment to the commercial fishery. It should be noted, however, that recruitment to bass stocks is currently high and that there is no problem with reproductive sustainability.
II. Option 3 The benefits of Option 2 could be achieved over a longer time frame but with reduced economic impact on the commercial catching sector if the increase to 45 cm were to be introduced in a number of stages. This could be achieved by staged increases of the MLS to 39 cm, 41 cm and 45 cm over a three year period. This would extend the time frame for achieving the objective of more bigger fish by around two years. A longer period would extend the time frame for achieving the objective even further.
Question 5: Would the lessened impact on catches from staging the increases be offset by the additional cost of replacing gear?
I. Option 4 Commercial fishermen in North West England report very small catches of any bass above 45 cm and argue that the current proposal would simply put them out of business such that there would be no fleet to enjoy the projected benefits of more and bigger fish. They have suggested that there should be a form of regionalisation of any increase in the MLS based on average landing sizes for defined geographic areas. In practice, this might only serve to consolidate the current exploitation patterns, and would create significant enforcement problems. Further there would be considerable opportunity for vessels to “invade” an area to fish for smaller fish thus creating pressure on the local stock.
Question 6: Do similar variations occur in Welsh territorial waters?
I. Option 5 The Bass Anglers Sportfishing Society’s Bass Management Plan argued that the MLS should be increased to 55 cm, possibly via a stepped change over a number of years but moving to 45 cm in the first phase. However, it would be at least 6 years before fish currently protected by the 36 cm MLS were recruited to the commercial fishery at 55 cm. Even if such an increase in the MLS were to be introduced over a number of years, there is considerable doubt that bass over 55 cm would be available to many parts of the inshore fishery.
Business sectors affected
I. The proposals will affect approximately 120 Welsh commercial vessels. If the availability of larger fish generates an increased interest from anglers, the proposals would benefit the estimated 400,000 sea anglers (according to BASS), who regularly fish for bass and supporting industries including the tourism sector.
Issues of equity and fairness
I. The impact of the proposed regulations will fall on all those commercial fishermen who take bass in their catches. Although bass landings will decrease in the short term, in the medium term (i.e. by 2008/9) there will be an increase in the number of larger bass taken in those parts of the commercial fishery where these fish are available. All fishermen using enmeshing gear whose catch is expected to comprise more than 10% bass will need to use mesh of at least 105-110 mm, although some vessels may already be using this larger size. It is also possible that very small fishing companies or individual vessels that rely very heavily on the market for bass could be adversely affected in the short term.
II. Merchants will also be affected by these proposals. The majority of catches landed by trawlers and the over 10m sector is sold through merchants. These proposals will reduce catches and therefore trade significantly in the short term. Processors will not be affected to the same degree as their supplies are also sourced from farmed bass.
Compliance costs for business
I. Option 1. There would be no additional costs under Option 1.
II. Option 2. Enmeshing gear costs in the region of £300 (for 10 sheets , generally 200m stretched length) or £900 (for 10 sheets, completely rigged), although nets are usually replaced every 12-18 months. Some fishermen may already be using nets larger than the current 90-95 mm mesh size.
III. Some fishermen prosecute bass in a particular season (many inshore fishermen), or when they are close to meeting quota allocations for other species (e.g. pair-trawlers). The majority of catches over the last few years are those measuring approximately 36-45 cm, which would be unavailable under this option. Simulations of the bass stock suggest that by 2008/9 the abundance of large fish available to the fishery should have increased significantly.
IV. Option 3. A staged increase in the MLS would allow fishermen to keep a greater proportion of their present levels of catches initially, but at a cost of reduced benefits to the stock and fishery in the medium term. For example, it is estimated that loss of earnings to commercial fisheries of a two-year staged increase in MLS to 45 cm would be reduced by approximately 50% in the first year, but that immediate introduction of 45 cm MLS would outperform the phased scenarios by between 1 and 27% in each subsequent year. Simulations of the bass stock show that a significant increase in larger fish would not be seen for at least 5 years. A staged increase in the MLS would be introduced with complementary increases in mesh sizes; these would impose further additional costs on the fishery.
V. Option 4. It has not been possible to assess the compliance costs for this option, though they would be significantly less than for option 2 since there would be only a small loss of undersized bass from any one fishery with an MLS based on the average size of fish in the fishery.
VI. Option 5 Initial losses to the commercial catching sector would be the same as for those associated with option 2 (MLS increase to 45cm), until the average size of the stock increased, but further losses would occur with the final stage of the increase in mls to 55cm but would increase again when the MLS is raised to 55 cm.
Impact on small businesses
I. This measure would apply to all UK registered vessels (with the exemptions given in para. 4). Approximately 95% of those fishing for bass work from vessels of 10 m or less. All companies affected by these proposals are understood to have less than 250 employees.
I. The measures could give rise to further costs to Government if the economic impact on commercial fishers is such they have to resort to a greater call on social security benefits. Enforcement of the legislation would be undertaken by the existing enforcement bodies. This would be achieved within existing budgets.
I. There would be no negative competitive impact arising from this measure. The proposal neither restricts the ability of firms to choose the price, quality, range or location of their products, nor will it lead to a differentiation in costs between new and existing commercial fishermen. The measure is unlikely to affect the market structure.
II. The measures would not apply to fishing vessels from other Member States who either have historic rights to fish within the 6 to 12 mile zone (France and Belgium) or fish exclusively outside the 12 mile limit. They would be able to continue to fish for bass at the EU 36cm MLS. At present it is only approximately 16 (?)French vessels which target bass. Other vessels would take bass as bycatch as and when shoals are encountered. They would not, therefore, suffer the short or medium term losses that are envisaged for UK fishermen and thus their competitive advantage would be increased.
Enforcement, sanctions, monitoring and review
35. Enforcement of the legislation would be undertaken through a joint agency approach by the Marine Fisheries Agency and the local Sea Fisheries Committees, on a targeted/risk assessment basis (as set out in the Hampton Principles of Inspection and Enforcement(note 3). Penalties, fines, are consistent with other measures taken to restrict fishing activities. Their experience from enforcement activities, together with monitoring work by CEFAS, and anecdotal information from the coast, will all serve to provide information on the effectiveness of any measures in meeting the objective. We envisage conducting a formal review in 2008/9 when it should be possible to assess whether the abundance of large fish has increased significantly in line with simulations outlined in this RIA.
Mrs Hannah Hess
Welsh Assembly Government
Government Buildings CP2
ANNEX A – CEFAS SCIENTIFIC PAPER
Bass management plan: scientific advice on increased MLS and complementary mesh sizes for enmeshing nets.
Basis for a 45 cm MLS.
Calculations of yield to the fishery per bass recruit at age 3 (before they enter the fishery) have been used to show that the predicted benefits of the 1990 bass management package – a 30-40% higher yield to the fishery – did indeed take place, and a paper has been published in Fisheries Research (Pawson, Pickett and Smith, 2005). The objective in 1990 was to protect juvenile bass and raise the age at first capture from 3-5 to 5-6, by implementing a MLS of 36 cm, a banned range of mesh sizes in enmeshing nets at 65-89 mm, and prohibition of fishing for bass in areas where undersized fish are particularly vulnerable to capture (the “bass nursery areas”). These calculations made no assumptions about changes in the fishery or levels of recruitment. Since 1990, recruitment has increased (largely due to a favourable climate change, especially warmer winters), and both effort and catches in the fishery have also increased (shown in a paper submitted to the ICES Science Journal; Pawson, Kupschus and Pickett).
We have used the same approach to model the likely effects of a further increase in MLS, based on our current assessments of the bass fishery. For example, in ICES Divisions VIIa,f,g the yield per recruit (YPR) curve is relatively flat at current levels of fishing (F multiplier of 1.0), but the highest YPR occurs at around 45 cm (line in the pink band) and decreases thereafter (Figure below). This result is consistent with that obtained for the North Sea and SW England in the 1980s.
This also shows that a 55 cm MLS (as requested by BASS) would not realise the increases in yield to the fishery, unless fishing effort was increased considerably.
A first exploitation size at 45 cm also confers considerable protection of female bass up to the size at which they first spawn, which is consistently above 42 cm in NW Europe (Pawson and Pickett, 1996).
Impact of a 45 cm MLS on the bass population.
Using the same assessment, we have carried out simulations imposing a MLS of 45 cm on the west coast bass fishery, to indicate how the numbers of bigger bass in the population and yields to the fishery things might develop over the next 10 years. Because we have little information on the most recent year classes, which are not yet large enough to enter the fishery, we have stepped back 5 years to use the 1997 year class. These fish were the most abundant year class in the 1990s, and feature well in our assessments, so can be used as a proxy for the 2002 year class which will enter the fishery in 2006/7. We have assumed that new year classes will be of average abundance recorded over the 199Os.
If an effective MLS of 45 cm (and complementary mesh size for enmeshing nets) is imposed in the fishery, this is equivalent to removing all bass of 6 years and younger from the fishery’s catch, and leaves many more fish to survive to be bigger than 45 cm. The following table shows how the number of bass in the 2002 year class (the first that would be protected by new measures) on the west coast is predicted to change over the next 8 years, if an effective MLS of 45 cm is introduced in 2006, assuming that fishing effort will remain the same as in 2004. (F<7 = 0 implies no fishing mortality by any gear on bass under 7 years old; FLN<7 = 0 implies no fishing mortality by lines or nets on bass under 7 years old; FL<7 = 0 implies no fishing mortality by lines on bass under 7 years old)
This suggests that a measurable increase in the numbers of the 2002 year class should be apparent by 2008/9, and that this increase would be largest if the measures apply effectively to all fishing gears, and least if they only applied to lines (i.e. just a 45 cm MLS). It is important, therefore, that the whole fishery is subject to measures that protect undersized bass.
Impact of protection of bass < 45 cm on fishery.
Because the reduction of mortality on younger fish allows more to survive to be caught when older (and larger), the catch of 7 years and older bass is increased for all gears. Landings (weight) for trawls, nets and lines show initial declines, but these recover and will be close to (trawls) or above (nets and lines) the current level after 5 years. The greatest increase in landings is in the line fishery when appropriate measures are applied either to all gears or to lines and nets only, and the largest reduction in the overall commercial catch from the 2002 year class will be obtained when the measures are implemented for lines only.
This analysis assumes that the larger bass will not be targeted as effectively as smaller fish, but we expect the fishery to adapt rapidly to any new management measures, and the recovery in landings to occur that much faster. One benefit will be that the increase in average size of fish in the catch will attract higher value per kg on the market.
Note that we have assumed discards in the trawl (and sometimes net) fishery are landed/killed. Thus, the numbers of larger fish in the population are underestimated if discarded fish survive. We could also model the size distribution of each age group (rather than just assuming all bass under 7 years will be protected), and include a modified gill net selection pattern that will take more larger fish (see below). It is unlikely that the results will be markedly different from the above.
Estimating gillnet mesh size consistent with a MLS of 45cm for bass
In consultations on bass management measures in the late 1980s, we argued that it was necessary to restrict the use of small mesh sizes in all enmeshing nets because:
a) undersized fish caught in such gear have a low probability of survival even if discarded, due to the damage caused when extracting them from the meshes;
b) it is not possible to identify a “bass gill net fishery”, not least for the purposes of bringing prosecutions for infringements of regulations. The term “gill net” is applied to an increasing variety of enmeshing nets, which are often used to take a mixture of species, the relative proportions of which vary with grounds fished and season;
c) approximately one third of the commercial bass catch in the UK was taken by enmeshing nets; and
d) the method is commonly used by casual and part-time fishermen, with whom enforcement of any management measure (particularly specific ones such as a MLS) can be very difficult.
All four points are still valid, except that b) may no longer be applicable if we need to constrain bass exploitation quantitatively in order to achieve the management objective (more, bigger bass).
We carried out extensive trials to determine mesh selection characteristics for bass in enmeshing gears (drift and fixed nets, see Reis and Pawson, 1992), and analytically demonstrated that a minimum gill net mesh size of 90 mm complements an MLS of 36 cm for bass (as enshrined in national and EU regulations).
For the present purposes, we have used two approaches based on the length structured catch data for a range of mesh sizes used by Reis & Pawson (1992). The first method (following McCombie and Fry, 1960) is based on a relationship between mesh size and the length and maximum girth of fish captured in gill nets. These are used to produce a “master curve” that describes the characteristics of bass being retained by gill nets, viz: fish with a small girth slip through the net, those with too large a girth bounce off, those between have a range of probabilities of being retained within a mesh.
This model indicates that the mesh size that retains 10% of the cumulative distribution of bass above 45 cm is 107 mm (i.e. 10% of the bass caught in a 107 mm net would be <45 cm, assuming equal numbers of all sizes encounter the net). The optimum size of capture for this mesh is 48-49 cm.
Our second approach was to fit mesh selection curves directly to the length frequency observations (Sparre et al. 1989) and allow the shape of the selection curve to become wider with increasing mesh size (as it would in practice). This method also produces good fits of observed length distributions of bass in known mesh sizes (70-92 mm). It indicates that a mesh size of approximately 109 mm is needed to obtain a catch where the proportion of bass less than 45 cm is 10% of the cumulative distribution.
These two methods give similar results, and we believe that the approach is sufficiently robust to suggest that a minimum mesh size (stretched from knot to opposite knot) of between 105 and 110 mm would ensure that the majority of bass caught in enmeshing nets are above 45 cm. Reis and Pawson (1992) noted that extrapolation of such modelled retention curves for nets outside the monitored mesh size range normally used for bass (82-100 mm) is not without uncertainty, and it may be necessary to seek the views of the industry as to an appropriate mesh size for a bass MLS of 45 cm.
Implementation of a mesh size regulation.
On the assumption that the new bass MLS will be 45 cm, and that a 105-110 mm minimum mesh size would support this by reducing the chances of undersized fish being caught in nets and (probably) killed, we propose the following approach to a control measure.
This is, to stipulate that sea bass cannot be landed in an enmeshing net fishery unless a mesh size of at least 105-110 mm is used, and/or that bass comprise less than 10% by weight of the landed catch taken in nets with a smaller mesh size (but still subject to EU regulation 850/98, which only applies to fixed gears). Taken together, this means that those targeting bass with any fixed or drifting enmeshing net must use nets with a 105-110 mm minimum mesh size, thus minimising the chances of bass under 45 cm being caught, whilst the 45 cm MLS protects bass taken as bycatch in fisheries targeting other species. Because the growth and biological characteristics of bass do not vary greatly around the British Isles, we suggest that one comprehensive national regulation is to be preferred to local variations.
This measure would have an immediate impact on most netting fisheries in which bass comprise a significant part (> 10% by weight, and much more by value) of landings (even seasonally), in that mesh sizes would have to be increased and there would be a loss not only of small bass but also of some by-catch species (mullet, sea trout). As shown above, bass catches would soon recover to a similar level to that experienced at the moment. It would have no implications for other netting fisheries, where existing mesh sizes would continue, though the increased bass MLS would result in higher levels of discards in areas where bass < 45 cm were vulnerable.
McCombie, A.M. and Fry, F.E.J. 1960. Selectivity of gill-nets for lake whitefish, Coregonus clupeaformis. Trans. Am. Fish. Soc., 89:176-184.
Pawson, M. G. and Pickett, G.D., 1996. “The annual pattern of condition and maturity in bass (Dicentrarchus labrax L) in waters around the UK.” J. Mar. Biol. Assoc. UK, 76: 107-126.
M.G.Pawson, S.Kupschus, and G.D. Pickett. The status of sea bass (Dicentrarchus labrax) stocks around England and Wales, derived using a separable catch-at-age model, and implications for fisheries management submitted to ICES Science Journal
M.G. Pawson, G.D. Pickett and M.T. Smith, (2005). The role of technical measures in the recovery of the UK sea bass (Dicentrarchus labrax) fishery 1980 – 2002. Fisheries Research, 76, 91-105.
Reis, E.G. & Pawson, M.G. 1992. determination of gill-net selectivity for bass (Dicemtrarchus labrax L) using commercial catch data. Fish. Res., 13:173-187.
Sparre, P., Ursin, E. & Venema, S.C., 1989. Introduction to tropical fish stock assessment . Part 1. Manual. FAO Fish. Tech. Pap. 306.1. 337p. FAO, Rome.
Making a response
May we suggest you read the web page ‘how you can help’ before submitting your response to the proposals outlined in the consultation document
Please remember, a response using your own words is far more effective than copying an example.