436 research outputs found
Principles for management of inshore scallop fisheries around the United Kingdom
Fisheries for scallops, particularly the great scallop Pecten maximus and to a lesser extent the queen scallop, Aequipecten opercularis, are of considerable economic importance to the United Kingdom (UK) fishing industry. Landings of great scallops have been growing steadily since the 1970s and now consistently place this fishery in the top five most valuable species in the UK. Queen scallop catches have been much more variable over the same time period. Great scallops are predominately taken using Newhaven scallop dredges while queen scallops are mostly captured with otter trawls. A very small percentage (< 5 %) of the great scallop catch is taken by hand by SCUBA divers. There are no catch limits on UK scallop fisheries and licence number restrictions are widely regarded as ineffective. Instead great scallop fisheries are mostly managed through minimum sizes, restrictions on dredge number and seasonal closures in some regions. The use of towed fishing gear (dredges and trawls) is also prohibited in a few small areas, generally for conservation purposes. There are few management measures for queen scallops. UK fisheries for great scallops appear to be stable at present, but there is considerable evidence that their productivity could be improved dramatically by better management. This is because at present the fishery has a number of negative effects on juvenile scallops and provides few spawning refuges for replenishment of stocks. The use of towed fishing gear also damages much of the habitat that is crucial for the settlement and survival of young scallops. The negative effects of towed fishing gear, particularly scallop dredges, on benthic habitats and communities are also of considerable conservation concern. In general, areas subject to high fishing pressure tend to lose structural complexity and have lower biodiversity, species richness, species abundance and rates of benthic production. Biogenic reefs / substrates are the most sensitive to disturbance, followed by sandy / gravel areas. However, sandy / gravel substrates have strong potential for recovery if protected. Shallow, sandy areas subject to high levels of natural disturbance are more resilient to fishing disturbance, but tend to support few scallops and lower diversity of benthic species in general. Scallop fisheries also have a high by-catch of mobile benthic species such as crabs, starfish and some fish species. Although the ecological significance of this bycatch is unclear it has the potential to negatively affect crab fisheries. A new management regime for UK scallop fisheries that provided better protection to key scallop nursery and breeding areas, and maintained healthier benthic ecosystems in general would undoubtedly result in more productive and sustainable fisheries. We therefore examined a series of well managed scallop fisheries from around the world to glean how this might be achieved. These fisheries provide good insight into successful management practices for scallops. In Australia the Queensland scallop fishery was incorporated into the Management of the Great Barrier Reef Marine Park as a whole showing that an ecosystem level approach is feasible. In fisheries such as the US sea scallop where the stock was officially declared overfished, reduction in fishing effort resulted in a return to healthy biomass levels. This has included improvement of the size class structure, a characteristic which would be of great benefit to the UK fishery. Protection of juveniles has proven to be a key factor in several cases and in the French fishery in the Bay of Saint Brieuc it was considered a main reason for their success by increasing the number of virgin (previously undisturbed / captured) scallops and therefore the yield per recruit. Habitat mapping has proven invaluable in most examples for providing information on the location of areas that should be protected for the benefit of juvenile scallop settlement and nursery grounds for other commercial species as well as habitat types that should be protected in their own right to conserve biodiversity. There appear to be two successful ways of implementing these changes. One way is with firm government legislation, which includes tight fishing restrictions that is backed up by a strong enforcement plan. This would include measures such as satellite tracking, patrol boats, on board observers and dockside monitoring. An alternative strategy would be to confer on the fishers a level of ownership of their resource and in some cases this has lead to an industry funded and managed recovery of the resource. This strategy ultimately requires little policing. We suggest a UK management plan primarily based on conferring a level of ownership to fishers operating within the 6 mile zone. This may be met with some resistance in the first instance and we would envisage that a level of enforcement may be required at first. This has been found in other examples but as time passes less enforcement is necessary. This should be set within a framework of zones that should consider all users. We further suggest that all interested parties should be included in an ecosystem level management plan and that the scallop fishery should fit into that plan. Provision should be made to minimize the negative effects of one user group on another such as scallop dredges damaging crabs and tangling in crab pots. The inshore area up to 3 miles should be considered a low impact zone with the 3-6 mile area being a medium impact zone. The low impact zone would include fully protected areas, areas just for static gear fisheries (e.g. crab fishers) and scallop divers and other low impact uses such as recreation. Most of the inshore scallop fleet which uses dredges or trawls should operate within the medium impact zone. The larger vessels in the nomadic offshore fleet should operate outside 6 miles. The key to the success of this scheme for the scallop fishery would be to improve the productivity by increasing spawning stock biomass and improving the size class structure of the populations. Recommended management measures include reducing fishing effort, increasing minimum dredge belly ring size and protecting juveniles and key habitats. If these measures were to be put in place, the UK scallop industry has the potential to provide a much more profitable and stable income for its stakeholders
Celebrity chefs and the sustainable seafood movement : Smokescreen or a dish to savour?
Celebrity chefs are a major part of British media culture, with several highly prominent on television and able to amass formidable book sales. Sales of endorsed products often increase subsequent to the release of these cookery books. The ethical leanings of a chef may therefore impact behavioural trends of consumers. This study examined the books of ten celebrity chefs over three time periods; 2005-07, 2009-11 and 2012, with a view to establishing the sustainability of the seafood featured within them. The Marine Conservation Societyâs Fishonline website (www.fishonline.org) was used to assess the sustainability of an average gram of seafood in each book. This was combined with a grading of the introduction, recipes and alternative suggested species in each book to produce an overall âsustainabilityâ score. Hugh Fearnley-Whittingstallâs books achieved the highest ranking across all three time frames, with an average score of 87%. However, Delia Smith scored consistently low â between 17% and 22%. Raymond Blanc showed the greatest improvement, rising from 22% to 85%, reflecting a general improvement among most chefs over time. Continued promotion of sustainable seafood by celebrity chefs could help improve the management of marine resources, but uptake of the concept is still highly variable between individuals
Fisheries Discards â Waste of a Resource or a Necessary Evil? : Report to the EU on the reform of the Common Fisheries Policy
Fisheries discards are often seen as an enormous waste of resources and an impediment to the rebuilding of fish stocks. However, many traditional fisheries management measures have effectively encouraged discarding in an effort to enforce catch quotas and protect undersize fish or undesirable species. Discarding is currently a particularly contentious issue in European fisheries, prompting the European Commission to review its approach to managing discards. Of key concern is the North Sea which accounts for some of the highest discard rates in the world. It is jointly managed under two different policies (The European Common Fisheries Policy and the Norwegian Marine Resources Act). In Norwegian waters discarding is banned, whereas in EU waters discarding is widespread. To assess the ecological and economic effectiveness of the Norwegian ban on discards we examined its effect on Northeast Arctic fish stocks. These are considered to be biologically isolated from those in the North Sea, allowing for a meaningful comparison. By analysing normalised spawning stock biomass over a 20 year period we provide evidence that the Norwegian approach in the Northeast Arctic has been more successful than the joint approach in the North Sea for the sustainable management of cod (Gadus morhua), haddock (Melanogrammus aeglefinus), saithe (Pollachius virens) and herring (Clupea harengus). By considering the short term economic costs and the current status of the North Sea fish stocks, we then ask if the Norwegian discard policy should be transferred to the North Sea stocks in order to make management of this area more effective and harmonious. Based on the results of this study we conclude that combined with a system of real time area closures and gear modifications, a ban on the discarding of cod, haddock, saithe and herring in the North Sea would provide substantial benefits to the stocks with minimal short term costs to the fishing industry. The major obstacle preventing the implementation of a discard ban would be the difficulties faced in enforcing it. However, new monitoring technology such as on board CCTV may dramatically improve compliance
The dredge fishery for scallops in the United Kingdom (UK) : effects on marine ecosystems and proposals for future management
The king scallop fishery is the fastest growing fishery in the UK and currently the second most valuable. The UK is also home to the largest queen scallop fishery out of all of Europe. However, concerns have been raised about the effects of this recent growth of UK scallop fisheries among scientists and conservation bodies, as well as amongst the public following recent media campaigns (e.g. Hughâs Fish Fight). This is because the majority of scallop landings (95%) are made by vessels towing scallop dredges, a type of fishing gear known to cause substantial environmental impacts. In addition, several scallop stocks are showing signs of overexploitation and there is concern over future impacts of ocean warming and acidification. Although, there have been several recent improvements in the management of scallop fisheries in parts of the UK, information on many scallop stocks around the UK is still lacking. This report therefore proposes that better monitoring and stock assessments are needed for these scallop fisheries and stocks. With recent legislation soon to result in the development of a new network of marine protected areas (MPAs) around the UK, and improved management of fisheries in European Marine Sites, now is a crucial time to review the UK scallop dredge fishery and its impacts on the wider environment so that this new legislation can support a sustainable future for the UK scallop fishery. This report was therefore commissioned by the Sustainable Inshore Fisheries Trust with the aim of collating existing knowledge on the management and environmental impacts of scallop fisheries around the UK
PHOSGENEâFREE ROUTE TO TOLUENE DIISOCYANATE
A Gulf Coast production plant was designed for a phosgene-free route manufacture of 2,4-toluene diisocyanate (TDI) from toluene diamine (TDA). The process was designed to generate 300 million pounds of TDI per year within the required process specifications. Two reactors were to be installed in order to improve the overall yield of TDI, followed by a series of three distillation columns to ensure highly pure market competitive product. Safety concerns, the start-up process, and other potential considerations are also included.
The results of economic analysis for the base case of the project returned a Net Present Value (NPV) of $20,653,700 with an initial rate of return (IRR) of 18.05% and a return on investment (ROI) of 12.03%. Further analysis on the assumptions made in these calculations may be required before final project approval is granted
Brexit and fishing: How can the UK deliver a 'successful' fisheries policy after Brexit?
Halfway through the Brexit negotiations and delivering on the promises made to voters in the run up to the Brexit vote with regards to fishing remains an incredibly tough task. Richard Barnes, Chris Williams, Bryce Stewart, Bethan O'Leary, Thomas Appleby, and Griffin Carpenter write that 'success' for the UK will only be possible by working with its EU neighbours, and listening to both stakeholder groups and the diverse actors within them
It's still uncertain how the UK will deliver a 'successful' fisheries policy after Brexit
Halfway through the Brexit negotiations and delivering on the promises made to voters in the run-up to the Brexit vote with regards to fishing remains an incredibly tough task. Richard Barnes, Chris Williams, Bryce Stewart, Bethan OâLeary, Thomas Appleby, and Griffin Carpenter write that âsuccessâ for the UK will only be possible by working with its EU neighbours and listening to both stakeholder groups and the diverse actors within them
Building a bridge over troubled waters : an analysis of fishersâ trust in UK fisheries management
1. Effective management of fisheries relies on high levels of trust between the fishing industry and managers and scientists. We therefore used an online questionnaire to examine how well the UK fishing industry trusted the key governing and scientific bodies, and how the views of fishers aligned with UK Governments stated management goals and measures. 2. Participants in our study had low levels of trust in nearly all the institutions included in the survey, however, there was high variation between individual responses. Only the Centre for Environment, Fisheries and Aquaculture Science (CEFAS) had a mean score above 3 of out 5, significantly higher than Defra, the Marine Management Organisation (MMO) and NGOs. 3. The management goals of fishers aligned well with several goals from Defraâs 25-year Environment Plan, particularly sustainability and the need to protect the seabed. However, increasing the coverage of marine protected areas (MPAs) was the least popular goal among participants. Increased use of selectivity devices was most favoured as a management tool, while MPAs were again the least popular. 4. More encouragingly, those fishers who had previously collaborated with scientists and managers showed higher levels of trust across the board. We recommend increased use of fishing industry-science partnerships and co-management as key ways to increase trust as the UK seeks to reform and improve its management of fisheries after Brexit
Metal pollution as a potential threat to shell strength and survival in marine bivalves
Marine bivalve molluscs, such as scallops, mussels and oysters, are crucial components of coastal ecosystems, providing a range of ecosystem services, including a quarter of the worldâs seafood. Unfortunately, due to human activity, coastal marine areas often suffer from metal contamination. We establish that increased levels of metal pollution (zinc, copper and lead) in sediments near the Isle of Man, resulting from historical mining, strongly correlate with significant weakening of shell strength in king scallops, Pecten maximus. This weakness increases mortality during fishing and leaves individuals more exposed to predation. Comparative structural analysis revealed that shells from the contaminated area were thinner and exhibited a pronounced mineralisation disruption parallel to the shell surface within the foliated region of both the top and bottom valves. Our data suggest that these disruptions caused reduced fracture strength and hence increased mortality, even at subcritical contamination levels with respect to current international standards. This hitherto unreported effect is important since such non-apical responses rarely feed into environmental quality assessments, with significant implications for population survival. Hence, our findings highlight the impact of metal pollution on shell mineralisation in bivalves, and urge a reappraisal of currently accepted critical contamination levels
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