Biodiversity Offsets: A Cost-Effective Interim Solution to Seabird Bycatch in Fisheries?

The concept of biodiversity offsets is well established as an approach to environmental management. The concept has been suggested for environmental management in fisheries, particularly in relation to the substantial numbers of non-target species--seabirds in particular--caught and killed as incidental bycatch during fishing activities. Substantial areas of fisheries are being closed to protect these species at great cost to the fishing industry. However, other actions may be taken to offset the impact of fishing on these populations at lower cost to the fishing industry. This idea, however, has attracted severe criticism largely as it does not address the underlying externality problems created by the fishing sector, namely seabird fishing mortality. In this paper, we re-examine the potential role of compensatory mitigation as a fisheries management tool, although from the perspective of being an interim management measure while more long-lasting solutions to the problem are found. We re-model an example previously examined by both proponents and opponents of the approach, namely the cost effectiveness of rodent control relative to fishery area closures for the conservation of a seabird population adversely affected by an Australian tuna fishery. We find that, in the example being examined, invasive rodent eradication is at least 10 times more cost effective than area closures. We conclude that, while this does not solve the actual bycatch problem, it may provide breathing space for both the seabird species and the industry to find longer term means of reducing bycatch.     

Spearfishing regulation benefits artisanal fisheries: the ReGS indicator and its application to a multiple-use Mediterranean marine protected area

The development of fishing efficiency coupled with an increase of fishing effort led to the overexploitation of numerous natural marine resources. In addition to this commercial pressure, the impact of recreational activities on fish assemblages remains barely known. Here we examined the impact of spearfishing limitation on resources in a marine protected area (MPA) and the benefit it provides for the local artisanal fishery through the use of a novel indicator. We analysed trends in the fish assemblage composition using artisanal fisheries data collected in the Bonifacio Strait Natural Reserve (BSNR), a Mediterranean MPA where the spearfishing activity has been forbidden over 15% of its area. Fish species were pooled into three response groups according to their target level by spearfishing. We developed the new flexible ReGS indicator reflecting shifts in species assemblages according to the relative abundance of each response group facing external pressure. The catch per unit effort (CPUE) increased by ca. 60% in the BSNR between 2000 and 2007, while the MPA was established in 1999. The gain of CPUE strongly depended on the considered response group: for the highly targeted group, the CPUE doubled while the CPUE of the untargeted group increased by only 15.5%. The ReGS value significantly increased from 0.31 to 0.45 (on a scale between 0 and 1) in the general perimeter of this MPA while it has reached a threshold of 0.43, considered as a reference point, in the area protected from spearfishing since 1982. Our results demonstrated that limiting recreational fishing by appropriate zoning in multiple-use MPAs represents a real benefit for artisanal fisheries. More generally we showed how our new indicator may reveal a wide range of impacts on coastal ecosystems such as global change or habitat degradation.     

Searching for responsible and sustainable recreational fisheries in the Anthropocene

Recreational fisheries that use rod and reel (i.e., angling) operate around the globe in diverse freshwater and marine habitats, targeting many different gamefish species and engaging at least 220 million participants. The motivations for fishing vary extensively; whether anglers engage in catch-and-release or are harvest-oriented, there is strong potential for recreational fisheries to be conducted in a manner that is both responsible and sustainable. There are many examples of recreational fisheries that are well-managed where anglers, the angling industry and managers engage in responsible behaviours that both contribute to long-term sustainability of fish populations and the sector. Yet, recreational fisheries do not operate in a vacuum; fish populations face threats and stressors including harvest from other sectors as well as environmental change, a defining characteristic of the Anthropocene. We argue that the future of recreational fisheries and indeed many wild fish populations and aquatic ecosystems depends on having responsible and sustainable (R&S) recreational fisheries whilst, where possible, addressing, or at least lobbying for increased awareness about the threats to recreational fisheries emanating from outside the sector (e.g., climate change). Here, we first consider how the concepts of R&S intersect in the recreational fishing sector in an increasingly complex socio-cultural context. Next, we explore the role of the angler, angling industry and decision-makers in achieving R&S fisheries. We extend this idea further by considering the consequences of a future without recreational fisheries (either because of failures related to R&S) and explore a pertinent case study situated in Uttarakahand, India. Unlike other fisheries sectors where the number of participants is relatively small, recreational angling participants are numerous and widespread, such that if their actions are responsible, they have the potential to be a key voice for conservation and serve as a major force for good in the Anthropocene. What remains to be seen is whether this will be achieved, or if failure will occur to the point that recreational fisheries face increasing pressure to cease, as a result of external environmental threats, the environmental effects of recreational fishing and emerging ethical concerns about the welfare of angled fish.     

Effects of fishing and acidification‐related benthic mortality on the southeast Australian marine ecosystem

Oceanic uptake of anthropogenic carbon dioxide (CO₂) is altering the carbonate chemistry of seawater, with potentially negative consequences for many calcifying marine organisms. At the same time, increasing fisheries exploitation is impacting on marine ecosystems. Here, using increased benthic‐invertebrate mortality as a proxy for effects of ocean acidification, the potential impact of the two stressors of fishing and acidification on the southeast Australian marine ecosystem to year 2050 was explored. The individual and interaction effects of the two stressors on biomass and diversity were examined for the entire ecosystem and for regional assemblages. For 61 functional groups or species, the cumulative effects of moderate ocean acidification and fishing were additive (30%), synergistic (33%), and antagonistic (37%). Strong ocean acidification resulted in additive (22%), synergistic (40%), and antagonistic (38%) effects. The greatest impact was on the demersal food web, with fishing impacting predation and acidification affecting benthic production. Areas that have been subject to intensive fishing were the most susceptible to acidification effect, although fishing also mitigated some of the decline in biodiversity observed with moderate acidification. The model suggested that ocean acidification and long‐term fisheries exploitation could act synergistically with the increasing sensitivity to change from long‐term (decades) fisheries exploitation potentially causing unexpected restructuring of the pelagic and demersal food webs. Major regime shifts occur around year 2040. Greater focus is needed on how differential fisheries exploitation of marine resources may exacerbate or accelerate effects of environmental changes such as ocean acidification.     

Fuel Use and Greenhouse Gas Emissions from Offshore Fisheries of the Republic of Korea

Greenhouse Gas (GHG) emissions from the offshore fisheries industry in the Republic of Korea (Korea) were examined in response to growing concerns about global warming and the contribution of emissions from different industrial sectors. Fuel usage and GHG emissions (CO₂, CH₄, N₂O) were analysed using the ‘Tier 1’ method provided by the Intergovernmental Panel on Climate Change (IPCC) from the offshore fishery, which is the primary domestic seafood production sector in Korea. In 2013, fuel usage in the offshore fishery accounted for 59.7% (557,463 KL) of total fuel consumption of fishing vessels in Korea. Fuel consumption and thus GHG emissions were not stable through time in this industry, increasing by 2.4% p.a. for three consecutive years, from 2011 to 2013, despite a decrease in the number of vessels operating. GHG emissions generated in offshore fisheries also changed through time and increased from 1,442,975 tCO₂e/year in 2011 to 1,477,279 tCO₂e/year in 2013. Changes in both fuel use and GHG emissions per kg offshore fish production appeared to be associated with decreasing catch rates by the fleet, which in turn were a reflection of decrease in fish biomass. Another important feature of GHG emissions in this industry was the high variation in GHG emission per kg fish product among different fishing methods. The long line fishery had approximately three times the emissions of the average production while the jigging fishery was more than two times higher than the average. Lowest emissions were from the trawl sector, which is regarded as having greatest environmental impact using traditional biodiversity metrics although had lowest environmental impact in terms of fuel and GHG emission metrics used in this study. The observed deterioration in fuel efficiency of the offshore fishery each year is of concern but also demonstrates that fuel efficiency can change, which shows there is opportunity to improve efficiency with changes to fishery management and harvesting operations.     

Characterizing fishing effort and spatial extent of coastal fisheries

Biodiverse coastal zones are often areas of intense fishing pressure due to the high relative density of fishing capacity in these nearshore regions. Although overcapacity is one of the central challenges to fisheries sustainability in coastal zones, accurate estimates of fishing pressure in coastal zones are limited, hampering the assessment of the direct and collateral impacts (e.g., habitat degradation, bycatch) of fishing. We compiled a comprehensive database of fishing effort metrics and the corresponding spatial limits of fisheries and used a spatial analysis program (FEET) to map fishing effort density (measured as boat-meters per km2) in the coastal zones of six ocean regions. We also considered the utility of a number of socioeconomic variables as indicators of fishing pressure at the national level; fishing density increased as a function of population size and decreased as a function of coastline length. Our mapping exercise points to intra and interregional 'hotspots' of coastal fishing pressure. The significant and intuitive relationships we found between fishing density and population size and coastline length may help with coarse regional characterizations of fishing pressure. However, spatially-delimited fishing effort data are needed to accurately map fishing hotspots, i.e., areas of intense fishing activity. We suggest that estimates of fishing effort, not just target catch or yield, serve as a necessary measure of fishing activity, which is a key link to evaluating sustainability and environmental impacts of coastal fisheries.     

The importance of using life cycle assessment in policy support to determine the sustainability of fishing fleets: a case study for the small-scale <Emphasis Type="Italic">xeito</Emphasis> fishery in Galicia,Spain

Purpose

Drift net fishing activities have undergone a thorough revision at a European Union level, since authorities argue that several loopholes still exist in the legislation that allow small-scale fisheries to use these gears. High incidental catches, or the lack of selectivity, are some of the primary scientific criteria behind this discussion. This new framework is of particular interest in the region of Galicia (NW Spain) due to the social importance of small-scale fishing vessels using drift nets. In fact, over 400 vessels have a licence to capture European pilchard (Sardina pilchardus) with a fishing gear called xeito, which is a small-scale drift net.

Methods

The main goal of this article is to provide stakeholders in the fishing sector with environmentally relevant results regarding the life cycle impacts linked to fishing practices performed by small-scale vessels using the xeito gear to target European pilchard. We hypothesize that environmental impacts computed with LCA will provide additional insights to the sustainability of the pilchard small-scale fishery in NW Spain, adding a series of criteria that may be useful for policy-makers to determine the consequences of forbidding this type of drift netting in the future.

Results and discussion

Results show that environmental impacts across impact categories and operational activities do not differ much from that of other similar fishing fleets examined in recent years, with fuel for propulsion being the main environmental burden in most impact categories. When conducting a statistical analysis, no significant difference in energy use was identified between this small-scale fleet and purse seiners targeting pilchard in Galicia. Moreover, the results obtained demonstrate, in line with previous studies, that European pilchard is still an energy-efficient source of animal protein option as compared to demersal fish alternatives, crustaceans, or livestock.

Conclusions

The results do not indicate that European pilchard landed with small-scale drift nets generates higher environmental life cycle impacts than pilchard landed by purse seiners in NW Spain. However, longer time frames for the analysis should be performed to attain results with lower uncertainty.

     

Toward the Ecological Footprint of the use and maintenance phase of buildings: Utility consumption and cleaning tasks

Due to poor design of buildings in terms of maintenance, there are a number of buildings today that remain extremely expensive to maintain, both economically and environmentally. In order to mitigate these overheads, the development of a cost database is needed with which the resources required to clean and maintain buildings can be estimated. This paper presents a methodology to estimate these costs and the environmental impact, in terms of Ecological Footprint (EF), associated to the utility consumption and to the cleaning tasks necessary during the service life of buildings. Given the numerous peculiarities identified for this type of activity compared to the construction of buildings, it is necessary to define a new methodology of calculation, with its own assumptions and formulae. This methodology is then applied to the case of a college hall of residence that houses up to 139 residents. The results show that the annual EF of cleaning tasks accounts for 11.42% of the EF of utility consumption. Together they total 67.334 global hectares per year (gha/yr), 88% of which corresponds to the carbon footprint. Within the EF of cleaning, about 71% is due to food consumed by labor, while 26% is due to the manufacture of cleaning products and tools, which are equally divided among the six categories of productive land. The development of this methodology is essential for the detailed quantification of the environmental impact of utility consumption and cleaning tasks that occur during the service life of buildings. The use of discount rates on results is included in terms of the EF of a baseline year, as an equivalent to the discount rate in economic terms.     

SMART: A Spatially Explicit Bio-Economic Model for Assessing and Managing Demersal Fisheries,with an Application to Italian Trawlers in the Strait of Sicily

Management of catches, effort and exploitation pattern are considered the most effective measures to control fishing mortality and ultimately ensure productivity and sustainability of fisheries. Despite the growing concerns about the spatial dimension of fisheries, the distribution of resources and fishing effort in space is seldom considered in assessment and management processes. Here we propose SMART (Spatial MAnagement of demersal Resources for Trawl fisheries), a tool for assessing bio-economic feedback in different management scenarios. SMART combines information from different tasks gathered within the European Data Collection Framework on fisheries and is composed of: 1) spatial models of fishing effort, environmental characteristics and distribution of demersal resources; 2) an Artificial Neural Network which captures the relationships among these aspects in a spatially explicit way and uses them to predict resources abundances; 3) a deterministic module which analyzes the size structure of catches and the associated revenues, according to different spatially-based management scenarios. SMART is applied to demersal fishery in the Strait of Sicily, one of the most productive fisheries of the Mediterranean Sea. Three of the main target species are used as proxies for the whole range exploited by trawlers. After training, SMART is used to evaluate different management scenarios, including spatial closures, using a simulation approach that mimics the recent exploitation patterns. Results evidence good model performance, with a noteworthy coherence and reliability of outputs for the different components. Among others, the main finding is that a partial improvement in resource conditions can be achieved by means of nursery closures, even if the overall fishing effort in the area remains stable. Accordingly, a series of strategically designed areas of trawling closures could significantly improve the resource conditions of demersal fisheries in the Strait of Sicily, also supporting sustainable economic returns for fishermen if not applied simultaneously for different species.     

Food security and marine capture fisheries: characteristics, trends, drivers and future perspectives

World population is expected to grow from the present 6.8 billion people to about 9 billion by 2050. The growing need for nutritious and healthy food will increase the demand for fisheries products from marine sources, whose productivity is already highly stressed by excessive fishing pressure, growing organic pollution, toxic contamination, coastal degradation and climate change. Looking towards 2050, the question is how fisheries governance, and the national and international policy and legal frameworks within which it is nested, will ensure a sustainable harvest, maintain biodiversity and ecosystem functions, and adapt to climate change. This paper looks at global fisheries production, the state of resources, contribution to food security and governance. It describes the main changes affecting the sector, including geographical expansion, fishing capacity-building, natural variability, environmental degradation and climate change. It identifies drivers and future challenges, while suggesting how new science, policies and interventions could best address those challenges.     

The state of exploitation of the commercial demersal fishery of Cameroon

The state of exploitation of the demersal fisheries resources of Cameroon has been assessed using the classic Schaefer's (1954) model and the Gulland'ss (1961) moving average. The euilibrium yield found with the Schaefer method is statistically different (95 % probability) and higher than the Gulland approach. Because equilibrium models consistently over-estimate MSY and its related optimum effort, management option should target the 95 % value of the estimated parameters. The resources are being over-fished; as an immediate alternative to the urgent concern, catch and/or effort quotas could be allocated to the various fishing companies, with the total allocated catch and/or effort (for all fishing companies) 5% less than the estimated parameters. Enforcement control of that policy would be simplified as fishing activities are localised in the two main estuaries of the “Cameroon River” and Riodel-Rey;results should be complemented by economic studies of the fishery, as these economic factors would explain or better predict the behaviour of the fishing industry.     

Permeable Boundaries: Outsiders and Access to Fishing Grounds in the Berau Marine Protected Area

The designation of Marine Protected Areas (MPAs) in Indonesia has been accelerated over the past two decades in line with international biodiversity conservation commitments and to secure a basis for decentralised fisheries resources management. The Berau MPA of northeast Kalimantan is one of them. This paper shows how the establishment of the park boundaries and zoning affects local fishers' livelihoods. Particular attention is paid to the position of outsider fishers or andon, who have a legal right to access the resource rich fishing grounds. Decentralised district government legitimises outsider fisheries activities because andon fishing permits bring in fees as a contribution to the regional income (PAD or pendapatan asli daerah), while international environmental organisations and local fishers regard the outsider fishers as illegitimately entering the MPA to access resources they regard as their own. Thus, MPA boundaries appear to be highly permeable, with both local fishers and environmental NGOs seeing the presence of andon as illegitimate and illicit, despite being legal.     

Inclusion of discard assessment indicators in fisheries life cycle assessment studies. Expanding the use of fishery-specific impact categories

Purpose

The main purpose of this article is to propose specific discard indexes for their development in fisheries life cycle assessment (LCA). The objective of these is to characterize and standardize discards in worldwide fisheries.

Methods

The global discard index (GDI) is intended to be an easily understood index whose use is extendible to any fishery in the world. It is presented as a dynamic index that aims to characterize and standardize discard rates between fisheries by direct comparison with the global discard rates reported periodically by FAO. Furthermore, a simplified approach excluding characterization is presented for scenarios in which the data quality linked to discards is poor. Two additional indicators, survival rate of discards and slipping, are proposed to improve the reporting and quantification of biomass waste by fishing vessels.

Results

GDI implementation, together with two other fishery-specific impact categories, showed remarkable differences in the environmental impacts of several fishing fleets when compared with the obtained results for conventional impact categories. Results for the conventional categories were strongly influenced by the energy use in the fishery, while results obtained for fishery-specific categories presented variable trends due to the dependence on a wider range of factors. GDI inclusion favored direct comparison with worldwide average discard rates on a time scale basis, from a wet weight or a net primary productivity perspective, depending on the selected approach.

Conclusions

Proposed indicators achieved the important objective of integrating discard data as a fishery-specific impact in fishery LCAs, increasing the benefits of implementing LCA in fisheries assessment. Specific advantages of these indicators include assessing changes in capture and landing composition, evaluating the selectivity of the fishing gears, and monitoring the behavior of fisheries in a normalized context respect to other fisheries. GDI was identified as an adequate methodological improvement for regular use in fisheries LCA. Future developments GDI include its harmonization for inclusion in damage assessment.     

Types and extent of fishing gear losses and their causes in the artisanal fisheries of Istanbul,Turkey

Fishing gear losses remain a serious problem for marine life; these losses are also the source of an invisible fishing mortality. This study is an analysis of this problem within the artisanal fisheries of Istanbul. From September 2009 through May 2010, face‐to‐face interviews were conducted in 27 fishing ports for a total of 282 questionnaires. Estimates of lost fishing gear were 229.48 km of set nets, 2700 m of longlines, and 14 fish traps. Turbot nets had the highest loss ratio (54.73%), followed by bonito nets (16%), red mullet nets (7.36%), and encircling trammel nets (4.83%). The four major causes of net loss were: conflicts with other gear types (trawl and purse seine), conflicts with cargo vessels, bottom structure hindrances, and bad weather conditions. Bottom structures were the single factor in net losses for longlines and fish traps. The study observed that large quantities of nets had been lost, and that each net type showed a positive relationship between the number of nets used and the number of nets lost. Separate zones for artisanal and industrial fisheries are recommended as a realistic approach to reduce the losses of fishing gear and the impact of ‘ghost fishing’.     

Changes in the feeding ecology of South American sea lions on the southern Brazilian coast over the last two decades of excessive fishing exploration

In the last decades, an increasing fishing effort and a decreasing trend in fish catches have been observed in southern Brazil. Considering that marine mammals and fisheries usually compete for the same resources, it is reasonable to presume that the feeding ecology of these predators is affected by the current scenario. To evaluate this hypothesis, long-term variation in the diet of the South American sea lion (Otaria flavescens) relative to fisheries exploitation was analyzed for two periods (1993–2003 versus 2004–2014). The degree of overlap between the relative biomass of the sea lions’ diet and the target species of six types of local fishery was analyzed. An increase in prey overlap between sea lions and fisheries was observed in the more recent sampling period, along with an increase in prey diversity, richness, and niche breadth of the sea lions’ diet. These results suggest that the overfishing scenario could partly explain the modified feeding ecology of the sea lions. In this context, we recommend a review and better regulation of the current fishing effort in the region, which we believe will be an important step to maintain the fish stocks and minimize the impact of fishing on marine top predators.     

Assessing the impact of toothed whale depredation on socio-ecosystems and fishery management in wide-ranging subantarctic fisheries

Marine predators feeding on fisheries catches directly on the fishing gear, a behaviour termed “depredation”, has emerged as a major human-wildlife conflict globally, often resulting in substantial socio-economic and ecological impacts. This study investigated the extent of this conflict in commercial Patagonian toothfish (Dissostichus eleginoides) fisheries across subantarctic waters where both killer whales (Orcinus orca) and sperm whales (Physeter macrocephalus) feed on toothfish caught on longline hooks. Using long-term datasets from six major fishing areas, from southern Chile to the Indian Ocean sector of the Southern Ocean, statistical models were developed to quantify the catch removals due to whale depredation interactions. The results indicated that these removals were large, totalling more than 6600 t of toothfish between 2009 and 2016 with an annual mean of 837 t [95% CI 480–1195 t], comprised of 317 t [232–403 t] and 518 t [247–790 t] removed by killer whales and sperm whales, respectively. Catch removals greatly varied between areas, with the largest estimates found at Crozet, where on average 279 t [179–379 t] of toothfish per year, equivalent to 30% [21–37%] of the total catches. Together, these findings provide metrics to assess the impacts of depredation interactions on the fishing industry, whale populations, fish stocks and associated ecosystems. With an estimated $15 M USD worth of fish depredated every year, this study highlights the large geographic scale and economic significance of the depredation issue and its potential to compromise the viability of some toothfish fisheries which are the primary socio-economic activity in subantarctic regions.

     

A framework for assessing the biodiversity and fishery aspects of marine reserves

1.  Resource management agencies are often charged with managing natural resources for economic and social goals, while also protecting and conserving biodiversity and ecosystem function. However, this may not always be possible. Ecosystem-based management is frequently suggested as a way to achieve multiple objectives in resource management and requires that trade-offs among conflicting objectives be identified and an effective means to utilize these trade-offs developed.
2.  We examine the relationship between area and species richness in a diverse assemblage of fishes along the US West Coast and then use parameters from this relationship as input for a model that considers trade-offs between fisheries yield and the number of species protected by different management strategies.
3.  The species–area relationship ( S  =  cA ^z ) for fishes along the US Pacific coast is well described by the relationship S  =   16·18 A ^0·226.
4.  There are nearly linear trade-offs between diversity and yield when fishing effort is low. However, the trade-offs become nonlinear as fishing effort increases and imposing MPAs increases both the conservation and fisheries value of the system when the system is overfished.
5.   Synthesis and applications . Solving conflicts between fisheries and conservation requires attention as to how conservation benefits accrue as fishing effort is reduced. However, scientists often lack quantitative information about the trade-offs inherent in human activities such as fisheries. The approach we develop here can begin to help frame the questions to be posed and evaluate the likely consequences of different management options.     

Computation of Operational and Environmental Benchmarks Within Selected Galician Fishing Fleets

Increasing the eco‐efficiency of fishing fleets is currently a major target issue in the seafood sector. This objective has been influenced in recent years by soaring fuel prices, a fact particularly relevant to a sector whose vessels present high energy consumption rates. Efforts to minimize fuel consumption in fishing fleets result in economic benefits and also in important reductions regarding environmental impacts. In this article, we combine life cycle assessment (LCA) and data envelopment analysis (DEA) to jointly discuss the operational and environmental performances of a set of multiple, similar entities. We applied the “five‐step LCA + DEA method” to a wide range of vessels for selected Galician fisheries, including deep‐sea, offshore, and coastal fleets. The environmental consequences of operational inefficiencies were quantified and target performance values benchmarked for inefficient vessels. We assessed the potential environmental performance of target vessels to verify eco‐efficiency criteria (lower input consumption levels, lower environmental impacts). Results revealed the strong dependence of environmental impacts on one major operational input: fuel consumption. The most intensive fuel‐consuming fleets, such as deep sea trawling, were found to entail the diesel consumption levels nearest to the efficiency values. Despite the reduced environmental contributions linked to other operational inputs, such as hull material, antifouling paint, or nets, these may contribute to substantial economic savings when minimized. Finally, given that Galicia is a major fishing region, many of the conclusions and perspectives obtained in this study may be extrapolated to other fishing fleets at the international level.     

The United Kingdom’s role in North Sea demersal fisheries: a hundred year perspective

This study compiles 100?years of North Sea demersal landings, focusing on the UK, and relating them to historical events and political, technological and economical drivers that influenced demersal fisheries. In the early twentieth century, aided by technological advances, the UK, and in particular England, had unchallenged dominance in North Sea demersal fisheries. Since then, the two World Wars and other political developments have had a great impact on British fisheries. Between the 1920s and 1960s, English ports shifted their interests away from the North Sea towards highly profitable distant waters, whereas the Scottish fleet relied less on these fishing grounds. Meanwhile, especially in the 1960s, other European countries expanded their fisheries, undermining Britain??s lead. In the 1970s and 1980s, Scotland benefitted from mainly fishing in the North Sea. Firstly, the assertion of 200 nautical miles Exclusive Economic Zones made the distant waters inaccessible to English fleets at a time when England??s fisheries were highly dependent on them. Secondly, the relatively minor activity in the North Sea by the English compared to the Scottish fleets coincided with the establishment of the Common Fisheries Policy. This had implications when total allowable catches were first implemented because quota allocations to countries were based on their recent catches from the North Sea. Thus, after the loss of fishing opportunities in distant waters, the North Sea once more became an important fishing ground for Britain, just as in the early twentieth century, however, the emphasis of fisheries had shifted from England to Scotland.     

Spatial management of the Mediterranean bottom-trawl fisheries: the case of the southern Aegean Sea

A time series of survey abundance indices for commercially important demersal fish and cephalopod species, inhabiting the narrow continental shelf of the southern Aegean Sea, is analyzed in relation to the topography of the area in order to evaluate the impact of different spatial fishery bans on the bottom-trawl fishery. With reference to the current situation, results suggested that implementation of the 1967/2006 EC Regulation, which bans bottom-trawl activities within 1.5 NM off the coast, will significantly increase (20–80%, depending on the species) the proportion of the populations that are inaccessible to the bottom-trawl fishery. It might also result in shifting of fishing activities toward deeper waters, adding fishing pressure onto slope resources inhabiting the slope. As depth determines, to a large extent, the distribution pattern of the species, it constitutes a variable of crucial importance for the spatial management of marine fisheries and should be taken into account when adopting relevant management regimes.