Fishers' experiences and perceptions of marine mammals in the South China Sea: Insights for improving community‐based conservation

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Fishermen's perception on the sustainability of small‐scale fisheries and dolphin–fisheries interactions in two increasingly fragile coastal ecosystems in western Greece

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Does full protection count for the maintenance of β‐diversity patterns in marine communities? Evidence from Mediterranean fish assemblages

1. Although it is widely recognized that protection may enhance size, abundance, and diversity of fish, its effect on spatial heterogeneity of fish assemblages and species turnover is still poorly understood.
2. Here the effect of full protection within a Mediterranean marine protected area on β‐diversity patterns of fish assemblages along a depth gradient comparing a no‐take zone with multiple unprotected areas is explored. The no‐take zone showed significantly higher synecological parameters, higher β‐diversity among depths, and lower small‐scale heterogeneity of fish assemblages relative to unprotected areas.
3. Such patterns might likely depend on the high level of fishing pressure outside the no‐take zone, as also abundance‐biomass curves seemed to indicate. Results suggested that full protection could play a role in maintaining high β‐diversity, thus reducing the fragility of marine communities and ecosystems, and spatial heterogeneity may represent a reliable predictor of how management actions could provide insurance against undesirable phase shifts.

     

Sea turtles bycatch in the Adriatic Sea set net fisheries and possible hot‐spot identification

1. Bycatch resulting from fishing activities is the main threat for the conservation of sea turtles in the Mediterranean Sea. Fixed nets are a matter of concern for sea turtles mainly in coastal areas during the neritic stage when both juvenile and adult life stages are affected. Mortality caused by entanglement in set nets is related to forced apnoea due to the high soak time of the nets and consequent drowning.
2. This study investigated the loggerhead turtle bycatch in set net coastal fisheries in the northern Adriatic Sea (General Fisheries Commission for the Mediterranean Geographical Sub‐Area 17, [GSA 17]) through an interview‐based approach, to understand the potential contribution of these fisheries to the general decline of the sea turtle population. A second goal was to identify a possible hot‐spot turtle bycatch area through on‐board observations.
3. The study estimates that more than 5400 turtles are caught in the west GSA 17 each year with the largest number in the summer. A hot‐spot for entanglement was also identified in an area located south of the River Po delta (41.5–69 m depth) during the summer. Sixty‐four turtles were caught over a period of 30 fishing days by either trammel nets and gillnets (0.7 and 0.5 turtle per km of net respectively) and was the greatest number that has been observed anywhere in the Mediterranean.
4. Possible management strategies to reduce bycatch include technical modification to gear setting (such as reducing netting slack and using small meshes), bycatch reducer devices (such as LED UV), and area and seasonal gear restrictions to small‐scale fisheries in areas of greatest concern in the northern Adriatic Sea.

     

Review of climate change impacts on marine fisheries in the UK and Ireland

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On sightings of (vagrant?) monk seals,Monachus monachus,in the Mediterranean Basin and their importance for the conservation of the species

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Understanding fishing‐induced extinctions in the Amazon

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A new large‐scale and cost‐effective restoration method for cold‐water coral gardens

1. Gorgonians dwelling on the Mediterranean continental shelf are among the most frequent fishing bycatch taxa. These species display several traits, such as long lifespans and slow growth, which make them very vulnerable to the impacts caused by fishing activities with far‐reaching and long‐lasting effects.
2. Hence, restoration and mitigation actions are crucial to enhance and speed up the natural recovery of damaged cold‐water coral gardens. Given the growing concern to develop effective and affordable restoration actions, the present study aims to propose and technically validate a new large‐scale and cost‐effective restoration method.
3. This technique, named ‘badminton method', consists of attaching bycatch Eunicella cavolini colonies to cobble supports and returning them to the continental shelf by gently throwing the gorgonian transplants directly from a boat.
4. Two consecutive field experiments were conducted in order to find the best cobble type support and gorgonian size to be used: first, to evaluate the landing efficiency of gorgonian transplants at different depths (from 5 to 30 m) and second, to evaluate their capability to maintain a correct position over time.
5. Natural cobbles with large gorgonians attached were the best option. Field results and modelling approaches suggest that the transplants would correctly land on the continental shelf seabed in a predicted area of around 60 m². Moreover, they would successfully maintain an upright position ensuring gorgonian survival over time.
6. The success of this method highlights the feasibility of large‐scale and low‐cost restoration actions with promising results for the conservation and recovery of cold‐water coral gardens.

     

Setting the net lower: A potential low-cost mitigation method to reduce cetacean bycatch in drift gillnet fisheries

1. Bycatch is the most significant threat to marine megafauna (sea turtles, marine mammals, elasmobranchs, seabirds) worldwide, and the leading cause of the decline of several cetacean species. The bycatch issue in the Indian Ocean is poorly understood, but high bycatch levels in gillnet fisheries have been documented for the past two decades, in both small-scale and semi-industrial fisheries. Unfortunately, methods to reduce bycatch are often unavailable, financially non-viable or socially unacceptable to fishermen.
2. Using a network of trained boat captains in the tuna drift gillnet fishery in the Arabian Sea, targeted catch and bycatch data were collected from 2013 to 2017 off the coast of Pakistan (northern Indian Ocean). Two fishing methods using multifilament gillnets were used: surface deployment and subsurface deployment (i.e. headline of net set below 2 m depth).
3. Predicted catch rates for targeted species did not differ significantly between the two fishing practices, although a drop in tuna (6.2%) and tuna-like (10.9%) species captures was recorded in subsurface sets. The probability of cetacean bycatch, however, was 78.5% lower in subsurface than in surface sets.
4. Cetacean bycatch in tuna drift gillnet fisheries has the potential to be significantly reduced at a relatively low cost for fishers. However, further research with an appropriate sampling design and a large sample size is required to confirm the efficacy of the proposed mitigation method. The acceptability and adoption of subsurface setting by fishers also needs to be further investigated. Despite some limitations, this preliminary study also highlights the importance of crew-based observer data as an alternative source of data when observers cannot be deployed on fishing vessels.

     

Sea turtle by‐catch in the Mediterranean

Sea turtle by‐catch data in the Mediterranean were reviewed and analysed with fishing effort. The results indicate over 132 000 captures per year, with probably over 44 000 incidental deaths per year, while many others are killed intentionally. Small vessels using set net, demersal longline or pelagic longline represent most of the Mediterranean fleet and likely cause more incidental or intentional deaths than large vessels typically using bottom trawl or pelagic longline. When interactions, mortality, intentional killing, size (a proxy for reproductive value) and turtle populations are considered, results indicate that Mediterranean green (Chelonia mydas) and loggerhead turtles (Caretta caretta) are more affected (i) by fishing gears such as bottom trawlers, demersal longlines and set nets, (ii) by small‐scale fisheries, and (iii) by fishing in the eastern basin. Although small‐scale fisheries should be the priority target, available measures are easier to implement on the fewer large vessels. Moreover, these measures are few, and they are not implemented yet, while others should still be tested for the Mediterranean fisheries. Thus, measures for reducing captures or mortality through changing gear‐specific characteristics may help, but probably a more holistic conservation strategy aimed to an ecosystem‐based fishery management for a sustainable fishing would be the only solution for the long‐term survival of Mediterranean Sea turtle populations and their habitats. Small‐scale fisheries should manage marine resources, including turtles, in a responsible and sustainable way. Turtles may not only benefit from but can also help this process if their non‐consumptive value is fully recognized.     

Identifying historical baseline at the onset of exploitation to improve understanding of fishing impacts

1. Marine communities have long been impacted by human activities, but the quantification of human‐driven changes often relies on recent data. This is because historical data on fish populations are lacking and are challenging to include in contemporary stock and ecological assessments. As a result, the impacts of early fishing pressure on marine communities are generally poorly documented worldwide.
2. Marine communities of Southeast Australia have a relatively short history of exploitation compared with other temperate systems and were sampled before and after the onset of commercial fishing. As such, they provide a rare opportunity to identify historical baselines and to understand ecological changes after the onset of commercial exploitation.
3. This study compares survey data collected around Tasmania, Southeast Australia, in 1909–1910 with data from the 1980s. The period considered precedes the establishment of a trawl fishery in Southeast Australia in 1915, of other important commercial fisheries in Tasmania, and of a fisheries data collection programme in 1984. Nominal catch rates are used to examine changes across all families of demersal fish recorded in catches and generalized linear models are used to estimate and compare standardized indices of abundance between the 1909–1910 and 1980s data for key commercial families.
4. Results show significant, and thus far unreported, fishing‐induced changes in marine communities after the establishment of commercial fishing in the region. Changes mostly relate to shifts in catch composition and steep declines in the abundance of the main commercial families.
5. This study illustrates a method for analysing low‐quality historical catch data and provides estimates of pre‐commercial fishing abundance that can be included in stock and ecological assessments. More broadly, this study demonstrates the significant role of early fishing in shaping marine communities and increases our understanding about general patterns of exploitation that have been difficult to identify with longer but less detailed fishing histories.

     

Effectiveness of shore‐based remote camera monitoring for quantifying recreational fisher compliance in marine conservation areas

1. Marine conservation areas require high levels of compliance to meet conservation objectives, yet little research has assessed compliance quantitatively, especially for recreational fishers. Recreational fishers take 12% of global annual fish catches. With millions of people fishing from small boats, this fishing sector is hard to monitor, making accurate quantification of non‐compliance an urgent research priority.
2. Shore‐based remote camera monitoring was tested for quantifying recreational non‐compliance in near‐shore, coastal rockfish conservation areas (RCAs) in the Salish Sea, Canada.
3. Six high definition trail cameras were used to monitor 42 locations between July and August 2014.
4. Seventy‐nine percent of monitored conservation area sites showed confirmed or probable fishing activity, with no significant difference in fishing effort inside and outside RCAs.
5. Mixed effects generalized linear models were used to test environmental and geographic factors influencing compliance. Sites with greater depth had significantly higher fishing effort, which may imply high, barotrauma‐induced, rockfish mortality in RCA sites.
6. Non‐compliance estimates were similar to aerial fly‐over compliance data from 2011, suggesting that trail camera monitoring may be an accurate and affordable alternative method of assessing non‐compliance in coastal conservation areas, especially for community‐based organizations wishing to monitor local waters.
7. Widespread non‐compliance could compromise the ability of RCAs to protect and rebuild rockfish populations. Increased education, signage, and enforcement is likely to improve compliance.

     

Changes in a coral reef fishery along a gradient of fishing pressure in an Indonesian marine protected area

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Biological implications of recreational shore angling and harvest in a marine reserve: the case of Cape Creus

• 1. Recreational shore fishing along the coast of the marine reserve of Cap de Creus (NW Mediterranean) was studied in 2007 and 2009 based on roving creel surveys (on‐site angler surveys during which anglers' harvests are examined by the survey clerk). The study aimed to assess the biological impacts of this leisure activity on coastal fish stocks and the potential risks arising from the use of exotic baits.
• 2. Recreational shore fishers employ seven different fishing techniques, of which the bottom fishing rod (a fishing rod whose hooks, together with the bait, lie on the bottom or near it by means of a heavy weight) is by far the most widely used method (nearly 90% of observations). In total, 25 fish species were identified in the catch from the bottom fishing rod.
• 3. The estimated annual shore fishing catches (c.3 tons) are much lower than those obtained by recreational boat and spear fishing (c.20 tons each), and those from commercial (artisanal) fishing (c.50 tons). The weighted mean vulnerability index and trophic level values in the catch from the bottom fishing rod are 52.2 and 4.03, respectively.
• 4. A minimum of 43% of the baits used by the shore anglers were live, non‐native species (mostly polychaetes).
• 5. Overall, results highlight the impact of shore angling on coastal fish communities of a protected area and the increasing environmental risks arising from the use of exotic marine baits, which constitute a potential and unregulated vector of introduction of non‐native species in the Mediterranean. Copyright © 2011 John Wiley & Sons, Ltd.

     

Cold‐water coral Madrepora oculata in the eastern Ligurian Sea (NW Mediterranean): Historical and recent findings

1. Cold‐water coral (CWC) ecosystems are long‐lived, slow‐growing and fragile, which makes them especially vulnerable to physical damage. In recent decades, CWCs have been severely threatened by fisheries, hydrocarbon extraction, pollution and other human activities.
2. In the Mediterranean Sea, some investigations have been carried out on CWC ecosystems, mostly focused on their distributions within the central and eastern basins.
3. Historical reports and fishermen's maps for the eastern Ligurian Sea (NW Mediterranean) from the 1960s document the occurrence of extensive banks of living CWC, mostly Madrepora oculata, between depths of 200 and 500 m.
4. In 2013/2014, multibeam, side scan sonar (SSS) and remotely operated vehicle (ROV) surveys were carried out in that area, specifically in the Levante Canyon, to assess the occurrence, distribution and conservation status of CWC.
5. The SSS and ROV showed numerous trawl tracks and small (10 cm high), dead, buried colonies at 300–500 m. Deeper, between 525 and 575 m, dense populations of living, 1 m high colonies of Madrepora oculata were found on the flanks of Levante Canyon. The deep sites showed colonies overturned or entangled by long‐line fishing activities.
6. The discovery of new CWC banks not yet heavily damaged by fishing activities, suggests that urgent measures for conservation should be taken in the Mediterranean and worldwide. The present limitation of trawl‐fishing to above 1000 m depth, established by the General Fisheries Commission for the Mediterranean (GFCM) in 2005, seems to be ineffective, since CWCs are mostly located at less than 1000 m depth in the Ligurian Sea. A network of high‐seas/deep‐sea marine protected areas (MPAs) would favour a better strategy for protecting substantial areas of CWCs.

     

Illustrating the critical role of human dimensions research for understanding and managing recreational fisheries within a social‐ecological system framework

Effective management of recreational fishing requires understanding fishers and their actions. These actions constitute critical links between social and ecological systems that result in outcomes that feedback and influence recreational fishers' actions and the management of these actions. Although much research exists on recreational fishers and their actions, this research is often disconnected from management issues. One way to help to overcome this disconnect is to illustrate how past research on the social component of recreational fishing fits within an emerging coupled social‐ecological system (SES) framework. Herein, a conceptual SES is first developed with specific attention to recreational fisheries. This SES is then used to illustrate the importance of considering human dimensions research for articulating, studying and ultimately managing key outcomes of recreational fisheries (e.g. fish population conservation, fisher well‐being) using the example of harvest regulations and a brief review of past interdisciplinary research on recreational fishing. The article ends by identifying key research needs including understanding: how factors such as management rules affect the diversity of actions by recreational fishers; how governance and management approaches adapt to changing social and resource conditions; and how recreational fishers learn and share information.     

Strengthening the synergies among global biodiversity targets to reconcile conservation and socio‐economic demands

1. Most of the world's nations adopted the 20 Aichi global biodiversity targets to be met by 2020, including the protection of at least 10% of their coastal and marine areas (Target 11) and the avoidance of extinction of threatened species (Target 12). However, reconciling these biodiversity targets with socio‐economic demands remains a great dilemma for implementing conservation policies.
2. In this paper, Aichi Targets 11 and 12 were simultaneously addressed using Brazil's exclusive economic zone as an example. Priority areas for expanding the current system of marine protected areas within the country's eight marine ecoregions were identified with data on threatened vertebrates under different scenarios. Additionally, the potential effects of major socio‐economic activities (small? and large‐scale fishing, seabed mining, and oil and gas exploration) on the representation of conservation features in proposed marine protected areas were explored.
3. Areas selected for expanding marine protected areas solely based on biodiversity data were different (spatial overlap from 62% to 93%) from areas prioritized when socio‐economic features were incorporated into the analysis. The addition of socio‐economic data in the prioritization process substantially decreased opportunity costs and potential conservation conflicts, at the cost of reducing significantly (up to 31%) the coverage of conservation features. Large? and small‐scale fisheries act in most of the exclusive economic zone and are the major constraints for protecting high‐priority areas.
4. Nevertheless, there is some spatial mismatch between areas of special relevance for conservation and socio‐economic activities, suggesting an opportunity for reconciling the achievement of biodiversity targets and development goals within the intricate Brazilian seascape by 2020 and beyond.

     

Patterns of species and functional diversity around a coastal marine reserve: a fisheries perspective

• 1. Marine protected areas (MPAs) are expected to function simultaneously as biological conservation and fisheries management tools, but empirical evidence linking biodiversity conservation with fisheries benefits is scarce. Around the Medes Islands marine reserve (Spain, NW Mediterranean) patterns of fish catch diversity, catch (CPUE) and income (IPUE) were assessed and the economic value of diversity for local fisheries was explored by combining a Geographic Information System (GIS) analysis with geostatistics.
• 2. Catch data were derived from the trammel net fleet operating around the MPA to gain information on species diversity, functional diversity, functional redundancy, CPUE and IPUE.
• 3. Results revealed significant impact of both the fishing prohibition in the MPA and the presence of seagrass beds on diversity metrics, catch and income. Clear differences in functional redundancy in fish assemblages were found within the study area, indicating greater resilience of the fish assemblage against fishing pressure or human impact close to the MPA (?2 km). In contrast, fish assemblages beyond 2 km of the MPA border are more vulnerable to disturbance. High values of diversity, CPUE and IPUE overlapped close to the MPA border and close to seagrass beds.
• 4. The spatial approach developed suggests that, in addition to the more commonly studied effect of density‐dependent spillover of adult fish, increased levels of ecological diversity and economic diversity can also result in fisheries benefits of an MPA. Hence, the fishing regulations in and around the Medes Islands marine reserve have shown that biological conservation and fisheries benefits can be complementary in the long‐term, which should be considered in future policies for MPAs or MPA networks.

Copyright © 2008 John Wiley & Sons, Ltd.     

A century of fishery data documenting the collapse of smooth‐hounds (Mustelus spp.) in the Mediterranean Sea

1. Conservation and management of shark populations is increasingly becoming important in many marine regions, since there is a growing body of evidence showing that several species are threatened and continuing to decline because of unregulated fishing. Quantifying the extent of sharks' decline, the risk of species extinction, and the consequences for marine ecosystems have been challenging and controversial, mostly due to data limitations.
2. In this study, more than one century of multiple‐sources of bibliographic records on presence and frequency of occurrence of three species of commercial sharks, the smooth‐hounds Mustelus spp., in the Mediterranean Sea were compiled and analysed. Generalized additive models for location, scale and shape (GAMLSS) were used to estimate the rate of change of two of these species, Mustelus mustelus and Mustelus punctulatus, in four Mediterranean regions.
3. Model results showed that smooth‐hounds have declined by 80–90% since the beginning of last century to almost disappear in a large part of their original distributional range during the 1980s and 1990s.
4. Based on modelling results, a revision of the current International Union for Conservation of Nature classification of Mediterranean smooth‐hounds would be advisable along with the application of urgent conservation measures.