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1.
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  1. Most research on anadromous fishes has been invested in their freshwater life‐phases, resulting in a relatively sparse understanding of their spatial ecology during marine life‐phases. However, understanding the marine dispersal of anadromous fishes is essential to identify threats and to implement conservation measures that fully encompass their lifecycle.
  2. The twaite shad Alosa fallax is an anadromous fish increasingly imperilled across its range due to pollution, harvesting, and impediments to freshwater migration, but little is known about its distribution and movements during its marine life‐phase. Here, the application of acoustic telemetry provided novel insights into the coastal dispersal of twaite shad in the UK and Ireland during 2018–2019, and the freshwater entry of individuals during the 2019 spawning season.
  3. Of 73 twaite shad acoustic‐tagged during their upstream migration in the River Severn in May 2018, 58 emigrated from the river. Twelve were subsequently detected 200 km to the south‐west at the Taw–Torridge Estuary between July 2018 and April 2019, where estuarine movements up to 5.8 km inland occurred in summer, winter, and spring. One was subsequently detected in the Munster Blackwater Estuary (Ireland) and then in the River Severn, indicating a minimum movement distance of 950 km. Thirty‐four (59%) of the emigrating individuals from 2018 re‐entered fresh water in the rivers Severn (n = 33) and Wye (n = 2) in April and May 2019.
  4. These results suggest year‐round use of estuarine and nearshore habitats by at least a subset of the twaite shad population during their marine phase, providing evidence of potential range overlap between populations that spawn in different areas in the UK and Ireland, which may be facilitated by substantial dispersal. The results also highlight the potential of telemetry for estimating freshwater and marine mortality, and the benefits of sharing detection data across networks.
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3.
  1. Sites and periods of spawning aggregations of two important fishery resources, the mutton snapper, Lutjanus analis, and the dog snapper, Lutjanus jocu, were identified and validated along the Brazilian north-east coast (latitude 8–15°S) using exploratory analysis of catch per unit effort (CPUE) data, gonadosomatic index analysis, and gonad histology.
  2. The CPUE analysis for both species allowed the identification of outliers and far outliers, representing fisheries with exceptional catches, which were used as proxies of possible aggregation.
  3. The presence of pre-spawning and recent spawning signs (hydrated oocytes and post-ovulatory follicles) in the ovary of females caught at sites with recurrent records of high CPUE allowed the validation of spawning activity at those specific sites for each species. All aggregation sites identified in this study were located on the outer shelf, close to the shelf break, a region that has been declared an Ecologically and Biologically Significant Marine Area.
  4. Comparison of two subregions showed significant differences in size structure of the fish sampled during landings, suggesting a fishing depletion effect in the north region.
  5. For both species, reproduction peaked twice in all regions studied, with a more marked peak during summer. However, spawning activity was observed in almost every month of the year, suggesting that seasonal closures could be more effective if combined with spatial measures.
  6. In the northern part of the study range, spawning grounds were found to lie just outside the boundaries of one of Brazil's largest marine protected areas. Inclusion of those grounds in the marine protected area would increase protection of these species and also mean increased protection of an Ecologically and Biologically Significant Marine Area, encompassing mesophotic reefs.
  7. The identification of these spawning aggregations sites on the north-east coast of Brazil was conducted in collaboration with local fishers that traditionally use bottom handline. Co-management approaches are suggested in view of the importance of these fishing sites for traditional fishing communities that may also face threats due to encroachment of mobile fleets.
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4.
  1. A small population of approximately 68 bottlenose dolphins, Tursiops truncatus, resident in Doubtful Sound, New Zealand, is subject to physiologically challenging conditions, and is exposed to anthropogenic pressure from tourism.
  2. A voluntary Code of Management incorporating dolphin protection zones (DPZs), in which tour boat access is limited, was established in 2008.
  3. Kernel density estimation (KDE) was used to quantify dolphin habitat use over a 13-year period in order to describe seasonal variation in habitat use and consistency of habitat use over a decadal period, and to provide quantitative estimates of the extent of overlap between DPZs and core areas (50% volume contour) of habitat use.
  4. Habitat use varied seasonally, with the inner fjord area used more frequently in warmer months, and with a shift in use to the outer fjord in colder months. Patterns in habitat use were highly consistent over the 13-year duration of the study.
  5. The spatial overlap between the area of core dolphin habitat and DPZs was low (<18%) overall, and some DPZs were rarely used during colder periods.
  6. Consistency in habitat use through time vindicates spatial management, but low overlap between core habitat and current DPZs suggests that an expansion of the DPZ areas would confer greater protection.
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  1. Marine protected area (MPA) planning often relies on scientific principles that help ensure that an area selected for conservation will effectively protect biodiversity. Capturing ecological processes in MPA network planning has received increased attention in recent years. High‐resolution seafloor maps, which show patterns in seafloor bio‐physical characteristics, can support our understanding of ecological processes.
  2. In part, owing to a global lack of high‐resolution seafloor maps, studies that aim to integrate seascape spatial pattern and conservation prioritization often focus on shallow biogenic habitats with less attention paid to deeper benthic seascapes (benthoscapes) mapped using acoustic techniques. Acoustic seafloor mapping strategies yield the spatial information required to extend conservation prioritization research into these environments, making incorporating seafloor ecological processes into conservation prioritization increasingly achievable.
  3. Here, a new method is proposed and tested that combines benthoscape mapping, landscape ecology metrics and a conservation decision support tool to prioritize areas with structural and potential connectivity value in MPA placement. Using a case study in eastern Canada, benthoscape composition and configuration were quantified using spatial pattern metrics and integrated into Marxan.
  4. Results illustrate how large patches of seafloor habitat in close proximity to neighbouring patches can be preferentially selected when benthoscape configuration is considered. The flexibility of the method for including relevant spatial pattern metrics or species‐specific movement data is discussed to illustrate how benthic habitat maps can improve existing conservation planning methods and complement existing and future work to support marine biodiversity conservation.
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  1. Based on optimal foraging theory, animals are expected to maximize foraging benefits whilst minimizing risks. Despite risking being subjected to anthropogenic impacts such as water contamination, marine traffic, and underwater noise, estuaries have been identified as the preferred habitat of the Indo‐Pacific humpback dolphin (Sousa chinensis, IPHD). However, it remains unclear why this vulnerable species favours such risky habitats.
  2. Here, an exploratory case study in Zhanjiang estuary, China, was conducted to test the hypothesis that IPHDs select estuarine habitats as a trade‐off that maximizes foraging opportunities whilst minimizing the risk of mortality.
  3. The results showed that IPHDs accept greater mortality risks for higher food rewards but select habitats with lower risks when food rewards are similar between two locations.
  4. Although this type of information is important for underpinning models for individual dolphins, its principal role is to show environmental protection agencies why IPHDs favour estuaries despite the increased mortality risks.
  5. Habitat conservation plans should carefully consider prey stocks, possibly through the presence of marine protected areas near estuaries, as local overfishing may lead vulnerable cetacean populations to take greater risks.
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10.
  1. The expansion and intensification of marine uses have severe cumulative impacts on marine ecosystems and human well-being, unless they are properly managed with an ecosystem-based management approach.
  2. A systematic conservation planning approach, using marxan with zones , was applied to generate alternative marine spatial plans for the Aegean Sea. Relevant human uses were included and their cumulative impact on a wide set of key biodiversity features was considered in the analysis. Different cost scenarios were developed to gain insight on the effects of the approaches used to assess socio-economic factors, and their potential impact on spatial plans.
  3. The spatial plans generated differed greatly depending on the method used to estimate opportunity costs and evaluate human activities in monetary terms.
  4. The vulnerability weights (the relative vulnerability of ecological features to specific human activities and their impacts) that were estimated based on a cumulative impact assessment, allowed the assessment of each zone in contributing to the achievement of conservation targets, through a transparent planning approach.
  5. Results indicate that special care should be given to how socio-economic activities, their impact on the ecosystems, and related costs are incorporated into planning.
  6. The proposed approach demonstrates how EU member states may effectively comply with the new Biodiversity Strategy 2030 targets, while planning for the sustainable use of their marine resources.
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11.
  1. Detailed knowledge about the distribution of species in need of protection is required for the management of Marine Protected Areas, a major tool to reduce marine biodiversity loss. Such knowledge is deficient for most marine invertebrates.
  2. Axinella polypoides is a marine sponge included on the list of protected species by the Barcelona Convention (1976) and the Bern Convention (1987). This large and erect species has an important ecological role in habitat forming and benthic–pelagic coupling.
  3. Bathymetrical, geographical and ecological data over the last 60 years were collated from publications and reports, together with new surveys to assess the distribution and protection status in Liguria of A. polypoides. It identified a more widespread distribution than previously thought, which points at a general need for dedicated investigations on the occurrence of species that require protection.
  4. Bathymetrical distribution was trimodal, with peaks corresponding to different geomorphological settings: coastal cliff bases (around 38 m depth), inner shelf shoals (52 m) and rocks amidst coarse sediment on the outer shelf (79 m). Density was significantly greater at the shallowest depths. The species was mostly found in the coralligenous biocoenosis, in association with other characteristic species or forming a monospecific facies.
  5. On (sub)vertical cliffs, A. polypoides often exhibited an unusual cane shape, rather than the typical bushy morphology, thus causing confusion with the congeneric A. cannabina, a more southern species. Records of the latter in the Ligurian Sea therefore need confirmation.
  6. Only a minority (22.6%) of A. polypoides records were in Marine Protected Areas, the remainder being located in areas with no current environmental protection plans in place. While the occurrence of this species in MPAs remained stable over the decades, the only quantitative historical data available indicated that populations in non-protected areas were declining owing to anthropogenic impacts (fishing and anchoring).
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12.
  1. Sawfishes (Family: Pristidae) are one of the most imperilled fish families worldwide. There is an increasingly urgent need to better understand the biology, ecology, and population status of the five sawfish species to develop more effective conservation measures. The dwarf sawfish, Pristis clavata, is one of the least researched members of the pristids, with literature limited to analysing disparate datasets or collations of rare encounters in northern Australia.
  2. This study examined the spatial ecology of dwarf sawfish using targeted surveys and acoustic telemetry to determine its habitat use in a macrotidal estuary in northern Australia. Seventeen dwarf sawfish were tagged with acoustic transmitters and monitored in the Fitzroy River estuary and adjacent King Sound (Kimberley, Western Australia) between August 2015 and November 2017.
  3. Dwarf sawfish observed within the Fitzroy River estuary and King Sound were juveniles, ranging between 740 and 2,540 mm in total length. Catch per unit effort of dwarf sawfish in the late dry season was relatively high in the estuary, with the catch rate in 2015 being one of the highest reported for any sawfish species.
  4. Acoustic detections revealed a distinct seasonal pattern in the use of different parts of the estuary and King Sound, which was found to be driven by salinity. Dwarf sawfish predominately occupied a single large pool near the terminus of the tidal limit in the late dry season (August–November), before transitioning to regions in closer proximity to the river mouth or in King Sound in the wet and early dry seasons (December–July).
  5. Given the high abundance and residency of dwarf sawfish in the Fitzroy River estuary, this area is an important nursery for the species during the late dry season and should be formally recognized as a habitat protection area for the species.
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  1. The protection of evolutionary processes and maintenance of genetic diversity is necessary for the persistence of biodiversity and ecosystem resilience. The importance of genetic diversity has been reflected in a range of marine policy mechanisms, and the genetic ‘toolbox’ has great potential to support marine protection and marine spatial planning (MSP) at multiple scales. Despite scientific advances in the application of genetics in marine protection and management, systematic integration of genetic information has been generally lacking, primarily due to a knowledge and communication disconnect between geneticists and the marine policy and management community.
  2. To meet these outstanding needs, a ‘geospatial genetics’ approach to spatially map species-specific genetic data and associated information in a way that can be readily integrated by practitioners into marine protection and MSP decisions was developed. Techniques to derive geospatial genetic data layers, which can be viewed and mapped alongside other kinds of spatial data commonly used by conservation practitioners, hold promise for increasing the accessibility of genetic data to support policy decisions more fully.
  3. While applicable to many mobile and sessile taxa, an initial focus was placed on marine mammals, and the approach was developed and refined through a series of international meetings and published papers, as well as the development of interactive, expert-reviewed case studies hosted on the MSP tool SeaSketch.
  4. Outcomes of the work to date are currently serving in the policy arena by informing the identification of Important Marine Mammal Areas, an initiative led by the IUCN Marine Mammal Protected Areas Task Force to apply criteria to identify marine mammal habitats across the world's ocean, seas and relevant inland waters through a standardized process.
  5. It has become clear that geospatial genetics has great potential to foster increased collaboration among an intersectional community of geneticists, spatial ecologists, and practitioners. This increased opportunity for dialogue and cooperation will help ensure that evolutionary processes are factored into marine protection and MSP processes, and potentially for freshwater and terrestrial systems.
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15.
  1. Effective management of marine resources requires an understanding of the spatial distribution of biologically important communities.
  2. The north‐western Gulf of Mexico contains diverse marine ecosystems at a large range of depths and geographic settings. To better understand the distribution of these marine habitats across large geographic areas under consideration for marine sanctuary status, presence‐only predictive modelling was used.
  3. Results confirmed that local geographic characteristics can accurately predict the probability of occurrence for marine habitat types, and include a novel technique for assigning a single, most likely habitat in areas where multiple habitats are predicted.
  4. The highest resolution bathymetric data (10 m) available for the region was used to develop raster layers that represent characteristics that have been shown to influence species occurrence in other settings.
  5. A georeferenced historical photo record collected via remotely operated vehicle was classified according to six commonly found mesophotic habitats across the 18 reefs and banks under consideration for Flower Garden Banks National Marine Sanctuary boundary expansion.
  6. Using maximum entropy modelling, the influence of local geographic characteristics on the presence of these habitats was measured and a spatial probability distribution was developed for each habitat type across the study area.
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16.
  1. Protecting critical habitats of the Indo‐Pacific humpback dolphin, Sousa chinensis, is a hot topic of discussion for marine biodiversity conservation in China and many Southeast Asian countries. In practice, sound habitat protection action (HPA) planning often suffers from information gaps in macroscopic habitat configurations and changes in the habitat conditions of humpback dolphins.
  2. Recent publications in the journal Aquatic Conservation: Marine and Freshwater Ecosystems (AQC) have served to advance humpback dolphin conservation in Chinese waters by resolving such habitat configurations and indicating significant changes in distribution patterns and habitat characteristics under intense coastal anthropogenic activity.
  3. We highlight an integrative research framework to investigate habitat configuration and long‐term habitat changes when planning a holistic HPA programme for humpback dolphins. When constructing habitat configuration baselines, field surveys should be designed and conducted in a systematic manner to ensure survey efforts cover diverse environments equally, in either a spatially stratified or gridded pattern, to minimize potential spatial sampling biases. Long‐term habitat changes can be revealed by comparing satellite images from different decades. Changes in habitat preferences and habitat characteristics can be explored through questionnaire surveys on local ecological knowledge, associating historical occurrences with coastline features and projecting historical habitat configuration by species distribution modelling exercises.
  4. A lack of good communication and sharing of information between research and management sectors can still be an obstacle to the implementation of sound conservation practices, however, even though there is robust scientific evidence to fill knowledge gaps in distribution and habitat baselines. We have addressed the need to establish a mechanism to improve and streamline information sharing between research teams, management sectors, and stakeholder groups.
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17.
  1. The estuaries within the Pearl River Delta are sites for large-scale urban development and offshore construction. These projects have conservation stakeholders calling for more protection for the Indo-Pacific humpback dolphins whose habitat overlaps with current and proposed construction sites.
  2. Efforts to improve impact assessments are hindered by the lack of baseline data and comprehensive understanding of how often the dolphins are present in areas near or within locations targeted for further development. The Modaomen Estuary within the Pearl River Delta is a good example of this, with little consideration for the dolphins as no data on their diurnal and seasonal occurrences within the estuary exist.
  3. A passive acoustic monitoring system was deployed over a calendar year from October 2016 to September 2017 to monitor the presence of humpback dolphins in the Modaomen Estuary.
  4. Results indicated that the estuary is an important area for humpback dolphins, with regular diel rhythms and seasonality in detection rates. For example, higher detections were seen during the wet season than during the dry season. However, there was no significant difference in detection rates between the flood and ebb tides, or between high and low tidal phases.
  5. Since the Modaomen Estuary is targeted for further development in the near future, these data provide the rationale for resource management and consent processes to consider potential impacts on the dolphins, as well as to aid marine spatial planning and conservation measures.
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18.
  • 1. The intensity of marine activities in the exclusive economic zone (EEZ) of British Columbia, Canada, was quantified.
  • 2. Humans use the ocean for a multitude of purposes, many of which have a direct impact on marine life and habitat. Yet such uses are seldom assessed in an integrated fashion.
  • 3. Using a GIS approach, spatial information for 39 marine activities was mapped, including commercial and recreational fishing areas, transportation and infrastructure uses, and terrestrial activities along the coast of British Columbia.
  • 4. A relative scale was used to rank both the impact of marine activities and the extent of stressors beyond the location of occurrence. Limited information on the latter led to the application of three ranges of buffer distances to the data (0–1 km, 0–5 km, and 0–25 km).
  • 5. The most conservative estimate (?1 km buffers) indicates at least 83% of the continental shelf and slope of British Columbia is currently being used by humans. The largest buffer assumption shows 98% of the continental shelf and slope being affected by stressors from anthropogenic activities.
  • 6. This analysis provides a baseline for assessing future changes in the state of British Columbia's marine environment, and could assist in identifying areas of conservation potential.
Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

19.
  1. Evidence-based decisions relating to effective marine protected areas as a means of conserving biodiversity require a detailed understanding of the species present. The Caribbean island nation of St Lucia is expanding its current marine protected area network by designating additional no-take marine reserves on the west coast. However, information on the distribution of fish species is currently limited.
  2. This study used baited remote underwater stereo-video to address this shortcoming by investigating the effects of depth and seabed habitat structure on demersal fish assemblages and comparing these assemblages between regions currently afforded different protection measures.
  3. From the 87 stations visited a total of 5,921 fish were observed comprising 120 fish taxa across 22 families. Species richness and total abundance were higher within the highly managed region, which included no-take reserves. Redundancy analysis explained 17% of the total variance in fish distribution, driven predominantly by the seabed habitats. The redundancy analysis identified four main groups of demersal fishes each associated with specific seabed habitats.
  4. The current no-take marine reserves protected two of these groups (i.e. fishes associated with the ‘soft corals, hard corals or gorgonians’ and ‘seagrass’ groups). Importantly, habitats dominated by sponges, bacterial mats, algal turfs or macroalgae, which also supported unique fish assemblages, are not currently afforded protection via the marine reserve network (based on the five reserves studied). These results imply that incorporation of the full breadth of benthic habitat types present would improve the efficacy of the marine reserve network by ensuring all fish assemblages are protected.
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20.
  1. Species distribution modelling has been used to identify critical habitats for the delimitation of Marine Protected Areas. Although Marine Protected Areas may often overlap with the distribution of key marine species, illegal human activities often continue within these areas, causing negative impacts on the local biodiversity.
  2. A generalized linear model with spatial eigenvector mapping was used to investigate, for the first time, the influence of environmental variables and anthropic activities on the number of Guiana dolphin, Sotalia guianensis sightings/grid, and to determine whether a Marine Reserve, in south‐eastern Brazil, is adequate for the protection of the local population. Data were collected between May 2007 and October 2013 onboard a 7.5‐m vessel with an inboard engine.
  3. The models for the different periods (annual, dry, and rainy seasons) all indicated that depth, the distance to seafood farms and fishing grounds, and mean sea surface temperatures influenced the distribution of the dolphins within the study area. The annual and seasonal models predicted that the dolphins prefer a continuous area between Cedro and Pico Islands, a large area that lies outside the limits of the Marine Reserve.
  4. Although the habitat of Ilha Grande bay is still much less degraded than that inhabited by other nearby Guiana dolphin populations, the results of the present study indicate that anthropic activities in this area influence habitat use by the dolphins. Less than 30% of the area used by the dolphins is protected by the Tamoios Ecological Station (ESEC Tamoios).
  5. Sotalia guianensis is classified as ‘Vulnerable’ in Brazil, although the marine reserve (ESEC Tamoios) does not protect the core area used by the local dolphin population. The results of the present study provide specific locations for the creation of a new multiple‐use MPA, as suggested by the Brazilian National Action Plan for the Conservation of Small Cetaceans, or the inclusion of a special management programme for the area between Cedro and Pico islands to better protect the dolphins in the ESEC Tamoios buffer zone. The continuation of surveys to better understand the current and future impacts of human activities, and the development of a closer interaction with both the local community and local stakeholders will help to safeguard Ilha Grande Bay and the local Guiana dolphin population.
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