National frameworks for marine conservation — a hierarchical geophysical approach

1. Development of environmental protected areas has been driven ‘more by opportunity than design, scenery rather than science’ (Hackman A. 1993. Preface. A protected areas gap analysis methodology: planning for the conservation of biodiversity. World Wildlife Fund Canada Discussion Paper; i–ii). If marine environments are to be protected from the adverse effects of human activities, then identification of types of marine habitats and delineation of their boundaries in a consistent classification is required. Without such a classification system, the extent and significance of representative or distinctive habitats cannot be recognized. Such recognition is a fundamental prerequisite to the determination of location and size of marine areas to be protected. 2. A hierarchical classification has been developed based on enduring/recurrent geophysical (oceanographic and physiographic) features of the marine environment, which identifies habitat types that reflect changes in biological composition. Important oceanographic features include temperature, stratification and exposure; physiographic features include bottom relief and substrate type. 3. Classifications based only on biological data are generally prohibited at larger scales, due to lack of information. Therefore, we are generally obliged to classify habitat types as surrogates for community types. The data necessary for this classification are available from mapped sources and from remote sensing. It is believed they can be used to identify representative and distinctive marine habitats supporting different communities, and will provide an ecological framework for marine conservation planning at the national level. Copyright © 2000 John Wiley & Sons, Ltd.     

Predictive modelling of mesophotic habitats in the north‐western Gulf of Mexico

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.

     

Distribution of demersal fish assemblages along the west coast of St Lucia: Implications for planning no-take marine reserves

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.

     

Conservation of Mediterranean habitats and biodiversity countdowns: what information do we really need?

• 1. The relentless increase in both human activities and exploitation of marine resources is a threat to marine habitats and species.
• 2. For marine systems, several protection initiatives have been outlined over the past decade to significantly reduce the current rate of biodiversity loss at global, regional, and national levels, and to establish representative networks of marine protected areas with the aim of protecting 10–30% of marine habitats.
• 3. Reliable estimates of the total area occupied by each habitat are crucial to set adequate protection initiatives. Habitat mapping requires a sound habitat classification. Many classification schemes have been developed in different areas of the world, sometimes based on questionable criteria.
• 4. A critical analysis of the most recent marine habitat classification list produced for the Mediterranean Sea from the Regional Activity Centre for Specially Protected Areas (RAC/SPA) showed that (i) 39% of habitats and associated species considered in the list are scarcely covered by scientific knowledge from Web‐based resources; (ii) 62% of the species/genera included in the list are primary producers; (iii) quantitative information about the geographical distribution of selected habitats and associated species is scant; and (iv) when available, information is largely unbalanced and biased towards the shallow western Mediterranean Sea.
• 5. Improved inventories of marine habitats are needed to support accurate and consistent mapping activities. The combination of large‐scale mapping and sound habitat classifications will allow better estimates of biodiversity distribution, to reverse regional/global habitat loss rates through the achievement of conservation targets and deadlines that, for the moment, are systematically not met. Copyright © 2011 John Wiley & Sons, Ltd.

     

Benthic habitat modelling and mapping as a conservation tool for marine protected areas: A seamount in the western Mediterranean

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Intertidal habitat conservation: identifying conservation targets in the absence of detailed biological information

• 1. Growing concern associated with threats to the marine environment has resulted in an increased demand for marine reserves that conserve representative and adequate examples of biodiversity. Often, the decisions about where to locate reserves must be made in the absence of detailed information on the patterns of distribution of the biota. Alternative approaches are required that include defining habitats using surrogates for biodiversity. Surrogate measures of biodiversity enable decisions about where to locate marine reserves to be made more reliably in the absence of detailed data on the distribution of species.
• 2. Intertidal habitat types derived using physical properties of the shoreline were used as a surrogate for intertidal biodiversity to assist with the identification of sites for inclusion in a candidate system of intertidal marine reserves for 17 463 km of the mainland coast of Queensland, Australia. This represents the first systematic approach, on essentially one‐dimensional data, using fine‐scale (tens to hundreds of metres) intertidal habitats to identify a system of marine reserves for such a large length of coast. A range of solutions would provide for the protection of a representative example of intertidal habitats in Queensland.
• 3. The design and planning of marine and terrestrial protected areas systems should not be undertaken independently of each other because it is likely to lead to inadequate representation of intertidal habitats in either system. The development of reserve systems specially designed to protect intertidal habitats should be integrated into the design of terrestrial and marine protected area systems.

Copyright © 2005 John Wiley & Sons, Ltd.     

An alternative approach for managing scuba diving in small marine protected areas

• 1. As the interest of divers in exploring marine protected areas grows, so does their impact on sensitive marine organisms and communities. This situation has led managers to adopt a variety of measures to manage scuba diving in marine reserves. However, if marine areas need to be managed and protected from the adverse effects of human activities, then the characterization of marine habitats and the communities they contain, along with the potential effects of scuba diving, will need to be evaluated on scientific lines.
• 2. To this end, the use of benthic mapping, together with an evaluation of community vulnerability, constitutes a complementary tool for managing scuba diving, as is demonstrated in the present study.
• 3. The identification and evaluation of the different communities observed in Cabo de Palos‐Islas Hormigas Marine Reserve enables managers to propose different measures for controlling potential diver impact and also for evaluating the effects of these measures, thus reducing the degradation of the benthic organisms and communities, benefiting the local tourism industry and allowing a more sustainable use of the marine reserve resources.

Copyright © 2006 John Wiley & Sons, Ltd.     

Habitat diversity relative to wave action on rocky shores: implications for the selection of marine protected areas

• 1. Current selection of marine protected areas in South Africa is based on objective criteria including biogeographic representation and habitat heterogeneity. This paper specifically examines rocky shores on the west coast of South Africa to determine whether they are divisible into discrete ‘habitats’ that need independent conservation.
• 2. Seventeen rocky shores spanning the full spectrum of wave exposure were compared in terms of maximum wave forces, biomass, species richness and diversity among zones and sites. Three biotic assemblages were identified, characterizing sheltered, semi‐exposed to exposed, and very exposed habitats. Differences among these were clear‐cut low on the shore but disappeared at the top of the shore where wave action was attenuated and desiccation uniformly intense.
• 3. The recognition of three discrete biologically‐defined habitats means that rocky shores cannot be regarded as a uniform habitat for conservation purposes. All three components need protection if the full spectrum of rocky‐shore communities is to be conserved.
• 4. It is argued that this approach allows habitats to be defined in an objective manner, and that once this has been done, habitat heterogeneity constitutes a better measure of conservation value of an area than a ‘hotspot’ approach based on species richness and endemism.

Copyright © 2008 John Wiley & Sons, Ltd.     

Habitat configuration for an obligate shallow‐water delphinid: The Indo‐Pacific humpback dolphin,Sousa chinensis,in the Beibu Gulf (Gulf of Tonkin)

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Putting marine sanctuaries into context: a comparison of estuary fish assemblages over multiple levels of protection and modification

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The influence of bottom type and shelf position on biodiversity of tropical fish inside a recently enlarged marine reserve

• 1. A necessary component of implementing a successful marine reserve is the quantification of the biological resources that fall under its protection. Without such an initial assessment, the future effects of the reserve on the local habitat and biotic community cannot be quantified and will remain the subject of debate.
• 2. This study provides such a baseline assessment of fish diversity and habitat types within a recently enlarged marine reserve. Buck Island Reef National Monument, US Virgin Islands, was recently enlarged from approximately 4 km² to over 76 km². Areas of sand, seagrass, and hard‐bottom under protection were increased from 0.29 km², 0.47 km², and 1.96 km² to 2.70 km², 2.89 km², and 18.30 km² respectively when the Monument was expanded. A 53 km² area of pelagic/deep‐water habitat with unknown bottom type is now also protected by the Monument.
• 3. Visual counts of fish within 25×4 m² transects conducted during the day were used to assess fish community structure and habitat utilization patterns. Species richness, diversity, assemblage structure, and fish density were evaluated and compared among sand, seagrass, and hard‐bottom habitats. Hard‐bottom sites had over twice the mean species richness and diversity as sand and seagrass sites, and several times greater mean fish density.
• 4. Quantification of the fish community in pelagic and deep‐water habitats within the reserve is recommended to provide a more comprehensive assessment of the offshore areas of the reserve. Fish numbers, size, and diversity outside the reserve boundaries must also be evaluated to allow quantification of the effects of the marine reserve on the adjacent fish communities.

Copyright © 2004 John Wiley & Sons, Ltd.     

Assessing the effectiveness of a long‐standing rocky intertidal protected area and its contribution to the regional conservation of species,habitats and assemblages

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Frameworks for marine conservation — non‐hierarchical approaches and distinctive habitats

• 1. Conservation efforts have traditionally been directed to ‘flagship’ species (whales, seals, migratory birds, etc.) that capture public attention. Often these flagship species occupy distinctive habitats. Distinctive habitats appear to be distinguished because of anomalous physical structures and unique oceanographic processes occurring within them, whereas representative habitats are not notable in this way. Distinctive habitats are found in areas of various physical anomalies described primarily by temperature, chlorophyll and topography.
• 2. Several different kinds of distinctive habitats can be defined by their anomalous physical structures and oceanographic and biological processes. Species diversity may be either higher or lower in distinctive than in representative habitats. Distinctive habitats predominantly belong to a class of environments called ‘ergoclines’, and are typically associated with elevated resources at some ‘trophic level’.
• 3. These elevated resources may be either the product of true production (i.e. they are generated (in situ), or they are the product of physical accumulation due to circulation mechanisms. These processes lie at the heart of the ecology of distinctive habitats, and are fundamental to maintenance of ecosystem health, ecological integrity, distributions, abundances and recruitment of species, patterns of animal migrations, and potential or actual fisheries yields.
• 4. Conservation strategies need to examine the relationships between distinctive and representative habitats and species diversity. A strategy, leading from studies on flagship or other focal species, could have several advantages. It should rejuvenate the inherent appeal and significance of ‘species’ approaches to marine conservation, provide a rationale for human interest and a new foundation for examination of marine ecological interactions. It would also require a novel synthesis of relationships between ‘species’ and ‘spaces’ approaches to marine conservation by asking how we can take the best advantage of both approaches, rather than seeing them as in conflict.

Copyright © 2002 John Wiley & Sons, Ltd.     

Contributions of marine infrastructures to marine planning and protected area networking

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Seabed habitat mapping in the Kent Group of islands and its role in Marine protected area planning

• 1. Mapping of seabed habitats is increasingly being used to identify the distribution and structure of marine ecosystems and as surrogate measures of biodiversity for marine protected area (MPA) planning. In this study, the distribution of seabed habitats to the 3 nmi limit around the Kent Group of islands, south‐eastern Australia were mapped using video ground‐truthed single‐beam acoustics at the mesoscale level (10 m to 1 km) as part of an MPA planning process.
• 2. Six distinct seabed habitat types (continuous reef, patchy reef, sand, hard sand, sparse sponge, and seagrass) were identified based primarily on visual differences in the first and second echo and a further four (low, medium and high profile reef, and sand hills) on variations in seabed profile identified in the echogram. Extensive acoustic and video transects allowed an estimate of the broad‐scale spatial distribution of seabed habitats defined at several hierarchical levels and provided information on the cover of the dominant benthic species or assemblages.
• 3. The island group supports a range of consolidated habitats, including rocky reefs of varying profile dominated by the macroalgae Phyllospora comosa and Ecklonia radiata in depths down to around 45 m, adjacent to deeper sponge‐dominated reefs containing encrusting, erect and branching forms. Unconsolidated habitats occurred broadly through the island group, with the offshore region dominated by hard sand (sand with scallop shells and/or shell grit) and sparse sponge‐habitats (sand interspersed with low cover of sponge‐dominated assemblages). The sheltered coves were dominated by sand and seagrass habitats consisting of beds of the seagrasses Halophila australis, Zostera tasmanica and Posidonia australis, with variations in species composition, patchiness and percentage cover evident within and between coves.
• 4. In February 2004 the Kent Group MPA was announced, covering all waters out to the 3 nmi limit containing two areas defined as a Sanctuary Zone (‘no take’) and a Habitat Protection Zone (‘restricted take’). Overall, seabed habitat mapping generated a capability to define the boundary and size of potential MPA zones within the Kent Group of islands and was an essential component of the planning process to improve the likelihood that the MPA was comprehensive, adequate and representative (CAR).
• 5. The need to define habitats at multiple scales within a hierarchical classification scheme that are meaningful in terms of biodiversity and CAR principles and identifiable using mapping techniques is discussed.

Copyright © 2004 John Wiley & Sons, Ltd.     

Food risk trade‐off in the Indo‐Pacific humpback dolphin: An exploratory case study

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.

     

Sea cucumbers in the Seychelles: effects of marine protected areas on high‐value species

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Bonefish (Albula vulpes) home range to spawning site linkages support a marine protected area designation

1. A spatial approach to coastal management, such as marine protected areas, is being increasingly used to address biodiversity and fishery declines resulting from habitat loss, degradation, and overfishing. This approach is especially applicable in regions and fisheries that are data poor, and which often lack regulations and adequate capacity for enforcement. In data-poor situations, species that have economic, cultural, and charismatic value can provide leverage for ecosystem protection.
2. In this study, acoustic telemetry was used to confirm a pre-spawning aggregation site, acting as critical information for protection of essential habitat for bonefish. Additionally, data sharing with an acoustic telemetry study on smalltooth sawfish (Pristis pectinata) documented linkages between the pre-spawning aggregation site and bonefish home ranges ≥70 km distant, thus providing an estimate of the catchment area.
3. These data provided post hoc support for a marine national park designated in 2002, and demonstrate that the park is of the appropriate spatial scale.

     

Bio‐physical models of marine environments reveal biases in the representation of protected areas

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