Functional ecosystems depend on biotic and abiotic connections among different environmental realms, including terrestrial, freshwater, and marine habitats. Accounting for such connections is increasingly recognized as critical for conservation of ecosystems, especially given growing understanding of the way in which anthropogenic landscape disturbances can degrade both freshwater and marine habitats. This need may be paramount in conservation planning for tropical island ecosystems, as habitats across realms are often in close proximity, and because endemic organisms utilize multiple habitats to complete life histories. In this study, we used Marxan analysis to develop conservation planning scenarios across the five largest islands of Hawaii, in one instance accounting for and in another excluding habitat connectivity between inland and coastal habitats. Native vegetation, perennial streams, and areas of biological significance along the coast were used as conservation targets in analysis. Cost, or the amount of effort required for conservation, was estimated using an index that integrated degree and intensity of anthropogenic landscape disturbances. Our results showed that when connectivity is accounted for among terrestrial, freshwater, and marine habitats, areas identified as having high conservation value are substantially different compared to results when connectivity across realms is not considered. We also showed that the trade-off of planning conservation across realms was minimal and that cross-realm planning had the unexpected benefit of selecting areas with less habitat degradation, suggesting less effort for conservation. Our cross-realm planning approach considers biophysical interactions and complexity within and across ecosystems, as well as anthropogenic factors that may influence habitats outside of their physical boundaries, and we recommend implementing similar approaches to achieve integrated conservation efforts.
Conservation Targets & Planning
Habitat loss is accelerating a global extinction crisis. Conservation requires understanding links between species and habitats. Emerging research is revealing important associations between vegetated coastal wetlands and marine megafauna, such as cetaceans, sea turtles, and sharks. But these links have not been reviewed and the importance of these globally declining habitats is undervalued. Here, we identify associations for 102 marine megafauna species that utilize these habitats, increasing the number of species with associations based on current InternationalUnion for the Conservation of Nature (IUCN) species assessments by 59% to 174, accounting for over 13% of all marine megafauna. We conclude that coastal wetlands require greater protection to support marine megafauna, and present a simple, effective framework to improve the inclusion of habitat associations within species assessments.
Current international commitments on ocean protection targets include protecting 10% of the ocean through marine protected areas (MPAs) until 2020, while also complying with efficiency and equity requirements. This has led to a race to designate large MPAs, but despite the valid marine conservation efforts, conferring adequate protection is still at risk. While fully protected areas are considered the most efficient tools to effectively protect the integrity of ecosystems, most existing or proposed MPAs are far from being fully or strongly protected. Portugal, with the 20th largest EEZ of the world is well positioned to lead ocean conservation efforts and provides a suitable case study for analysis of protection conferred by existing MPAs. To this end, Portuguese MPAs were assessed according to different types of classification systems and it was found that most MPAs confer little or no additional protection compared to outside areas. The results differ according to the classification system used, revealing the importance of finding a common system for evaluating progress in ocean conservation. The relevance of adequately labelling and understanding the levels of protection in place is demonstrated. Not differentiating the type of protection conferred by MPA regulations, while rushing towards international targets, may give a potentially false impression to society.
As the configuration of global environmental governance has become more complex over the past fifty years, numerous scholars have underscored the importance of understanding the transnational networks of public, private and nonprofit organizations that comprise it. Most methodologies for studying governance emphasize social structural elements or institutional design principles and focus less attention on the social interactions that generate diffuse, hybrid regimes. Yet capturing the dynamics of these networks requires a relational methodology that can account for a range of elements that constantly shift and change relative to overlapping institutional boundaries. Collaborative Event Ethnography draws on insights from multi-sited, team, and institutional ethnography to assemble teams of researchers to study major international conferences, which offer important political spaces where public, private, and nonprofit actors align around sanctioned logics and techniques of governance. Drawing on insights generated from these conferences and field sites across the globe, we trace the constitutive forces behind paradigm shifts in biodiversity conservation, specifically the interconnected rise of market-based approaches, global targets, and new conservation enclosures. We show how the iterative refining of the methodology over five events generated an increasingly robust understanding of global conservation governance as processual, dynamic, and contingent, constituted through constantly shifting assemblages of state and nonstate actors, devices and narratives that collectively configure fields of governance. Finally, we reflect on how our team, as an evolving combination of researchers, research interests, and data collection tools—itself an assemblage, —has informed the continual refinement of the methodology and generated novel understandings of global conservation governance.
Mangrove forests provide critical services around the globe to both human populations and the ecosystems they occupy. However, losses of mangrove habitat of more than 50% have been recorded in some parts of the world, and these losses are largely attributable to human activities. The importance of mangroves and the threats to their persistence have long been recognized, leading to actions taken locally, by national governments, and through international agreements for their protection. In this review, we explore the status of mangrove forests as well as efforts to protect them. We examine threats to the persistence of mangroves, consequences, and potential solutions for effective conservation. We present case studies from disparate regions of the world, showing that the integration of human livelihood needs in a manner that balances conservation goals can present solutions that could lead to long-term sustainability of mangrove forests throughout the world.
The coastal zone of China contains extensive coastal wetlands but it is also one of the most densely populated areas. Rapid changes of land use pattern associated with socio-economic development in the coastal zone have had tremendous impacts on the health of coastal wetlands and their provision of ecological services. In this study, we used a landscape development intensity index and landscape stress index to evaluate the conservation efficacy of the coastal zone and coastal protected areas along the coastline of China from 1990 to 2015. We then analyzed the impact of population density and gross domestic product (GDP) on landscape development intensity. The results showed that landscape development intensity in coastal zone increased over the 25 year period, but the growth rate of landscape development intensity and landscape stress slowed between 2005 and 2015. Higher levels of landscape development intensity were widespread in the coastal zone of northern China compared with southern China, and the coastal zones of the Huanghai Sea and the Bohai Sea were the focus of coastal wetlands conservation in mainland China. A number of coastal protected areas, including 33 coastal national nature reserves and 67 national special marine reserves, have been established in mainland China, protecting 16.80% of the coastline. Coastal wetlands have been effectively protected to some extent by building these protected areas, with results showing lower landscape development intensity. The conservation efficacy of coastal wetlands as a whole was affected by population expansion and GDP, but the effects were not necessarily all negative. A higher population density or GDP did not necessarily lead to stronger landscape development intensity in local areas.
Sharks constitute a vital sector of marine and estuarine nekton and are of great commercial importance all over the world. International concern over the fate of shark fisheries has grown recently. However, information concerning the species diversity, geographic distribution and life histories of sharks in the Indo-Pacific region is highly limited. Comprehensive research on the species composition, distribution and seasonal occurrence of sharks in the southern South China Sea (SSCS) was conducted for four years. A total of 4742 sharks belonging to 10 families and 28 species were recorded from 6 fishing ports in SSCS. The families recorded included Squalidae, Heterodontidae, Orectolobidae, Hemiscylliidae, Alopiidae, Scyliorhinidae, Triakidae, Hemigaleidae, Carcharhinidae and Sphyrnidae. Seventeen of 28 shark species were landed at various developmental stages from in the ranges of or even less than the length at birth and from newborn juveniles to fully-mature. The results suggest that these sharks were born just before fishing and landing, and reproductive-stage sharks were also fished and landed. In total, 15 species, four species and one species in 28 shark species were categorized as Near Threatened, Vulnerable and Endangered species, respectively, on the IUCN Red List. Sharks are not targeted by fisheries practices in the SSCS, but are caught as bycatch throughout the year in various developmental stages. Thus, current fisheries practices in the SSCS area might lead to further decline to critical levels and lead to extinction of some of species in the future. These results suggest that the need for gear selectivity of the commercial fishing gears in order to reduce mortality and to conserve shark stocks.
Identifying critical aggregation sites and behavioral patterns of imperiled species contributes to filling knowledge gaps essential for their conservation. Manta rays present a prominent example of such species, the populations of which are declining globally due to directed fishery, by-catch, and other anthropogenic stressors. Our goal was to explore manta ray aggregation sites in the Philippines in order to determine the factors governing the mantas’ visits – a knowledge gap essential to understand manta ecology, facilitate ecosystem-based fishery management, and promote sustainable manta-based ecotourism. Diving surveys, environmental conditions assessment, and autonomous cameras were employed to study manta behavior and visit patterns to a cleaning station cluster on a commonly fished seamount, visited by both Mobula birostris and Mobula alfredi. Our findings reveal several environmental conditions (e.g., sea state, moon illumination, and flow) that serve as predictors of manta presence/absence at the site. We suggest that these conditions affect both the behavior of the manta’s food (i.e., the spatial distribution of plankton) and the cleaning effectiveness of the cleaner wrasse, which consequently influence manta activity. The findings suggest a trade-off between cleaning and foraging: i.e., mantas tend to visit the cleaning stations when environmental conditions are less favorable for foraging but suitable for effective cleaning; while being absent from the cleaning stations when environmental conditions form plankton aggregations, ideal for efficient feeding. This study sheds light on manta behavior and habitat use on dynamic, small spatio-temporal scales (i.e., hundreds of meters to a few kilometers, hours to days). The acquired data may be applied in the planning of marine protected areas and in fishery management (e.g., to reduce the chances of manta bycatch by limiting fishing activities to periods of manta absence) as well as contribute to enhancing sustainable exploitation, such as ecotourism, by increasing the chances of diving encounters with manta rays.
Animals are central to numerous ecological processes that shape the structure and function of ecosystems. It follows that species that are strongly linked to specific functions can represent these functions spatially and hence be useful in conservation planning. Here we test this notion of ‘functional species surrogacy’ for the conservation of seagrass meadows that have been impacted by stressors. We measured algal herbivory and herbivorous fish assemblages across a range of seagrass meadows in the Moreton Bay Marine Park, Queensland, Australia. We determined the suitability of herbivorous fish to act as a surrogate for the function of algal herbivory and modelled the abundance of this surrogate, and thus herbivory, in seagrass meadows to compare the spatial distribution of this function within existing reserves. We used underwater video systems to determine the abundance of all herbivorous fish species in seagrass meadows. The abundance of the dusky rabbitfish (Siganus fuscescens) was the best predictor of algal herbivory in seagrass meadows, supporting the suitability of this species as a functional surrogate. The distribution of dusky rabbitfish, and therefore the ecological function of herbivory, was not well represented in the Moreton Bay Marine Park protected areas. Only 7% of the equivalent area of seagrass meadows protected in marine reserves were found to have high abundances of dusky rabbitfish. We demonstrate that the abundance of functionally important herbivores can be suitable as a surrogate for herbivory in seagrass conservation. Our findings show that data on the spatial distribution of ecological functions can alter priorities for reserve design, and we suggest that our functional approach to species surrogacy is likely to improve conservation performance in seagrass ecosystems.
Identifying the species that are at risk of local extinction in highly diverse ecosystems is a big challenge for conservation science. Assessments of species status are costly and difficult to implement in developing countries with diverse ecosystems due to a lack of species-specific surveys, species-specific data, and other resources. Numerous techniques are devised to determine the threat status of species based on the availability of data and budgetary limits. On this basis, we developed a framework that compared occurrence data of historically exploited reef species in Kenya from existing disparate data sources. Occurrence data from archaeological remains (750-1500CE) was compared with occurrence data of these species catch assessments, and underwater surveys (1991-2014CE). This comparison indicated that only 67 species were exploited over a 750 year period, 750-1500CE, whereas 185 species were landed between 1995 and 2014CE. The first step of our framework identified 23 reef species as threatened with local extinction. The second step of the framework further evaluated the possibility of local extinction with Bayesian extinction analyses using occurrence data from naturalists’ species list with the existing occurrence data sources. The Bayesian extinction analysis reduced the number of reef species threatened with local extinction from 23 to 15. We compared our findings with three methods used for assessing extinction risk. Commonly used extinction risk methods varied in their ability to identify reef species that we identified as threatened with local extinction by our comparative and Bayesian method. For example, 12 of the 15 threatened species that we identified using our framework were listed as either least concern, unevaluated, or data deficient in the International Union for the Conservation of Nature red list. Piscivores and macro-invertivores were the only functional groups found to be locally extinct. Comparing occurrence data from disparate sources revealed a large number of historically exploited reef species that are possibly locally extinct. Our framework addressed biases such as uncertainty in priors, sightings and survey effort, when estimating the probability of local extinction. Our inexpensive method showed the value and potential for disparate data to fill knowledge gaps that exist in species extinction assessments.