Marine spatial planning (MSP) is increasingly utilized to sustainably manage ocean uses. Marine protected areas (MPAs), a form of spatial management in which parts of the ocean are regulated to fishing, are now a common tool in MSP for conserving marine biodiversity and managing fisheries. However, the use of MPAs in MSP often neglects, or simplifies, the redistribution of fishing and non-fishing activities inside and outside of MPAs following their implementation. This redistribution of effort can have important implications for effective MSP. Using long-term (14 yr) aerial surveys of boats at the California Channel Islands, we examined the spatial redistribution of fishing and non-fishing activities and their drivers following MPA establishment. Our data represent 6 yr of information before the implementation of an MPA network and 8 yr after implementation. Different types of boats responded in different ways to the closures, ranging from behaviors by commercial dive boats that support the hypothesis of fishing-the-line, to behaviors by urchin, sport fishing, and recreational boats that support the theory of ideal free distribution. Additionally, we found that boats engaged in recreational activities targeted areas that are sheltered from large waves and located near their home ports, while boats engaged in fishing activities also avoided high wave areas but were not constrained by the distance to their home ports. We did not observe the expected pattern of effort concentration near MPA borders for some boat types; this can be explained by the habitat preference of certain activities (for some activities, the desired habitat attributes are not inside the MPAs), species' biology (species such as urchins where the MPA benefit would likely come from larval export rather than adult spillover), or policy-infraction avoidance. The diversity of boat responses reveals variance from the usual simplified assumption that all extractive boats respond similarly to MPA establishment. Our work is the first empirical study to analyze the response of both commercial and recreational boats to closure. Our results will inform MSP in better accounting for effort redistribution by ocean users in response to the implementation of MPAs and other closures.
Human impacts (e.g., fishing, pollution, and shipping) on pelagic ecosystems are increasing, causing concerns about stresses on marine food webs. Maintaining predator-prey relationships through protection of pelagic hotspots is crucial for conservation and management of living marine resources. Biotic components of pelagic, plankton-based, ecosystems exhibit high variability in abundance in time and space (i.e., extreme patchiness), requiring investigation of persistence of abundance across trophic levels to resolve trophic hotspots. Using a 26-yr record of indicators for primary production, secondary (zooplankton and larval fish), and tertiary (seabirds) consumers, we show distributions of trophic hotspots in the southern California Current Ecosystem result from interactions between a strong upwelling center and a productive retention zone with enhanced nutrients, which concentrate prey and predators across multiple trophic levels. Trophic hotspots also overlap with human impacts, including fisheries extraction of coastal pelagic and groundfish species, as well as intense commercial shipping traffic. Spatial overlap of trophic hotspots with fisheries and shipping increases vulnerability of the ecosystem to localized depletion of forage fish, ship strikes on marine mammals, and pollution. This study represents a critical step toward resolving pelagic areas of high conservation interest for planktonic ecosystems and may serve as a model for other ocean regions where ecosystem-based management and marine spatial planning of pelagic ecosystems is warranted.
Global warming is predicted to drive preferential survival of warm adapted genotypes that have migrated to cooler locations, and result in an overall decline in genetic diversity due to bleaching-related mortality. Population genomic analysis of Acropora millepora on the Great Barrier Reef (GBR) revealed that most populations were demographically distinct with preferential southward migration from lower (warmer) to higher (cooler) latitudes. Still, no recent increase in southward migration was detectable, and predicted migration rates remained closely correlated with those derived from a biophysical model based on ocean currents. There was also no evidence of recent declines in genetic diversity. A multi-locus adaptation model suggested that standing genetic variation spread across latitudes might be sufficient to fuel continuous adaptation of A. millepora metapopulation over 100-200 years of gradual warming. However, the model also predicted increase in severity of local mortality events induced by thermal anomalies.
Artificial reefs (ARs) have long been practiced to manage and enhance fisheries resources worldwide. Here, we aimed to identify relevant indicator species for the specific environmental conditions of ARs by comparing fish diversity against control sites (Conts). We used a combination of non-metric multidimensional scaling and indicator value analysis to identify the indicator species of the specific AR environments. More individuals and species of fish were present in ARs compared to Conts. Water temperature over the seasons was the most important environmental factor associated with the trophic group composition of fish. In particular, macrocarnivores and benthic invertivores/cleaners closely reflected habitat conditions in a consistent manner. Some dominant fish species were detected at all sites, while the indicator species were more predominant under certain environmental conditions. Altogether, ARs should be monitored at regular intervals to optimize management of their health by detecting the community representativeness via indicator species.
Given the great overfishing of the demersal resources in the Northern Adriatic Sea (geographical sub-area [GSA] 17), along with the fishing pressure in marine habitats, evidence strongly supports the need to evaluate appropriate management approaches. Several fishing activities operate simultaneously in the area, and the need to minimize conflicts among them is also a social concern. We applied a spatially and temporally explicit fish and fisheries model to assess the impact of a suite of spatial plans suggested by practitioners that could reduce the pressure on the four demersal stocks of high commercial interest in the GSA 17 and that could promote space sharing between mutually exclusive activities. We found that excluding trawlers from some areas has lowered the effective fishing effort, resulting in some economic losses but providing benefit to the set netters. Not every simulated fishing vessel is impacted in the same way because some fishing communities experienced different economic opportunities, particularly when a 6-nautical mile buffer zone from the coast was implemented in the vicinity of important fishing grounds. Along this buffer zone, the four stocks were only slightly benefiting from the protection of the area and from fewer discards. In contrast, assuming a change in the ability of the population to disperse led to a large effect: Some fish became accessible in the coastal waters, therefore increasing the landings for range-limited fishers, but the discard rate of fish also increased, greatly impairing the long-term biomass levels. Our evaluation, however, confirmed that no effort is displaced onto vulnerable benthic habitats and to grounds not suitable for the continued operation of fishing. We conclude that the tested spatial management is helpful, but not sufficient to ensure sustainable fishing in the area, and therefore, additional management measures should be taken. Our test platform investigates the interaction between fish and fisheries at a fine geographical scale and simulates data for varying fishing methods and from different harbor communities in a unified framework. We contribute to the development of effective science-based inputs to facilitate policy improvement and better governance while evaluating trade-offs in fisheries management and marine spatial planning.
One aim of Marine Protected Areas (MPAs) is to protect a representative portion of the environment through spatial closures to extractive practices such as fisheries. Although they usually involve the displacement of fisheries, their design rarely takes into account the effect of displacing that fishery on the target fish population. We used a spatially explicit population model of Antarctic toothfish in the Ross Sea region to investigate the effects of the endorsed Ross Sea region MPA on the fishery dynamics and the spatial distribution of the toothfish population. Our study indicates that the MPA will likely improve protection of the juvenile population residing on the Antarctic Shelf, while the number of areas with high levels of depletion is unlikely to increase compared to status quo management. Results also suggested a small increase in the catch limit under the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) harvest management rules, but with a slight reduction in catch rates. We have showed that spatial modelling tools can help inform MPA planning by simultaneously quantifying potential effects on the fish population and the ability to achieve conservation goals.
This report provides an assessment of emerging evidence on the socio-economic impacts of Scotland’s Marine Protected Areas (MPAs). The reports objectives are to develop a methodology for monitoring the socioeconomic impacts of MPA management measures and to gather and analyse evidence on the ex post socioeconomic impacts of MPA management measures. This report presents evidence from key informant interviews, analysis of fishing activity data and three case studies.
It has been reported that global warming has negative effects on coral ecosystems in the past 50 years and the effects vary in different ocean environment. In order to make clear the coral reef status in the background of global warming along the south coast of Hainan Island of China, satellite and in situ data are used to retrieve the information of the coral reef status and surrounding environmental factors. The results show that cool water induced by upwelling along the south coast of Hainan Island is found in the area every summer month, especially in the relatively strong El Niño years (2002–2003 and 2005). From the NOAA satellite data, degree heating week (DHW) index does not exceed 3 in Sanya Bay even in the relatively strong El Niño years. By comparison of a coral reef growth rate in the Sanya Bay with respect to El Niño events from 1957 to 2000, coral’s growth rate is relatively greater during 1972, 1991–1994 and 1998 El Niño event. By analyzing the environmental factors, it is found that the cool water induced by upwelling may be the main reason for protecting corals from global warming effects.
Coral reef fishes, like many other marine organisms, are affected by anthropogenic stressors such as fishing and pollution and, owing to climate change, are experiencing increasing water temperatures and ocean acidification. Against the backdrop of these various stressors, a mechanistic understanding of processes governing individual organismal performance is the first step for identifying drivers of coral reef fish population dynamics. In fact, physiological measurements can help to reveal potential cause-and-effect relationships and enable physiologists to advise conservation management by upscaling results from cellular and individual organismal levels to population levels. Here, we highlight studies that include physiological measurements of coral reef fishes and those that give advice for their conservation. A literature search using combined physiological, conservation and coral reef fish key words resulted in ~1900 studies, of which only 99 matched predefined requirements. We observed that, over the last 20 years, the combination of physiological and conservation aspects in studies on coral reef fishes has received increased attention. Most of the selected studies made their physiological observations at the whole organism level and used their findings to give conservation advice on population dynamics, habitat use or the potential effects of climate change. The precision of the recommendations differed greatly and, not surprisingly, was least concrete when studies examined the effects of projected climate change scenarios. Although more and more physiological studies on coral reef fishes include conservation aspects, there is still a lack of concrete advice for conservation managers, with only very few published examples of physiological findings leading to improved management practices. We conclude with a call to action to foster better knowledge exchange between natural scientists and conservation managers to translate physiological findings more effectively in order to obtain evidence-based and adaptive management strategies for the conservation of coral reef fishes.
A rapid review of the literature on closed areas that recognize key ecosystem-based management (EBM) principles of fisheries and biodiversity conservation and had fisher involvement was employed to review closed areas worldwide from a fisheries perspective and to develop a scorecard that can assess their efficacy. The review provided 523 abstracts of which 19 areas from various regions worldwide had peer-reviewed studies that met strict selection criteria. Criteria included fisher involvement, biodiversity conservation and fisheries management objectives. A repeat search without “fisher” and synonyms found, 62,622 papers indicating that most closed area studies had no mention of any fisher involvement. The general success of the areas selected suggests that fisher involvement benefits both biological conservation and fisheries management. Fisheries and biodiversity conservation outcomes were not exclusive to any one type of management closure (e.g. MPA, Fishery Closure). Twenty-four indicators were selected, designed to provide measurable targets. High scoring indicators included management, planning and socio-economic indicators such as local support (100%), habitat protection (100%), conservation and fisheries objectives (100%), monitoring (91.7%) and fishers concerns (91.7%). Bio-ecological-based indicators scored lower in most cases for all types of areas. Fisheries closures rated as highly as the MPAs with respect to both fisheries and bio-ecological indicators. The scorecard provided a reasonable means to evaluate management success in the light of often qualitative or missing data. Addressing the interests and utilizing knowledge of those affected by closures and familiar with the area, most often local fishers, is key to achieving management objectives.
Low-frequency noise that is part of the acoustic environment for baleen whales has increased in many areas of the Northeast Pacific Ocean that contain whale habitat. We conducted a spatially explicit risk assessment of noise from commercial shipping to blue, fin, and humpback whale habitats in Southern California waters and explored how noise is affected by several place-based management techniques: a National Marine Sanctuary, an Area to be Avoided (ATBA), and a Traffic Separation Scheme (TSS). We used shipping data to model noise at 2 frequencies that are part of the acoustic environment for these species and capture the variable contributions from shipping to noise. Predicted noise levels in Southern California waters suggest high, region-wide exposure to shipping noise. Our risk assessment identified several areas where the acoustic environment may be degraded for blue, fin, and humpback whales because their habitat overlaps with areas of elevated noise from shipping traffic and 2 places where blue and humpback whale feeding areas overlap with lower predicted noise levels. One of the places with lower predicted noise occurs in the Channel Islands National Marine Sanctuary (CINMS). Noise has not been directly managed within the CINMS; instead, reduced noise in this portion of the CINMS is likely an ancillary benefit of the ATBA surrounding most of the Sanctuary. Areas of elevated noise in the CINMS also occur, primarily where a TSS intersects the Sanctuary’s boundaries. Our risk assessment framework can be used to evaluate how shipping traffic affects acoustic environments and explore management strategies.
The purpose of this article is to present the Mexican experience related to the US-Mexico joint Gulf of Mexico Large Marine Ecosystem-Based Assessment and Management Project, particularly the community involvement and mangrove wetland restoration, and the challenges for its replication and up-scaling. Results focus on community engagement, environmental education and social participation, strategies for hydrological restoration of mangrove, and difficulties and recommendations for the implementation of the Strategic Action Program. The main conclusions are that the community-based hydrologic restoration approach, is a good way to ensure long-term restoration of wetlands. Changing from mangrove plantations to the hydrological restoration of wetlands, and construction of human capacities resulted in a more efficient strategy for ecosystem restoration and had influenced the forest environmental policy. The involvement of government and education institutions as execution agencies will contribute to a more efficient appropriation of the project and LME approach. The development of economic alternatives and the ecological monitoring are some of the identified challenges within the implementation phase of the Strategic Action Program.
Given the major ongoing influence of environmental change on the oceans, there is a need to understand and predict the future distributions of marine species in order to plan appropriate mitigation to conserve vulnerable species and ecosystems. In this study we use tracking data from seven large seabird species of the Southern Ocean (Black-browed Albatross Thalassarche melanophris, Grey-headed Albatross T. chrysostoma, Northern Giant Petrel Macronectes halli, Southern Giant Petrel M. giganteus, Tristan Albatross Diomedea dabbenena Wandering Albatross D. exulans and White-chinned Petrel Procellaria aequinoctialis , and on fishing effort in two types of fisheries (characterised by low or high-bycatch rates), to model the associations with environmental variables (bathymetry, chlorophyll-a concentration, sea surface temperature and wind speed) through ensemble Species Distribution Models. We then project these distributions according to four climate change scenarios built by the Intergovernmental Panel for Climate Change for 2050 and 2100. The resulting projections were consistent across scenarios, indicating that there is a strong likelihood of poleward shifts in distribution of seabirds, and several range contractions (resulting from a shift in the northern, but no change in the southern limit of the range in four species). Current trends for southerly shifts in fisheries distributions are also set to continue under these climate change scenarios at least until 2100; some of these may reflect habitat loss for target species that are already over-fished. It is of particular concern that a shift in the distribution of several highly threatened seabird species would increase their overlap with fisheries where there is a high-bycatch risk. Under such scenarios, the associated shifts in distribution of seabirds and increases in bycatch risk will require much-improved fisheries management in these sensitive areas to minimise impacts on populations in decline.
Continued anthropogenic carbon dioxide emissions are acidifying our oceans, and hydrogen ion concentrations in surface oceans are predicted to increase 150% by 2100. Ocean acidification (OA) is changing ocean carbonate chemistry, including causing rapid reductions in calcium carbonate availability with implications for many marine organisms, including biogenic reefs formed by oysters. The impacts of OA are marked. Adult oysters display both decreased growth and calcification rates, while larval oysters show stunted growth, developmental abnormalities, and increased mortality. These physiological impacts are affecting ecosystem functioning and the provision of ecosystem services by oyster reefs. Oysters are ecologically and economically important, providing a wide range of ecosystem services, such as improved water quality, coastlines protection, and food provision. OA has the potential to alter the delivery and the quality of the ecosystem services associated with oyster reefs, with significant ecological and economic losses. This review provides a summary of current knowledge of OA on oyster biology, but then links these impacts to potential changes to the provision of ecosystem services associated with healthy oyster reefs.
The increasing popularity of marine wildlife tourism (MWT) worldwide calls for assessment of its conservation outcomes and the development of appropriate management frameworks to ensure the conservation of the species and habitats involved as well as the long-term sustainability of this industry. While many studies have examined the positive and/or negative implications of particular forms of MWT, few have attempted to identify factors of concern shared across different types of marine tourism, or examine their implications for sustainability in a broader perspective. We reviewed the existing literature to highlight common impacts on animal behaviour, health and ecology, and to identify successful cases based on minimal negative affects and/or lack of chronic/irreversible impacts on target species or habitats. To ensure the achievement of both economic and ecologic objectives, the following steps should be integrated in MWT management: 1) Increase of research on the biology and ecology of target species/habitat and application of relevant information for the development of suitable policies, frameworks and management strategies; 2) Structured enforcement of existing policies and enhancement of ecological awareness of visitors through active education; 3) Application of an adaptive management framework to continuously improve the codes of conduct employed; 4) Involvement of different stakeholders and local communities in the development and improvement of the MWT activity. Combining these strategies with the extrapolation of frameworks and policies from cases where adverse ecological impacts have been addressed and successfully resolved can further contribute in ensuring the long-term health and conservation of the species/habitats involved in MWT activities.
Although mangroves are known to play a critical part in the lives and life histories of many fish species, these values have rarely been definitively quantified. Despite this, claims such as “an estimated 75% of commercially caught fish depend directly on mangroves” are common across a range of government and non-government documents from around the world, to the extent that the idea that 75% or more of fish depend on mangroves has become a truism widely used to support the value of mangroves. I investigated the basis for these claims that I summarize as the “75% rule.” The “75% rule” is imprecisely defined, and invariably cannot be traced back to definitive scientific data. Moreover, the claim is illogical because we simply do not have adequate knowledge of how many fish occupy different habitats or even how many species of fish there actually are. Moreover, even when the simplest proposition, of how many species use mangroves, is tested using global data bases, the best estimates fall far short of 75%. Clearly, the “75% rule” is wildly inaccurate, unsubstantiated and, at least give our current knowledge and methods, impossible to substantiate. Mangroves are critical to many species but using an indefensible pseudoscientific paradigm such as this to support conservation efforts, management actions and legal decisions, greatly weakens any arguments that build upon it, putting at risk outcomes that rely on the integrity of the claim.
Scientists increasingly rely on protected areas to assist in biodiversity conservation, yet the efficacy of these areas are rarely systematically assessed, often as a byproduct of underfunding, particularly in developing countries. Still, adaptive management strategies to maximize conservation success often rely on understanding the temporal and spatial dynamism of population therein. Environmental DNA (eDNA) has been employed as a time and cost-effective method to monitor species’ distribution, with quantitative PCR (qPCR) techniques also assisting in our knowledge about abundance of aquatic taxa. To date however, this novel methodology remains underutilized by conservation managers in assessing populations in protected areas. In this study, we used eDNA concentration of the critically endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) to circumscribe population ecology in the Tian e-Zhou National Nature Reserve in Hubei, China. We developed, validated, and optimized a qPCR-based eDNA method and applied this protocol to diagnose the geographical reserve use across seasons. Our results suggest spatio-temporal idiosyncrasies, highlighting previously undescribed site and habitat preferences, and a propensity for post-breeding population dispersal. eDNA thus presents a quick and cost-effective method for assessing population-wide utilization of a protected area and, when accounting for environmental-specific nuances, can prove useful for current and future conservation goals.
This paper presents a preliminary attempt to estimate the awareness and value that society gives to the maintenance and protection of marine protected areas, linking the ecological and economic value scale assigned to the study. To accomplish this, we took as illustrative example the Biophysical Interest Zone of Avencas (ZIBA), in Portugal. The ZIBA spans over one ha and its coastal ecosystems present a very rich biodiversity, providing several socio-economic opportunities to society. To estimate the value that society attributes to this area we conducted a contingent valuation exercise, considering two different aspects: 1) the direct economic value that people state to conserve the ecosystem and 2) the willingness to contribute through the allocation of hours of voluntary work to its conservation. The values obtained indicate the dependence and importance of this ecosystem to local population (willing to pay to conserve it of 60 € per household per year and willing to give 3 h of voluntary work per year). The proximity of the local population to the protected area increases the willing to pay for its conservation; this could reveal a good local indicator of ecosystem valuation. This valuation exercise highlights the importance of coastal ecosystem services to society and draws attention to the benefits that local populations derive from those systems. These results have also implications in future governance actions regarding protected areas, as well as to justify for sustainable investments in coastal management efforts, to sustain the flow of coastal ecosystem services for current and future generations.
What did coral reef ecosystems look like before human impacts became pervasive? Early efforts to reconstruct baselines resulted in the controversial suggestion that pristine coral reefs have inverted trophic pyramids, with disproportionally large top predator biomass. The validity of the coral reef inverted trophic pyramid has been questioned, but until now, was not resolved empirically. We use data from an eight-year tag-recapture program with spatially explicit, capture-recapture models to re-examine the population size and density of a key top predator at Palmyra atoll, the same location that inspired the idea of inverted trophic biomass pyramids in coral reef ecosystems. Given that animal movement is suspected to have significantly biased early biomass estimates of highly mobile top predators, we focused our reassessment on the most mobile and most abundant predator at Palmyra, the grey reef shark (Carcharhinus amblyrhynchos). We estimated a density of 21.3 (95% CI 17.8, 24.7) grey reef sharks/km2, which is an order of magnitude lower than the estimates that suggested an inverted trophic pyramid. Our results indicate that the trophic structure of an unexploited reef fish community is not inverted, and that even healthy top predator populations may be considerably smaller, and more precarious, than previously thought.
Despite covering around 70 percent of the earth's surface, the ocean has long been ignored by sociology or treated as merely an extension of land-based systems. Increasingly, however, oceans are assuming a higher profile, emerging both as a new resource frontier, a medium for geopolitical rivalry and conflict, and a unique and threatened ecological hot spot. In this article, I propose a new sociological specialty area, the “sociology of oceans” to be situated at the interface between environmental sociology and traditional maritime studies. After reviewing existing sociological research on maritime topics and the consideration of (or lack of consideration) the sea by classic sociological theorists, I briefly discuss several contemporary sociological approaches to the ocean that have attracted some notice. In the final section of the paper, I make the case for a distinct sociology of oceans and briefly sketch what this might look like. One possible trajectory for creating a shared vision or common paradigm, I argue, is to draw on Deleuze and Guattari's dialectical theory of the smooth and the striated.