Due to increasing worldwide anthropogenic pressure and in order to promote adequate environmental conservation strategies, quantification of non-biological diversity, such as considering marine and beach litter, is becoming increasingly useful. Information on beach litter in terms of richness and diversity may have a consistent influence regarding the evaluation of its pressure and impact on coastal ecosystems. Highlighted are strengths, weaknesses and caveats concerning the use of uni- and bi-variate diversity metrics applied to a class of man-made non-biological objects periodically accumulated on the beaches. Two case studies show evidence that the application of diversity metrics on non-biological objects may have different implications. In absence of a universal and standardized non-biological taxonomy, it is important to be cautious when comparing values obtained from non-living assemblages, in particular if different sites, time or operators are considered. Moreover, different indices provide different information. Therefore, users should pay particular attention on the application of diversity metrics, addressing specific research questions and avoiding automatic calculation of redundant and “magic” indices.
Recently, the role which fisheries play in the provision of marine ecosystem services has been more widely acknowledged, largely as a result in recent years of fisheries management organisations developing and adopting more ecosystem-based approaches to fisheries management (EAFM). Accordingly, several important management and science challenges have been identified. We argue that these challenges represent a number of important steps which underpin effective science based fisheries management, and when taken together and integrated, offer a logical framework by which to best achieve an EAFM. The challenges, or steps of the framework, identified and described are, i. defining appropriate spatial management units based upon significant and coherent ecosystem production processes, ii. assessing multi-species stock dynamics, iii. developing mixed fisheries management approaches, and iv. assessing the impacts of fisheries on non-target species and ecosystem components. The paper considers how the knowledge gained from research on these challenges can be applied to a risk-based management framework as an essential step towards the achievement of the Sustainable Development Goal (SDG) 14 with respect to the conservation and sustainable use of marine resources for sustainable development.
Expanding human populations favors a few species while extinguishing and endangering many others (Maxwell et al., 2016; Pimm et al., 2014). Understanding how animals perceive and learn about dangers and rewards can aid conservationists seeking to limit abundant or restore rare species (Schakner and Blumstein, 2016; Greggor et al., 2014; Angeloni et al., 2008; Fernández-Juricic and Schulte, 2016). Cognition research is informing conservation science by suggesting how naïve prey learn novel predators (Griffin et al., 2000; Moseby et al., 2015; Schakner et al., 2016; Blumstein, 2016), the mechanisms underlying variation in tolerance of human disturbance (Bostwick et al., 2014), and when natural aversions and fear learning can be leveraged to humanely control predators (Nielsen et al., 2015; Colman et al., 2014; Norbury et al., 2014; Lance et al., 2010; Cross et al., 2013). Insights into the relationships between cognition and adaptability suggest that behavioral inflexibility often presages species rarity (Amiel et al., 2011; Reif et al., 2011; Sol et al., 2008; Zhang et al., 2014; but see Kellert, 1984). Human compassion and restraint are ultimately required to conserve species. Cognitive science can therefore further inform conservation by revealing the complex inner worlds of the animals we threaten and, in partnership with environmental psychologists, explore how such newfound knowledge affects our empathy for other species and ultimately the public’s actions on behalf of species in need of conservation (Collado et al., 2013; Zhang et al., 2014).
Global mean sea level rise (GMSLR) stemming from the multiple effects of human-induced climate change has potentially dramatic effects for inland land use planning and habitability. Recent research suggests that GMSLR may endanger the low-elevation coastal zone sooner than expected, reshaping coastal geography, reducing habitable landmass, and seeding significant coastal out-migrations. Our research reviews the barriers to entry in the noncoastal hinterland. Using three organizing clusters (depletion zones, win-lose zones, and no-trespass zones), we identify principal inland impediments to relocation and provide preliminary estimates of their toll on inland resettlement space. We make the case for proactive adaptation strategies extending landward from on global coastlines and illustrate this position with land use planning responses in Florida and China.
Climate change threatens coral reefs across the world. Intense bleaching has caused dramatic coral mortality in many tropical regions in recent decades, but less obvious chronic effects of temperature and other stressors can be equally threatening to the long-term persistence of diverse coral-dominated reef systems. Coral reefs persist if coral recovery rates equal or exceed average rates of mortality. While mortality from acute destructive events is often obvious and easy to measure, estimating recovery rates and investigating the factors that influence them requires long-term commitment. Coastal development is increasing in many regions, and sea surface temperatures are also rising. The resulting chronic stresses have predictable, adverse effects on coral recovery, but the lack of consistent long-term data sets has prevented measurement of how much coral recovery rates are actually changing. Using long-term monitoring data from 47 reefs spread over 10 degrees of latitude on Australia's Great Barrier Reef (GBR), we used a modified Gompertz equation to estimate coral recovery rates following disturbance. We compared coral recovery rates in two periods: 7 years before and 7 years after an acute and widespread heat stress event on the GBR in 2002. From 2003 to 2009, there were few acute disturbances in the region, allowing us to attribute the observed shortfall in coral recovery rates to residual effects of acute heat stress plus other chronic stressors. Compared with the period before 2002, the recovery of fast-growing Acroporidae and of “Other” slower growing hard corals slowed after 2002, doubling the time taken for modest levels of recovery. If this persists, recovery times will be increasing at a time when acute disturbances are predicted to become more frequent and intense. Our study supports the need for management actions to protect reefs from locally generated stresses, as well as urgent global action to mitigate climate change.
Global coral reef related tourism is one of the most significant examples of nature-based tourism from a single ecosystem. Coral reefs attract foreign and domestic visitors and generate revenues, including foreign exchange earnings, in over 100 countries and territories. Understanding the full value of coral reefs to tourism, and the spatial distribution of these values, provides an important incentive for sustainable reef management. In the current work, global data from multiple sources, including social media and crowd-sourced datasets, were used to estimate and map two distinct components of reef value. The first component is local “reef-adjacent” value, an overarching term used to capture a range of indirect benefits from coral reefs, including provision of sandy beaches, sheltered water, food, and attractive views. The second component is “on-reef” value, directly associated with in-water activities such diving and snorkelling. Tourism values were estimated as a proportion of the total visits and spending by coastal tourists within 30 km of reefs (excluding urban areas). Reef-adjacent values were set as a fixed proportion of 10% of this expenditure. On-reef values were based on the relative abundance of dive-shops and underwater photos in different countries and territories. Maps of value assigned to specific coral reef locations show considerable spatial variability across distances of just a few kilometres. Some 30% of the world's reefs are of value in the tourism sector, with a total value estimated at nearly US$36 billion, or over 9% of all coastal tourism value in the world's coral reef countries.
The European Marine Strategy Framework Directive (MSFD) aims at implementing a precautionary and holistic ecosystem-based approach for managing European marine waters. Marine mammals are included as a functional group for the assessment and reporting under Descriptor 1-Biodiversity. Conservation of mobile marine megafauna such as cetaceans requires transboundary cooperation, which the MSFD promotes through regional instruments, such as the Regional Sea Conventions and other regional cooperation structures such as ACCOBAMS (Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and Contiguous Atlantic Area). A questionnaire survey and an exploratory analysis of MSFD implementation in the Mediterranean and Black Seas were conducted. The analysis revealed (i) the saliency of cetacean conservation, and (ii) heterogeneity among countries in the implementation of the MSFD that may hinder transboundary collaboration. ACCOBAMS can stimulate collaboration among scientists involved in cetacean monitoring and can foster transboundary initiatives that would align with MSFD objectives.
The coralligenous habitats found in the Mediterranean Sea are hotspots comparable in biodiversity to tropical reefs. Coralligenous reefs are vulnerable to many human pressures, thus they are among the most threatened habitats in the Mediterranean Sea. In this study, we assessed the impacts on coralligenous habitats of activities associated with salvaging the wreck of the Costa Concordia cruise ship. After its partial foundering in 2012, the Costa Concordia remained adjacent to the eastern coast of Giglio Island (Tuscany, Italy), in the Tyrrhenian Sea, for over two years. Its salvage required high-impact engineering works, during the course of which monitoring of benthic communities was undertaken. We performed Rapid Visual Assessment (RVA) sampling (using recorded video) from 17 stations located between 35 and 76 m depth and characterized by coralligenous habitats. Sampling activity was performed during the summers of 2012, 2013, and 2014. In parallel, chemical and physical water parameters were measured continuously from summer 2012 to the end of summer 2014, in order to detect any perturbation in natural conditions caused by salvage activities. We assessed the ecological quality of coralligenous habitats by applying the COARSE (COralligenous Assessment by ReefScape Estimate) index, based on the RVA approach. Slight modifications were applied to one of the descriptors of the COARSE index in order to adjust for study site features. There was clear evidence of a reduction in coralligenous habitats quality. Assemblages, slope, type of pressure, and distance from the source of disturbance played a pivotal role in characterizing bottom quality. The index was shown to have an easy and cost-effective application, even in waters deeper than its calibration specification; furthermore, the modification reported here may increase its potential applications.
With the rapid rise in pollution-associated nitrogen inputs to the western Pacific, it has been suggested that even the open ocean has been affected. In a coral core from Dongsha Atoll, a remote coral reef ecosystem, we observe a decline in the 15N/14N of coral skeleton–bound organic matter, which signals increased deposition of anthropogenic atmospheric N on the open ocean and its incorporation into plankton and, in turn, the atoll corals. The first clear change occurred just before 2000 CE, decades later than predicted by other work. The amplitude of change suggests that, by 2010, anthropogenic atmospheric N deposition represented 20 ± 5% of the annual N input to the surface ocean in this region, which appears to be at the lower end of other estimates.
A priority for modern conservation is finding and managing regions with environmental and biodiversity portfolio characteristics that will promote adaptation and the persistence of species during times of rapid climate change. The latitudinal edges of high-diversity biomes are likely to provide a mixture of environmental gradients and biological diversity that meet the portfolio criteria needed for adaptive systems. Northern Mozambique and the Quirimbas Islands represent the edge of a coral reef diversity center with limited potential to expand because of geologic and oceanographic limits on the southern edges. This region does, however, have the potential to be its own discrete adaptive center if it contains climate refugia and there are environmental gradients that promote acclimatization, ecological reorganization, and natural selection. Consequently, to evaluate this potential we tested for strong regional environmental spatial heterogeneity that might indicate a climate-adaptive center. Additionally, we evaluated human influences and environmental and demographic data on finfish, coral, and sea urchins in 66 reefs across ~4° of latitude to evaluate ecological changes and human threats. A number of clear gradients in environmental and human influences were observed. For example, temperature increased and became more centralized and right-skewed, while water quality decreased to the south. Coral communities susceptible to thermal stress were found in the north where dispersed temperatures indicated a location with either tolerance to or refugium from recent thermal disturbances. Nevertheless, high coral diversity was found in southern deep-water channels. Further, spatial patterns for corals and fish differed indicating complex geographic-fishing-biodiversity gradients. Consequently, environmental conditions for an adaptive portfolio exist and include refugia for preserving climate-sensitive and for numbers of coral taxa. Fishing and urban threats were observable as reduced fish biomass, diversity, and body sizes but higher biomass of sea urchins. We observed that many remote and protected areas had fish biomass values lower than expected or near maximum sustainable yields. This indicates low compliance and widespread migratory fishing, which is reducing fish diversity below maximum levels. Recommendations to sustain this adaptive center are to maintain fish biomass >500 kg/ha by increasing fisheries restrictions and compliance.
Isolated marine protected areas (MPAs) may not be enough to sustain viable populations of marine species, particularly the many small coastal MPAs which resulted due to social, economic and political constraints. Properly designed MPA networks can circumvent such limitations due to their potential synergistic positive effects, but this crucial step is frequently obstructed by lack of baseline ecological information. In this paper, we use systematic conservation planning on European Nature Information System coastal habitat information available for Portugal to demonstrate how an ecologically coherent nation-wide MPA network can be designed. We used the software Marxan to obtain near optimal solutions for each of three pre-determined conservation targets (10%, 30% and 50% protection) while maintaining the cost of including conservation units as low as possible. Marxan solutions were subsequently optimized with MinPatch by keeping each MPA above a minimum size that reflects the existing information on habitat use by some key marine fishes. Results show that 10% protection for all habitats would only require a relatively small increase in the number (from 6 to 10) and area (from 479 km2to 509 km2) of already existing MPAs in mainland Portugal whereas substantial increases would be required to achieve the 50% target. This rather simple approach offers the added benefit of allowing design improvement as more relevant ecological information becomes available, including deeper habitat mapping across the whole continental shelf, allowing a coherent, adaptive and inclusive optimal MPA network to be designed.
Costa Rica is considering expanding their marine protected areas (MPAs) to conserve marine resources. Due to the importance of households’ responses to an MPA in defining the MPA’s ecological and economic outcomes, this paper uses an economic decision framework to interpret data from near-MPA household surveys to inform this policy discussion. The model and data suggest that the impact of expanding MPAs relies on levels of enforcement and on-shore wages. If larger near-shore MPAs can produce high wages through increased tourism, MPA expansions could provide ecological benefits with low burdens to communities. Due to distance costs and gear investments, however, MPAs farther off-shore may place high burdens on off-shore fishers.
It is acknowledged that an effective path to globally protect marine ecosystems is through the establishment of eco-regional scale networks of MPAs spanning across national frontiers. In this work we aimed to plan for regionally feasible networks of MPAs that can be ecologically linked with an existing one in a transboundary context. We illustrate our exercise in the Ensenadian eco-region, a shared marine ecosystem between the south of California, United States of America (USA), and the north of Baja California, Mexico; where conservation actions differ across the border. In the USA, California recently established a network of MPAs through the Marine Life Protection Act (MLPA), while in Mexico: Baja California lacks a network of MPAs or a marine spatial planning effort to establish it. We generated four different scenarios with Marxan by integrating different ecological, social, and management considerations (habitat representation, opportunity costs, habitat condition, and enforcement costs). To do so, we characterized and collected biophysical and socio-economic information for Baja California and developed novel approaches to quantify and incorporate some of these considerations. We were able to design feasible networks of MPAs in Baja California that are ecologically linked with California's network (met between 78.5 and 84.4% of the MLPA guidelines) and that would represent a low cost for fishers and aquaculture investors. We found that when multiple considerations are integrated more priority areas for conservation emerge. For our region, human distribution presents a strong gradient from north to south and resulted to be an important factor for the spatial arrangement of the priority areas. This work shows how, despite the constraints of a data-poor area, the available conservation principles, mapping, and planning tools can still be used to generate spatial conservation plans in a transboundary context.
The benefit of engaging volunteers in marine citizen science projects goes beyond generation of data and has intrinsic value with regards to community capacity-building and education. Yet, despite the documented benefits of citizen science, there can be barriers to the process of developing strategic citizen science projects and translating data into valued results with natural resource management applications. This paper presents four case-studies from fifteen years of Reef Check Australia (RCA) marine citizen science research and education projects. These case studies convey approaches and lessons-learned from the process of designing, implementing and sharing citizen science programs with the goal to create valuable social and environmental outcomes:
(1) Demonstrating citizen science data quality through a precision study on data and analysis of 15 years of standardized Reef Check (RC) reef health data in Queensland, Australia.
(2) Identifying and responding to data gaps through volunteer monitoring of sub-tropical rocky reefs in South East Queensland, Australia.
(3) Adapting citizen science protocols to enhance capacity building, partnerships and strategic natural resource management applications through reef habitat mapping.
(4) Tailoring new pathways for sharing citizen science findings and engaging volunteers with the community via a Reef Check Australia Ambassadors community outreach program.
These case studies offer insights into considerations for developing targeted and flexible citizen science projects, showcasing the work of volunteers and project stakeholders, and collaborating with partners for applications beneficial to research, management and education.
Marine protected areas (MPA) that are created opportunistically must be evaluated in an ecological context to ensure that conservation goals and societal expectations are achievable. This study used acoustic telemetry to investigate movements of reef fish relative to the boundary of the Virgin Islands Coral Reef National Monument (VICRNM) in Coral Bay, U.S. Virgin Islands. Although created to enhance ecosystem protection, VICRNM boundaries were established purely on the basis of adjacency to public versus privately owned lands. Transmitters were implanted into a diversity of reef fish species representative of the local community whose movements were logged for one year on an array of acoustic-receivers that were positioned within, outside, and along the MPA boundary. Results indicate that the boundary has coincidentally aligned with a deep sandy area that does not cross through continuous reef or mangrove habitat. This acted as a natural barrier to movements of species such as Lutjanus griseus, Epinephelus guttatus, Cephalopholus cruentatus, Holocentrus rufus, and Sparisoma aurofrenatum. Other species were more mobile and were routinely detected outside VICRNM, especially at night, such as L. synagris, Haemulon plumierii, and H. sciurus. In addition to fish movements in relation to the VICRNM boundary, network analysis revealed several hotspots of concentrated fish activity including a reef promontory and bay mouths. Investment in enforcement of existing regulations to protect fish is warranted to realize the full potential of this MPA. Using these types of data, management actions in this and other MPAs can be focused on those species and locations that would experience the greatest benefit.
Over the past decades, much research has focused on understanding the critical factors for marine extinctions with the aim of preventing further species losses in the oceans. Although conservation and management strategies are enabling several species and populations to recover, others remain at low abundance levels or experience further declines. To understand these discrepancies, we asked which intrinsic and extrinsic factors are critical for the recovery of marine mammals. Building on a published database on abundance trends of 137 marine mammal populations worldwide, we compiled data on 28 potential critical factors and used random forests and additive mixed models in our analytical approach. Our results highlight that a mix of life-history characteristics, ecological traits, phylogenetic relatedness, population size, geographic range, human impacts and management efforts were important in explaining why populations recover or not. Generally, species with lower age at maturity and intermediate habitat area were more likely to recover, which is consistent with life-history and ecological theory. Body size and ocean basin were also important, as well as trophic level, social interactions, the dominant habitat and habitat disturbance. Overall, our results highlight that not one or two, but a range of intrinsic and extrinsic factors are important for recovery, pointing to cumulative effects. This new line of research provides important information for improving conservation and management strategies particularly for those populations that have been unable to recover to date.
The incorporation of local and traditional knowledges into environmental governance regimes is increasingly recognised as a critical component of effective and equitable conservation efforts. However, there remain significant barriers to integration of community-based knowledge within mainstream environmental governance. This paper explores community-based knowledge in the context of Environmental Impact Assessment (EIA), a widely-used governance tool designed to predict and manage the impacts of development. Drawing on a social survey and interviews, the paper documents local community knowledge of environmental changes associated with dredging and the construction of Liquefied Natural Gas (LNG) plants in a large industrial harbour located in the Great Barrier Reef World Heritage Area, and compares this knowledge with public consultation opportunities offered throughout the project lifecycle, including during assessment and after project approval. The findings highlight a misalignment between community knowledge of environmental change, which is acquired largely after impacts become apparent, and the public participation opportunities afforded through EIA, which generally occur before construction or dredging is undertaken.
In recent decades, the flow of fixed—that is, biologically usable—nitrogen from human activities into the environment has grown substantially. The sources include excess production and use of nitrogen fertilizers; ammonia emitted from animal husbandry and sewage; and nitrogen oxides emitted by automobiles, airplanes, and fossil fuel power plants. The resulting nitrogen flux into the ocean may approach the magnitude of natural sources (1–3). However, it is difficult to specify the integrated increase over natural sources precisely because there is very little data for when nitrogen sources were mostly natural. On page 749 of this issue, Ren et al. use the nitrogen isotope composition of a 50-year coral core from the South China Sea to show that the natural upwelling flux of fixed nitrogen has risen by 20% during the past two decades (4).
Due to rapid declines of shark populations across many species and regions of the world, the need for large-scale conservation measures has become widely recognized. Some coastal states have opted to implement ‘Shark Sanctuaries’, which prohibit commercial shark fishing and the export of shark products across large areas, typically their entire Exclusive Economic Zones. Although shark sanctuaries cover almost as much area globally as marine protected areas (MPAs), their success has yet to be evaluated. Here, key features and regulatory details for eleven shark sanctuaries (covering 3% of global ocean area) are summarized, highlighting their commonalities and differences. Catch data are then used to shed light on the impact current shark sanctuaries could have on shark catch, foreign fleets, trade and abundance. Based on this comparative analysis, recommendations are made to implement program evaluation measures within existing and future shark sanctuaries that would explicitly outline goals and measures of success or failure. In summary, although shark sanctuaries may have the intended effect of reducing shark mortality, there appears a need to address bycatch within shark sanctuary regulations, and to collect baseline data that can be used to monitor sanctuary effectiveness.
Vegetated marine habitats are globally important carbon sinks, making a significant contribution towards mitigating climate change, and they provide a wide range of other ecosystem services. However, large gaps in knowledge remain, particularly for seagrass meadows in Africa. The present study estimated biomass and sediment organic carbon (Corg) stocks of four dominant seagrass species in Gazi Bay, Kenya. It compared sediment Corg between seagrass areas in vegetated and un-vegetated ‘controls’, using the naturally patchy occurence of seagrass at this site to test the impacts of seagrass growth on sediment Corg. It also explored relationships between the sediment and above-ground Corg, as well as between the total biomass and above-ground parameters. Sediment Corg was significantly different between species, range: 160.7–233.8 Mg C ha-1 (compared to the global range of 115.3 to 829.2 Mg C ha-1). Vegetated areas in all species had significantly higher sediment Corg compared with un-vegetated controls; the presence of seagrass increased Corg by 4–6 times. Biomass carbon differed significantly between species with means ranging between 4.8–7.1 Mg C ha-1 compared to the global range of 2.5–7.3 Mg C ha-1. To our knowledge, these are among the first results on seagrass sediment Corg to be reported from African seagrass beds; and contribute towards our understanding of the role of seagrass in global carbon dynamics.