Sandstone reefs may be considered a unique geomorphologic feature within the subtropical Southwestern Atlantic Ocean region; however, biodiversity on these reefs has received little to no attention. Herein, we recorded the fish assemblage and benthic cover of sandstone reefs between 23 and 29 m depth in Southern Brazil and evidenced potential threats to habitat health. Video analysis and underwater censuses recorded 30 fish species. The unexpected high biomass of Epinephelus marginatus indicated that sandstone reefs may contain suitable habitats for the recovery of this endangered species. A rich benthic coverage including bryozoans, algae, hydrozoans, sponges, and octocorals increased local habitat structural complexity. However, a wide diversity of tangled fishing gear and broken sandstone slabs suggested that a valuable feature from Southern Brazil seascape is being lost by cumulative fishing impacts. An extensive mapping of sandstone reefs is urgently needed for better delineation of marine protected areas network in Southeast and Southern Brazil.
Mangrove degradation threatens the capacity of these important ecosystems to provide goods and services that contribute to human wellbeing. This study uses a deliberative choice experiment to value non-market mangrove ecosystem services (ES) at Mida Creek, Kenya. The attributes assessed include “shoreline erosion protection”, “biodiversity richness and abundance”, “nursery and breeding ground for fish”, and “education and research”. Unpaid labour (volunteer time) for mangroves conservation was used as the payment mechanism to estimate willingness to pay (WTP). Results suggest that respondents were willing to volunteer: 5.82 h/month for preserving the mangrove nursery and breeding ground functions to gain an additional metric ton of fish; 21.16 h/month for increasing biodiversity richness and abundance; 10.81 h/month for reducing shoreline erosion by 1 m over 25 years; and 0.14 h/month for gaining 100 student/researcher visits/month. The estimation of WTP for mangrove ES provides valuable insights into the awareness of local communities about the contribution of mangrove forests to ES delivery. This knowledge could assist decision-making for the management and conservation of mangroves in Mida Creek and its environs.
Marine protected areas (MPAs) are the preferred tool for preventing marine biodiversity loss, as reflected in international protected area targets. Concerns have been raised that opposition from resource users is driving MPAs into low‐pressure areas while high‐use areas remain unprotected, with serious implications for biodiversity conservation. We apply a novel test of the spatial relationships between different pressures on marine biodiversity and protection in the world's MPAs. We find that as pressures from pelagic and artisanal fishing, shipping and introductions of invasive species by ship increase, the likelihood of protection decreases, and this relationship persists under even the most relaxed categories of protection. In contrast, as pressures from dispersed, diffusive sources such as pollution and ocean acidification increase, so does the likelihood of protection. We conclude that MPAs are systematically established in areas where there is low political opposition, limiting the capacity of existing MPAs to manage key drivers of biodiversity loss. We suggest that conservation efforts should focus on biodiversity outcomes rather than prescribing area‐based targets and that alternative approaches to conservation are needed in areas where protection is not feasible.
Changes in structure and function of coral reefs are increasingly significant and few sites in the Caribbean can tolerate local and global stress factors. Therefore, we assessed coral reef condition indicators in reefs within and outside of MPAs in the southeastern Dominican Republic, considering benthic cover as well as the composition, diversity, recruitment, mortality, bleaching, the conservation status and evolutionary distinctiveness of coral species. In general, we found that reef condition indicators (coral and benthic cover, recruitment, bleaching, and mortality) within the MPAs showed better conditions than in the unprotected area (Boca Chica). Although the comparison between the Boca Chica area and the MPAs may present some spatial imbalance, these zones were chosen for the purpose of making a comparison with a previous baseline presented. In actuality these indicators found in the MPAs have improved when compared to results from previous reports (2001) in the same reefs and others in the Caribbean. Additionally, we found no evidence of massive bleaching during the El Niño-Southern Oscillation (ENSO) of 2015. Reef-building species belonging to Orbicella species complex dominate MPAs, while small colonies of Pseudodiploria strigosa and Siderastrea siderea with low structural complexity dominate the unprotected sites. Key findings include the potential offered by MPAs as a network; our results show that a combination of MPAs protect the variation in diversity and promote the conservation of coral while maintaining historical evolution traits. This study offers an evaluation framework that considers multiple aspects of relevance in the conservation of Caribbean coral reefs, presenting a baseline of ecological indicators in the southeastern region of the Dominican Republic. It also recognizes some protected reefs in this region that can be designated as places of hope, with excellent conditions in the coral community.
The current development of citizen science is an opportunity for marine biodiversity surveys to use recreational SCUBA diver data. In France, the DORIS project is extensively used for marine species identification, while many initiatives offer volunteer divers the means to record their observations. Thanks to the scientific synergy generated by the flagship project of the artificial reefs (ARs) of Prado Bay, located off the coast of Marseille (France), a multi-annual biodiversity survey was performed by a team of recreational divers certified by the French Federation for Submarine Sports and Education (FFESSM). The analysis of their observations with other citizen science data showed a good taxonomic coverage for fishes and mollusks. These observations also allowed (1) to follow AR colonization over the study period, with the increasing number of taxa and the growing occurrence of large fishes, and (2) to characterize taxa distribution between the different AR types, revealing the inefficiency of one type of AR which failed to provide the results expected from its design. This example demonstrates that the transition from species identification to ecologically relevant observation is perfectly feasible using volunteer naturalist SCUBA divers, on condition that both the protocols and the data are validated by professional scientists.
Cetacean communities face significant threats from adverse interactions with human activities such as bycatch, vessel collision, and environmental pollution. Monitoring of marine mammal populations can help to assess and safeguard marine biodiversity for future generations. Traditional surveys can be costly and time-consuming to undertake, but we explore the ability of citizen science to inform environmental assessments and subsequent conservation management. We use data collected from platforms of opportunity within the Bay of Biscay to investigate spatial changes in cetacean diversity, with the aim of identifying hotspots which may be suitable for further investigation and conservation. Seventeen species of cetaceans were recorded over a ten year period, many of which are data deficient in European waters (e.g. Bottlenose dolphin, Short-beaked common dolphin, Striped dolphin, Risso's dolphin, Long-finned pilot whale, Killer whale, Northern bottlenose whale, Cuvier's beaked whale, Sowerby's beaked whale and True's beaked whale). Biodiversity (determined by Simpson's Diversity index) ranged from 0.19 to 0.77. The central and southern areas of the survey area indicated the highest biodiversity (0.65–0.77), and these locations may benefit most from protection as Important Marine Mammal Areas. We present a case for this designation, and discuss the benefits and limitations of citizen science for informing conservation action.
Nares Strait is the northern most outflow gateway of the Arctic Ocean, with a direct connection to the remaining multi-year ice covered central Arctic Ocean. Nares Strait itself flows into the historically highly productive North Water Polynya (Pikialasorsuaq). Satellite data show that Nares Strait ice is retreating earlier in the season. The early season surface chlorophyll signal, which was a characteristic of the North Water, has also moved north into Nares Strait. However, given the vast differences in the hydrography and physical oceanographic structure of the North Water and Nares Strait there is no a priori reason to assume that the species assemblages and overall productivity of this region between Greenland and Canada will be maintained in the face of ongoing sea ice decline. The North Water’s high marine mammal and bird populations are dependent on seasonally persistent diatom dominated phytoplankton productivity, and although there have been several studies on North Water phytoplankton, virtually nothing is known about the communities in Nares Strait. Here we investigated the microbial eukaryotes, including phytoplankton in Nares Strait using high-throughput amplicon sequencing. Samples were collected from Kennedy Channel below the northern ice edge of Nares Strait through the Kane Basin and into the northern limit of the North Water. The physical oceanographic structure and initial community rapidly changed between the faster flowing Kennedy Channel and the comparatively wider shallower Kane Basin. The community changes were evident in both the upper euphotic zone and the deeper aphotic zone. Heterotrophic taxa were found in the deeper waters along with ice algae that would have originated further to the north following release from the ice. Although there was a high proportion of pan-Arctic species throughout, the Nares Strait system showed little in common with the Northern North Water station, suggesting a lack of connectivity. We surmise that a direct displacement of the rich North Water ecosystem is not likely to occur. Overall our study supported the notion that the microbial eukaryotic community, which supports ecosystem function and secondary productivity is shaped by a balance of historic and current processes, which differed by seascape.
States at the United Nations have begun negotiating a new treaty to strengthen the legal regime for marine biodiversity in areas beyond national jurisdiction. Failure to ensure the full scope of fish biodiversity is covered could result in thousands of species continuing to slip through the cracks of a fragmented global ocean governance framework.
Over the past 70 years, commercial fisheries have expanded farther and deeper into the open ocean1,2,3,4, impacting many forms of marine biodiversity that exist in areas beyond national jurisdictions (ABNJ; generally, the area beyond 200 nautical miles from shore)5,6. The growth of other industries, such as shipping, has further expanded the presence of humans in the open ocean, while new activities, such as seabed mining, are on the horizon1. These impacts are compounded by the effects of a changing climate, deoxygenation and ocean acidification7,8,9.
In 2017, after more than a decade of informal discussions at the United Nations (UN) regarding gaps in the legal framework for the conservation and management of marine biodiversity beyond national jurisdiction (known as the BBNJ process), states agreed to convene an intergovernmental conference for the negotiation of an legally binding instrument under the UN Convention on the Law of the Sea (UNCLOS) (an ‘implementing agreement’)10.
The agreement to launch the negotiations was partly achieved by the consensus that any new instrument “should not undermine existing legal instruments and frameworks and relevant global, regional and sectoral bodies”10. This has generally been assumed to mean that the new instrument should complement and strengthen the existing framework and prevent the adoption of weaker or dissonant management measures. However, a small number of states wish to see commercial fisheries (including all forms of fish biodiversity, which they group as a commercial resource whether or not it is harvested) excluded from a new agreement and are concerned that any new provisions will inevitably undermine existing fisheries management bodies. However, there is a significant difference between the number of fish species subject to management and the number of fish species in ABNJ that may be impacted by commercial fishing activities. As fish are a major component of marine biodiversity in ABNJ and have a major role in marine ecosystem functioning, it is important to understand what regional fisheries management organizations (RFMOs) are in fact responsible for monitoring and managing. Here, we contrast fish biodiversity estimates in ABNJ with a comprehensive database of existing fish population assessments to help delineate the current competencies of RFMOs and identify areas of improvement that could be addressed both through the new agreement as well as by strengthening the mandates and actions taken by such bodies.
We first describe the overarching legal framework for high-seas fisheries, then enumerate how many fish species are either targeted, affected or simply unstudied and potentially at risk of slipping through the cracks of the current management arrangements. The final section analyses how these gaps are relevant to ongoing negotiations at the UN for a new treaty and concludes with specific recommendations.
Within the context of global climate change and overfishing of fish stocks, there is some evidence that cephalopod populations are benefiting from this changing setting. These invertebrates show enhanced phenotypic flexibility and are found from polar regions to the tropics. Yet, the global patterns of species richness in coastal cephalopods are not known. Here, among the 370 identified-species, 164 are octopuses, 96 are cuttlefishes, 54 are bobtails and bottletails, 48 are inshore squids and 8 are pygmy squids. The most diverse ocean is the Pacific (with 213 cephalopod species), followed by the Indian (146 species) and Atlantic (95 species). The least diverse are the Southern (15 species) and the Arctic (12 species) Oceans. Endemism is higher in the Southern Ocean (87%) and lower in the Arctic (25%), which reflects the younger age and the “Atlantification” of the latter. The former is associated with an old lineage of octopuses that diverged around 33 Mya. Within the 232 ecoregions considered, the highest values of octopus and cuttlefish richness are observed in the Central Kuroshio Current ecoregion (with a total of 64 species), followed by the East China Sea (59 species). This pattern suggests dispersal in the Central Indo-Pacific (CIP) associated with the highly productive Oyashio/Kuroshio current system. In contrast, inshore squid hotspots are found within the CIP, namely in the Sunda Shelf Province, which may be linked to the occurrence of an ancient intermittent biogeographic barrier: a land bridge formed during the Pleistocene which severely restricted water flow between the Pacific and Indian Oceans, thereby facilitating squid fauna differentiation. Another marked pattern is a longitudinal richness cline from the Central (CIP) toward the Eastern Indo-Pacific (EIP) realm, with central Pacific archipelagos as evolutionary dead ends. In the Atlantic Ocean, closure of the Atrato Seaway (at the Isthmus of Panama) and Straits of Gibraltar (Mediterranean Sea) are historical processes that may explain the contemporary Caribbean octopus richness and Mediterranean sepiolid endemism, respectively. Last, we discuss how the life cycles and strategies of cephalopods may allow them to adapt quickly to future climate change and extend the borealization of their distribution.