In coastal waters around the world, the dominant primary producers are benthic macrophytes, including seagrasses and macroalgae, that provide habitat structure and food for diverse and abundant biological communities and drive ecosystem processes. Seagrass meadows and macroalgal forests play key roles for coastal societies, contributing to fishery yields, storm protection, biogeochemical cycling and storage, and important cultural values. These socio-economically valuable services are threatened worldwide by human activities, with substantial areas of seagrass and macroalgal forests lost over the last half-century. Tracking the status and trends in marine macrophyte cover and quality is an emerging priority for ocean and coastal management, but doing so has been challenged by limited coordination across the numerous efforts to monitor macrophytes, which vary widely in goals, methodologies, scales, capacity, governance approaches, and data availability. Here, we present a consensus assessment and recommendations on the current state of and opportunities for advancing global marine macrophyte observations, integrating contributions from a community of researchers with broad geographic and disciplinary expertise. With the increasing scale of human impacts, the time is ripe to harmonize marine macrophyte observations by building on existing networks and identifying a core set of common metrics and approaches in sampling design, field measurements, governance, capacity building, and data management. We recommend a tiered observation system, with improvement of remote sensing and remote underwater imaging to expand capacity to capture broad-scale extent at intervals of several years, coordinated with stratified in situ sampling annually to characterize the key variables of cover and taxonomic or functional group composition, and to provide ground-truth. A robust networked system of macrophyte observations will be facilitated by establishing best practices, including standard protocols, documentation, and sharing of resources at all stages of workflow, and secure archiving of open-access data. Because such a network is necessarily distributed, sustaining it depends on close engagement of local stakeholders and focusing on building and long-term maintenance of local capacity, particularly in the developing world. Realizing these recommendations will produce more effective, efficient, and responsive observing, a more accurate global picture of change in vegetated coastal systems, and stronger international capacity for sustaining observations.
Harbour porpoise (Phocoena phocoena) are protected in the UK by the Wildlife and Countryside Act (1981). Understanding the impact of anthropogenic pressures is fundamental for effective protection under this act and successful conservation generally. Land-based observations (n = 146) were conducted over a three-month period, during which, porpoise presence, behaviour, vessel type, and locations were recorded. A total of 2461 behavioural observations were recorded, along with a total frequency of marine vessels of 1377.
Principal Component Analysis (76.44%, p = <0.001) revealed a moderate negative correlation between component one (vessels) and two (porpoises and feeding behaviour) (−0.413), indicating that P. phocoena presence and feeding behaviour reduced in response to increasing vessel frequencies. In addition, P. phocoena were sighted more frequently during periods of rising tide at a 1% significance level, consistent with previous results obtained by other Authors.
Using measures outlined by the European Commission, the impacts recorded here make this population of porpoises eligible for possible protection under a Special Area of Conservation or for inclusion within the Torbay Marine Conservation Zone as a “priority species”.
Misali, an uninhabited islet along the east coast of Pemba Island off the mainland Tanzanian coast, is a biodiversity hotspot and Marine Protected Area (MPA), consisting of a core non-extraction zone (NEZ) surrounded by a larger area where some artisanal fishing is allowed. Within a year of receiving official protection under a co-management agreement, the island underwent a catastrophic bleaching event in 1998, and funding and enforcement in the protected area have been inconsistent since a restructuring of management in 2006. In this study, we investigate current health of the island's fish community, and report 186 observed fish species. We estimate that, including unseen species and those outside the study area, the total species richness may be comparable to the historical baseline of 244 species; however, this represents a decline from the 270 species estimated in 2001 and the 350 species observed in 2004, after several years of successful protections. Patterns of species richness over time likely reflect changes in management effectiveness and engagement of Misali's fishing communities. Diversity of indicator (Chaetodontidae) and keystone (Scarinae) taxa were comparable to historical levels and greatest inside the NEZ, suggesting continued reef health and resilience. However, we found no other significant differences between fish communities inside and outside the NEZ, which observations indicate is poorly enforced, and the disproportionate loss of large predatory fish species may indicate overfishing. The case study of Misali suggests that a temporary reduction in fishing pressure while the island was recovering from a severe bleaching event may have had long-lasting benefits for reef health and resilience. For future management, we recommend consideration of species-specific protections, a possible re-designation of NEZ boundaries to include more unique habitat types, and reintegration of local fishing communities into MPA co-management.
Seafloor mapping can offer important insights for marine management, spatial planning, and research in marine geology, ecology, and oceanography. Here, we present a method for generating regional bathymetry and geomorphometry maps from crowd-sourced depth soundings (Olex AS) for a small fraction of the cost of multibeam data collection over the same area. Empirical Bayesian Kriging was used to generate a continuous bathymetric surface from incomplete and, in some areas, sparse Olex coverage on the Newfoundland and Labrador shelves of eastern Canada. The result is a 75m bathymetric grid that provides over 100x finer spatial resolution than previously available for the majority of the 672,900 km2 study area. The interpolated bathymetry was tested for accuracy against independent depth data provided by Fisheries and Oceans Canada (Spearman correlation = 0.99, p<0.001). Quantitative terrain attributes were generated to better understand seascape characteristics at multiple spatial scales, including slope, rugosity, aspect, and bathymetric position index. Landform classification was carried out using the geomorphons algorithm and a novel method for the identification of previously unmapped tributary canyons at the continental shelf edge are also presented to illustrate some of many potential benefits of crowd-sourced regional seafloor mapping.
The rapid environmental changes in Australia prompt a more thorough investigation of the influence of transportation, local emissions, and optical–chemical properties on aerosol production across the region. A month-long intensive measurement campaign was conducted during spring 2016 at Mission Beach, a remote coastal site west of the Great Barrier Reef (GBR) on the north-east coast of Australia. One aerosol pollution episode was investigated in early October. This event was governed by meteorological conditions and characterized by the increase in black carbon (BC) mass concentration (averaged value of 0.35 ± 0.20 μg m−3). Under the influence of the continental transportation, a new layer of nucleation-mode aerosols with an initial size diameter of 20 nm was observed and aerosol number concentrations reached the peak of 6733 cm−3 at a diameter of 29 nm. The averaged aerosol extinction coefficient at the height of 2 km was 150 Mm−1, with a small depolarized ratio (3.5–5%). Simultaneously, the boundary layer height presented a fall–rise trend in the presence of these enhanced aerosol concentrations and became stable in a later stage of the episode. We did not observe clear boundary layer height diurnal variations from the LiDAR observations or from the Weather Research and Forecasting (WRF) model outputs, except in an earlier stage of the aerosol episode for the former. Although the sea breeze may have been responsible for these particles, on the balance of available data, we suggest that the aerosol properties at the GBR surface during this period are more likely influenced by regional transportation of continental sources, including biomass-burning aerosols.
In the context of ecosystem-based fisheries management, which should consider changing and uncertain environmental conditions, the development of ecosystem-based biological reference points (EBRPs) to account for important multi-species (MS) interactions, fishery operations, and climate change, is of paramount importance for sustainable fisheries management. However, EBRPs under varying plankton productivity states and fisheries management strategies are seldom developed, and the ecosystem effects of these changes are still largely unknown. In this study, ecosystem-based FMSY(fishing mortality rate at MSY) values were estimated within an end-to-end ecosystem model (OSMOSE) for three focused fish species (Pacific Herring, Clupea pallasii; Pacific Cod, Gadus macrocephalus; Lingcod, Ophiodon elongatus) under three plankton productivity states of differing plankton biomass at high, current, and low levels. In addition, ecosystem effects were compared across different plankton productivity and fisheries management strategies with the latter consisting of two fishery scenarios (i.e. single-species-focused (SS) and MS-focused), various fishing mortality rates, and two harvest policies (with and without harvest control rules, HCRs). Main findings of this study include: (i) plankton productivity change affected the values of ecosystem-based FMSY, which increased as plankton productivity states changed from low to high plankton biomass; (ii) ecosystem-based FMSY for Pacific Herring and Pacific Cod stocks increased when fishery scenarios shifted from SS-focused to MS-focused; (iii) fisheries management incorporating HCR yielded more stable system catch and system biomass; and (iv) high plankton biomass combined with fisheries management using HCR could maintain stable ecosystem production and sustainable fisheries. Based on our findings, we highlight possible adaptive fisheries management strategies in the face of future climate and ocean changes. Overall, EBRPs complement SS stock assessments by incorporating key ecological processes and ecosystem properties, thus providing supporting evidence for better incorporation of ecosystem considerations into scientific advice for sustainable fisheries management.
Spatial planning is an extremely powerful tool, which can be used for shaping the development of the largest spaces, including maritime space. In order to improve maritime management, the European Union decided to establish a framework in the form of a Directive to support planning processes in these areas. The result of the EU legislation will be land use plans, which will organize human activities in maritime areas in such a way as to meet environmental, economic and social objectives. The EU law applies to the Baltic Sea, Black Sea, Mediterranean Sea and the North-East Atlantic. However, since the internal regulations of individual EU countries differ from one another, the Polish part of the Baltic Sea was selected as an example. The conducted considerations include an analysis of the legal provisions that are to lead to the preparation of the above-mentioned plans. The research material includes both the provisions of the international and of the national laws. For the evaluation of the maritime spatial planning system, which is based on the above-mentioned research material, the SWOT/TOWS analysis has been used. This technique has been aimed at determining the directions of development of maritime spatial planning in Poland based on the current conditions of the spatial planning procedure for these areas as well as the future phenomena related to the implemented procedure for creating maritime area land use plans. It has been pointed out that maritime spatial planning should be carried out using the strengths of the current procedure and the external opportunities that would increase the importance of Polish maritime areas.
Marine protected areas (MPAs) are vital to marine conservation, but their coverage and distribution is insufficient to address declines in global biodiversity and fisheries. In response, many countries have committed through the Aichi Target 11 of the Convention on Biological Diversity to conserve 10% of the marine environment through ‘ecologically representative’ and ‘equitably managed’ MPAs by 2020. The rush to fulfill this commitment has raised concerns on how efforts to increase MPA coverage will affect other elements of Target 11, including representation and equity. We used a Philippines case study to assess and compare three alternative MPA planning approaches for biodiversity representation and equitable distribution of costs to small‐scale fishers. MPAs in an ‘opportunistic approach’ were identified and supported by coastal communities. A ‘donor‐assisted approach’ utilised local knowledge to select MPAs through a national‐scale and donor‐assisted conservation project. A ‘systematic conservation planning approach’ identified MPA locations through the spatial prioritization software ‘Marxan with Zones’ to achieve biodiversity objectives with minimal and equitable costs to fishers. The opportunistic approach was ineffective at representing biodiversity and resulted in inequitable costs to fishers. MPAs selected through the donor‐assisted approach affected fishers disproportionately but provided near‐optimal representation of a study region extent. With approximately the same MPA coverage, the systematic approach was the only approach that achieved all representation targets with minimal and equitable costs to fishers. Our results demonstrate the utility of systematic conservation planning to address key elements of Target 11 and highlight opportunities and pitfalls for planning MPAs in similar contexts.
Mangroves play an essential ecological role in the maintenance of the coastal zone and are extremely important for the socioeconomics of coastal communities. However, mangrove ecosystems are impacted by a range of anthropogenic pressures, and the loss of this habitat can be attributed primarily to the human occupation of the coastal zone. In the present study, we analyzed the spatial patterns of land use in the mangrove of the Brazilian Amazon coast, and evaluated the anthropogenic drivers of this impact, using a remote sensing approach. We mapped the road network using RapidEye images, and human settlements using global data. The results of these analyses indicate that the Brazilian Amazon coast has a low population density and low rates of anthropogenic impact in most of the coastal microregions investigated, factors that contribute to the maintenance and conservation of the region’s mangrove. The study also revealed that the paved road network is one of the principal drivers of land use in the mangrove, whereas other factors, such as population density, urban centers, and the number of settlements are much less important. While the region has 2024 km of paved highways, unpaved roads (17,496 km) facilitate access to the mangrove, with approximately 90% of anthropogenic impact being recorded within a 3 km radius of these roads. While the network of paved highways is relatively reduced in extension, preventive measures are urgently required to impede any major shift in the current scenario, caused by the expansion of major development programs. The results of the study indicate that biophysical, economic, and political factors may also contribute to the reduction, stability, and development of one of the world’s largest areas of mangrove forest.
Marine protected areas (MPAs) are important tools for managing marine ecosystems. MPAs are expected to replenish nearby exploited populations through the natural dispersal of young, but the models that make these predictions rely on assumptions that have recently been demonstrated to be incorrect for most species of fish. A meta‐analysis showed that fish reproductive output scales “hyperallometrically” with fish mass, such that larger fish produce more offspring per unit body mass than smaller fish. Because fish are often larger inside MPAs, they should exhibit disproportionately higher reproductive output as compared to fish outside of MPAs. We explore the consequences of hyperallometric reproduction for a range of species for population replenishment and the productivity of exploited species. We show that the reproductive contribution of fish inside MPAs has been systematically underestimated and that fisheries yields can be enhanced by the establishment of reservoirs of larger, highly fecund fish.