Marine conservation zones (MCZs) are a form of spatial marine management, increasingly popular since the move towards ecosystem-based fisheries management. Implementation, however, is somewhat contentious and as a result of their short history, their effects are still widely unknown and understudied. Here, we investigate the population and health of the European lobster (Homarus gammarus) in the Lundy Island Marine Conservation Zone, Bristol Channel, UK. Using the fished refuge zone (RZ) as a control area, catch per unit effort was calculated for both the no-take zone (NTZ) and RZ and binomial logistic regression models were used to examine the effects of site, sex, landing size, and loss of chelae on the probability of shell disease and injury presence in individuals. Lobsters were also tested for the causative agent of gaffkaemia, Aerococcus viridans var. homari, and white spot syndrome virus (WSSV). The analysis revealed a higher lobster density and larger lobsters in the NTZ compared with the RZ. Shell disease was present in 24% of lobsters and the probability of shell disease occurrence increased notably for individuals over the minimum landing size (MLS) of 90 mm carapace length. Shell disease was also more prevalent in lobsters displaying injury, and in males. Injury was present in 33% of lobsters sampled and prevalence was higher in lobsters in the NTZ compared with the RZ, and in lobsters >MLS. Aerococcus viridans var. homari was detected in <1% of individuals, but WSSV was absent from all sampled lobsters. Overall, the study demonstrates both positive and potentially negative effects of NTZs, methods for effective non-lethal sampling of disease agents, and highlights the need for more comprehensive, long-term monitoring within highly protected MCZs, both before and after implementation.
Nearshore bathymetry is likely to be the coastal variable that most limits the investigation of coastal processes and the accuracy of numerical models in coastal areas, as acquiring medium spatial resolution data in the nearshore is highly demanding and costly. As such, the ability to derive bathymetry using remote sensing techniques is a topic of increasing interest in coastal monitoring and research. This contribution focuses on the application of the linear transform algorithm to obtain satellite-derived bathymetry (SDB) maps of the nearshore, at medium resolution (30 m), from freely available and easily accessible Landsat 8 imagery. The algorithm was tuned with available bathymetric Light Detection and Ranging (LiDAR) data for a 60-km-long nearshore stretch of a highly complex coastal system that includes barrier islands, exposed sandy beaches, and tidal inlets (Ria Formosa, Portugal). A comparison of the retrieved depths is presented, enabling the configuration of nearshore profiles and extracted isobaths to be explored and compared with traditional topographic/bathymetric techniques (e.g., high- and medium-resolution LiDAR data and survey-grade echo-sounding combined with high-precision positioning systems). The results demonstrate that the linear algorithm is efficient for retrieving bathymetry from multi-spectral satellite data for shallow water depths (0 to 12 m), showing a mean bias of − 0.2 m, a median difference of − 0.1 m, and a root mean square error of 0.89 m. Accuracy is shown to be depth dependent, an inherent limitation of passive optical detection systems. Accuracy further decreases in areas where turbidity is likely to be higher, such as locations adjacent to tidal inlets. The SDB maps provide reliable estimations of the shoreline position and of nearshore isobaths for different cases along the complex coastline analysed. The use of freely available satellite imagery proved to be a quick and reliable method for acquiring updated medium-resolution, high-frequency (days and weeks), low-cost bathymetric information for large areas and depths of up to 12 m in clear waters without wave breaking, allowing almost constant monitoring of the submerged beach and the shoreface.
Wave power devices offer great prospects for the marine renewable energy sector. But in comparison to wind energy, wave power is still in its infancy, mainly prototype-based, with technological gaps akin to those experienced in the wind sector some 15 years ago. Several aspects that did not seem significant at a first glance in the design phase, such as the interaction with the marine environment, turned out to be important when the first prototypes were put in the water. In fact, these devices have to face great challenges once at sea and several prototypes have not survived. Firstly, ocean waves are not such an innocuous, predictable flow of water and secondly, life thrives in the ocean. Wave power devices are perfect artificial reefs suitable for algal growth and colonization by many species. And they will have to sustain harsh conditions for over two decades while producing energy. For obvious reasons, there is a lack of existing literature on the subject. In this short review we address a simple question: how tough will the life of wave power devices at sea be? The answer is based on available evidence. We provide as well some ideas to take up the challenge.
In Norwegian fisheries policy, strict gear regulation is a central instrument actively used to achieve fisheries political objectives. Gear regulations are locked in rigid regulative structures that limit the actors׳ ability to adapt practices to changing conditions. This article shows that gear liberalization could take place within the framework of sustainable resource harvest, while also contributing to improved economic efficiency and reduced greenhouse gas emissions. Institutions, such as gear regulations, do not exist in a vacuum, but are linked to other institutional structures. Hence, within a framework of sustainability, the relaxation of one regulation may induce new regulations and institutions.
Marine animals face increased pressure through expanded shipping and recreational activities. Effective conservation and management of large species like marine mammals or sea turtles depend on knowledge of movement and habitat use. Previous studies have used data collected from either satellite or acoustic telemetry but rarely both. In this study, data from satellite and acoustic technologies were used to: determine the efficacy of satellite and acoustic telemetry to define dugong movement patterns; compare the benefits and limitations of each approach; examine the costs of each approach in relation to the amount and type of data provided; and relate telemetry data to the boundaries of a Go Slow area designed to protect dugongs and turtles from vessel strike within an urbanised coastal embayment (Moreton Bay, Queensland, Australia). Twenty-one dugongs were captured in seagrass habitats on the Eastern Banks of Moreton Bay in July–September 2012 and July 2013 and fitted with GPS and acoustic transmitters. Both satellite and acoustic telemetry produced reliable presence and movement data for individual dugongs. When the dugongs were within the range of the acoustic array, there was relatively good correspondence between the overall space use measures derived from GPS and acoustic transmitters, demonstrating that acoustic tracking is a potentially valuable and cost-effective tool for monitoring local dugong habitat use in environments equipped with acoustic receiver arrays. Acoustic technology may be particularly useful for species that establish home ranges with stable residency especially near large urban or port environs. However, the relative merits of the two technologies depend on the research question in the context of the species of interest, the location of the study and whether the study site has an established acoustic array.
A fully four-dimensional (3D × time) object-oriented biophysical dispersal model was developed to simulate the movement of marine larvae over semi-continuous surfaces. The model is capable of handling massive numbers of simulated larvae, can accommodate diverse life history patterns and distributions of characteristics, and saves point-level information to a relational database management system. The model was used to study Australia's northwest marine region, with attention given to connectivity patterns among Australia's north-western Commonwealth Marine Reserves (CMRs). Animations of larval movement near the Gascoyne canyon CMR, dispersal surfaces over depth and time for CMRs and Key Ecological Features in the northwest, as well as matrices of connectivity values among CMRs are shown. The matrices are further analysed to identify the sensitivity and elasticity of their values. The results generated by this model can aid in designing and managing marine protected area networks that incorporate extensive and complex benthic terrain (including the identification of marine ‘corridors’), and for developing targeted field sampling strategies.
This article aims to identify conditions of success for European fisheries co-management and its integration in broader strategies for sustainable resource management. Co-management of fisheries, broadly defined as the involvement of users in management, developed in Europe in various experimental forms of participation of fishermen in the management process, in advisory roles or through delegation and sharing of power. During its history, fisheries co-management has been revealed as multi-functional, addressing different knowledge and resource management problems, with varying success. This analysis focuses on knowledge-related issues that are important for the functioning of co-management, especially the combination of scientific and local knowledge. First we review European literature on co-management and secondly we analyse two exemplary case studies (EU Regional Advisory Councils and Fisheries Local Action Groups). Thereupon the possibilities for future development of co-management in Europe are discussed with regard to knowledge integration and environmental governance. Under the influence of the ideas of adaptive governance and sustainable resource management, modifications of forms and functions of co-management systems are described.
Bahrain, a group of islands, is facing several environmental challenges, including degradation of coastal and marine environments due to intensive dredging and reclamation activities. Presently, reclamation activities have resulted in adding around 110 km2 representing an increase of 14% of the total land area of Bahrain. Recognizing the role of Environmental Impact Assessment (EIA) in protecting environment from degradation and pollution associated with coastal developments, Bahrain formally adopted EIA in its environmental system in 1998. The present study investigated the practice and effectiveness of EIA in protecting coastal and marine environments in Bahrain by reviewing selected EIA reports and soliciting views of EIA experts, consultants, academics and other relevant bodies. Shortcomings in environmental and ecological assessment practices related to coastal and marine developments were recognized and constrains that restrict the effectiveness of EIA in protecting coastal and marine environments in Bahrain were identified. Maintaining a sustainable use of coastal and marine natural resources in Bahrain requires measures to holistically address the interactions among the several dredging and reclamation projects and their additive and cumulative impacts. This could be achieved through enhancing the current practice of EIA process and adopting Strategic Environmental Assessment (SEA) for dredging and reclamation activities.
The coastal zones face much higher risks disasters and vulnerability to natural and anthropogenic forcing because of their location in extremely high-energy and rapidly developing environment. We develop and implement an updated set of indicators of coastal vulnerability that characterise relatively low-lying coastal segments with negligible tidal range but affected by substantial storm surges driven by atmospheric factors. The study area is about 90 km long coast of Lithuania in the south-eastern Baltic Sea. The classical methods for building the coastal vulnerability index (CVI) are combined with the outcome analytical hierarchical process (AHP) based approach for incorporating experts' judgements to specify the weights of used criteria. The CVI relies mostly on geological parameters (shoreline change rate, beach width/height, underwater slope, sand bars, and beach sediments) and involves only significant wave height as the representative of direct physical drivers. The selected criteria were integrated into CVI calculation using two options: (I) all criteria contribute equally, (II) each criteria may have a different contribution. Based on the weights and scores derived using AHP vulnerability maps are prepared to highlight areas with very low, low, medium, high and very high vulnerability. CVIw calculation based on option II highlighted 32% of the coast being of very high to high vulnerability, 22% of moderate vulnerability and 41% of low to very low vulnerability. Although these numbers vary to some extent depending on the viewpoint, in general about 10% of the coast in the study area is under very high risk, which calls for urgent planning and protective measures.
The consequences of human actions are a source of changes in ecosystems. These result from alterations in the structure and patterns of interaction of the ecosystem, often with negative consequences in terms of losses of ecosystem function and the extinction of species. As a result, establishing protected areas as Brazil's Extractive Reserves (Resex) is a necessity. Ecological networks can be used as a tool to assess whether the Resex are effective in conserving marine biodiversity and the livelihoods of fishers. By analysing the structure of networks, e.g., their nestedness and modularity, it is possible to understand how species interact with each other, both directly and indirectly. The aim of this study was to analyse and compare the interactions and the management activities affecting fishers and fish at the Canavieiras Resex. The data were collected between April and August 2012 through semi-structured interviews with fishers to identify their target species and the fishing gear that they use to identify the structural patterns of the fish-fisherman, fish-guilds, and functional-group-guilds networks. The target species were Centropomus spp., Lutjanus jocu, Eugerres brasilianus and Mugil spp. Cast nets and trammel nets were the types of fishing gear that were most frequently used. High nestedness and significative modularity patterns were observed in the networks, indicating that generalist and specialist fishers primarily capture their target species. These patterns also indicate the extent of harvesting pressure on these fish. The fishers who use these networks include a high level of fish biodiversity in their catches. The structural pattern that was found implied that fishing pressure on these species, coupled with a lack of management tools, has created a situation in which priority must be given to the development of scientific conservation techniques and sustainable management plans.