The protection of predators inside marine reserves is expected to generate trophic cascades with predator density increasing but prey density decreasing; however, predators and prey often both increase inside reserves. This mismatch between the expected and observed change in prey density has been explained because prey also are harvested; that is, the protection of prey compensates for the additional predation inside the reserve. Here, we show that this mechanism alone cannot increase densities of predator and prey; other mechanisms are required, and we hypothesized that movement of predator and/or prey might provide such a mechanism. We therefore built two spatially implicit two-patch predator–prey models with movement of predator and prey between reserve and fishing grounds. We show that post-settlement movement of predators (but not prey) altered the strength of trophic cascades and could increase densities of both predator and focal prey. We further built a more general model that shows that predator post-settlement movement can reinforce and even supplement the effect of two previously investigated mechanisms producing trophic cascades: a prey size refuge and predator density-dependent mortality. Our study increases understanding of mechanisms that can alter the strength (and direction) of prey responses inside marine reserves and highlights the importance of movement in human-induced heterogeneous systems.
For the past decade, state and regional ocean planning authorities across the United States have been designing and conducting integrated and comprehensive marine planning processes in accordance with national, regional, and state mandates or guidance. Understanding and characterizing a variety of human uses of the ocean through combined data collection and stakeholder engagement initiatives is a core component of these processes.
Marine recreation has been a primary focus for these efforts, largely because there is a general lack of data characterizing this sector, despite its significant social and economic importance. Planning and management authorities as well as marine industry stakeholders have recognized this data gap. To fill this gap, planning authorities have been working closely with marine recreational industry leaders and experts on a number of studies which have resulted in datasets that are relevant to planning and management agencies and are also considered trustworthy by the industries. While these studies have employed a variety of approaches, techniques, and tools to characterize a diverse set of marine industries, a number of common themes and observations have emerged. This paper highlights these overarching best practices and insights distilled from SeaPlan’s experience with collaborative marine human use characterization studies in the Northeastern U.S.
These common methodological best practices and strategies are framed within a collaborative data collection and engagement model developed and adapted through designing and conducting successive marine recreational use studies between 2009-2016. Employing this collaborative model was instrumental in generating trusted data credible to all parties and creating an avenue for direct industry participation in the ocean planning process. We also offer two key strategies which can be used within the model’s framework. The first frames data as a shared asset, where information is intentionally developed to meet planning, management, and industry goals simultaneously. The second strategy encourages engagement approaches which are tailored toward unique industry characteristics, such as geographical distribution, seasonality, and existing industry organization.
This paper presents four case studies which demonstrate how the collaborative model’s best practices and associated strategies have been put into practice in the Northeastern U.S. over the past seven years. These studies include the 2010 Massachusetts Recreational Boater Survey, the 2012 Northeast Recreational Boater Survey, the 2015 Northeast Coastal and Marine Recreational Use Characterization Survey, and the 2013-2016 Pilot Charter and Party Vessel Fishing Mapping Project. Reflecting on the outcomes of these studies, we present a summary of lessons learned from this body of work. The intent in sharing this experience is, specifically, to inform others’ efforts as existing marine plans are implemented and as other regions and states embark on similar marine industry characterizations, and, more broadly, to contribute to the growing body of work in marine social sciences.
Halimeda bioherms occur as extensive geological structures on the northern Great Barrier Reef (GBR), Australia. We present the most complete, high-resolution spatial mapping of the northern GBR Halimeda bioherms, based on new airborne lidar and multibeam echosounder bathymetry data. Our analysis reveals that bioherm morphology does not conform to the previous model of parallel ridges and troughs, but is far more complex than previously thought. We define and describe three morphological sub-types: reticulate, annulate, and undulate, which are distributed in a cross-shelf pattern of reduced complexity from east to west. The northern GBR bioherms cover an area of 6095 km2, three times larger than the original estimate, exceeding the area and volume of calcium carbonate in the adjacent modern shelf-edge barrier reefs. We have mapped a 1740 km2 bioherm complex north of Raine Island in the Cape York region not previously recorded, extending the northern limit by more than 1° of latitude. Bioherm formation and distribution are controlled by a complex interaction of outer-shelf geometry, regional and local currents, coupled with the morphology and depth of continental slope submarine canyons determining the delivery of cool, nutrient-rich water upwelling through inter-reef passages. Distribution and mapping of Halimeda bioherms in relation to Great Barrier Reef Marine Park Authority bioregion classifications and management zones are inconsistent and currently poorly defined due to a lack of high-resolution data not available until now. These new estimates of bioherm spatial distribution and morphology have implications for understanding the role these geological features play as structurally complex and productive inter-reef habitats, and as calcium carbonate sinks which record a complete history of the Holocene post-glacial marine transgression in the northern GBR.
The Mediterranean region hosts around 400 coastal lagoons, covering a surface of over 641 000 ha differing in both their typology and use. Fisheries and various forms of aquaculture have been traditionally carried out in Mediterranean coastal lagoons since ancient times and are part of the cultural heritage of the region. Traditional lagoon management linked to extensive aquaculture and fish harvesting has certainly contributed, over time, to preserve these peculiar ecosystems, although much of the coastal lagoon areas have progressively disappeared due to land reclamation and other uses. Recently, coastal lagoons have become a relevant environmental concern: land claiming, pollution and the lack of management, among other factors, have strongly modified both the structure and functioning of these sensitive coastal ecosystems. In particular, the management of traditional aquaculture and capture fisheries activities has been identified as the main instrument to maintain lagoons’ ecological features and to prevent the degradation of their sensitive habitats, both from an environmental and socioeconomic point of view. To guarantee the sustainability of aquaculture and capture fisheries in lagoons, proper management plans should be established so as to ensure the preservation of both biodiversity and local knowledge. This should also be considered as a fundamental pillar for any programme aiming at the preservation and restoration of lagoons’ environment.
Artificial reefs have been used for a long time around the world and have served many purposes ranging from habitat restoration, fish stock enhancement and fisheries management to research and recreation. At present, fish stock enhancement and fisheries management are the main reasons driving reef construction in the Mediterranean Sea, while habitat restoration is the main purpose for their use in the Black Sea. The increasing interest for artificial reefs has given rise to several concerns regarding their possible negative impacts, due to the use of unsuitable materials and to waste dumping. Consequently, the need emerged over the past fifteen years to develop guidelines in order to support managers and scientists in the use of artificial reefs in European seas. Based on such existing guidelines, this document aims to further provide up‐to‐date information and guidance regarding specific management practices for the planning, siting, construction and anchoring of artificial reefs in the Mediterranean and the Black Sea and for monitoring their effectiveness from an ecological and socio‐economic point of view. After providing an overview of existing definitions and legislations relating to the deployment of artificial reefs, this document illustrates the main aspects related to the different steps involved in the planning, siting and construction phases. A detailed presentation of the specific types and purposes of artificial reefs follows, with a description of their possible impacts and of existing methodologies to monitor and assess their effectiveness. Finally, these guidelines give insights about the socio‐economic effects of artificial reefs and control, surveillance and maintenance issues.
In January 2016 New Zealand released a consultation document proposing a new act on marine protected areas designed to significantly reform current and now dated policy. This article explores those reform proposals in the context of the current regulatory regime, international obligations, and the best practice of selected other states. While the proposed act provides for a much firmer legislative base from which to develop an MPA network to conserve biodiversity and ecosystem function, nevertheless it is limited in geographic and functional scope. As such, it represents a missed opportunity and undermines New Zealand's claims to be an international leader in ocean management.
The effects of climate change on marine ecosystems are accelerating. Identifying and protecting areas of the ocean where conditions are most stable may provide another tool for adaptation to climate change. To date, research on potential marine climate refugia has focused on tropical systems, particularly coral reefs. We examined a northeast Pacific temperate region – Canada’s Pacific – to identify areas where physical conditions are stable or changing slowly. We analyzed the rate and consistency of change for climatic variables where recent historical data were available for the whole region, which included sea surface temperature, sea surface height, and chlorophyll a. We found that some regions have been relatively stable with respect to these variables. In discussions with experts in the oceanography of this region, we identified general characteristics that may limit exposure to climate change. We used climate models for sea surface temperature and sea surface height to assess projected future changes. Climate projections indicate that large or moderate changes will occur throughout virtually the entire area and that small changes will occur in only limited portions of the coast. Combining past and future areas of stability in all three examined variables to identify potential climate refugia indicates that only 0.27% of the study region may be insulated from current and projected future change. A greater proportion of the study region (11%) was stable in two of the three variables. Some of these areas overlap with oceanographic features that are thought to limit climate change exposure. This approach allowed for an assessment of potential climate refugia that could also have applications in other regions and systems, but revealed that there are unlikely to be many areas unaffected by climate change.
New innovations are emerging which offer opportunities to improve forecasts of wave conditions. These include probabilistic modelling results, such as those based on an ensemble of multiple predictions which can provide a measure of the uncertainty, and new sources of observational data such as GNSS reflectometry and FerryBoxes, which can be combined with an increased availability of more traditional static sensors. This paper outlines an application of the Bayesian statistical methodology which combines these innovations. The method modifies the probabilities of ensemble wave forecasts based on recent past performance of individual members against a set of observations from various data source types. Each data source is harvested and mapped against a set of spatio-temporal feature types and then used to post-process ensemble model output. A prototype user interface is given with a set of experimental results testing the methodology for a use case covering the English Channel.
The government of China aims to protect and improve the marine ecological environment, exploit and develop marine resources in a rational manner, and improve capacities for comprehensive marine management. In light of these objectives, commencing from the beginning of 2010, preparatory work toward the development of a new round of marine functional zoning revisions was initiated. Based on the National Marine Functional Zoning scheme of 2002, and in accordance with the Law of the People's Republic of China on the Administration of the Use of Sea Area sand Marine Environment Protection Law of the People's Republic of China, in conjunction with other relevant laws, regulations, and specific policies for national marine protection and development, China has launched the National Marine Functional Zoning Scheme for the period from 2001 to 2020. This paper focuses on the development of China's marine functional zoning system. Based on an analysis of existing problems entailed in the implementation process of original marine functional zoning, it discusses the main adjustments made to improve the scheme. It also reflects on these problems in new Marine Functional Zoning and suggests how they can be addressed during a future round of revisions.
Marine fisheries in Costa Rica have become characterized by overexploitation, ineffective centralized management and increased conflict among fishing sectors. Despite high economic and socio-cultural importance of small-scale fisheries, no formal mechanisms existed until recently to facilitate the participation of fishers in management. Marine Areas for Responsible Fishing (Áreas Marinas para la Pesca Responsable, AMPR) were legally recognized in 2009 as a co-management approach, enabling the designation of spatial management areas to be implemented collaboratively by artisanal fishers and government agencies. In this paper, we examine property and access relations shaping this emerging participatory management model using case studies primarily from the Gulf of Nicoya region. The policy demonstrably improves upon some aspects of management, for instance, by allowing artisanal fishers to determine gear restrictions within designated areas. However, the model lacks other attributes of more successful co-management scenarios, particularly exclusive access. The fugitive nature of resources further complicates property relations over these fisheries. The cases explored also illustrate broader institutional and systemic issues that preclude effective participatory management. Lessons from the region are used to propose significant shifts to the management of small-scale fisheries in Costa Rica.