Scuba diving and snorkeling with manta rays (M. birostris, M. alfredi) at sites in Hawaii, USA, have become popular, with upward of 30 tour boats and 300 participants daily. This article examined whether conflicts are occurring within and between these activities and if so, what types of conflict are prevalent and how would participants respond (support restrictions, sanction others). Data from surveys of 444 participants following evening trips to view manta rays showed that 79% of snorkelers experienced in-group conflict with other snorkelers, and 53% of scuba divers reported conflict with other divers. Most conflicts were interpersonal (physical interactions among individuals interfering with experiences). Conflict behaviors included bumping into people (up to 92%), not being aware (up to 73%), and blinding people with underwater flashlights (up to 56%). There were fewer out-group conflicts between different activities (snorkelers vs. scuba divers) and minimal social values conflicts (negative preconceptions, no physical interactions among individuals). Participants supported limiting numbers of snorkelers, scuba divers, and boats, and providing education on how to behave with others. Those experiencing conflicts were more supportive of these strategies and more likely to directly sanction participants causing conflicts, but were not more likely to indirectly sanction managers and operators.
Research on enclosure has often examined the phenomenon as a process and outcome of state, neoliberal, and hybrid territorial practices with detrimental impacts for those affected. The proliferation of increasingly complex environmental governance regimes and new enclosures, such as those now seen in the oceans, challenge these readings, however. Using the case of U.S. marine spatial planning (MSP), this article reexamines enclosure through the lens of assemblage. A comprehensive new approach to oceans governance based on spatial data and collaborative decision making, MSP appears to follow past governance programs toward a broad-scale rationalization and enclosure of U.S. waters. Yet this appearance might only be superficial. As an assemblage, U.S. MSP—and its shifting actors, associations, and practices—holds the potential to both close and open the seas for oceans communities, environments, and other actors. Planning actors use three practices to stabilize U.S. MSP for governance and enclosure: narrativizing MSP, creating a geospatial framework to underlie planning, and engaging stakeholders. These practices, however, simultaneously provide opportunities for communities and environments to intervene in U.S. MSP toward alternative outcomes. Rather than a closed seas, U.S. MSP presents opportunities for enclosure to happen differently or not at all, producing alternative outcomes for coastal and oceans communities, environments, and governance.
The effect of various anthropogenic sources of noise (e.g. sonar, seismic surveys) on the behaviour of marine mammals is sometimes quantified as a dose–response relationship, where the probability of an animal behaviourally ‘responding’ (e.g. avoiding the source) increases with ‘dose’ (or received level of noise). To do this, however, requires a definition of a ‘significant’ response (avoidance), which can be difficult to quantify. There is also the potential that the animal ‘avoids’ not only the source of noise but also the vessel operating the source, complicating the relationship. The proximity of the source is an important variable to consider in the response, yet difficult to account for given that received level and proximity are highly correlated. This study used the behavioural response of humpback whales to noise from two different air gun arrays (20 and 140 cubic inch air gun array) to determine whether a dose–response relationship existed. To do this, a measure of avoidance of the source was developed, and the magnitude (rather than probability) of this response was tested against dose. The proximity to the source, and the vessel itself, was included within the one-analysis model. Humpback whales were more likely to avoid the air gun arrays (but not the controls) within 3 km of the source at levels over 140 re. 1 µPa2 s−1, meaning that both the proximity and the received level were important factors and the relationship between dose (received level) and response is not a simple one.
The microbial contribution to ecological resilience is still largely overlooked in coral reef ecology. Coral-associated bacteria serve a wide variety of functional roles with reference to the coral host, and thus, the composition of the overall microbiome community can strongly influence coral health and survival. Here, we synthesize the findings of recent studies (n = 45) that evaluated the impacts of the top three stressors facing coral reefs (climate change, water pollution and overfishing) on coral microbiome community structure and diversity. Contrary to the species losses that are typical of many ecological communities under stress, here we show that microbial richness tends to be higher rather than lower for stressed corals (i.e., in ~60% of cases), regardless of the stressor. Microbial responses to stress were taxonomically consistent across stressors, with specific taxa typically increasing in abundance (e.g., Vibrionales, Flavobacteriales, Rhodobacterales, Alteromonadales, Rhizobiales, Rhodospirillales, and Desulfovibrionales) and others declining (e.g., Oceanosprillales). Emerging evidence also suggests that stress may increase the microbial beta diversity amongst coral colonies, potentially reflecting a reduced ability of the coral host to regulate its microbiome. Moving forward, studies will need to discern the implications of stress-induced shifts in microbiome diversity for the coral hosts and may be able to use microbiome community structure to identify resilient corals. The evidence we present here supports the hypothesis that microbial communities play important roles in ecological resilience, and we encourage a focus on the microbial contributions to resilience for future research.
Ectotherms often attain smaller body sizes when they develop at higher temperatures. This phenomenon, known as the temperature–size rule, has important consequences for global fisheries, whereby ocean warming is predicted to result in smaller fish and reduced biomass. However, the generality of this phenomenon and the mechanisms that drive it in natural populations remain unresolved. In this study, we document the maximal size of 74 fish species along a steep temperature gradient in the Mediterranean Sea and find strong support for the temperature–size rule. Importantly, we additionally find that size reduction in active fish species is dramatically larger than for more sedentary species. As the temperature dependence of oxygen consumption depends on activity levels, these findings are consistent with the hypothesis that oxygen is a limiting factor shaping the temperature–size rule in fishes. These results suggest that ocean warming will result in a sharp, but uneven, reduction in fish size that will cause major shifts in size-dependent interactions. Moreover, warming will have major implications for fisheries as the main species targeted for harvesting will show the most substantial declines in biomass.
This article analyses the interplay between inter-State obligations to increase scientific knowledge, develop research capacity and transfer marine technology in accordance with Sustainable Development Goal (SDG) 14.a, with a view to contributing to enhanced implementation of the international law of the sea (SDG 14.c), and providing access for small-scale artisanal fishers to marine resources (SDG 14.b). It proposes to do so by relying not only on the international law of the sea, but also on international biodiversity law (particularly the Convention on Biological Diversity) and international human rights law (particularly the human right to science). The article seeks to provide a reflection on the opportunities arising from a mutually supportive interpretation of different international law instruments with regard to the means of implementation for SDG 14 in synergy with other SDGs (particularly SDG 17 on ‘Partnerships for the Goals’ and its targets related to technology transfer, capacity-building and partnerships).
With over 30 years’ experience of managing Marine Protected Areas (MPAs), China has established more than 250 MPAs in its coastal and marine areas, but the overall management effectiveness is unimpressive . Recently, China has made commitments to expand the MPA coverage in its waters ([7,52,53]) and develop an “ecological barrier” along the coast by connecting MPAs and islands by 2020 (The State Council 2015). In this context, this study reviews major challenges in current MPA practices in China, including the lack of systematic and scientific approaches, inadequate laws and regulations, ineffective governance mechanisms, conflicts between conservation and exploitation, limited funding, and inadequate monitoring programs. Four scenarios for developing China's MPA networks are developed and analyzed based on a literature review of experience in the United States, Canada, Australia, New Zealand, the European Union and the Philippines, as well as a set of interviews with Chinese MPA experts. These scenarios include: 1) creating a national system with an inventory of MPAs, 2) developing social networks, 3) developing regional ecological networks, and 4) developing a national representative network. The first two scenarios focus on the enhancement of the governance system through connecting individual MPAs as a social, institutional, and learning network, which could provide opportunities for creating an ecologically coherent network, while the latter two emphasized ecological connectivity and representativeness. Given different focuses, they can be applied at different stages of implementation and combinations of scenarios can be used depending on China's needs.
Serial depletions and the use of indiscriminate gears have led to increased fishing pressure on many previously untargeted species. A largely unregulated global extraction of seahorses (Hippocampus spp.) has emerged, of which Vietnam is one of the main sources. Quantifying this extraction is a major empirical and enforcement challenge. Using catch landings surveys of small-scale fishing boats, we determined the fishing pressure on seahorse populations around Phu Quoc Island – a major source of seahorses in Vietnam’s trade – from April to July 2014. We focused on two fishing methods, bottom trawling and compressor diving, that either targeted seahorses or caught them incidentally along with a multitude of other species. The seahorse catch consisted of three species – H. kuda, H. spinosissimus and H. trimaculatus – with relative proportions varying by gear type and fishing ground. Fishers that targeted seahorses caught mean rates of 23 and 32 seahorses per boat per day by bottom trawling and diving, respectively. Trawls and divers that did not target seahorses caught mean rates of 1 and 3 seahorses per day respectively, and caught higher proportions of juvenile seahorses. The total catch from the island was approximately 127,000–269,000 seahorses per year from a fleet of 124 trawl boats and 46 compressor diver vessels. This is up to four times higher than the catch of similarly sized fisheries that obtain seahorses and is likely placing high pressure on local seahorse populations. Our research emphasizes the need to monitor these fisheries and develop effective management efforts for sustainable seahorse populations.
Maritime Spatial Planning (hereinafter mentioned as MSP) is developing and growing rapidly and constantly worldwide. It is acknowledged as a key instrument to balance sectoral interests and achieve sustainable use of marine resources with the ecosystem-based approach as the underpinning principle (EC, 2010). Nevertheless, there are different planning approaches and different levels of implementation of maritime/marine spatial planning (MSP) processes in the world. Among the plans implemented in Europe, and based on the planning processes developed, different aims for MSP can be noted which translate into either strategic, fully integrated, forward-looking and participative planning or “spatial optimization” elements. On the other hand there are areas where MSP is in an immature phase and where mutual learning, improved governance or capacity building is needed, or areas where a strategic approach to facilitate coordination of MSP arrangements would be necessary. This paper addresses current MSP attitudes, challenges and future trends and discusses the MSP planning and management conceptual approaches, options and styles, mainly as defined through the European regulatory framework.
Many fishers diversify their income by participating in multiple fisheries, which has been shown to significantly reduce year-to-year variation in income. The ability of fishers to diversify has become increasingly constrained in the last few decades, and catch share programs could further reduce diversification as a result of consolidation. This could increase income variation and thus financial risk. However, catch shares can also offer fishers opportunities to enter or increase participation in catch share fisheries by purchasing or leasing quota. Thus, the net effect on diversification is uncertain. We tested whether diversification and variation in fishing revenues changed after implementation of catch shares for 6,782 vessels in 13 US fisheries that account for 20% of US landings revenue. For each of these fisheries, we tested whether diversification levels, trends, and variation in fishing revenues changed after implementation of catch shares, both for fishers that remained in the catch share fishery and for those that exited but remained active in other fisheries. We found that diversification for both groups was nearly always reduced. However, in most cases, we found no significant change in interannual variation of revenues, and, where changes were significant, variation decreased nearly as often as it increased.