Shipping is the dominant marine anthropogenic noise source in the world's oceans, yet we know little about vessel encounter rates, exposure levels and behavioural reactions for cetaceans in the wild, many of which rely on sound for foraging, communication and social interactions. Here, we used animal-borne acoustic tags to measure vessel noise exposure and foraging efforts in seven harbour porpoises in highly trafficked coastal waters. Tagged porpoises encountered vessel noise 17–89% of the time and occasional high-noise levels coincided with vigorous fluking, bottom diving, interrupted foraging and even cessation of echolocation, leading to significantly fewer prey capture attempts at received levels greater than 96 dB re 1 µPa (16 kHz third-octave). If such exposures occur frequently, porpoises, which have high metabolic requirements, may be unable to compensate energetically with negative long-term fitness consequences. That shipping noise disrupts foraging in the high-frequency-hearing porpoise raises concerns that other toothed whale species may also be affected.
Synchronised multispecies mass spawning events are striking features of reproduction in corals. This synchronous gamete release of thousands of animals over vast stretches of reef is thought to be cued by rhythms of the Moon. However, the mechanisms are not fully understood. We propose an explanation that may contribute to understanding this mechanism, that spawning is triggered by the coincidence of two factors, each in different lunar rhythms. We investigate this proposal in case studies using seven years of coral spawning data from two locations: Kochi, Japan and Lizard Island, Australia. Our calculations show that a feature in a lunar synodic rhythm (the third quarter) will synchronise with a feature in a lunar non-synodic rhythm (the zero declination) usually once, although occasionally twice in a year. Supported by data on the date of spawning from the two locations, we suggest that this coincidence of lunar factors exerts an important influence on the timing of annual mass spawning in corals. This coincidence may be associated with low atmospheric pressure. Spawning at the time of the third lunar quarter may favour fertilisation success due to the reduced currents during neap tides associated with the lower gravitational pressure of the lunar quarters.
Fishing Reserves (FRs) are primarily designated for the enhancement of local fisheries and, secondarily, for biodiversity conservation. In Spain, FRs are considered marine protected areas (MPAs) and included in the country's MPA network. MPAs’ ecological effectiveness is linked to a number of legal, managerial and bio-physical factors. With the amount of MPA area rapidly rising and conservation funds largely stagnant or decreasing, rapid, cost-effective MPA assessment techniques are becoming increasingly useful to verify fulfillment of global conservation targets and ascertain potential conservation effectiveness. Here, a rapid MPA protection assessment framework and one MPA ecological effectiveness framework were applied to the Spanish Network of 10 FRs (FRN): the MaPAF and NEOLI frameworks. The FRN was moderately legally protected, with over 50.5% of its area having three or more overlapping legal designations, but only 3.8% of the FRN's area being no-take. All FRs had management plans and active surveillance. According to MaPAF, Columbretes FR was the most highly legally protected whereas Cabo de Palos was the FR with the greatest managerial effort. Both rank highest in protection. In contrast, Masía Blanca FR and Alborán FR were the least legally protected whereas Alborán FR and Graciosa FR were the least managerially protected FRs of the FRN and rank the lowest in protection, respectively. According to the NEOLI framework, Columbretes would also be the most effective FR whereas Masía Blanca FR would be the least ecologically effective. These results can help to spur and better allocate conservation efforts across the fastly growing Spanish MPA network.
Ship’s ballast water has been a vector for the spreading of nonindigenous invasive species (NIS) around the globe for more than a century and has had devastating impact on aquatic ecosystems in many regions. Due to the harsh climate, shipping activities in Arctic waters have been limited compared to many parts of the world but will increase in the coming years due to climate changes. This will potentially affect the pristine Arctic marine ecosystems by introduction of NIS. In this chapter, we present the international ballast water regulations that have entered into force and the specific challenges of ballast water management in relation to the Arctic environment and marine ecosystems. We discuss the risk of NIS affecting the Arctic marine ecosystems including the impact of increased shipping activity, changes in living conditions of marine organisms because of climate changes and lack of knowledge of the eco-physiological boundaries and distributions of Arctic marine species. It is concluded that at present only a few marine NIS have been recorded in the Arctic area. Despite the existing and planned ballast water regulations, NIS establishment in the region will increase with an unknown magnitude due to lack of biological data.
The Arctic has been an integrated part of the international system for centuries, and systemic developments have deeply influenced the region and its communities. Central Arctic Ocean marine resource governance is in the nexus of climate change and international systemic developments. The international systemic context for the Arctic is: The rise of China and emerging Asian economies driving gradual power transition from Western to Eastern states. Struggles continue over the domestic order and international position of post-Soviet Russia, where either side considers whether to escalate the Ukraine crisis horizontally to the Arctic. The USA and China interact concerning governing Arctic marine resources as Arctic Ocean coastal state/status quo power and fishing nation/rising power. Russia and the West choose not to escalate the Ukraine crisis horizontally into Arctic marine resource management. Co-creating of knowledge and epistemic communities are important for Arctic status quo and rising Asian countries to manage power transition in the Arctic and for Russia and the West to continue Arctic cooperation despite political crisis elsewhere.
Future estimates indicate that the reduction of the Arctic ice cap will open up new areas and increase the viability of the region to be increasingly used for international shipping (Liu and Kronbak, J Trans Geo 18(3):434–444. doi:https://doi.org/10.1016/j.jtrangeo.2009.08.004, 2010). The Arctic sea routes and related coastal area are therefore gaining increasing levels of interest, as they become a more attractive alternative for maritime transport. This demand for new infrastructure and development in areas where there has previously been little or none, presents a unique situation to analyze. The increased interest and demand for new development along Arctic sea routes through an environmentally sensitive region make the Arctic an ideal area of which to study the transition toward liquefied natural gas becoming the prominent marine fuel.
We must develop a better understanding of how and under what conditions such a transition will take place and who will make decisions that will influence any such transition. Exploring past and current aspects of maritime and energy governance is an important step in developing an understanding of how a transition towards liquefied natural gas could re-shape our understanding of Arctic governance.
In Easter Island, most of fisheries regulations are top-down implemented by the central fisheries authority located ~4000 km eastwards. This could generate problems in regulations compliance, given the cultural differences between the western worldview and Polynesian culture of Easter Island. A total of 18 issues that must be considered previously to an intervention in the island were identified. Four of them scored the highest difference between Rapanui and public services representatives. Among them, “Integrating traditions and culture” had a little priority for the public services representatives, but was the most important for the Rapanui. According to the public services representatives in Easter Island and local fishermen, there is a little compliance with regulations related to fisheries and, due to cultural aspects, it is not possible to enforce regulations and apply sanctions. The low compliance with fisheries regulations is due to the lack of representativeness of regulations. Interventions in the island are based on western worldview that does not fit with social and ecological domains of social-ecological system. A flexible governance system, based on decision making at local level in line with local tradition is needed to navigate to a resource management and conservation in Easter Island.
This literature review encompasses more than one-hundred and sixty worldwide studies on artificial reefs (ARs) in terms of their design, application, performance and management. Over the past three decades, research on ARs has increased remarkably, suggesting an increase in social and economic aspects of ARs. The scope of AR research has largely expanded from early AR design and deployment to improve fisheries to various additional purposes. In particular, recent research on ARs has had a tendency to focus on variations in the community structure or composition of ARs, suggesting that the purpose of AR research has shifted from improving fisheries as a resource to rehabilitation of marine ecosystems. Most countries are expected to make active use of AR functions, even if the objective of deployment might be different for each case. Consequently, AR research will most likely expand and evolve to span multiple purposes in the future.
During the past decade, global environmental policy discussions have encouraged countries to engage in an ecosystem approach to managing the oceans. An ecosystem approach involves the integrated management of species, other natural services, and the multiple uses of the coast. Improving ecosystem based management efforts requires a better understanding of how it is included within national level policies that influence marine resource management. Chile has committed to implement international recommendations to include ecosystem based management. This study operationalizes an approach to assess the extent to which ecosystem based management is being implemented at national scales through the synthesis of agenda setting documents and national level policy/regulatory responses. The study specifically searches for ecosystem based management principles, as defined by the Convention of Biological Diversity in State of the Nation presidential speeches, national sectorial policies, national decrees and national programs issued between 1990 and 2014 (n = 1335 documents). Results show that although national level policies in Chile increasingly share common grounds with ecosystem based management principles, the overall approach is poorly mainstreamed into agenda setting speeches and reports. Working with existing institutional settings and institutional capacity are key features to maintain trajectories for the implementation of ecosystem based management in national policies. The approach presented complements research on marine policy implementation by effectively informing how national level policies can be analyzed under the lens of ecosystem based management.
Increasingly, marine renewable energy developments are viewed as an opportunity to meet climate change obligations, with the added benefit of powering the economy and the creation of jobs. Technical, economic and engineering challenges co-exist with governance challenges in the development of large-scale marine renewable energy projects. This paper addresses the question, if the prerequisites for sustainable project development are evident in selected case studies. It also asks what lessons can be learned from current practice in the context of energy governance at the local level. The authors argue that these lessons can be central enablers to support decision makers in future programmes, to better understand how to build the enabling conditions for programme implementation towards renewable energy at higher spatial scales of governance, importantly the national level. The study builds on a multiple stakeholder approach involving interviews and group discussions with key individuals from industry, government and civil society in emerging pilot programmes along the East Coast of the United States (U.S.). New policy windows were opening at the time of the analysis and ambitious development was underway by a range of actors who are driving progress in the sector and positioning the area to become a major provider of blue energy.
Fisheries represent a fundamental resource linking social and ecological systems. Yet, unsustainable fishing regimes prevail across many tropical regions as a result of growing consumer demand and market expansion. Using the extensive reef-fish trade between Chuuk and Guam (Micronesia) as a case study, we examined 12 years of commercial reef-fish export data to capture both inter-annual and intra-annual trends. Reef-fish exports from Chuuk increased steadily between 2003 and 2010 fueled by increasing demand on Guam, but declined sharply from 2010 to 2014 as export costs grew and profit margins were reduced. Intra-annual examinations furthered that low winds and new moon periods were the strongest drivers of daily exports during the initial years of the study, but the governmental disbursement of food-stamp allowances on Guam became the strongest driver in later years when profit margins were lower. Seasonal cycles were also influential, as exports within each year peaked during the Catholic lent season. In sum, the Chuuk-Guam reef-fish trade industry became increasingly dependent on opportunistic demand from Guam, while environmental regimes evolved to become secondary drivers of export volume. The ability to meet foreign demand may suggest a sustainable fishery in Chuuk, however, mounting evidence suggests that consistent supply to international markets masks growing, unsustainable harvesting regimes. Dwindling profits may lead to instability in Guam’s fresh reef-fish trade industry, and also suggested uncertain futures for Chuuk fishers, Guam retailers, and a society dependent on healthy protein. We last compared the sequential expansion of Guam’s reef-fish acquisition footprint across the Indo-Pacific with expansions reported for the Hong Kong live reef food fish trade industry, highlighting the growing impacts of population centers on small-scale coral-reef fisheries as markets globalize.
The freshwater–marine transition that characterizes an estuarine system can provide multiple entry options for invading species, yet the relative importance of this gradient in determining the functional contribution of invading species has received little attention. The ecological consequences of species invasion are routinely evaluated within a freshwater versus marine context, even though many invasive species can inhabit a wide range of salinities. We investigate the functional consequences of different sizes of Corbicula fluminea—an invasive species able to adapt to a wide range of temperatures and salinity—across the freshwater–marine transition in the presence versus absence of warming. Specifically, we characterize how C. fluminea affect fluid and particle transport, important processes in mediating nutrient cycling (NH4-N, NO3-N, PO4-P). Results showed that sediment particle reworking (bioturbation) tends to be influenced by size and to a lesser extent, temperature and salinity; nutrient concentrations are influenced by different interactions between all variables (salinity, temperature, and size class). Our findings demonstrate the highly context-dependent nature of the ecosystem consequences of invasion and highlight the potential for species to simultaneously occupy multiple components of an ecosystem. Recognizing of this aspect of invasibility is fundamental to management and conservation efforts, particularly as freshwater and marine systems tend to be compartmentalized rather than be treated as a contiguous unit. We conclude that more comprehensive appreciation of the distribution of invasive species across adjacent habitats and different seasons is urgently needed to allow the true extent of biological introductions, and their ecological consequences, to be fully realized.
The Coral Triangle (CT) region of the Indo-Pacific realm harbors an extraordinary number of species, with richness decreasing away from this biodiversity hotspot. Despite multiple competing hypotheses, the dynamics underlying this regional diversity pattern remain poorly understood. Here, we use a time-calibrated evolutionary tree of living reef coral species, their current geographic ranges, and model-based estimates of regional rates of speciation, extinction, and geographic range shifts to show that origination rates within the CT are lower than in surrounding regions, a result inconsistent with the long-standing center of origin hypothesis. Furthermore, endemism of coral species in the CT is low, and the CT endemics are older than relatives found outside this region. Overall, our model results suggest that the high diversity of reef corals in the CT is largely due to range expansions into this region of species that evolved elsewhere. These findings strongly support the notion that geographic range shifts play a critical role in generating species diversity gradients. They also show that preserving the processes that gave rise to the striking diversity of corals in the CT requires protecting not just reefs within the hotspot, but also those in the surrounding areas.
Anthropogenic activities have led to the biotic homogenization of many ecological communities, yet in coastal systems this phenomenon remains understudied. In particular, activities that locally affect marine habitat-forming foundation species may perturb habitat and promote species with generalist, opportunistic traits, in turn affecting spatial patterns of biodiversity. Here, we quantified fish diversity in seagrass communities across 89 sites spanning 6° latitude along the Pacific coast of Canada, to test the hypothesis that anthropogenic disturbances homogenize (i.e., lower beta-diversity) assemblages within coastal ecosystems. We test for patterns of biotic homogenization at sites within different anthropogenic disturbance categories (low, medium, high) at two spatial scales (within and across regions) using both abundance- and incidence-based beta-diversity metrics. Our models provide clear evidence that fish communities in high anthropogenic disturbance seagrass areas are homogenized relative to those in low disturbance areas. These results were consistent across within-region comparisons using abundance- and incidence-based measures of beta-diversity, and in across-region comparisons using incidence-based measures. Physical and biotic characteristics of seagrass meadows also influenced fish beta-diversity. Biotic habitat characteristics including seagrass biomass and shoot density were more differentiated amongst high disturbance sites, potentially indicative of a perturbed environment. Indicator species and trait analyses revealed fishes associated with low disturbance sites had characteristics including stenotopy, lower swimming ability, and egg guarding behaviour. Our study is the first to show biotic homogenization of fishes across seagrass meadows within areas of relatively high human impact. These results support the importance of targeting conservation efforts in low anthropogenic disturbance areas across land- and seascapes, as well as managing anthropogenic impacts in high activity areas.
For conservation science to effectively inform management, research must focus on creating the scientific knowledge required to solve conservation problems. We identified research questions that, if answered, would increase the effectiveness of conservation and natural resource management practice and policy in Oceania's small-island developing states. We asked conservation professionals from academia, governmental, and nongovernmental organizations across the region to propose such questions and then identify which were of high priority in an online survey. We compared the high-priority questions with research questions identified globally and for other regions. Of 270 questions proposed by respondents, 38 were considered high priority, including: What are the highest priority areas for conservation in the face of increasing resource demand and climate change? How should marine protected areas be networked to account for connectivity and climate change? What are the most effective fisheries management policies that contribute to sustainable coral reef fisheries? High-priority questions related to the particular challenges of undertaking conservation on small-island developing states and the need for a research agenda that is responsive to the sociocultural context of Oceania. Research priorities for Oceania relative to elsewhere were broadly similar but differed in specific issues relevant to particular conservation contexts. These differences emphasize the importance of involving local practitioners in the identification of research priorities. Priorities were reasonably well aligned among sectoral groups. Only a few questions were widely considered answered, which may indicate a smaller-than-expected knowledge-action gap. We believe these questions can be used to strengthen research collaborations between scientists and practitioners working to further conservation and natural resource management in this region.
The Arctic Ocean and its surrounding shelf seas are warming much faster than the global average, which potentially opens up new distribution areas for temperate-origin marine phytoplankton. Using over three decades of continuous satellite observations, we show that increased inflow and temperature of Atlantic waters in the Barents Sea resulted in a striking poleward shift in the distribution of blooms of Emiliania huxleyi, a marine calcifying phytoplankton species. This species’ blooms are typically associated with temperate waters and have expanded north to 76°N, five degrees further north of its first bloom occurrence in 1989. E. huxleyi's blooms keep pace with the changing climate of the Barents Sea, namely ocean warming and shifts in the position of the Polar Front, resulting in an exceptionally rapid range shift compared to what is generally detected in the marine realm. We propose that as the Eurasian Basin of the Arctic Ocean further atlantifies and ocean temperatures continue to rise, E. huxleyi and other temperate-origin phytoplankton, could well become resident bloom formers in the Arctic Ocean.
Mortality of fish has been reported in tide pools during warm days. That means that tide pools are potential ecological traps for coastal organisms, which happen when environmental changes cause maladaptive habitat selection. Heat-waves are predicted to increase in intensity, duration and frequency, making it relevant to investigate the role of tide pools as traps for coastal organisms. However, heat waves can also lead to acclimatization. If organisms undergo acclimatization prior to being trapped in tide pools, their survival chances may increase. Common tide pool species (46 species in total) were collected at a tropical and a temperate area and their upper thermal limits estimated. They were maintained for 10 days at their mean summer sea surface temperature +3°C, mimicking a heat-wave. Their upper thermal limits were estimated again, after this acclimation period, to calculate each species’ acclimation response. The upper thermal limits of the organisms were compared to the temperatures attained by tide pool waters to investigate if 1) tide pools could be considered ecological traps and 2) if the increase in upper thermal limits elicited by the acclimation period could make the organisms less vulnerable to this threat. Tropical tide pools were found to be ecological traps for an important number of common coastal species, given that they can attain temperatures higher than the upper thermal limits of most of those species. Tide pools are not ecological traps in temperate zones. Tropical species have higher thermal limits than temperate species, but lower acclimation response, that does not allow them to survive the maximum habitat temperature of tropical tide pools. This way, tropical coastal organisms seem to be, not only more vulnerable to climate warming per se, but also to an increase in the ecological trap effect of tide pools.
Global change has been acknowledged as one of the main threats to the biosphere and its provision of ecosystem services, especially in marine ecosystems. Seagrasses play a critical ecological role in coastal ecosystems, but their responses to ocean acidification (OA) and climate change are not well understood. There have been previous studies focused on the effects of OA, but the outcome of interactions with co-factors predicted to alter during climate change still needs to be addressed. For example, the impact of higher CO2 and different hydrodynamic regimes on seagrass performance remains unknown. We studied the effects of OA under different current velocities on productivity of the seagrass Zostera noltei, using changes in dissolved oxygen as a proxy for the seagrass carbon metabolism, and release of dissolved organic carbon (DOC) in a four-week experiment using an open-water outdoor mesocosm. Under current pH conditions, increasing current velocity had a positive effect on productivity, but this depended on shoot density. However, this positive effect of current velocity disappeared under OA conditions. OA conditions led to a significant increase in gross production rate and respiration, suggesting that Z. noltei is carbon-limited under the current inorganic carbon concentration of seawater. In addition, an increase in non-structural carbohydrates was found, which may lead to better growing conditions and higher resilience in seagrasses subjected to environmental stress. Regarding DOC flux, a direct and positive relationship was found between current velocity and DOC release, both under current pH and OA conditions. We conclude that OA and high current velocity may lead to favourable growth scenarios for Z. noltei populations, increasing their productivity, non-structural carbohydrate concentrations and DOC release. Our results add new dimensions to predictions on how seagrass ecosystems will respond to climate change, with important implications for the resilience and conservation of these threatened ecosystems.
The Intergovernmental Panel on Climate Change (IPCC) is an authoritative and influential source of reports on climate change. The lead authors of IPCC reports include scientists from around the world, but questions have been raised about the dominance of specific disciplines in the report and the disproportionate number of scholars from the Global North. In this paper, we analyze the as-yet-unexamined issue of gender and IPCC authorship, looking at changes in gender balance over time and analyzing women’s views about their experience and barriers to full participation, not only as women but also at the intersection of nationality, race, command of English, and discipline. Over time, we show that the proportion of female IPCC authors has seen a modest increase from less than 5% in 1990 to more than 20% in the most recent assessment reports. Based on responses from over 100 women IPCC authors, we find that many women report a positive experience in the way in which they are treated and in their ability to influence the report, although others report that some women were poorly represented and heard. We suggest that an intersectional lens is important: not all women experience the same obstacles: they face multiple and diverse barriers associated with social identifiers such as race, nationality, command of English, and disciplinary affiliation. The scientific community benefits from including all scientists, including women and those from the Global South. This paper documents barriers to participation and identifies opportunities to diversify climate science.
To design effective marine reserves and support fisheries, more information on fishing patterns and impacts for targeted species is needed, as well as better understanding of their key habitats. However, fishing impacts vary geographically and are difficult to disentangle from other factors that influence targeted fish distributions. We developed a set of fishing effort and habitat layers at high resolution and employed machine learning techniques to create regional-scale seascape models and predictive maps of biomass and body length of targeted reef fishes for the main Hawaiian Islands. Spatial patterns of fishing effort were shown to be highly variable and seascape models indicated a low threshold beyond which targeted fish assemblages were severely impacted. Topographic complexity, exposure, depth, and wave power were identified as key habitat variables which influenced targeted fish distributions and defined productive habitats for reef fisheries. High targeted reef fish biomass and body length were found in areas not easily accessed by humans, while model predictions when fishing effort was set to zero showed these high values to be more widely dispersed among suitable habitats. By comparing current targeted fish distributions with those predicted when fishing effort was removed, areas with high recovery potential on each island were revealed, with average biomass recovery of 517% and mean body length increases of 59% on Oahu, the most heavily fished island. Spatial protection of these areas would aid recovery of nearshore coral reef fisheries.