The monitoring of beached litter along the coast is an onerous obligation enshrined within a number of legislative frameworks (e.g. the MSFD) and which requires substantial human resources in the field. Through this study, we have optimised the protocol for the monitoring of the same litter along coastal stretches within an MPA in the Maltese Islands through aerial drones, with the aim of generating density maps for the beached litter, of assisting in the identification of the same litter and of mainstreaming this type of methodology within national and regional monitoring programmes for marine litter. Concurrent and concomitant in situ monitoring of beached litter enabled us to ground truth the aerial imagery results. Results were finally discussed within the context of current and future MSFD monitoring obligations, with considerations made on possible future policy implications.
This paper evaluates the effectiveness of a public information campaign, which was conducted on a major Greek Island (Syros), aimed at reducing plastic waste - and specifically plastic bags - in the local coastal/marine environment. A choice experiment was conducted to evaluate the effects on individual preferences for reducing plastic waste pollution under different status of environmental awareness, after the information campaign. The evaluation process was quite independent of the information campaign. Two samples of respondents were taken; one consisting of participants in the environmental campaign and the other consisting of non-participants. The results show: (a) significant differences between the preferences of the two samples; (b) variations in the willingness to pay values between the two samples for protection of the coastal/marine environment, but; (c) not significant differences in their commitment to take action (i.e. in their willingness to alter their current plastic bag use behavior).
During the last fifty years, there has been a dramatic increase in the development of anthropogenic activities, and this is particularly threatening to marine coastal ecosystems. The management of these multiple and simultaneous anthropogenic pressures requires reliable and precise data on their distribution, as well as information (data, modelling) on their potential effects on sensitive ecosystems. Focusing on Posidonia oceanicabeds, a threatened habitat-forming seagrass species endemic to the Mediterranean, we developed a statistical approach to study the complex relationship between human multiple activities and ecosystem status. We used Random Forest modelling to explain the degradation status of P. oceanica (defined herein as the shift from seagrass bed to dead matte) as a function of depth and 10 anthropogenic pressures along the French Mediterranean coast (1700 km of coastline including Corsica). Using a 50 × 50 m grid cells dataset, we obtained a particularly accurate model explaining 71.3% of the variance, with a Pearson correlation of 0.84 between predicted and observed values. Human-made coastline, depth, coastal population, urbanization, and agriculture were the best global predictors of P. oceanica's degradation status. Aquaculture was the least important predictor, although its local individual influence was among the highest. Non-linear relationship between predictors and seagrass beds status was detected with tipping points (i.e. thresholds) for all variables except agriculture and industrial effluents. Using these tipping points, we built a map representing the coastal seagrass beds classified into four categories according to an increasing pressure gradient and its risk of phase shift. Our approach provides important information that can be used to help managers preserve this essential and endangered ecosystem.
In recent years, some scientists have expressed concern about the negative representation of the state of the oceans in the media. To examine this concern empirically, we analyzed the content of 169 articles in mainstream U.S. newspapers covering ocean-related research between 2001 and 2015. Content was categorized according to main issue, basis of evidence, causal attribution, presence of solutions and uncertainty, and coded for doom and gloom and optimistic language. Science journalism about ocean issues most commonly addressed climate change and the status of ocean species or populations. The majority of articles cited peer-reviewed research. Most articles attributed change to anthropogenic causes, although ocean science articles addressing climate change were less likely to do so. Uncertain language and solutions were observed in nearly half of all articles. Optimistic language outnumbered doom and gloom language across all categories. While doom and gloom language was identified in 10% of all articles, optimistic language was present in 27%.
The mullet fishery system encompasses a complex arrange of ecological and socioeconomic factors interacting in multiple scales on the Southern-Southeastern Brazilian coast. Similarly, to other fisheries in developing countries, overfishing and poor governance have been threatening the resilience of the mullet fishery. In this paper, we explore aspects related to fisheries management from the perspective of the concept of resilience. The industrial and artisanal fishery sectors represent the different stakeholders. The main issues of concern are related to failures in the fisheries management to properly address equity in resource access and resource use sustainability among stakeholders. Asymmetry in technology and political and economic power affect food security and income generation especially for subsistence and small-scale fishing. Despite changes in rules-in-use, overfishing and conflicts between resource users are still relevant. Fishery dynamics and resource availability are greatly affected locally by forces such as pollution, urbanization, non-selective fishing, and regionally, by the El Niño Southern Oscillation (ENSO), and industrial (purse-seine) fishery. Considering the influence of ENSO on this fishery, a time span of at least 7 years to investigate this system could provide better answers to improve the management. Effective resilient fisheries should rely on three aspects. First, there should be a flexible fish allocation system based on ecosystem variability. Secondly, fish allocation should prioritize food security and poverty alleviation. Thirdly, a monitoring system should be implemented that takes into consideration ecosystem, fisheries and human dimensions to support a flexible and adaptive fisheries management, with resilient fisheries as an ultimate goal.
This study explored the ethics of provisioning wildlife to enhance tourist interactions at a whale shark tourism site in Oslob, Philippines. TripAdvisor comments (n = 947) and tourist surveys (n = 761) were used to better understand tourists' perceptions of whale shark provisioning in Oslob. The ethical decisions made were then critically assessed using utilitarian and animal welfare ethical philosophies. The majority of respondents supported whale shark provisioning, despite many being aware of the ethical complications of provisioning sharks for tourism purposes. Respondents justified their participation in this activity using mainly economic, human enjoyment, and animal welfare arguments. A utilitarian assessment of the potential costs and benefits of this activity highlighted the gaps in our knowledge regarding the economic and social benefits of this activity, as well as the negative impacts on the sharks’ welfare. Until such analyses are completed, significant ethical questions remain regarding the provisioning of these sharks.
Variable density dependence within multispecies fisheries results in species restructuring as exploitation intensifies that is poorly understood. We examined unique species-based records across 25 years of exploitation to evaluate patterns, consequences, and predictions of species replacements within three coral-reef fisheries. Body-size was an expected determinant of species replacements, as larger fishes were consistently replaced by smaller, faster-growing counterparts. However, many species with similar sizes and growth rates responded differently. Naso unicornis, a primary component of coral-reef fisheries across the Pacific, was one of the most resilient species to exploitation despite having a similar maximum size and growth as many large parrotfishes that slowly disappeared from landings. Assessments conducted for all primary target species revealed clear distinctions in compensatory responses: 31% had diminishing size structures, 18% had diminishing proportional contribution, but only 5% showed both. Standard approaches to fisheries management assume constant rates of size-and-age restructuring and rely upon metrics such as fishing-versus-natural mortality. Instead, a deeper appreciation for varying recruitment rates may help to (re)define fisheries management units and reduce complexity in multispecies fisheries. We last consider our results alongside traditional knowledge and management in the Pacific that clearly appreciated species responses, but have been lost over the years.
Wildlife tourism can provide sustainable livelihoods, but can also significantly impact vulnerable species if improperly managed. To manage these impacts whilst continuing to support livelihoods, it is important to know the interests of tourists. Using the Best-Worst scaling method, we identified taxa that were most important to scuba dive tourism on shallow soft sediment habitats in Southeast Asia. We further identified differences in interest between demographic groups. We then investigated the current conservation status and research effort into the species driving this branch of tourism. The highest ranked taxa included fishes and invertebrates such as cephalopods and crustaceans. More than 200 respondents indicated that the species most important to muck dive tourism are mimic octopus/wunderpus, blue ringed octopus, rhinopias, flamboyant cuttlefish and frogfish. Diver interests were most influenced by sex, age and dive experience. The extinction risk of six of the top ten species has not yet been assessed by the International Union for Conservation of Nature. On average, the species driving this multi-million dollar tourism industry had less than one paper published every two years over the past two decades. The lack of research and conservation effort toward these species is at odds with their economic and social importance. Considering their high economic tourism value and unknown vulnerability, there is an urgent need for more research on fauna from shallow soft sediment and other habitats important to tourism.
Microplastics can be present in the environment as manufactured microplastics (known as primary microplastics) or resulting from the continuous weathering of plastic litter, which yields progressively smaller plastic fragments (known as secondary microplastics). Herein, we discuss the numerous issues associated with the analysis of microplastics, and to a less extent of nanoplastics, in environmental samples (water, sediments, and biological tissues), from their sampling and sample handling to their identification and quantification. The analytical quality control and quality assurance associated with the validation of analytical methods and use of reference materials for the quantification of microplastics are also discussed, as well as the current challenges within this field of research and possible routes to overcome such limitations.
Coral reefs feed millions of people worldwide, provide coastal protection and generate billions of dollars annually in tourism revenue1. The underlying architecture of a reef is a biogenic carbonate structure that accretes over many years of active biomineralization by calcifying organisms, including corals and algae2. Ocean acidification poses a chronic threat to coral reefs by reducing the saturation state of the aragonite mineral of which coral skeletons are primarily composed, and lowering the concentration of carbonate ions required to maintain the carbonate reef. Reduced calcification, coupled with increased bioerosion and dissolution3, may drive reefs into a state of net loss this century4. Our ability to predict changes in ecosystem function and associated services ultimately hinges on our understanding of community- and ecosystem-scale responses. Past research has primarily focused on the responses of individual species rather than evaluating more complex, community-level responses. Here we use an in situ carbon dioxide enrichment experiment to quantify the net calcification response of a coral reef flat to acidification. We present an estimate of community-scale calcification sensitivity to ocean acidification that is, to our knowledge, the first to be based on a controlled experiment in the natural environment. This estimate provides evidence that near-future reductions in the aragonite saturation state will compromise the ecosystem function of coral reefs.
Aquatic acidification, caused by elevating levels of atmospheric carbon dioxide (CO2), is increasing in both freshwater and marine ecosystems worldwide. However, few studies have examined how acidification will affect oxygen (O2) transport and, therefore, performance in fishes. Although data are generally lacking, the majority of fishes investigated in this meta-analysis exhibited no effect of elevated CO2 at the level of O2 uptake, suggesting that they are able to maintain metabolic performance during a period of acidosis. Notably, the mechanisms that fish employ to maintain performance and O2 uptake have yet to be verified. Here, we summarize current data related to one recently proposed mechanism underpinning the maintenance of O2 uptake during exposure to aquatic acidification, and reveal knowledge gaps that could be targeted for future research. Most studies have examined O2 uptake rates while fishes were resting and did not calculate aerobic scope, even though aerobic scope can aid in predicting changes to whole-animal metabolic performance. Furthermore, research is lacking on different age classes, freshwater species and elasmobranchs, all of which might be impacted by future acidification conditions. Finally, this Review further seeks to emphasize the importance of developing collaborative efforts between molecular, physiological and ecological approaches in order to provide more comprehensive predictions as to how future fish populations will be affected by climate change.
As global average sea‐level rises in the early part of this century there is great interest in how much global and local sea level will change in the forthcoming decades. The Paris Climate Agreement's proposed temperature thresholds of 1.5°C and 2°C have directed the research community to ask what differences occur in the climate system for these two states. We have developed a novel approach to combine climate model outputs that follow specific temperature pathways to make probabilistic projections of sea‐level in a 1.5°C and 2°C world. We find median global sea‐level (GSL) projections for 1.5°C and 2°C temperature pathways of 44 and 50 cm, respectively. The 90% uncertainty ranges (5%–95%) are both around 48 cm by 2100. In addition, we take an alternative approach to estimate the contribution from ice sheets by using a semi‐empirical GSL model. Here we find median projections of 58 and 68 cm for 1.5°C and 2°C temperature pathways. The 90% uncertainty ranges are 67 and 82 cm respectively. Regional projections show similar patterns for both temperature pathways, though differences vary between the median projections (2–10 cm) and 95th percentile (5–20 cm) for the bulk of oceans using process‐based approach and 10–15 cm (median) and 15–25 cm (95th percentile) using the semi‐empirical approach.
Developing the workforce to meet the needs of the blue economy will require changing undergraduate marine science programs to provide a wider range of skills developed by “doing” rather than just “reading.” Students also need training on how to effectively work in a team, critically analyze data, and be able to clearly communicate key points. With that in mind, we developed a new undergraduate course (called Ocean Observing) focused on conducting research by analyzing data collected and delivered to shore in near real time from the growing global network of ocean observatories. The course structure is based on student teams that use data to develop a range of data products, many of which have been suggested by state and federal agencies as well as from maritime companies. Students can take the Ocean Observing course repeatedly throughout their undergraduate career. A complimentary second entry course (called Oceanography House) was developed to entrain freshmen first-term students into research on their first semester on campus. The Ocean Observing course has increased the number of marine science majors and the overall diversity of the marine science program and resulted in a dramatic increase in the number of independent student theses conducted each year. Over the last 10 years, student data profiles from the course emphasize the importance of conducting research in a public way so students can partake in the “adventure” of research before the outcome is known. To increase the public visibility of these “adventures,” collaborations between departments across the campus have developed nationally broadcast documentaries and outreach materials. Going forward, we seek to build on this success by developing an accelerated Masters of Operational Oceanography and link these undergraduate students with external companies through externships and coordinated research projects.
Nearshore fish populations are in decline in the main Hawaiian Islands, and effective, sustainable management is needed. There has been increasing emphasis on the value of ecosystem-based management and the conservation of essential fish habitat, but policy is encumbered by a lack of supporting information. This study uses science and technology to support traditional knowledge in identifying juvenile fish habitats, providing a basis for effective resource management in a rural Hawaiian community. Building on existing local knowledge of nearshore resources, we quantitatively assessed juvenile fish-habitat associations. We conducted fine-scale in situ ecological surveys of juvenile reef fishes and their habitats, and produced detailed benthic habitat maps using GIS and interpretation of satellite imagery, from which we extracted multi-scale seascape variables. Canonical correspondence analysis was used to assess fish-habitat relationships at multiple scales. Depth, coral cover, structural complexity, scattered rock and coral habitat, and distance to shore emerged as primary factors associated with juvenile reef fish abundance. We identified the habitat associations of 2 important food resource species in the study area of Hā‘ena, Kaua‘i: the convict tang Acanthurus triostegus sandvicensis, an endemic subspecies, and the redlip parrotfish Scarus rubroviolaceus. Results from this study played an important role in the successful approval of the Hā‘ena community-based fishery management plan by the state governing agency. We argue that an ecosystem-based co-management approach, informed by conventional survey methods, remote sensing technology, and traditional knowledge, can help to ensure the sustainability of fisheries worldwide.
We assessed the potential role played by two vital Northeastern Pacific Ocean forage fishes, the Pacific sand lance (Ammodytes personatus) and Pacific herring (Clupea pallasii), as conduits for the vertical transfer of microfibres in food webs. We quantified the number of microfibres found in the stomachs of 734 sand lance and 205 herring that had been captured by an abundant seabird, the rhinoceros auklet (Cerorhinca monocerata). Sampling took place on six widely-dispersed breeding colonies in British Columbia, Canada, and Washington State, USA, over one to eight years. The North Pacific Ocean is a global hotspot for pollution, yet few sand lance (1.5%) or herring (2.0%) had ingested microfibres. In addition, there was no systematic relationship between the prevalence of microplastics in the fish stomachs vs. in waters around three of our study colonies (measured in an earlier study). Sampling at a single site (Protection Island, WA) in a single year (2016) yielded most (sand lance) or all (herring) of the microfibres recovered over the 30 colony-years of sampling involved in this study, yet no microfibres had been recovered there, in either species, in the previous year. We thus found no evidence that sand lance and herring currently act as major food-web conduits for microfibres along British Columbia's outer coast, nor that the local at-sea density of plastic necessarily determines how much plastic enters marine food webs via zooplanktivores. Extensive urban development around the Salish Sea probably explains the elevated microfibre loads in fishes collected on Protection Island, but we cannot account for the between-year variation. Nonetheless, the existence of such marked interannual variation indicates the importance of measuring year-to-year variation in microfibre pollution both at sea and in marine biota.
This study examines the role of risk preferences in explaining the public's willingness to pay for marine turtle conservation in China. Respondents (n = 218) were randomly selected from eight districts in Beijing. They were interviewed in person and participated in a risk experiment. The results show that residents in Beijing had some knowledge about marine turtles. The typical respondent in Beijing is risk averse. We found that the risk preferences of individuals have significant effects on their willingness to pay for marine turtle conservation. Risk taking respondents are more likely to support the marine turtle conservation program. Results also indicate that increases in the bid value, household income levels, years of education and participation in public environmental issues have significant effects on the public's acceptance of marine turtle conservation. The findings of this study can help resource managers and/or policy makers to improve the conservation of marine turtles in China.
Population replenishment of marine life largely depends on successful dispersal of larvae to suitable adult habitat. Ocean acidification alters behavioural responses to physical and chemical cues in marine animals, including the maladaptive deterrence of settlement-stage larval fish to odours of preferred habitat and attraction to odours of non-preferred habitat. However, sensory compensation may allow fish to use alternative settlement cues such as sound. We show that future ocean acidification reverses the attraction of larval fish (barramundi) to their preferred settlement sounds (tropical estuarine mangroves). Instead, acidification instigates an attraction to unfamiliar sounds (temperate rocky reefs) as well as artificially generated sounds (white noise), both of which were ignored by fish living in current day conditions. This finding suggests that by the end of the century, following a business as usual CO2 emission scenario, these animals might avoid functional environmental cues and become attracted to cues that provide no adaptive advantage or are potentially deleterious. This maladaptation could disrupt population replenishment of this and other economically important species if animals fail to adapt to elevated CO2 conditions.
The efficacy of a Mediterranean Marine Protected Area (National Marine Park of Zakynthos – NMPZ, Ionian Sea, Greece) that implements a seasonal no-take zone as part of its management scheme was assessed using fish data collected in situ with underwater visual census. Sampling was conducted at two habitat types (Posidonia oceanica meadows and rocky reefs) that occur at sites of different protection level with respect to fisheries (high protection: seasonal no-take zone within the MPA; intermediate: zones within the MPA where small-scale fishing is allowed; none: areas outside the MPA, where all types of fishing are allowed, including trawlers, purse seiners, and recreational fishing). The data were used to examine the effects of protection level and habitat type on community parameters, trophic structure and functional diversity of fish populations that occupy the upper sublittoral zone. Overall, habitat type had a more pronounced effect than protection level on all investigated parameters. Biomass, density and number of fish species with low commercial value were higher in sites of intermediate protection, but no substantial fisheries-related ecological benefits were detected for targeted fish in the seasonal no-take zone. Conducted 8 years after the initial implementation of the seasonal no-take management scheme, our study suggests that existing fishing regulations in the NMPZ provide some measurable effects, but fall short of maintaining sufficient protection for the recovery of apex predators or other commercially important fish species. A revision of the existing zoning system to include permanent no-take zones, alongside the regulation of professional fishing and all extractive activities in the rest of the MPA, are strongly encouraged in order to enhance the effectiveness of fisheries management.
Anthropogenic noise pollution is recognized as a major global stressor of animals. While many studies have assessed the unimodal impacts of noise pollution with a focus on intraspecific acoustic communication, little is known about noise pollution on the perception of visual and chemical information. The ‘distracted prey hypothesis’ posits that processing noise interferes with processing other information in the brain. Here, we found evidence for such a cross-modal effect of noise on the antipredator behaviour of a freshwater prey fish, the fathead minnow, Pimephales promelas. In laboratory trials, exposure to noise from a motorboat caused the total absence of the classical fright reaction of minnows to conspecific alarm cues, whereas an ambient noise control had no such impact. In natural habitats, the impairment of such antipredator behaviour due to noise pollution could have major fitness consequences. We discuss how our findings translate to animal ecology and the need for future studies that target specific management decisions regarding noise pollution.
For thousands of years humankind has sought to explore our oceans. Evidence of this early intrigue dates back to 130,000 BCE, but the advent of remotely operated vehicles (ROVs) in the 1950s introduced technology that has had significant impact on ocean exploration. Today, ROVs play a critical role in both military (e.g. retrieving torpedoes and mines) and salvage operations (e.g. locating historic shipwrecks such as the RMS Titanic), and are crucial for oil and gas (O&G) exploration and operations. Industrial ROVs collect millions of observations of our oceans each year, fueling scientific discoveries. Herein, we assembled a group of international ROV experts from both academia and industry to reflect on these discoveries and, more importantly, to identify key questions relating to our oceans that can be supported using industry ROVs. From a long list, we narrowed down to the 10 most important questions in ocean science that we feel can be supported (whole or in part) by increasing access to industry ROVs, and collaborations with the companies that use them. The questions covered opportunity (e.g. what is the resource value of the oceans?) to the impacts of global change (e.g. which marine ecosystems are most sensitive to anthropogenic impact?). Looking ahead, we provide recommendations for how data collected by ROVs can be maximised by higher levels of collaboration between academia and industry, resulting in win-win outcomes. What is clear from this work is that the potential of industrial ROV technology in unravelling the mysteries of our oceans is only just beginning to be realised. This is particularly important as the oceans are subject to increasing impacts from global change and industrial exploitation. The coming decades will represent an important time for scientists to partner with industry that use ROVs in order to make the most of these ‘eyes in the sea’.