Life for many of the world’s marine fish begins at the ocean surface. Ocean conditions dictate food availability and govern survivorship, yet little is known about the habitat preferences of larval fish during this highly vulnerable life-history stage. Here we show that surface slicks, a ubiquitous coastal ocean convergence feature, are important nurseries for larval fish from many ocean habitats at ecosystem scales. Slicks had higher densities of marine phytoplankton (1.7-fold), zooplankton (larval fish prey; 3.7-fold), and larval fish (8.1-fold) than nearby ambient waters across our study region in Hawai‘i. Slicks contained larger, more well-developed individuals with competent swimming abilities compared to ambient waters, suggesting a physiological benefit to increased prey resources. Slicks also disproportionately accumulated prey-size plastics, resulting in a 60-fold higher ratio of plastics to larval fish prey than nearby waters. Dissections of hundreds of larval fish found that 8.6% of individuals in slicks had ingested plastics, a 2.3-fold higher occurrence than larval fish from ambient waters. Plastics were found in 7 of 8 families dissected, including swordfish (Xiphiidae), a commercially targeted species, and flying fish (Exocoetidae), a principal prey item for tuna and seabirds. Scaling up across an ∼1,000 km2 coastal ecosystem in Hawai‘i revealed slicks occupied only 8.3% of ocean surface habitat but contained 42.3% of all neustonic larval fish and 91.8% of all floating plastics. The ingestion of plastics by larval fish could reduce survivorship, compounding threats to fisheries productivity posed by overfishing, climate change, and habitat loss.
The following titles are freely-available, or include a link to a preprint or postprint.
Eco-engineering and the installation of green infrastructure such as artificial floating islands (AFIs), are novel techniques used to support biodiversity. The European Convention on Biological Diversity highlighted the development of green infrastructure as a key method of enhancement in degraded habitats. Research specifically on AFIs in marine environments has largely focused on their ecological functioning role and engineering outcomes, with little consideration for the social benefits or concerns. The aim of this study was to gain an understanding of public perception of coastal habitat loss in the UK and AFIs as a method of habitat creation in coastal environments. This was achieved via a survey, consisting of six closed and two open questions. Of the 200 respondents, 94.5% were concerned about the loss of coastal habitats in the UK, but less than a third were aware of habitat restoration or creation projects in their area of residence. There was a positive correlation between proximity of residency to the coast and knowledge of habitat restoration or creation projects. The majority of the respondents understood the ecological functioning role of AFIs and 62% would preferably want successful plant growth and avian species utilising the AFI. Nearly a third of the respondents had concerns about AFI installations, such as the degradation of the plastic matrix, long term maintenance and disturbance of native species. Despite 90.9% of the respondents supporting the installation of AFIs, the concerns of the public must be addressed during the planning stages of any habitat creation project.
Most assessments of coastal vulnerability are undertaken from the perspective of the risk posed to humans, their property and activities. This anthropocentric view is based on widespread public perception (a) that coastal change is primarily a hazard to property and infrastructure and (b) that sea defences (whether soft or hard) are required to mitigate and eliminate coastal hazards. From the perspective of coastal ecosystems such a view is both perverse and damaging. In this paper we present an alternative approach to coastal assessment that centres on the physical integrity of the coast and its associated ecosystems both now and in the near-future. The shoreline health approach represents a new paradigm for coastal management and is intended to provide a much-needed ecosystem perspective. Its premise is to categorize coasts on the degree to which their ability to function morphodynamically has been compromised by human intervention. We present an expert assessment approach involving five categories that range from "Good Heath" (with "Heath Warning" and "Minor Wounds" sub-divisions), through "Minor Injury", "Major Injury", "On Life Support" to "Deceased". We illustrate the concept using tabulated examples of each category from cliffed, clastic and delta coasts and demonstrate its utility through two applications. This approach has the potential to quantify the degree to which coastal ecosystems have been damaged and to focus attention on the cumulative impact of human activities on coastal ecosystems.
This study combines published datasets with unpublished data on plastic ingestion in several North Sea fish species. The combined dataset of 4389 individuals from 15 species allows the analysis of spatial distribution and temporal variability of plastic uptake in fish. Airborne fibre contamination was observed to be the main contributor to fibres encountered in the samples. The number of fibres in samples was strongly related to the time needed to process a sample, not to the number of individual fishes in the sample. Accurate correction for secondary fibre contamination was not possible, but corrections required would be similar to fibre numbers observed in the samples. Consequently, all fibres were omitted from further analysis. The frequency of occurrence and the average number of plastics in fish is generally low (1.8% and 0.022 pieces per organism respectively), with only cod having a higher prevalence (12.3%). While latitude of catch locations influences plastic uptake in fish, no correlation with the distance to the coast was found. Slightly less plastics were ingested in winter, and a decrease in plastics ingested was observed between 2009 and 2018. These factors should be considered when fish species, catch location and time are discussed as indicators for plastic pollution in the European Marine Strategy Framework Directive. We recommend considering demersal cod and pelagic sprat as two species suitable for monitoring plastic ingestion in biota, both on the seafloor and in the water column.
The present study deals with the monitoring for a real implementation of management policies in marine environments and the potential conflicts between professional and recreational fishery in the coastal areas of the Mediterranean Sea. A comprehensive database of fishing effort and fisheries infringements from professional small-scale and recreational fisheries was screened to identify hotspots areas of fishing pressure in the coastal zones of Ionian Sea. Mapping points showed that the number of the recorded infringements conducted both by professional and recreational fishers are too low (1 and 6 recorded infringements per 104 km2 of vessel days per year) and that fishing effort, and subsequently the recorded infringements, are not evenly distributed but concentrated on specific fishing grounds. These revealed high-risk areas prone to illegal fishing activities and are implying problems in the implementation of the fisheries regulations rather than a low delinquency of the fishers to comply with the rules. Findings represents a step forward in applying tracking technology to the surveillance of small-scale fishery and are crucial towards the specification of the critical zones for setting an efficient control system.
Synthetic polymer-based materials are ubiquitous in aquatic environments, where weathering processes lead to their progressive fragmentation and the leaching of additive chemicals. The current study assessed the chemical content of freshwater and marine leachates produced from car tire rubber (CTR), polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS) and polyvinyl chloride (PVC) microplastics, and their adverse effects on the microalgae Raphidocelis subcapitata (freshwater) and Skeletonema costatum (marine) and the Mediterranean mussel Mytilus galloprovincialis. A combination of non-target and target chemical analysis revealed a number of organic and metal compounds in the leachates, including representing plasticizers, antioxidants, antimicrobials, lubricants, and vulcanizers. CTR and PVC materials and their corresponding leachates had the highest content of tentatively identified organic additives, while PET had the lowest. The metal content varied both between polymer leachates and between freshwater and seawater. Notable additives identified in high concentrations were benzothiazole (CTR), phthalide (PVC), acetophenone (PP), cobalt (CTR, PET), zinc (CTR, PVC), lead (PP) and antimony (PET). All leachates, except PET, inhibited algal growth with EC50 values ranging from 0.5% (CTR) and 64% (PP) of the total leachate concentration. Leachates also affected mussel endpoints, including the lysosomal membrane stability and early stages endpoints as gamete fertilization, embryonic development and larvae motility and survival. Embryonic development was the most sensitive parameter in mussels, with EC50 values ranging from 0.8% (CTR) to 65% (PET) of the total leachate. The lowest impacts were induced on D-shell larvae survival, reflecting their ability to down-regulate motility and filtration in the presence of chemical stressors. This study provides evidence of the relationship between chemical composition and toxicity of plastic/rubber leachates. Consistent with increasing contamination by organic and inorganic additives, the leachates ranged from slightly to highly toxic to mussels and algae, highlighting the need for a better understanding of the overall impact of plastic-associated chemicals on aquatic ecosystems.
In a nutshell,
- We used an insurance industry catastrophe model from RMS to quantify the flood reduction benefits of mangroves across Florida
- Annually, across multiple storms, mangroves reduce flood damages by 25.5% to properties behind them in Collier County
- During Hurricane Irma, over 626,000 people living behind mangrove forests saw reduced flooding in census tracts across Florida
- During Hurricane Irma, mangroves averted $1.5 billion in surge-related flood damages to properties; which represents a 25% savings in counties with mangroves
- Every hectare of mangroves with properties behind them provided, on average, $7,500 in risk reduction benefits during Hurricane Irma
One of the most robust metrics for assessing the effectiveness of protected areas is the temporal trend in the abundance of the species they are designed to protect. We surveyed coral-reef fish and living hard coral in and adjacent to a sanctuary zone (SZ: where all forms of fishing are prohibited) in the World Heritage-listed Ningaloo Marine Park during a 10-year period. There were generally more individuals and greater biomass of many fish taxa (especially emperors and parrotfish) in the SZ than the adjacent recreation zone (RZ: where recreational fishing is allowed) — so log response ratios of abundance were usually positive in each year. However, despite this, there was an overall decrease in both SZ and RZ in absolute abundance of some taxa by up to 22% per year, including taxa that are explicitly targeted (emperors) by fishers and taxa that are neither targeted nor frequently captured (most wrasses and butterflyfish). A concomitant decline in the abundance (measured as percentage cover) of living hard coral of 1–7% per year is a plausible explanation for the declining abundance of butterflyfish, but declines in emperors might be more plausibly due to fishing. Our study highlights that information on temporal trends in absolute abundance is needed to assess whether the goals of protected areas are being met: in our study, patterns in absolute abundance across ten years of surveys revealed trends that simple ratios of abundance did not.
Fusilier (Pisces: Caesionidae) gillnet, called jaring lalosi, have been used since decades by fishers from Assilulu village, meanwhile its scientific information is limited. The aim of this study is to learn the reef fish species selectivity of jaring lalosi and to assess its bycatch using productivity and susceptibility assessment (PSA). This study was conducted at Pulau Tiga waters, Central Maluku Regency, for 3 months observation: October 2017, February and April 2018. Jaring lalosi which means fusilier gillnet, caught dark-banded fusilier, Pterocaesio tile, 94.4% of the total catch. The rest of the catch we represented as by-catch of jaring lalosi. As a high resilience and low vulnerability species, the sustainability of dark-banded fusilier fisheries is unlikely to be fully concerned. As high mobility schooling species, dark-banded fusilier was caught at different communities of reef fishes. MDS analysis showed discrepancy of species selectivity of fusilier gillnet by monthly catch rate. The PSA for bycatch resulted 2 reef species are least likely to be sustainable, 12 reef species are most likely to be sustainable on the criteria of recovery axis and 3 pelagic species are the most sustainable species. We concluded that the practiced of jaring lalosi has low impacts on reef fish community and tendency to overfishing is almost none as long as there is no increasing on fishing pressure. For the implementation of fisheries management based on ecosystem approach (EAFM), bycatch assessment should be applied to other fishing gears.
Tracking data have led to evidence-based conservation of marine megafauna, but a disconnect remains between the many 1000s of individual animals that have been tracked and the use of these data in conservation and management actions. Furthermore, the focus of most conservation efforts is within Exclusive Economic Zones despite the ability of these species to move 1000s of kilometers across multiple national jurisdictions. To assist the goal of the United Nations General Assembly’s recent effort to negotiate a global treaty to conserve biodiversity on the high seas, we propose the development of a new frontier in dynamic marine spatial management. We argue that a global approach combining tracked movements of marine megafauna and human activities at-sea, and using existing and emerging technologies (e.g., through new tracking devices and big data approaches) can be applied to deliver near real-time diagnostics on existing risks and threats to mitigate global risks for marine megafauna. With technology developments over the next decade expected to catalyze the potential to survey marine animals and human activities in ever more detail and at global scales, the development of dynamic predictive tools based on near real-time tracking and environmental data will become crucial to address increasing risks. Such global tools for dynamic spatial and temporal management will, however, require extensive synoptic data updates and will be dependent on a shift to a culture of data sharing and open access. We propose a global mechanism to store and make such data available in near real-time, enabling a holistic view of space use by marine megafauna and humans that would significantly accelerate efforts to mitigate impacts and improve conservation and management of marine megafauna.
Environmental DNA is increasingly being used in marine invasive species surveillance despite the inability to discriminate between contemporary intracellular (i.e., living) and extracellularly persistent (i.e., legacy) DNA fragments. Environmental RNA is emerging as a powerful alternative when distinguishing the living portion of a community is essential. A positive relationship between DNA and RNA signals may justify the use of DNA only for more rapid and cost-effective detections. In this study environmental DNA and RNA were co-extracted from settlement plates and water samples collected in an Auckland harbor, New Zealand. Samples were analyzed using a specific droplet digital PCR assay for the invasive Mediterranean fanworm (Sabella spallanzanii), combined with metabarcoding of metazoan communities (Cytochrome c oxidase subunit I). The number and magnitude of S. spallanzanii detections was higher in DNA compared to RNA, and in water samples. An assessment of detection sensitivity and specificity using a Receiver Operator Characteristics (ROC) analysis supported a relationship between the magnitude of DNA signal and the likelihood of RNA detection for both sampled matrices. A prediction threshold of 400 COI copies in DNA samples provides an indicator for the detection of eRNA, hence the putative presence of living S. spallanzanii population under the conditions tested in this study. Metabarcoding community analysis revealed the taxonomic composition of the water samples to be more diverse than the plate samples which were largely dominated by mollusks. There was a strong association between mollusks and presumed extracellular droplet digital PCR signals. Nevertheless, droplet digital PCR detection signals based on environmental DNA were negatively correlated with metabarcoding diversity indices on plates. This highlights complex interactions between environmental DNA and RNA detections and environmental matrices that can affect targeted approaches. These interactions need to be considered when designing surveillance programs.
Fresh submarine groundwater discharge (fresh SGD), the efflux of terrestrial groundwater directly into the ocean, is a ubiquitous pathway for nutrient-rich freshwater to coastal ecosystems, altering their hydrography, hydrochemistry, and primary productivity. Yet only little is known about the effects of fresh SGD on the fitness of higher trophic levels such as teleost fish. Otolith analysis revealed that somatic growth rates were significantly higher and settlement to reef habitat took place significantly earlier in juvenile gray demoiselle Chrysiptera glauca exposed to fresh SGD as compared to strictly marine conditions. Contrary to expectations, feeding conditions were comparable in both habitats. We propose that physiologically beneficial environmental conditions brought about by the submarine influx of cold acidic freshwater enabled juvenile fish to exhibit elevated growth rates, thereby increasing their survival potential. This effect would directly link changes in groundwater on land to variations in marine primary and secondary consumer biomass at the coast.
In 2013, South Australia experienced unusually high and variable water temperatures (5°C above the historic average), with a peak sea surface temperature of approximately 27°C over a wide geographic area covering both gulfs and shelf waters. Over the same period and similar geographic area, a prolonged and widespread marine mortality event occurred. From January to May 2013, low level rates of incidental morbidity and mortality of abalone (Haliotis rubra and H. laevigata) and at least 29 fish species were observed. Mortalities were geographically extensive from Port MacDonnell on the South Coast of South Australia to Point Drummond on Eyre Peninsula, and including two gulf systems, spanning approximately 2,900 km of coastline. Mortalities were investigated using gross pathology, histopathology, bacterial culture and polymerase chain reaction (PCR) techniques. Water samples were collected to assess water column nutrient status and phytoplankton biomass levels and community composition. High nutrient concentrations were suggestive of high phytoplankton productivity, with conditions conducive to diatom blooms. A harmful (abrasive) diatom, Chaetoceros coarctatus, was observed in higher concentrations than the historical average. Observed fish mortalities were restricted to a small proportion of the populations and primarily comprised of temperate small-bodied benthic inshore species. Fish histopathology was suggestive of prolonged stress (melanomacrophage aggregation in spleens and kidneys), physical gill damage (focal gill lesions likely caused by C. coarctatus) and lethal bacterial septicaemia. Infectious and notifiable diseases were ruled out in all fish and abalone samples. Abalone mortalities were also restricted to a small proportion of the population with thermal stress a likely contributing factor that resulted in terminal secondary bacterial infections. A marine heatwave event, which promoted blooms of algae, including C. coarctatus, was likely the primary cause of widespread marine mortalities throughout South Australia in 2013. With marine heatwaves projected to increase in frequency, duration and spatial extent, this investigation demonstrated that most at risk will be temperate species in shallow water habitats already at their upper thermal tolerance limits, particularly those with high site fidelity. This should be considered in future climate proofing strategies, including risk and impact assessments underpinning the management of marine resources, fisheries, aquaculture and ecotourism.
The papers in this special issue provide new insights into ongoing research to value coastal and marine ecosystem services, and offer meaningful information for policymakers and resource managers about the economic significance of coastal resources for planning, restoration, and damage assessment. Study areas encompass a broad geographic scope from the Gulf of Mexico in the United States, to the Caribbean, the European Union, Australia, and Southeast Asia. The focus of these papers ranges from theoretical perspectives on linkages between ecosystem services and resource management, to the actual integration of valuation information in coastal and marine resource policy decisions, and to the application of economic valuation methods to specific coastal and marine resource management problems. We hope readers will appreciate these new contributions to the growing literature on coastal and marine resource ecosystem services valuation.
- Deep‐sea marine protected areas (MPAs) present particular challenges for management. Their remote location means there is limited knowledge of species and habitat distribution, and rates and scales of change. Yet, evaluating the attainment of conservation objectives and managing the impact of human activities both require a quantitative understanding of natural variability in species composition/abundance and habitat conditions.
- Ocean Networks Canada (ONC) and Fisheries and Oceans Canada are collaborating in the development of remote monitoring tools for the Endeavour Hydrothermal Vents MPA in the north‐east Pacific. This 98.5 km2 MPA, located 250 km offshore Vancouver Island, encompasses five major fields of hydrothermal vents, at depths of 2200–2400 m. A real‐time cabled observatory was installed at the Endeavour site in 2010.
- Scientific research for the conservation, protection and understanding of the area is permitted within the MPA and is the primary activity impacting the area. Research activities require the use of submersibles for sampling, surveying and observatory infrastructure maintenance. Data and imagery from remotely operated vehicle dives and fixed subsea observatory sensors are archived in real time using ONC's Oceans 2.0 software system, enabling evaluation of the spatial footprint of research activity in the MPA and the baseline level of natural ecosystem change.
- Recent examples of database queries that support MPA management include: (1) using ESRI ArcGIS spatial analysis tools to create kernel density ‘heat maps’ to quantify the intensity of sampling and survey activity within the MPA; and (2) quantifying high‐frequency variability in vent fauna and habitat using sensor and fixed camera data.
- Collaboration between researchers and MPA managers can help mitigate the logistical challenges of monitoring remote MPAs. Recognition at the policy level of the importance of such partnerships could facilitate the extension of scientific missions to support more formal monitoring programmes.
- The world's oceans are often perceived as barriers that separate countries. To counter these divisions and improve protection of ocean resources, marine protected area (MPA) managers have formed alliances that bridge jurisdictional boundaries to share strategies and resources with other protected areas.
- The National Oceanic and Atmospheric Administration's Office of National Marine Sanctuaries has embraced this sister site approach to connect MPA management based on ecological and cultural links. Designed to strengthen the management of ecologically and culturally connected areas, these relationships between protected areas serve as catalysts for effective stewardship of the ocean's biological resources and show the important benefits of transnational cooperation.
- This paper summarizes the lessons from over a decade of sister site partnerships, including case studies from Stellwagen Bank National Marine Sanctuary and four sites in the Caribbean working together to protect a shared population of humpback whales; the Gulf of Mexico Sister Site Network being developed by the USA, Mexico, and Cuba; Papahānaumokuākea Marine National Monument and Rapa Nui in Chile; and broader collaboration among MPAs in the USA and Chile on the Pacific coast.
Shallow rocky reef fish assemblages were studied in sites of low versus high fishing pressure (FP) across the Aegean Sea, in order to assess community structure at a large scale and investigate spatial variability in relation to FP, depth, and geographic location. A total of 15 pairs of high and low FP sites were selected (18 sites in North Aegean, 12 in South Aegean). The level of FP was defined based on a fishing pressure index specifically developed for coastal small-scale fisheries in the region. In each site, fish communities were investigated at two depth zones (5 and 15 m). Number of species, fish size (Total Length; TL) and abundance were recorded along strip transects through underwater visual surveys. Abundance and TL were used to estimate biomass, and fish species were assigned to distinct trophic and commercial status groups. An 8-fold range in fish density and a 14-fold range in fish biomass were detected, while community structure was affected by all variables considered (FP, depth, geographic location). The N Aegean sites scored higher in number of species and biomass of carnivorous fish, whereas the S Aegean had a higher biomass of several allochthonous and thermophilous species. Abundance and biomass estimates were higher in low FP sites, and primarily at the 15 m depth zone, where low FP sites had the double abundance and 2.8 times higher biomass. Biomass of carnivores was generally very low, except at deep sites of low FP. Given that sites of lower FP represent areas of lower conflicting interests for fisheries whilst providing enhanced biomass levels, they should be included in future marine conservation planning schemes, as they could contribute to the replenishment of fisheries and the boosting of conservation benefits provided by MPAs, once properly managed.
The number of marine watercraft is on the rise—from private boats in coastal areas to commercial ships crossing oceans. A concomitant increase in underwater noise has been reported in several regions around the globe. Given the important role sound plays in the life functions of marine mammals, research on the potential effects of vessel noise has grown—in particular since the year 2000. We provide an overview of this literature, showing that studies have been patchy in terms of their coverage of species, habitats, vessel types, and types of impact investigated. The documented effects include behavioral and acoustic responses, auditory masking, and stress. We identify knowledge gaps: There appears a bias to more easily accessible species (i.e., bottlenose dolphins and humpback whales), whereas there is a paucity of literature addressing vessel noise impacts on river dolphins, even though some of these species experience chronic noise from boats. Similarly, little is known about the potential effects of ship noise on pelagic and deep-diving marine mammals, even though ship noise is focused in a downward direction, reaching great depth at little acoustic loss and potentially coupling into sound propagation channels in which sound may transmit over long ranges. We explain the fundamental concepts involved in the generation and propagation of vessel noise and point out common problems with both physics and biology: Recordings of ship noise might be affected by unidentified artifacts, and noise exposure can be both under- and over-estimated by tens of decibel if the local sound propagation conditions are not considered. The lack of anthropogenic (e.g., different vessel types), environmental (e.g., different sea states or presence/absence of prey), and biological (e.g., different demographics) controls is a common problem, as is a lack of understanding what constitutes the ‘normal’ range of behaviors. Last but not least, the biological significance of observed responses is mostly unknown. Moving forward, standards on study design, data analysis, and reporting are badly needed so that results are comparable (across space and time) and so that data can be synthesized to address the grand unknowns: the role of context and the consequences of chronic exposures.
Many coastal areas host rich marine ecosystems and are also centers of economic activities, including fishing, shipping and recreation. Due to the socioeconomic and ecological importance of these areas, predicting relevant indicators of the ecosystem state on sub-seasonal to interannual timescales is gaining increasing attention. Depending on the application, forecasts may be sought for variables and indicators spanning physics (e.g., sea level, temperature, currents), chemistry (e.g., nutrients, oxygen, pH), and biology (from viruses to top predators). Many components of the marine ecosystem are known to be influenced by leading modes of climate variability, which provide a physical basis for predictability. However, prediction capabilities remain limited by the lack of a clear understanding of the physical and biological processes involved, as well as by insufficient observations for forecast initialization and verification. The situation is further complicated by the influence of climate change on ocean conditions along coastal areas, including sea level rise, increased stratification, and shoaling of oxygen minimum zones. Observations are thus vital to all aspects of marine forecasting: statistical and/or dynamical model development, forecast initialization, and forecast validation, each of which has different observational requirements, which may be also specific to the study region. Here, we use examples from United States (U.S.) coastal applications to identify and describe the key requirements for an observational network that is needed to facilitate improved process understanding, as well as for sustaining operational ecosystem forecasting. We also describe new holistic observational approaches, e.g., approaches based on acoustics, inspired by Tara Oceans or by landscape ecology, which have the potential to support and expand ecosystem modeling and forecasting activities by bridging global and local observations.