Marine Ecosystem Health Research Articles

Exploring the Impact of Contaminants of Emerging Concern on Fish and Invertebrates Physiology in the Mediterranean Sea.

In this historical context, the Mediterranean Sea faces an increasing threat from emerging pollutants such as pharmaceuticals, personal care products, heavy metals, pesticides and microplastics, which pose a serious risk to the environment and human health. In this regard, aquatic invertebrates and fish are particularly vulnerable to the toxic effects of these pollutants, and several species have been identified as bio-indicators for their detection. Among these, bivalve molluscs and elasmobranchs are now widely used as bio-indicators to accurately assess the effects of contaminants. The study focuses on the catshark Scyliorhinus canicular and on the Mediterranean mussel Mytilus galloprovincialis. The first one is a useful indicator of localised contamination levels due to its exposure to pollutants that accumulate on the seabed. Moreover, it has a high trophic position and plays an important role in the Mediterranean Sea ecosystem. The bivalve mollusc Mytilus galloprovincialis, on the other hand, being a filter-feeding organism, can acquire and bioaccumulate foreign particles present in its environment. Additionally, because it is also a species of commercial interest, it has a direct impact on human health. In conclusion, the increasing presence of emerging pollutants in the Mediterranean Sea is a serious issue that requires immediate attention. Bivalve molluscs and elasmobranchs are two examples of bio-indicators that must be used to precisely determine the effects of these pollutants on the marine ecosystem and human health.

Seasonal and vertical variations of nutrient cycling in the world’s deepest blue hole

Nutrient cycling in anoxic seawaters is essential to marine ecosystem health and sustainability, yet it remains poorly understood. In this work, we analyzed dissolved inorganic nutrients as well as hydrochemical parameters in the Yongle Blue Hole (YBH) of the South China Sea in October 2019, which is the world’s deepest blue hole and is characterized by anoxia below the depth of 100 m. Nutrient data collected in two sampling campaigns in 2017 were also incorporated to examine the seasonal and vertical variations of nutrient cycling across steep redox gradients in the YBH. In response to the changes in redox conditions in different seasons, nutrients in the YBH showed significant seasonal variations. The nitrate maximum rose from a depth of 90 m in March 2017 to 60-80 m in October 2019, while the primary nitrite maximum concentration decreased from 0.5 μmol/L to 0.1 μmol/L. In October 2019, the nitrite decreased to below the detection limit at about 100 m, while in March 2017, it was 140 m. The regeneration of phosphate and silicate both started from around 40 m in October 2019 and from 80 m in March 2017. Silicate shows non-conservative adding behaviors relative to phosphate and DIN, and phosphate shows a similar but weaker adding behavior relative to DIN. The nutrient ratios also varied seasonally, especially for N/P, which fluctuated greatly on the surface at 80 m, while Si/N and Si/P fluctuated above 50 m. At the oxic-anoxic interface, extreme values of nutrient ratios were observed, and below 150 m, the N/P, Si/N, and Si/P were kept constant at about 17, 1.5, and 26, respectively. Seasonal and vertical variations of nutrient concentrations and ratios in the YBH reflect the impact of redox conditions on nutrient cycling in anoxic seawaters, especially during the transition from oxic to anoxic zone. And the high-resolution distributions of nutrients and hydrochemical parameters are helpful to better understand the nutrient cycling processes in highly dynamic coastal environments that are suffering deoxygenation.

Blue Economy Literature Review

This article overviews the blue economy, its origins, dimensions, and its impact on the global economy. The blue economy is a concept that promotes the sustainable use of ocean resources for economic growth while also preserving the health of marine ecosystems. The chapter discusses the different dimensions of the blue economy, including marine transportation, fisheries, energy, tourism, and biotechnology. It highlights the significant contribution of the blue economy to the world economy, creating jobs, generating wealth, and supporting livelihoods.
 
 However, the chapter also highlights the challenges facing the blue economy, such as overfishing, pollution, and climate change, which threaten the health and sustainability of the marine environment. The chapter concludes by calling for greater cooperation and investment in research, innovation, and technology to address these challenges and ensure the long-term sustainability of the blue economy.

Designing Law and Policy for the Health and Resilience of Marine and Coastal Ecosystems—Lessons From (and for) Aotearoa New Zealand

Ecosystem-based approaches to marine management, which integrate marine law and policy across sectors, communities, and scales, are increasingly advocated for in international policy debates and scholarly literature. We highlight critical and timely opportunities in Aotearoa New Zealand’s evolving legal context to support an ecosystem-based approach across fisheries regulation, biodiversity conservation, environmental effects management, and Indigenous or customary rights. Given the scale of proposed law reform affecting the ocean in Aotearoa New Zealand, there are important global lessons to be elucidated from (and for) the Aotearoa New Zealand experience, revealing the potential for law to center the health of ocean ecosystems and related people in integrated marine decision making.

Application of Synthetic DINCAE–BME Spatiotemporal Interpolation Framework to Reconstruct Chlorophyll–a from Satellite Observations in the Arabian Sea

Chlorophyll–a (Chl–a) concentration is an indicator of phytoplankton pigment, which is associated with the health of marine ecosystems. A commonly used method for the determination of Chl–a is satellite remote sensing. However, due to cloud cover, sun glint and other issues, remote sensing data for Chl–a are always missing in large areas. We reconstructed the Chl–a data from MODIS and VIIRS in the Arabian Sea within the geographical range of 12–28° N and 56–76° E from 2020 to 2021 by combining the Data Interpolating Convolutional Auto–Encoder (DINCAE) and the Bayesian Maximum Entropy (BME) methods, which we named the DINCAE–BME framework. The hold–out validation method was used to assess the DINCAE–BME method’s performance. The root–mean–square–error (RMSE) and the mean–absolute–error (MAE) values for the hold–out cross–validation result obtained by the DINCAE–BME were 1.8824 mg m−3 and 0.4682 mg m−3, respectively; compared with in situ Chl–a data, the RMSE and MAE values for the DINCAE–BME–generated Chl–a product were 0.6196 mg m−3 and 0.3461 mg m−3, respectively. Moreover, DINCAE–BME exhibited better performance than the DINEOF and DINCAE methods. The spatial distribution of the Chl–a product showed that Chl–a values in the coastal region were the highest and the Chl–a values in the deep–sea regions were stable, while the Chl–a values in February and March were higher than in other months. Lastly, this study demonstrated the feasibility of combining the BME method and DINCAE.

Diversity and phylogeny of seagrasses in Singapore

Seagrasses are vital to the health of coastal marine ecosystems and are threatened with habitat destruction as well as other anthropogenic pressures, but their diversity and taxonomy remain poorly studied. Seagrasses can exhibit large morphological variation in response to environmental variables, resulting in field observations being unreliable for identification. Therefore, molecular phylogenetic approaches can be informative in delimiting and identifying seagrass species. In this study, molecular phylogenetic analyses and morphological examinations of nearly 100 seagrasses collected from six sites distributed across Singapore’s northern and southern coasts were integrated to assess their diversity and phylogeny. The nuclear ITS and plastid matK loci were amplified and sequenced for phylogenetic analyses. Our analyses and morphological examinations recovered 10 well-supported lineages corresponding to 10 seagrass species in Singapore (Thalassia hemprichii, Enhalus acoroides, Halophila beccarii, Halophila spinulosa, Halophila major, Halophila ovalis, Halodule uninervis, Oceana serrulata, Syingrodium isoetifolium, and Cymodocea rotundata), including one new local record of Halophila major. Although Halophila ovata, Halodule pinifolia and Halophila decipiens are reflected in historical local records, they were not found in the field, hence raising the possibility that these species could have been locally extirpated. The molecular markers used here, ITS and matK, could clearly delineate most seagrass species but some species-level clades within Halodule and Halophila remain unresolved. Continued work on seagrass phylogenetics will help resolve species complexes and provide more precise species richness estimates, which are critical for seagrass meadow conservation and management.

Assessment of macrobenthos community and ecological status of the Jiaozhou Bay, China

Jiaozhou Bay is one of the most economically and ecologically important semi-enclosed waters along the southern Yellow Sea coast of China. Anthropogenic activities like bivalve aquaculture, sewage discharge, and oil industry have severely impacted the bay environment in the past years. Macrobenthos plays an important role in monitoring marine ecosystem health. Species composition and community structure typically shift as a response to the effects of pollution and disturbance. In this study, macrobenthos community was characterized and assessed with the sediment samples collected from 15 stations in the Jiaozhou Bay in November 2018. Abundance, biomass, species composition, diversity and community structure along with environmental variables were determined to assess the benthic ecosystem health. The ecological status of the bay was also assessed by using abundance biomass comparison curve (ABC plot) and the widely used benthic indices AMBI and M-AMBI. The results showed that combination of five variables (water depth, Cha, Pha, sediment type, and biomass of different cultured bivalve species) were the main determinants for the macrobenthos community structure in the bay. Despite for most of the stations in the bay, relatively high species richness, evenness and diversity, and the undisturbed condition indicated by ABC plots and W statistics, the dominance of opportunistic polychaetes like Micronephthys oligobranchia could show that there is some degree of disturbance in the bay. ABC plot clearly indicated the disturbance of bivalve culture of Ruditapes philippinarum on the macrobenthos community at station J3. As a comparison, the highest abundance and species richness of macrobenthos at station J4 may indicate a positive role of oyster culture Magallana gigas on the improvement of ecological condition. The benthic indices AMBI and M-AMBI suggested that the benthic ecosystem of Jiaozhou Bay was slightly disturbed and the overall ecological status of the bay was in good condition.

Assessment of marine ecosystem health and its key influencing factors in Laizhou Bay, China

IntroductionMajor bays worldwide have been disturbed by human pressures to varying degrees in recent years, resulting in many ecological and environmental issues. Maintaining the health of the bay ecosystem has national and international significances, as it enhances the environmental regulation function and resource development value of the region. This study aims to examine the evolution trend and regulatory mechanism of ecosystem health in Laizhou Bay (LZB), China.MethodsA comprehensive DPSIR-based indicator framework is established, comprising 40 representative indicators of the natural environment status, ecological service function, and social values of the LZB ecosystem. The subjective and objective integrated weighting method is applied to determine the indicator weight. The Ecosystem Health Index is then calculated to assess the LZB ecosystem health from 1980 to 2019 and key influencing factors are identified through the scenario analysis. ResultsThe results show that the health status of the LZB ecosystem has fluctuated and then increased overall over the past 40 years, with a fairly healthy state in the 1980s, an unhealthy state in 2005, and then a rebound to a subhealthy state. The key factors affecting the LZB ecosystem health are mostly pressure items, with land-based pollution, particularly agricultural non-point source pollution, having a more significant impact than reclamations.DiscussionReasonable recommendations are finally put forward on improving the ecosystem health in the study area, including refining the legislation and integrated mechanism related to regional management, building a coordinated land-sea governance system and exploring new technologies for integrated marine management. This study fills the knowledge gap of ecosystem health assessment for the entire LZB in such a long-time scale, and the research outcomes are expected to provide scientific references and guidance for decision-making and social-economic sustainable development in LZB and other bays.

Marine Ecological Function Zoning and Management Countermeasures: A Case Study of the Sea Area of Zhejiang Province

The contradiction between the development of marine resources and ecological protection in Zhejiang is prominent, which restricts the high-quality and continuous supply of marine ecological products. As a result, the efficient maintenance of the ecological security pattern of inshore waters relies on the scientific division of marine ecological function zones and the management and maintenance of zoning areas. This paper constructs a technical framework for marine ecological function zoning from the aspects of marine ecosystem health, marine ecosystem diversity and economic and social development balance using GIS-based overlay analysis and the three-dimensional matrix discriminant model to divide marine ecological function zones in the managed waters of Zhejiang Province. The results indicate that the managed sea areas in Zhejiang Province are divided into ten marine ecological function areas, including three marine ecological supply areas (54%), four marine mariculture and resting areas (24%) and three marine ecological restoration areas (22%). As per the zoning results of the marine ecological function, this study further proposes protection and management strategies for different zoning units, in the hopes of providing technical support and practical reference for the division and management of marine ecological function areas in other sea areas.

Enrichment of geogenic phosphorus in a coastal groundwater system: New insights from dissolved organic matter characterization

High concentrations of geogenic phosphorus (P) in coastal aquifer systems pose a serious and continuous threat to the health of marine ecosystems. A major source for geogenic P enrichment in aquifer systems is the mineralization of P-containing organic matter. However, the mechanisms that drive the enrichment remain unclear. Therefore, our study sought to characterize the occurrence, sources, and enrichment mechanisms of geogenic P in a coastal confined aquifer system of the Pearl River Delta, southern China. To achieve this, we conducted Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and fluorescence excitation-emission-matrix spectra (EEMs) as well as hydrochemistry and stable carbon isotope analyses. Our findings indicated that intense degradation of P-containing organic matter produced up to 8.07 mg/L of geogenic P in a reducing environment with abundant organic matter. The dissolved organic matter (DOM) of high-P groundwater (P > 1 mg/L) contained more humic-like fluorophores and exhibited higher humification. Groundwater with high P concentrations contained more aliphatic compounds and highly unsaturated-low O compounds, and the enrichment of P was mostly associated with CHOP compounds in the region of aliphatic compounds and CHON2P compounds in the region of highly unsaturated-low O compounds. Different types of dissolved organic phosphorus (DOP) can be mineralized into P, and even the mineralization of phosphonates takes precedence over the more unstable phosphate esters. P produced by the metabolism of different types of DOP was assimilated by marine microorganisms (e.g., heterotrophic bacteria and archaea), and the newly synthesized organic P compounds by chemosynthesis were subsequently released into the groundwater. Over time, P continues to be enriched in the aquifer system. This study provides new insights into subsurface P cycling in coastal aquatic systems.

Dynamic cyp1a1 transcript responses in the caudal fin of coho salmon (Oncorhynchus kisutch) smolts to low sulfur marine diesel water accommodated fraction exposures and depuration

Oil spills that occur in high traffic coastal environments can have profound consequences for the health of marine ecosystems and the commercial and social interests that are dependent upon these habitats. Given that the global reliance on marine fuels is not abating, it is imperative to develop sensitive and robust tools to monitor oil contamination and remediation in a timely manner. Such tools are increasingly important for ascertaining the immediate and long-term effects of oil contamination on species of interest and local habitats as water-soluble components of oils, such as polycyclic aromatic hydrocarbons (PAHs), can persist post-remediation. We previously demonstrated that 3-methylcholanthrene responsive cytochrome P450–1a (cyp1a1) transcript abundance in the liver and caudal fin of coho salmon smolts (Onchorhynchus kisutch) was sensitive to exposure to low sulfur marine diesel (LSMD) seawater accommodated fractions (seaWAF) in cold water. We expanded upon this paradigm by assessing the utility of the cyp1a1 transcript to track both exposure to LSMD seaWAF and recovery from exposure by measuring cyp1a1 abundance in coho smolts using quantitative polymerase chain reaction (qPCR). Smolts were exposed to either 100 mg/L LSMD seaWAF or clean seawater (control) for 4 days. Fish were then transferred to clean seawater for depuration and tissues sampled at 0, 1, 2, 4, and 8 days from both treatments. Livers and caudal fins were dissected from 40 smolts per group (ntotal = 400 smolts). The LSMD seaWAF-induced cyp1a1 transcript levels significantly decreased one day after depuration in the liver and caudal fin in a sex-independent manner in genotyped females and males. After four days of depuration, cyp1a1 transcript abundance decreased to baseline control levels, regardless of tissue or sex. The present study demonstrates the value of using the caudal fin as a reliable, sensitive, and non-lethal sampling and monitoring tool.

RETROSPECTIVE REVIEW OF NEUROLOGIC DISEASE IN STRANDED ATLANTIC HARBOR SEALS (PHOCA VITULINA CONCOLOR) ALONG THE NEW ENGLAND COAST.

Harbor seals (Phoca vitulina) are a common species admitted to marine mammal rehabilitation facilities. As important indicators of marine ecosystem health, monitoring trends of disease in harbor seal populations is critical. However, few studies have evaluated neurologic disease in this species. The general objective of this study was to retrospectively review and delineate neurologic disease in free-ranging Atlantic harbor seals (P. vitulina concolor) that stranded along the New England (United States) coast and entered a rehabilitation facility between 2006 and 2019. Any Atlantic harbor seal that stranded live along the New England coast during the study period and was diagnosed with neurologic disease on either antemortem or postmortem evaluation was included; medical records and pathologic reports were reviewed. From 211 records, 24 animals met the inclusion criteria. Prevalence of neurologic disease was 11% in the study population and six major categories of neurologic disease were identified including: inflammatory (54%), idiopathic (33%), trauma (4%), congenital (4%), and degenerative (4%). Of the seals diagnosed with neurologic disease, 13 (54%) seals died during rehabilitation, 10 (42%) seals were euthanized, and 1 (4%) seal survived to release. Unique cases seen included a seal with Dandy-Walker-like malformation and another seal with histopathologic findings compatible with neuroaxonal dystrophy, a degenerative process that has not been previously reported in marine mammals. This study contributes to the overall knowledge of the health of free-ranging Atlantic harbor seals and may aid clinicians in characterizing neurologic conditions that may be present in seals undergoing rehabilitation.

Modelling seabirds biodiversity through Bayesian Spatial Beta regression models: A proxy to inform marine protected areas in the Mediterranean Sea

Seabirds are bioindicators of marine ecosystems health and one of the world's most endangered avian groups. The creation of marine protected areas plays an important role in the conservation of marine environment and its biodiversity. The distributions of top predators, as seabirds, have been commonly used for the management and creation of these figures of protection.The main objective of this study is to investigate seabirds biodiversity distribution in the Mediterranean Sea through the use of Bayesian spatial Beta regression models. We used an extensive historical database of at-sea locations of 19 different seabird species as well as geophysical, climatology variables and cumulative anthropogenic threats to model species biodiversity. We found negative associations between seabirds biodiversity and distance to the coast as well as concavity of the seabed, and positive with chlorophyll and slope. Further, a positive association was found between seabirds biodiversity and coastal impact.In this study we define as hot spot of seabird biodiversity those areas with a posterior predictive mean over 0.50. We found potential hot spots in the Mediterranean Sea which do not overlap with the existing MPASs and marine IBAs. Specifically, our hot spots areas do not overlap with the 52.04% and 16.87% of the current MPAs and marine IBAs, respectively. Overall, our study highlights the need for the extension of spatial prioritization of conservation areas to seabirds biodiversity, addressing the challenges of establishing transboundary governance.

Ca-STANet: Spatiotemporal Attention Network for Chlorophyll-a Prediction With Gap-Filled Remote Sensing Data

Long-term chlorophyll-a (Chl-a) prediction has the potential to provide an early warning of red tide, and support fishery management and marine ecosystem health. The existing learning-based Chl-a prediction methods mostly predict a single point or multiple points with monitoring data. However, the monitoring data are subject to sparse sampling and difficult to be measured in a large-scale and synchronous way. Moreover, the advanced learning-based models for point Chl-a prediction, such as long short-term memory (LSTM) and convolutional neural network (CNN)-LSTM, are unable to fully mining the spatio-temporal correlation of Chl-a variations. Therefore, by using the satellite remote sensing data with extensive coverage, we design a framework, namely Ca-STANet, to simultaneously predict the Chl-a of all the locations in a large-scale area from the perspective of spatio-temporal field. Specifically in our method, the original data are firstly divided into multiple sub-regions to capture the spatial heterogeneity of large-scale area. Then, two modules are respectively operated to mine the spatial correlation and long-term dependency features. Finally, the outputs from the two modules are integrated by a fusion module to fully mine the spatio-temporal correlations, which are exploited to attain the final Chl-a prediction. In this paper, the proposed Ca-STANet is comprehensively evaluated and compared with the legacy methods based on the OC-CCI Chl-a 5.0 data of the Bohai Sea. The results demonstrate that the proposed Ca-STANet is highly effective for Chl-a prediction and achieves higher prediction accuracy than the baseline methods. Moreover, as the OC-CCI Chl-a 5.0 data have many missing areas, we introduce DINEOF method to fill the data gaps before using them for prediction.

Colonization dynamics of periphytic protozoa in a tropical marine ecosystem

Abstract For the bioassessment of tropical marine ecosystem, a survey of protozoa colonizing artificial substrate was conducted in the coastal waters of northern Bay of Bengal, Bangladesh. Protozoan samples were collected using glass slides from 1 and 2 m water depths at time intervals of 3, 7, 10, 14, 21, and 28 days during winter and monsoon seasons. Thus, the colonization processes of protozoa were assigned into three stages namely the initial (3 days), transitional (7 days), and equilibrium stages (10–28 days) at two depths in two seasons. Regression analyses demonstrated that the colonization dynamics of protozoa were well fitted to the MacArthur-Wilson model and logistic equation. Species richness reached equilibrium after 10–14 days and species abundance was maximum at a depth of 1 m. These results suggest that samples of protozoa can be collected at 1 m depth in winter season for monitoring the ecological health of tropical marine ecosystems.

Ocean Monitoring and Prediction Network for the Sustainable Development of the Gulf of Mexico and the Caribbean

The need to understand and forecast disasters driven by anthropogenic and natural forces in the Gulf of Mexico and to support management responses to hazardous events led policymakers, scientists, and industry representatives in Mexico to launch an ocean observation and modeling project (2015–2023) aimed at collecting multi-layered baseline information and continuous monitoring of the ocean environment across the southern Gulf of Mexico. The observational network and modeling efforts, led by the Consorcio de Investigación del Golfo de México (Research Consortium for the Gulf of Mexico, CIGoM), include developing a marine hazard warning system to investigate multiple stressors that are altering the state and health of this large marine ecosystem and its coastal communities. This warning system is intended to aid in the establishment of national contingency plans and mitigate the impacts of extreme events and long-term ocean trends. Stressors include hydrocarbon spills, tropical cyclones, marine heatwaves, long-term ocean surface warming, harmful algal blooms, and massive Sargassum landings.

PMEL Passive Acoustics Research: Quantifying the Ocean Soundscape from Whales to Wave Energy

Passive acoustic monitoring of the global ocean has increased dramatically over the last decade, providing insights into seasonal sea ice and wind/wave variability, biodiversity, geophysical hazards, and anthropogenic noise impacts. All of these phenomena are sentinels of marine ecosystem health and ocean climate change. Recognizing the utility of underwater sound, the Pacific Marine Environmental Laboratory (PMEL) formed a passive acoustic research program with the goal of quantifying deep-ocean and coastal soundscapes in support of NOAA’s mission to conserve and manage marine ecosystems. PMEL Acoustics Program researchers have built a stable of novel ocean technologies, including autonomous stationary hydrophones, mobile platforms, and near-real-time surface buoys with satellite communication capability. These passive acoustic monitoring systems have been deployed in every major ocean basin on Earth, enabling significant advancements in understanding of natural and anthropogenic sounds. This progress includes evaluation of human-made sound levels across US waters, observations of ship noise fluctuations during the COVID-19 pandemic, and evaluation of noise levels from offshore wave-energy devices. Our natural sound research includes assessment of seasonal variability in the presence of endangered cetacean species due to population recovery and/or changing ocean temperatures as well as early detection of the collapse of an Antarctic ice shelf.

Evaluation of a marine mammal status and trends contaminants indicator for European waters

Marine mammals are vulnerable to the bioaccumulation, biomagnification and lactational transfer of specific types of pollutants, such as industrial polychlorinated biphenyls (PCBs), due to their long-life spans, feeding at a high trophic level and unique fat stores that can serve as depots for these lipophilic contaminants. Currently, European countries are developing indicators for monitoring pollutants in the marine environment and assessing the state of biodiversity, requirements under both Regional Seas Conventions and European legislation. As sentinel species for marine ecosystem and human health, marine mammals can be employed to assess bioaccumulated contaminants otherwise below current analytical detection limits in water and lower trophic level marine biota. To aid the development of Regional Seas marine mammal contaminants indicators, as well as Member States obligations under descriptor 8 of the EU Marine Strategy Framework Directive, the current study aims to further develop appropriate methodological standards using data collected by the established UK marine mammal pollutant monitoring programme (1990 to 2017) to assess the trends and status of PCBs in harbour porpoises. Within this case study, temporal trends of PCB blubber concentration in juvenile harbour porpoises were analysed using multiple linear regression models and toxicity thresholds for the onset of physiological (reproductive and immunological) endpoints were applied to all sex-maturity groups. Mean PCB blubber concentrations were observed to decline in all harbour porpoise Assessment Units and OSPAR Assessment Areas in UK waters. However, a high proportion of animals were exposed to concentrations deemed to be a toxicological threat, though the relative proportion declined in most Assessment Units/Areas over the last 10 years of the assessment. Recommendations were made for improving the quality of the assessment going forward, including detailing monitoring requirements for the successful implementation of such an indicator.

Common characteristics of successful water quality improvement through point source pollution management

Ocean pollution from land-based sources, such as terrestrial runoff and wastewater discharge, has significant environmental, social and economic repercussions. Despite the importance of good water quality for coastal ecosystem health, there is limited information about the key management characteristics present in places where there has been successful water quality management and subsequent improvement in marine ecosystem health. In this study, we evaluated several well-known successful examples of point source pollution management that achieved a notable improvement in water quality and coastal and marine ecosystems recovery, using principles of effective management collated from several existing theoretical Integrated Coastal Zone Management (ICZM) frameworks. Principles related to strong legislation, nested level of governance, stakeholder engagement and coordination among involved entities were determined as key factors to achieve water quality improvement. Understanding consistent themes present in successful management of water quality enhances our ability to better design management strategies that protect marine ecosystems, biodiversity, and human well-being. • Success in marine water quality improvement is scarce. • Six large-scale water quality management have succeeded, measured by improvements in coastal and marine biodiversity. • Strong legislation in place and nested levels of governance were present in all water quality management projects. • Stakeholder engagement and participation in water quality management plan was also a prevalent theme. • The common themes across successful case studies can inform new and ongoing water quality management initiatives.

The Role of Microplastics in Marine Pathogen Transmission: Retrospective Regression Analysis, Experimental Design, and Disease Modelling

Marine wildlife and aquaculture species can accumulate large amounts of marine microplastic debris (MMD) (<1 mm) carrying pathogens, thus threatening the health of marine ecosystems and posing a risk to food safety and human health. Here, we outline a theoretical three-perspective approach for studying the relationship between MMD and disease. First, we provide a framework for retrospective analysis of MMD and pathogen loads in marine animal tissues to assess the relationship between these and other environmental variables in order to decide whether a compound or pathogen should be considered an emerging substance or organism. Second, we describe an experimental design for testing the effects of a variety of microplastics on infection intensity in two model species (oysters and zebrafish). Finally, we create a theoretical susceptible–infected microplastic particle and pathogen transmission model for bivalves and fish. Overall, the experiments and models we propose will pave the way for future research designed to assess the role of MMD as a vector for marine and human pathogens. This multi-faceted approach needs to be an urgent priority of the EU Strategic Research Innovation Agenda for addressing marine disease challenges related to MMD.