Plastics and microplastics (MPs) are emerging pollutants which have become a global environmental issue. They are abundant in oceanic and terrestrial environments, undergoing bioaccumulation and trophic transfer and potentially harming the entirety of mankind. Microplastics in the environment may be transferred to humans via different pathways, such as dietary intake and inhalation. This chapter summarizes the occurrences of MPs in seawaters, sediments, freshwaters, bivalves, and atmospheric fallouts. Generally, the spatial distribution of plastics and MPs in seawaters suggested that higher levels were found in areas which are closer to lands. Similarly, high levels of MPs in freshwaters, sediments, and aquatic organisms were associated with intensified human activities. The occurrences of MPs in bivalves from around the globe suggested a potential human exposure via dietary intake. Moreover, trophic transfer of MPs under controlled conditions suggested that MPs can be transferred to organisms at higher trophic levels. Plastics and MPs were found in atmospheric fallouts from urban, suburban, and remote mountain sites, suggesting the potential for long-range atmospheric transport of MPs. This chapter provides the reader with a snapshot of the plastic and MP pollution in the global oceans and planetary boundaries. Future studies are desirable for examining the exposure pathways, mechanisms of toxicity, and possible health effects.
Pollution and Marine Debris
Since the last Arctic Monitoring and Assessment Programme (AMAP) effort to review biological effects of the exposure to organohalogen compounds (OHCs) in Arctic biota, there has been a considerable number of new Arctic effect studies. Here, we provide an update on the state of the knowledge of OHC, and also include mercury, exposure and/or associated effects in key Arctic marine and terrestrial mammal and bird species as well as in fish by reviewing the literature published since the last AMAP assessment in 2010. We aimed at updating the knowledge of how single but also combined health effects are or can be associated to the exposure to single compounds or mixtures of OHCs. We also focussed on assessing both potential individual as well as population health impacts using population-specific exposure data post 2000. We have identified quantifiable effects on vitamin metabolism, immune functioning, thyroid and steroid hormone balances, oxidative stress, tissue pathology, and reproduction. As with the previous assessment, a wealth of documentation is available for biological effects in marine mammals and seabirds, and sentinel species such as the sledge dog and Arctic fox, but information for terrestrial vertebrates and fish remain scarce. While hormones and vitamins are thoroughly studied, oxidative stress, immunotoxic and reproductive effects need further investigation. Depending on the species and population, some OHCs and mercury tissue contaminant burdens post 2000 were observed to be high enough to exceed putative risk threshold levels that have been previously estimated for non-target species or populations outside the Arctic. In this assessment, we made use of risk quotient calculations to summarize the cumulative effects of different OHC classes and mercury for which critical body burdens can be estimated for wildlife across the Arctic. As our ultimate goal is to better predict or estimate the effects of OHCs and mercury in Arctic wildlife at the individual, population and ecosystem level, there remain numerous knowledge gaps on the biological effects of exposure in Arctic biota. These knowledge gaps include the establishment of concentration thresholds for individual compounds as well as for realistic cocktail mixtures that in fact indicate biologically relevant, and not statistically determined, health effects for specific species and subpopulations. Finally, we provide future perspectives on understanding Arctic wildlife health using new in vivo, in vitro, and in silico techniques, and provide case studies on multiple stressors to show that future assessments would benefit from significant efforts to integrate human health, wildlife ecology and retrospective and forecasting aspects into assessing the biological effects of OHC and mercury exposure in Arctic wildlife and fish.
Sunscreens can induce ecotoxicological effects and may cause significant impacts in the aquatic ecosystem. In spite of that, ecotoxicological responses of key marine species to sunscreens are scarcely studied in Mediterranean ecosystems, and literature data are lacking. Furthermore, changes in water salinity induced by global warming could significantly affect the ecotoxicological responses of marine species exposed to sunscreens. This research focuses on the evaluation of ecotoxicological responses of Phaeodactylum tricornutum (algae), Corophium orientalis(macroinvertebrate), and Paracentrotus lividus (echinoderms) exposed to sunscreens, which include both chemical- and physical-based. This study, also, analyzes the changes in ecotoxicological responses of the tested species linked to increase in salinity. Results showed that salinity stress significantly increases the toxicity of sunscreens on the tested marine species. Physical-based sunscreens resulted in more toxicity at higher salinity than chemical-based ones toward C. orientalis and P. tricornutum. This study evidenced that risk classifications of sunscreens recorded under standard salinity conditions could be significantly different from that recorded in the natural environment under salinity stress. The collection of a complete dataset on the ecotoxicological effects of sunscreens on marine species tested under salinity stress could be useful to correctly weigh risks for the marine environment under possible future ecological changing scenarios following the global changing driver.
In recent years, with the rapid development of China's economy, the coastal environment is facing large pressure. However, the coastal environment pollution has not attracted much attention as air pollution and land water pollution. Based on the data on economic development and marine ecosystem environmental pollution which collected from the National Bureau of Statistics and China's coastal marine environmental monitoring, the paper analyzes the overall coastal ecosystem environment pollution in China as well as the four sea areas the Bohai Sea, the Yellow Sea, the East China Sea and South China Sea. The paper finds that the coastal marine environment pollution differ in different sea areas, taking the seawater quality, over-standard pollutants, water quality of rivers entering seas and coastal marine environmental disasters, such as red tide as index. Couple of policy suggestions provided based on research findings.
The Caribbean Sea provides significant ecosystem services to the livelihood and well-being of countries in the region. Protection of the marine ecosystem requires policy on coastal water quality that considers ecologically-relevant thresholds and has a scientific foundation linking land-based discharges with seawater quality. This study demonstrates a practical method for setting local-scale coastal water quality targets by applying this approach to Cartagena Bay, Colombia, and setting targets for end-of-river suspended sediment loads to mitigate offshore coral reef turbidity. This approach considers reef thresholds for suspended sediments and applies a field-calibrated 3D hydrodynamic-water quality model (MOHID) to link the marine thresholds to fluvial loads. Monitoring data showed that suspended sediments were consistently above the coral reef ecosystem threshold of 10 mg/l, and the model adequately reproduced field observations. It was shown that ecosystem thresholds could be maintained within the extent of the bay by reducing suspended sediment loads in the Dique Canal from current load estimates of 6.4 × 103 t/d (rainy season) and 4.3 × 103 t/d (transitional season) to target loads of 500–700 t/d, representing reductions of ~80–90%. These substantial reductions reflect ongoing issues in the Magdalena watershed which has experienced severe erosional conditions and intense deforestation over the past four decades. The presented method is practical for countries without access to long-term datasets, and could be applied to other parameters or discharge types. The method is particularly beneficial for developing site-specific targets, which are needed considering the natural and anthropogenic variability between different coastal zones and water bodies.
Black consumer plastics are often contaminated with hazardous chemicals because of technological constraints on sorting dark plastic during recycling of municipal waste coupled with the convenience of waste electrical and electronic equipment (WEEE) as a secondary source of black plastic. In this study, samples of beached plastic litter (n = 524) from southwest England were categorised according to origin, appearance and colour (black versus non-black) before being analysed by x-ray fluorescence (XRF) spectrometry for elements that are characteristic of EEE. The small number of items of WEEE retrieved (n = 36) were largely restricted to wiring insulation and constructed of lead-stabilised polyvinyl chloride (PVC). Among the remaining samples, Br, Cd, Cr and Pb were commonly detected in all categories of black plastics (n = 264) with maximum concentrations of 43,400 mg kg−1, 2080 mg kg−1, 662 mg kg−1 and 23,800 mg kg−1, respectively. Moreover, concentrations of Br were significantly correlated with concentrations of the flame retardant synergist, Sb (n = 22), and 35 samples were potentially non-compliant with regard to limits defined by the Restriction of Hazardous Substances Directive. For plastics of other colours (n = 224), Br and Pb were detected in fewer samples and Br was co-associated with Sb in only two cases, with occasional high concentrations Cd, Cr and Pb largely attributed to the historical use of cadmium sulphide and lead chromate pigments. An avian physiologically-based extraction test applied to selected samples cut to mm-dimensions revealed bioaccessibilities ranging from <0.1% for Cr in a green fragment to about 2.4% (or about 580 mg kg−1) for Pb in black PVC. The recycling of WEEE into consumer, industrial and marine (e.g. fishing) plastics that are mainly coloured black appears to be an important vehicle for the introduction of hazardous chemicals into the environment and a source of their exposure to wildlife.
Plastic pollution is a major ecological catastrophe that endangers vulnerable species. Small plastic fragments and filaments enter the food web in the ocean threatening marine species health. Here microplastics between 0.5 and 5 mm were quantified from eight beaches of southwest Bay of Biscay (Spain) within Natura-2000 Special Protection Areas for birds. Sand samples were taken using a randomized quadrat-based protocol. Between 145 and 382 particles per kg of dry sand were found, which is relatively high in comparison with other European beaches. Microfibers were more abundant than microplastics. PERMANOVA revealed a significant effect of the beach location (inside versus outside the estuary). Open beaches contained a higher microplastic density than sheltered ones suggesting that many beached microplastics come from the ocean. Birds are at risk in the studied protected spaces as revealed from high concentrations of fibres in depositions of European shag and gulls.
In this study, a commercial CFD code, STARCCM+, is used to analyze the performance of a passive ocean plastic collector under rough sea conditions. The CFD code was first validated by comparing with data from a scaled model experiment conducted in the towing water tank in National Cheng Kung University, and it was proven to return accurate catch rate. Then thirty-eight test cases were setup to investigate the effects of four different parameters, namely, ocean current speed, wave height, wave length, and plastic density, on the plastic collector's catch rate, which is the percentage of incoming plastic debris intercepted by the plastic collector. It was found that the parameters of wave length and plastic density posed very little effect on catch rate. In contrast, the effects of the other two parameters were significant. Two important thresholds were found, and they were ocean current speed of 2.5 ms−1 and wave height of 0.4 m. The catch rate remained at high level until these thresholds were reached. The information found in this study is invaluable for the design of a practical passive ocean plastic collector.
Plastic debris is widespread and ubiquitous in the marine environment and ingestion of plastic debris by marine organisms is well-documented. Viscera and gills of 110 individual marine fish from 11 commercial fish species collected from the marine fish market were examined for presence of plastic debris. Isolated particles were characterized by Raman spectroscopy, and elemental analysis was assessed using energy-dispersive X-ray spectroscopy (EDX). Nine (of 11) species contained plastic debris. Out of 56 isolated particles, 76.8% were plastic polymers, 5.4% were pigments, and 17.8% were unidentified. Extracted plastic particle sizes ranged from 200 to 34,900 μm (mean = 2600 μm ±7.0 SD). Hazardous material was undetected using inorganic elemental analysis of extracted plastic debris and pigment particles. The highest number of ingested microplastics was measured in Eleutheronema tridactylumand Clarias gariepinus, suggesting their potential as indicator species to monitor and study trends of ingested marine litter.
It is critical to evaluate the in situ effects of multiple stressors on coastal community dynamics, especially those communities harboring high diversity such as coral reefs, in order to understand the resilience of these ecosystems, prepare coastal management for future scenarios, and aid in prioritizing restoration efforts. In this in situstudy, at 2 sites with gradients of submarine groundwater discharge (SGD), a suite of physical parameters (wave exposure index, wind exposure index, and depth) and an all-encompassing SGD chemical parameter (average nitrate + nitrite daily load) were measured along spatially cohesive and temporally relevant scales and used to model macroalgal growth, biomass, and diversity in Maunalua Bay, Hawai‘i. We showed that (1) species-specific macroalgal biomass is significantly related to SGD and one of the 2 exposure indices (i.e. wind exposure or wave exposure), (2) SGD and wave exposure play key roles in species-specific growth rates, and (3) SGD supports low diversity and increased biomass of species that can tolerate the biogeochemistry associated with SGD. Our work suggests that SGD and local hydrodynamics predict local variation in macroalgal growth, biomass, and diversity in tropical reefs.