Plastic pollution and climate change have commonly been treated as two separate issues and sometimes are even seen as competing. Here we present an alternative view that these two issues are ...fundamentally linked. Primarily, we explore how plastic contributes to greenhouse gas (GHG) emissions from the beginning to the end of its life cycle. Secondly, we show that more extreme weather and floods associated with climate change, will exacerbate the spread of plastic in the natural environment. Finally, both issues occur throughout the marine environment, and we show that ecosystems and species can be particularly vulnerable to both, such as coral reefs that face disease spread through plastic pollution and climate-driven increased global bleaching events. A Web of Science search showed climate change and plastic pollution studies in the ocean are often siloed, with only 0.4% of the articles examining both stressors simultaneously. We also identified a lack of regional and industry-specific life cycle analysis data for comparisons in relative GHG contributions by materials and products. Overall, we suggest that rather than debate over the relative importance of climate change or marine plastic pollution, a more productive course would be to determine the linking factors between the two and identify solutions to combat both crises.
Display omitted
•Plastic pollution and climate change crises compete for public and policy attention.•These issues are linked, with some marine species and ecosystems vulnerable to both.•The root cause of both crises is the same, the overconsumption of finite resources.•Engagement in solving plastic pollution can increase action against climate change.•Integrated approaches include conserving blue carbon and a circular economy.
Microplastics (plastic < 5 mm in size) are now known to contaminate riverine systems but understanding about how their concentrations vary spatially and temporally is limited. This information is ...critical to help identify key sources and pathways of microplastic and develop management interventions. This study provides the first investigation of microplastic abundance, characteristics and temporal variation along the Ganges river; one of the most important catchments of South Asia. From 10 sites along a 2575 km stretch of the river, 20 water samples (3600 L in total) were filtered (60 samples each from pre- and post-monsoon season). Overall, 140 microplastic particles were identified, with higher concentrations found in the pre-monsoon (71.6%) than in post-monsoon (61.6%) samples. The majority of microplastics were fibres (91%) and the remaining were fragments (9%). We estimate that the Ganges, with the combined flows of the Brahmaputra and Meghna rivers (GBM), could release up to 1–3 billion (109) microplastics into the Bay of Bengal (north-eastern portion of the Indian Ocean) every day. This research provides the first step in understanding microplastic contamination in the Ganges and its contribution to the oceanic microplastic load.
Display omitted
•The microplastics identified were dominated by fibers (91%) and fragments (9%).•A greater number of microplastics were found pre-monsoon than post-monsoon•Microplastic concentrations increased from source to sea.•Approximately 1–3 billion microplastic pieces are discharged into the Bay of Bengal daily.
We estimate that up to 1–3 billion microplastics are released into the Bay of Bengal every day.
Seahorses (
Hippocampus spp.) are flagship species for many issues in marine conservation including overexploitation, incidental bycatch and habitat loss. Aquaculture has been proposed as one ...solution to address unsustainable trade for traditional medicine, aquarium fishes and curios. Here we review historical and current information on global seahorse aquaculture including characteristics of aquaculture operations, species in culture, contribution to international trade and technical issues associated with raising seahorses in captivity. We found that prior to the 1990s, seahorse aquaculture was plagued by problems with disease and feeding. In the late 1990s and early 2000s there was considerable expansion in the number and size of aquaculture operations and the number of species in culture. This was reflected in an increasing contribution of captive-bred seahorses to the aquarium trade but not in the larger traditional medicine market. Currently, the majority of seahorse aquaculture involves small-scale operations in developed countries, employing relatively few personnel and selling live animals for the home aquarium market. Although, there are still considerable technical problems with diseases and with breeding and raising some species, others are performing successfully in aquaculture. There are currently at least 13 species in commercial culture or under research for their culture potential. However, economic viability remains a concern to many current aquaculture operations including price competition with wild-caught animals. Large-scale aquaculture to supply the traditional medicine market or as a livelihood venture has not yet been demonstrated to be commercially viable, although it is being actively researched.
There is an increasing recognition that, although the climate change and biodiversity crises are fundamentally connected, they have been primarily addressed independently and a more integrated global ...approach is essential to tackle these two global challenges.
Nature‐based Solutions (NbS) are hailed as a pathway for promoting synergies between the climate change and biodiversity agendas. There are, however, uncertainties and difficulties associated with the implementation of NbS, while the evidence regarding their benefits for biodiversity remains limited.
We identify five key research areas where incomplete or poor information hinders the development of integrated biodiversity and climate solutions. These relate to refining our understanding of how climate change mitigation and adaptation approaches benefit biodiversity conservation; enhancing our ability to track and predict ecosystems on the move and/or facing collapse; improving our capacity to predict the impacts of climate change on the effectiveness of NbS; developing solutions that match the temporal, spatial and functional scale of the challenges; and developing a comprehensive and practical framework for assessing, and mitigating against, the risks posed by the implementation of NbS.
Policy implications. The Conference of the Parties (COP) for the United Nations Framework Convention on Climate Change (COP26) and the Convention on Biological Diversity (COP15) present a clear policy window for developing coherent policy frameworks that align targets across the nexus of biodiversity and climate change. This window should (a) address the substantial and chronic underfunding of global biodiversity conservation, (b) remove financial incentives that negatively impact biodiversity and/or climate change, (c) develop higher levels of integration between the biodiversity and climate change agendas, (d) agree on a monitoring framework that enables the standardised quantification and comparison of biodiversity gains associated with NbS across ecosystems and over time and (e) rethink environmental legislation to better support biodiversity conservation in times of rapid climatic change.
Policy implications. The Conference of the Parties (COP) for the United Nations Framework Convention on Climate Change (COP26) and the Convention on Biological Diversity (COP15) present a clear policy window for developing coherent policy frameworks that align targets across the nexus of biodiversity and climate change. This window should (a) address the substantial and chronic underfunding of global biodiversity conservation; (b) remove financial incentives that negatively impact biodiversity and/or climate change; (c) develop higher levels of integration between the biodiversity and climate change agendas; (d) agree on a monitoring framework that enables the standardised quantification and comparison of biodiversity gains associated with NbS across ecosystems and over time; and (e) rethink environmental legislation to better support biodiversity conservation in times of rapid climatic change.
Understanding the drivers of variability in the composition of fish assemblages across the Indo-Pacific region is crucial to support coral reef ecosystem resilience. Whilst numerous relationships and ...feedback mechanisms between the functional roles of coral reef fishes and reef benthic composition have been investigated, certain key groups, such as the herbivores, are widely suggested to maintain reefs in a coral-dominated state. Examining links between fishes and reef benthos is complicated by the interactions between natural processes, disturbance events and anthropogenic impacts, particularly fishing pressure. This study examined fish assemblages and associated benthic variables across five atolls within the Chagos Archipelago, where fishing pressure is largely absent, to better understand these relationships. We found high variability in fish assemblages among atolls and sites across the archipelago, especially for key groups such as a suite of grazer-detritivore surgeonfish, and the parrotfishes which varied in density over 40-fold between sites. Differences in fish assemblages were significantly associated with variable levels of both live and recently dead coral cover and rugosity. We suggest these results reflect differing coral recovery trajectories following coral bleaching events and a strong influence of 'bottom-up' control mechanisms on fish assemblages. Species level analyses revealed that Scarus niger, Acanthurus nigrofuscus and Chlorurus strongylocephalos were key species driving differences in fish assemblage structure. Clarifying the trophic roles of herbivorous and detritivorous reef fishes will require species-level studies, which also examine feeding behaviour, to fully understand their contribution in maintaining reef resilience to climate change and fishing impacts.
Rivers play a crucial role in transporting land-based plastic waste to the ocean, with the Ganges reported as the second largest contributing river of plastic pollution globally. To better quantify ...global plastic pollution transport and effectively reduce the sources and risks imposed, a clear understanding of the origin, transport, fate, and effects of riverine plastic debris is important. In this review paper, we discuss the current state of knowledge of plastic pollution in aquatic systems in Bangladesh and evaluate existing research gaps. Bangladesh has been recognized as an internationally significant nation in the plastic pollution crisis, but this paper identifies a major disconnect in knowledge, understanding and capacity to understand and address this critical environmental and public health issue. Here, we review all available scientific publications on plastic pollution in the freshwater and marine environment in Bangladesh and identify key research themes. A total of 24 studies relevant to plastic pollution were published from 2006 to 2019, of which 18 were selected for this study under the authors’ criteria. Nine focused on plastic pollution in the marine environment, eight focused on plastic waste generation and management and only one focused on the freshwater environment. We compared our findings with three other countries in the Global South with comparable per capita gross domestic product (GDP) and mismanaged waste, namely Cambodia, Kenya, and Tanzania, revealing similar knowledge gaps. This lack of research demonstrates a need for further work to monitor and model riverine plastic transport and examine the implications for aquatic organisms. This will facilitate the formulation of national management strategies aimed at addressing plastic pollution.
Display omitted
•Bangladesh was the first country in the world to ban plastic bags in 2002.•Plastic pollution in the diverse aquatic systems of Bangladesh is an emerging issue.•Bangladesh ranks 10th globally in terms of the levels of mismanaged plastic waste.•Our review finds plastic pollution studies in Bangladesh are very limited and skewed to overall observation/snapshot.•The River Ganges contributes the second largest amount of plastic to oceans, yet only one report exists.
Since the 1950s, industrial fisheries have expanded globally, as fishing vessels are required to travel further afield for fishing opportunities. Technological advancements and fishery subsidies have ...granted ever-increasing access to populations of sharks, tunas, billfishes, and other predators. Wilderness refuges, defined here as areas beyond the detectable range of human influence, are therefore increasingly rare. In order to achieve marine resources sustainability, large no-take marine protected areas (MPAs) with pelagic components are being implemented. However, such conservation efforts require knowledge of the critical habitats for predators, both across shallow reefs and the deeper ocean. Here, we fill this gap in knowledge across the Indo-Pacific by using 1,041 midwater baited videos to survey sharks and other pelagic predators such as rainbow runner (Elagatis bipinnulata), mahi-mahi (Coryphaena hippurus), and black marlin (Istiompax indica). We modeled three key predator community attributes: vertebrate species richness, mean maximum body size, and shark abundance as a function of geomorphology, environmental conditions, and human pressures. All attributes were primarily driven by geomorphology (35%-62% variance explained) and environmental conditions (14%-49%). While human pressures had no influence on species richness, both body size and shark abundance responded strongly to distance to human markets (12%-20%). Refuges were identified at more than 1,250 km from human markets for body size and for shark abundance. These refuges were identified as remote and shallow seabed features, such as seamounts, submerged banks, and reefs. Worryingly, hotpots of large individuals and of shark abundance are presently under-represented within no-take MPAs that aim to effectively protect marine predators, such as the British Indian Ocean Territory. Population recovery of predators is unlikely to occur without strategic placement and effective enforcement of large no-take MPAs in both coastal and remote locations.
Many drivers of mangrove forest loss operate over large scales and are most effectively addressed by policy interventions. However, conflicting or unclear policy objectives exist at multiple tiers of ...government, resulting in contradictory management decisions. To address this, we considered four approaches that are being used increasingly or could be deployed in Southeast Asia to ensure sustainable livelihoods and biodiversity conservation. First, a stronger incorporation of mangroves into marine protected areas (that currently focus largely on reefs and fisheries) could resolve some policy conflicts and ensure that mangroves do not fall through a policy gap. Second, examples of community and government comanagement exist, but achieving comanagement at scale will be important in reconciling stakeholders and addressing conflicting policy objectives. Third, private-sector initiatives could protect mangroves through existing and novel mechanisms in degraded areas and areas under future threat. Finally, payments for ecosystem services (PES) hold great promise for mangrove conservation, with carbon PES schemes (known as blue carbon) attracting attention. Although barriers remain to the implementation of PES, the potential to implement them at multiple scales exists. Closing the gap between mangrove conservation policies and action is crucial to the improved protection and management of this imperiled coastal ecosystem and to the livelihoods that depend on them. Muchos factores causantes de la pérdida de los manglares operan a grandes escalas y son abordados más efectivamente con las intervenciones políticas. Sin embargo, existen objetivos políticos conflictivos o confusos a múltiples niveles del gobierno, lo que resulta en decisiones de manejo contradictorias. Para abordar esto, consideramos 4 estrategias cuyo uso se ha incrementado o que podrían implementarse en el sureste asiático para asegurar medios de vida sustentables y la conservación de la biodiversidad. Primero, una mayor incorporación de los manglares dentro de las áreas marinas protegidas (AMP) (que actualmente se enfocan en su mayoría en los arrecifes y los sectores pesqueros) podría resolver algunos conflictos políticos y asegurar que los manglares no caigan en un vacío de políticas. Segundo, existen ejemplos de co-manejo entre las comunidades y el gobierno, pero lograrlo a escala será importante en la reconciliación de los accionistas y el acercamiento a los objetivos políticos conflictivos. Tercero, las iniciativas del sector privado podrían proteger a los manglares por medio de mecanismos existentes y novedosos en las áreas degradadas y en las áreas bajo amenaza a futuro. Finalmente, los pagos por servicios ambientales (PSA) son muy promisorios para la conservación de los manglares; los esquemas de carbono (conocidos como carbono azul) llaman la atención. Aunque permanecen barreras ante la implementación de los PSA, el potencial de implementarlos a escalas múltiples existe. Cerrar el vacío entre las políticas de conservación de los manglares y la acción es crucial para mejorar la protección y el manejo de estos ecosistemas costeros en riesgo y para los medios de vida que dependen de ellos.
Mangroves provide vital climate change mitigation and adaptation (CCMA) ecosystem services (ES), yet have suffered extensive tropics-wide declines. To mitigate losses, rehabilitation is high on the ...conservation agenda. However, the relative functionality and ES delivery of rehabilitated mangroves in different intertidal locations is rarely assessed. In a case study from Panay Island, Philippines, using field- and satellite-derived methods, we assess carbon stocks and coastal protection potential of rehabilitated low-intertidal seafront and mid- to upper-intertidal abandoned (leased) fishpond areas, against reference natural mangroves. Due to large sizes and appropriate site conditions, targeted abandoned fishpond reversion to former mangrove was found to be favourable for enhancing CCMA in the coastal zone. In a municipality-specific case study, 96.7% of abandoned fishponds with high potential for effective greenbelt rehabilitation had favourable tenure status for reversion. These findings have implications for coastal zone management in Asia in the face of climate change.
Display omitted
•The ecosystem services of rehabilitated and natural mangroves were assessed.•Low-intertidal and abandoned fishpond (FP) mangroves had good rehabilitation status.•Large rehabilitated FPs had higher carbon stocks and coastal protection potential.•A high level of pond abandonment was found in a municipality of dense aquaculture.•96.7% of FPs with high greenbelt rehabilitation potential had favourable tenure for reversion.
Rivers worldwide are now acting as major transport pathways for plastic pollution and discharge large quantities of waste into the ocean. Previous oceanographic modelling and current drifter data ...have been used to predict the movement and accumulation of plastic pollution in the marine environment, but our understanding of the transport and fate through riparian systems is still largely unknown. Here we undertook a proof of concept study by applying open source tracking technology (both GPS (Global Positing System) cellular networks and satellite technology), which have been successfully used in many animal movement studies, to track the movements of individual plastic litter items (500 ml PET (polyethylene terephthalate) drinks bottles) through the Ganges River system (known as the Ganga in India and the Padma and Meghna in Bangladesh, hereafter known as the Ganges) and the Bay of Bengal. Deployed tags were successfully tracked through the Ganges river system and into the Bay of Bengal marine system. The "bottle tags" were designed and built (e.g. shape, size, buoyancy) to replicate true movement patterns of a plastic bottle. The maximum distance tracked to date is 2845 km over a period of 94 days. We discuss lessons learnt from the development of these plastic litter tags, and outline how the potential widespread use of this open source technology has the ability to significantly increase understanding of the location of accumulation areas and the timing of large inputs of plastic pollution into the aquatic system. Furthermore, "bottle tags" may act as a powerful tool for stimulating social behaviour change, informing science-based policy, and as valuable educational outreach tools for public awareness.
PDF
