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The brackish water mytilid mussel Mytella strigata (Hanley, 1843) is recorded for the first time in July 2022 in Hong Kong. Native to Central and South America, the first reports of M. strigata in Asia were recorded in the Philippines, with subsequent reports from India, Singapore, Thailand, and Taiwan. Here, the mussels were found attached to hard, artificial substrates throughout the Tolo and Victoria Harbours in Hong Kong, with 13 accessible specimens collected and more inaccessible specimens observed. Mytella strigata tended to co-occurr with a previously recognised introduced mussel, Xenostrobus securis (Lamarck, 1819). The largest individual observed had a shell length of ~ 54 mm and the smallest ~ 22 mm, and all specimens were found in brackish water areas. Externally, the shells were generally black with a green tinge and internal surfaces were iridescent purple. Two small teeth on the internal anteroventeral margin, typical of Mytella, were observed. With the recent introduction of M. strigata throughout Asia, future research is required to document the full extent of the population within Hong Kong, as well as developing a greater understanding of the ecological and economic impacts of this highly invasive species. [ABSTRACT FROM AUTHOR]

Plastics are one of the most topical pollutants occurring in our ocean. Given concern regarding the impacts of both macro- and micro-plastics on environmental and human well-being, a range of management approaches are required. Key in the management of microplastics will be curative measures that facilitate the removal of legacy plastics from the environment as, without their removal, impacts will continue for centuries. While a strong focus has been placed on technical, engineered solutions to plastic removal, many of these techniques are unsuitable for microplastics. Therefore, here we argue for the exploration of nature-based solutions to such issues. As a case study, we combine information available in the published academic literature with experimental results from a pilot study to highlight the potential for filter-feeding organisms - specifically mussels - to remove microplastics from the water column by transferring them into biodeposits. Such biodeposits have the potential to be transported to other parts of the system (i.e., benthic regions), or collected and removed from the environment. While initial results indicate that such approaches are promising for microplastic removal from water sources, there are a number of areas that still need investigation before widespread application of such an approach could be adopted. Key knowledge gaps include identification of the appropriate methods to be used and assessment of unintended consequences including potential impacts of microplastics on benthic organisms. We argue that there is a need for ongoing funding and policy support for the development and application of such nature-based solutions targeting legacy plastic pollution., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Predator-prey interactions are important in shaping ecosystem structure. Consequently, impacts of accelerating global warming on predators will have notable implications. Effects are likely to be particularly marked for tropical organisms which are anticipated to be sensitive to further thermal stress. Here, we investigated effects of future ocean warming on the predatory dogwhelk Reishia clavigera and its predation of Saccostrea cucullata. Mortality of the predators rapidly increased under the extreme elevated temperature, while those exposed to moderate elevated temperature displayed similar mortality as the ambient. Predators that survived moderate temperature increases altered their oxygen consumption patterns, increased average feeding rates, and functional responses, although condition index and energy reserves were unchanged. Overall, we show extreme ocean warming scenarios can remove predators and their consumption of prey from an ecosystem, whereas moderate warming can intensify predator-prey interactions. Such temperature-dependent alterations to predator-prey interactions would lead to fundamental changes of ecosystem structure as the ocean warms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Tropical regions contain ecologically and socio-economically important habitats, and are home to about 3.8 billion people, many of which directly depend on tropical coastal waters for their well-being. At the basis of these ecosystems are biogeochemical processes. Climate change is expected to have a greater impact in the tropics compared to temperate regions because of the relatively stable environmental conditions found there. However, it was surprising to find only 660 research articles published focusing on the impact of climate change on the biogeochemistry of coastal tropical waters compared to 4823 for temperate waters. In this perspective, we highlight important topics in need of further research. Specifically, we suggest that in tropical regions compared to temperate counterparts climate change stressors will be experienced differently, that organisms have a lower acclimation capacity, and that long-term baseline biogeochemical datasets useful for quantifying future changes are lacking. The low number of research papers on the impacts of climate change in coastal tropical regions is likely due to a mix of reasons including limited resources for research and limited number of long time series in many developing tropical countries. Finally, we propose some action points that we hope will stimulate more studies in tropical coastal waters., (© 2023 John Wiley & Sons Ltd.)

Microplastics are ubiquitous in the marine environment, and their uptake by many organisms has been well documented. Concern about increasing plastic waste in ecosystems and organisms has led to the production of biodegradable alternatives. However, long breakdown times of biodegradable plastics in natural environments mean they still have the potential to induce ecological impacts. The impacts of microplastics on organisms remain unclear, especially as many experimental microplastic exposures employ particle concentrations orders of magnitude greater than those found in natural ecosystems. Here, we exposed the ecosystem engineer, the Asian green mussel Perna viridis, to non-biodegradable and biodegradable microplastics at two environmentally relevant concentrations (~17-20 particles L -1 and ~ 135-140 particles L -1 ). After four weeks of exposure, there were no significant effects of microplastic type or concentration on the mortality, oxygen consumption rate, clearance rate, or condition index of P. viridis. With the increasing body of microplastic literature, future exposure studies considering biotic effects should make efforts to employ environmentally relevant concentrations. Further, we suggest that, while a high-profile threat to ecosystems, investigating the effects of microplastics on ecosystems should be conducted alongside, and not draw focus away from, other major threats such as climate change., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)