Climate change alters fish community size-structure, requiring adaptive policy targets

Size‐based indicators are used worldwide in research that supports the management of commercially exploited wild fish populations, because of their responsiveness to fishing pressure. Observational and experimental data, however, have highlighted the deeply rooted links between fish size and environmental conditions that can drive additional, interannual changes in these indicators. Here, we have used biogeochemical and mechanistic niche modelling of commercially exploited demersal fish species to project time series to the end of the 21st century for one such indicator, the large fish indicator (LFI), under global CO2 emissions scenarios. Our modelling results, validated against survey data, suggest that the LFI's previously proposed policy target may be unachievable under future climate change. In turn, our results help to identify what may be achievable policy targets for demersal fish communities experiencing climate change. While fisheries modelling has grown as a science, climate change modelling is seldom used specifically to address policy aims. Studies such as this one can, however, enable a more sustainable exploitation of marine food resources under changes unmanageable by fisheries control. Indeed, such studies can be used to aid resilient policy target setting by taking into account climate‐driven effects on fish community size‐structure

Missing links in the study of solute and particle exchange between the sea floor and water column

Exchanges of solutes and solids between the sea floor and water column are a vital component of ecosystem functioning in marine habitats around the globe. This review explores particle and solute exchange processes, the different mechanisms through which they interact at the ecosystem level, as well as their interdependencies. Solute and particle exchange processes are highly dependent on the characteristics of the environment within which they takes place. Exchange is driven directly by a number of factors, such as currents, granulometry, nutrient, and matter inputs, as well as living organisms. In turn, the occurrence of exchanges can influence adjacent environments and organisms. Major gaps in the present knowledge include the temporal and spatial variation in many of the processes driving benthic/pelagic exchange processes and the variability in the relative importance of individual processes caused by this variation. Furthermore, the accurate assessment of some anthropogenic impacts is deemed questionable due to a lack of baseline data and long-term effects of anthropogenic actions are often unknown. It is suggested that future research should be transdisciplinary and at ecosystem level wherever possible and that baseline surveys should be implemented and long-term observatories established to fill the current knowledge gaps

A small-scale, portable method for extracting microplastics from marine sediments

• Cheap, effective method for microplastic extraction from sediments. • High, reproducible recovery rates - 95.8%. • Comparison of three commonly used floatation media. • Zinc chloride (1.5 g cm−3) deemed an effective floatation medium. • Method applied to environmental samples across a range of sediment types

Appreciating interconnectivity between habitats is key to Blue Carbon management

We welcome the recent synthesis by Howard et al. (2017), which drew attention to the role of marine systems and natural carbon sequestration in the oceans as a fundamental aspect of climate-change mitigation. The importance of long-term carbon storage in marine habitats (ie “blue carbon”) is rapidly gaining recognition and is increasingly a focus of national and international attempts to mitigate rising atmospheric emissions of carbon dioxide. However, effectively managing blue carbon requires an appreciation of the inherent connectivity between marine populations and habitats. More so than their terrestrial counterparts, marine ecosystems are “open”, with high rates of transfer of energy, matter, genetic material, and species across regional seascapes (Kinlan and Gaines 2003). We suggest that policy frameworks, and the science underpinning them, should focus not only on carbon sink habitats but also on carbon source habitats, which play critical roles in marine carbon cycling and natural carbon sequestration in the oceans

Long-term exposure to elevated pCO2 more than warming modifies juvenile shell growth patterns in a temperate gastropod

Co-occurring global change drivers, such as ocean warming and acidification, can have large impacts on the behaviour, physiology, and health of marine organisms. However, whilst early-life stages are thought to be most sensitive to these impacts, little is known about the individual level processes by which such impacts take place. Here, using mesocosm experiments simulating ocean warming (OW) and ocean acidification (OA) conditions expected for the NE Atlantic region by 2100 using a variety of treatments of elevated pCO2 and temperature. We investigated their impacts on bio-mineralization, microstructure, and ontogeny of Nucella lapillus (L.) juveniles, a common gastropod predator that exerts important top-down controls on biodiversity patterns in temperate rocky shores. The shell of juveniles hatched in mesocosms during a 14 month long experiment were analysed using micro-CT scanning, 3D geometric morphometrics, and scanning-electron microscopy. Elevated temperature and age determined shell density, length, width, thickness, elemental chemistry, shape, and shell surface damages. However, co-occurring elevated pCO2 modified the impacts of elevated temperature, in line with expected changes in carbonate chemistry driven by temperature. Young N. lapillus from acidified treatments had weaker shells and were therefore expected to be more vulnerable to predation and environmental pressures such as wave action. However, in some instances, the effects of both higher CO2 content and elevated temperature appeared to have reversed as the individuals aged. This study suggests that compensatory development may therefore occur, and that expected increases in juvenile mortality under OA and OW may be counteracted, to some degree, by high plasticity in shell formation in this species. This feature may prove advantageous for N. lapillus community dynamics in near-future conditions

Microplastics alter feeding selectivity and faecal density in the copepod, Calanus helgolandicus

Microplastics (1 μm–5 mm) are a ubiquitous marine contaminant of global concern, ingested by a wide range of marine taxa. Copepods are a key component of marine food webs, providing a source of food for higher trophic levels, and playing an important role in marine nutrient cycling. Microplastic ingestion has been documented in copepods, but knowledge gaps remain over how this affects feeding preference and faecal density. Here, we use exposure studies incorporating algal prey and microplastics of varying sizes and shapes at a concentration of 100 microplastics mL−1 to show: (1) prey selection by the copepod Calanus helgolandicus was affected by the size and shape of microplastics and algae they were exposed to; Exposure to nylon fibres resulted in a 6% decrease in ingestion of similar shaped chain-forming algae, whilst exposure to nylon fragments led to an 8% decrease in ingestion of a unicellular algae that were similar in shape and size. (2) Ingestion of microplastics with different densities altered the sinking rates of faecal pellets. Faeces containing low-density polyethylene sank significantly more slowly than controls, whilst sinking rates increased when faeces contained high-density polyethylene terephthalate. These results suggest that C. helgolandicus avoid ingesting algae that are similar in size and/or shape to the microplastic particles they are exposed to, potentially in a bid to avoid consuming the plastic

A conceptual framework for assessing the ecosystem service of waste remediation: In the marine environment

In the marine environment, the ecosystem service of Waste Remediation (WR) enables humans to utilise the natural functioning of ecosystems to process and detoxify a large number of waste products and therefore avoid harmful effects on human wellbeing and the environment. Despite its importance, to date the service has been poorly defined in ecosystem service classifications and rarely valued or quantified. This paper therefore addresses a gap in the literature regarding the application of this key, but poorly documented ecosystem service. Here we present a conceptual framework by which the ecosystem service of WR can be identified, placed into context within current ecosystem classifications and assessed. A working definition of WR in the marine context is provided as is an overview of the different waste types entering the marine environment. Processes influencing the provisioning of WR are categorised according to how they influence the input, cycling/detoxification, sequestration/storage and export of wastes, with operational indicators for these processes discussed. Finally a discussion of the wider significance of the service of WR is given, including how we can maximise the benefits received from it. It is noted that many methods used in the assessment, quantification and valuation of the service are currently hampered due to the benefits of the service often not being tangible assets set in the market and/or due to a lack of information surrounding the processes providing the service. Conclusively this review finds WR to be an under researched but critically important ecosystem service and provides a first attempt at providing operational guidance on the long term sustainable use of WR in marine environments

What are the local impacts of energy systems on marine ecosystem services: a systematic map protocol

Background: Increasing concentrations of atmospheric greenhouse gases (GHG) and its impact on the climate has resulted in many international governments committing to reduce their GHG emissions. The UK, for example, has committed to reducing its carbon emissions by 80% by 2050. Suggested ways of reaching such a target are to increase dependency on offshore wind, offshore gas and nuclear. It is not clear, however, how the construction, operation and decommissioning of these energy systems will impact marine ecosystem services, i.e. the services obtained by people from the natural environment such as food provisioning, climate regulation and cultural inspiration. Research on ecosystem service impacts associated with offshore energy technologies is still in its infancy. The objective of this review is to bolster the evidence base by firstly, recording and describing the impacts of energy technologies at the marine ecosystems and human level in a consistent and transparent way; secondly, to translate these ecosystem and human impacts into ecosystem service impacts by using a framework to ensure consistency and comparability. The output of this process will be an objective synthesis of ecosystem service impacts comprehensive enough to cover different types of energy under the same analysis and to assist in informing how the provision of ecosystem services will change under different energy provisioning scenarios. Methods: Relevant studies will be sourced using publication databases and selected using a set of selection criteria including the identification of: (i) relevant subject populations such as marine and coastal species, marine habitat types and the general public; (ii) relevant exposure types including offshore wind farms, offshore oil and gas platforms and offshore structures connected with nuclear; (iii) relevant outcomes including changes in species structure and diversity; changes in benthic, demersal and pelagic habitats; and changes in cultural services. The impacts will be synthesised and described using a systematic map. To translate these findings into ecosystem service impacts, the Common International Classification of Ecosystem Services (CICES) and Millennium Ecosystem Assessment (MEA) frameworks are used and a detailed description of the steps taken provided to ensure transparency and replicability

Modelling impacts and recovery in benthic communities exposed to localised high CO2

Regulations pertaining to carbon dioxide capture with offshore storage (CCS) require an understanding of the potential localised environmental impacts and demonstrably suitable monitoring practices. This study uses a marine ecosystem model to examine a comprehensive range of hypothetical CO2 leakage scenarios, quantifying both impact and recovery time within the benthic system. Whilst significant mortalities and long recovery times were projected for the larger and longer term scenarios, shorter-term or low level exposures lead to reduced projected impacts. This suggests that efficient monitoring and leak mitigation strategies, coupled with appropriate selection of storage sites can effectively limit concerns regarding localised environmental impacts from CCS. The feedbacks and interactions between physiological and ecological responses simulated reveal that benthic responses to CO2 leakage could be complex. This type of modelling investigation can aid the understanding of impact potential, the role of benthic community recovery and inform the design of baseline and monitoring surveys

MARLAN: Plymouth Marine Laboratory’s Marine Artificial Light at Night Research Facility

This document provides technical guidance about, and design description of, the Plymouth Marine Laboratory’s Marine Artificial Light At Night Research Facility (MARLAN), a bespoke seawater aquarium facility dedicated to the study of light pollution in the marine environment