Phytoplankton as indicators for eutrophication in Europe's regional seas

Eutrophication of marine and coastal waters is a growing concern throughout Europe's regional seas and an historical problem in the Black Sea and regions of the North-East Atlantic, particularly the North Sea. As the base of the marine pelagic food web, phytoplankton are sensitive indicators of environmental change and therefore may be used as indicators of eutrophication for the monitoring, management and mitigation of the effects of nutrient loading on coastal and marine ecosystems. However, due to the interactive effects of climate and eutrophication, it can be difficult to separate the climatedriven response of phytoplankton from changes induced by excess nutrients. Therefore, the aim of this work is to separate these two signals in order to explore eutrophication effects. Without historical knowledge of 'pristine' or unimpacted ecosystem states it is difficult to identify and assess the severity and magnitude of change. Even w~re spatially and temporally comprehensive ecological datasets are available, equivalent nutrient timeseries are rare and a method of linking phytoplankton dynamics to eutrophication is required. Because open sea ecosystems are less impacted by anthropogenic nutrients than those near shore, offshore regions may be used as reference areas in comparison with coastal systems to investigate the effects of nutrient loading. Changes observed solely in coastal systems are mo$1likely a result of local processes (such as eutrophication) while those observed in both open sea and coastal areas are probably a response to large-scale drivers (such as climate). Therefore the comparison of coastal and open sea data may reveal different (or similar) patterns ofchange in phytoplankton indicators. Throughout most of the North-East Atlantic climate appears to override the effects of nutrients on phytoplankton dynamics, although the two drivers have been found to have synergistic effects resulting in increasing chlorophyll levels in the coastal North Sea. Additionally, the 1980s North-East Atlantic regime shift is clearly visible in coastal and open sea chlorophyll concentrations and diatom and' dinoflagellate abundances, demonstrating the sensitivity of phytoplankton as indicators at both the biomass and functional group scales. In the Black Sea, an observed decrease in chlorophyll appears to be at least partially a result of changes in climate and is not solely attributable to the 'recovery' of the Black Sea ecosystem. Black Sea chlorophyll has also undergone a possible recent (2002) regime shift, although its significance is difficult to determine due to the short time-series of chlorophyll data available. . The successful use of phytoplankton as indicators of eutrophication in these two disparate sea regions at two different ecological scales suggests that the method of comparing coastal and open sea phytoplankton data could be applied to other European seas as a means of distinguishing betWeen the effects of climate and eutrophication.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Visions for the North Sea: The Societal Dilemma Behind Specifying Good Environmental Status.

We augment discussions about the Good Environmental Status of the North Sea by developing two extreme visions and assessing their societal benefits. One vision (‘Then’) assumes restoration of benthic functioning; we contend that trawling had already degraded the southern North Sea a century ago. Available information is used to speculate about benthic functioning in a relatively undisturbed southern North Sea. The second vision (‘Now’) draws on recent benthic functioning. The supply of five ecosystem services, supported by benthic functioning, is discussed. ‘Then’ offers confidence in the sustainable supply of diverse services but restoration of past function is uncertain and likely to be paired with costs, notably trawling restraints. ‘Now’ delivers known and valued services but sustained delivery is threatened by, for example, climate change. We do not advocate either vision. Our purpose is to stimulate debate about what society wants, and might receive, from the future southern North Sea

The Continuous Plankton Recorder survey: how can long-term phytoplankton datasets contribute to the assessment of Good Environmental Status?

Phytoplankton are crucial to marine ecosystem functioning and are important indicators of environmental change. Phytoplankton data are also essential for informing management and policy, particularly in supporting the new generation of marine legislative drivers, which take a holistic ecosystem approach to management. The Marine Strategy Framework Directive (MSFD) seeks to achieve Good Environmental Status (GES) of European seas through the implementation of such a management approach. This is a regional scale directive which recognises the importance of plankton communities in marine ecosystems; plankton data at the appropriate spatial, temporal and taxonomic scales are therefore required for implementation. The Continuous Plankton Recorder (CPR) survey is a multidecadal, North Atlantic–basin scale programme which routinely records approximately 300 phytoplankton taxa. Because of these attributes, the survey plays a key role in the implementation of the MSFD and the assessment of GES in the Northeast Atlantic region. This paper addresses the role of the CPR's phytoplankton time-series in delivering GES through the development and informing of MSFD indicators, the setting of targets against a background of climate change and the provision of supporting information used to interpret change in non-plankton indicators. We also discuss CPR data in the context of other phytoplankton data types that may contribute to GES, as well as explore future possibilities for the use of new and innovative applications of CPR phytoplankton datasets in delivering GES. Efforts must be made to preserve long-term time series, such as the CPR, which supply vital ecological information used to informed evidence-based environmental policy

mNCEA policy brief - Plenty more fish in the sea? Counting the cost of climate change on marine Natural Capital

This policy brief describes how predicted changes in productivity across the Atlantic will impact the amount of fish that the marine environment can support. This is bound to have important implications for marine food webs and our continued sustainable use of marine resources. Plankton form the foundation of commercially-valuable food chains to fish • Warming, stratification and reduced nutrient supply has already reduced plankton stocks • Reduced phytoplankton also means less efficient food chains • Even a modest (16-26%) continued decline in phytoplankton will magnify into a 38-55% decline in harvestable fish across the north Atlantic • Hotspots of this future decline in fish are in present-day fishing grounds • This risk-mapping approach provides a forward look for spatial protection and management This project was funded by the Department for Environment, Food and Rural Affairs (Defra) as part of the marine arm of the Natural Capital and Ecosystem Assessment (NCEA) programme. The marine NCEA programme is leading the way in supporting Government ambition to integrate natural capital approaches into decision making for the marine environment. Find out more at https://www.gov.uk/government/publications/natural-capital-and-ecosystem-assessment-programm

Knowledge Gaps in Quantifying the Climate Change Response of Biological Storage of Carbon in the Ocean

The ocean is responsible for taking up approximately 25% of anthropogenic CO2 emissions and stores >50 times more carbon than the atmosphere. Biological processes in the ocean play a key role, maintaining atmospheric CO2 levels approximately 200 ppm lower than they would otherwise be. The ocean's ability to take up and store CO2 is sensitive to climate change, however the key biological processes that contribute to ocean carbon storage are uncertain, as are how those processes will respond to, and feedback on, climate change. As a result, biogeochemical models vary widely in their representation of relevant processes, driving large uncertainties in the projections of future ocean carbon storage. This review identifies key biological processes that affect how ocean carbon storage may change in the future in three thematic areas: biological contributions to alkalinity, net primary production, and interior respiration. We undertook a review of the existing literature to identify processes with high importance in influencing the future biologically-mediated storage of carbon in the ocean, and prioritized processes on the basis of both an expert assessment and a community survey. Highly ranked processes in both the expert assessment and survey were: for alkalinity—high level understanding of calcium carbonate production; for primary production—resource limitation of growth, zooplankton processes and phytoplankton loss processes; for respiration—microbial solubilization, particle characteristics and particle type. The analysis presented here is designed to support future field or laboratory experiments targeting new process understanding, and modeling efforts aimed at undertaking biogeochemical model development

Are plankton nets a thing of the past? An assessment of in situ imaging of zooplankton for large-scale ecosystem assessment and policy decision-making

Zooplankton are fundamental to aquatic ecosystem services such as carbon and nutrient cycling. Therefore, a robust evidence base of how zooplankton respond to changes in anthropogenic pressures, such as climate change and nutrient loading, is key to implementing effective policy-making and management measures. Currently, the data on which to base this evidence, such as long time-series and large-scale datasets of zooplankton distribution and community composition, are too sparse owing to practical limitations in traditional collection and analysis methods. The advance of in situ imaging technologies that can be deployed at large scales on autonomous platforms, coupled with artificial intelligence and machine learning (AI/ML) for image analysis, promises a solution. However, whether imaging could reasonably replace physical samples, and whether AI/ML can achieve a taxonomic resolution that scientists trust, is currently unclear. We here develop a roadmap for imaging and AI/ML for future zooplankton monitoring and research based on community consensus. To do so, we determined current perceptions of the zooplankton community with a focus on their experience and trust in the new technologies. Our survey revealed a clear consensus that traditional net sampling and taxonomy must be retained, yet imaging will play an important part in the future of zooplankton monitoring and research. A period of overlapping use of imaging and physical sampling systems is needed before imaging can reasonably replace physical sampling for widespread time-series zooplankton monitoring. In addition, comprehensive improvements in AI/ML and close collaboration between zooplankton researchers and AI developers are needed for AI-based taxonomy to be trusted and fully adopted. Encouragingly, the adoption of cutting-edge technologies for zooplankton research may provide a solution to maintaining the critical taxonomic and ecological knowledge needed for future zooplankton monitoring and robust evidence-based policy decision-making

Plankton as prevailing conditions: A surveillance role for plankton indicators within the Marine Strategy Framework Directive

https://www.sciencedirect.com/science/article/pii/S0308597X17306711The Marine Strategy Framework Directive (MSFD) uses an indicator-based approach for ecosystem assessment; indicators of the state of ecosystem components ('state indicators') are used to determine whether, or not, these ecosystem components are at ‘Good Environmental Status’ relative to prevailing oceanographic conditions. Here, it is illustrated that metrics of change in plankton communities frequently provide indications of changing prevailing oceanographic conditions. Plankton indicators can therefore provide useful diagnostic information when interpreting results and determining assessment outcomes for analyses of state indicators across the food web. They can also perform a strategic role in assessing these state indicators by influencing target setting and management measures. In addition to their primary role of assessing the state of pelagic habitats against direct anthropogenic pressures, plankton community indicators can therefore also fulfil an important 'surveillance' role for other state indicators used to formally assess biodiversity status under the MSFD

mNCEA policy brief - Mind the Gap – The need to continue long-term plankton monitoring

This policy brief argues that while it is beneficial to explore novel plankton survey technology, it is essential that we also continue to maintain traditional long-term monitoring programmes to generate the necessary information to inform policy. Changes in plankton have important implications for the continued provision of ecosystem services, including supporting commercial fish stocks, carbon sequestration, and oxygen production. Such changes can only be detected by studying long-term, consistent plankton datasets which are needed to understand the pressures driving these changes and how we can manage them. Traditional long-term plankton monitoring relies on light microscopy to identify and count plankton taxa, with methods fully supported by national / international QA/QC standards and providing high quality trusted data. Novel technologies, including imaging and molecular methods, offer more efficient means of collecting some types of plankton data, filling targeted knowledge gaps left by traditional monitoring. However, these data are often semi-quantitative, lacking in QA/QC standards, and/or in taxonomic resolution. While these technologies are developed it remains critical to maintain the continuity of traditional plankton monitoring to inform policy assessments of important changes in biodiversity. Losing these time-series, many of which span multiple decades, would impair our ability to detect important change in pelagic habitats, as most changes cannot be detected from short-term data. This would also accelerate the loss of taxonomic expertise, already under threat globally, diminishing our UK skill-base. Novel technologies should be explored in parallel to traditional monitoring, as they can provide complementary data to support policy assessments and research, however, it is important that we do not attempt to replace traditional monitoring with new technology before it has been thoroughly integrated into long-term monitoring programmes. This project was funded by the Department for Environment, Food and Rural Affairs (Defra) as part of the marine arm of the Natural Capital and Ecosystem Assessment (NCEA) programme. The marine NCEA programme is leading the way in supporting Government ambition to integrate natural capital approaches into decision making for the marine environment. Find out more at https://www.gov.uk/government/publications/natural-capital-and-ecosystem-assessment-programme