Modelling the effect of physical variability on the midwater chlorophyll maximum

A coupled model, employing turbulence closure physics and cell-quota threshold limitation biology, has been used to simulate the evolution of the vertical distribution of phytoplankton in a seasonally stratified shelf sea. Predictions are compared with observations from the North Sea. Variations in surface wind stress, which episodically weaken the thermocline barrier to nutrient input to the photic zone, are shown to make an important contribution to the formation of a midwater chlorophyll maximum in Summer

Sediment and water nutrients and microalgae in a coastal shallow lagoon, Ria Formosa (Portugal): Implications for the Water Framework Directive

Coastal shallow lagoons are considered to be highly important systems, which have specific biogeochemical cycles and characteristics. The assessment of sediment–water interfaces is essential to understand nutrient dynamics and to evaluate the vulnerability to eutrophication, especially in regions of restricted water exchange (RRE), such as the Ria Formosa, which have natural conditions for the accumulation of nutrients. Water samples were collected during the years of 2006 and 2007–08 for nutrients, chlorophyll a and dissolved oxygen. Sediment samples were also collected for pore water nutrients and microphytobenthic chlorophyll a. Measurements of temperature, salinity and photosynthetic active radiation were also taken. The lagoon salinity is affected by occasional strong rainfall events. From comparison with previous work, a decrease in the nitrogen concentration in the water column can be observed, which may indicate an improvement of the water quality. Pore water nutrient concentrations were significantly larger than in the water column. Sediment–water exchanges are considered to be the most important processes in nutrient dynamics of the lagoon. Benthic microalgal biomass was also large compared with that of the phytoplankton. It represents about 99% of the total microalgal chlorophyll biomass of the system. The lagoon also contains (discontinuous) meadows of intertidal seagrass, but we did not study these. Due to the importance of sediments, the standard monitoring plans required by the Water Framework Directive may fail to track changes in the nutrient conditions and the microalgal responses to them

Development of an optimal methodology for the extraction of microphytobenthic chlorophyll

Benthic microalgae are important primary producers in intertidal shallow systems. Their biomass can be estimated by the assessment of chlorophyll a concentration. A rapid and reliable method of measuring chlorophyll a is by spectrophotometer. There is however, no standard protocol for the analysis of benthic chlorophyll a. Although the most common solvent generally used is 90% acetone, some authors showed better results with methanol and ethanol. Some pre-treatments, such as the addition of fine inert granules or ultrasound bath, have also been suggested as factors that improve the extraction efficiency. Sediment samples were collected from two sites, muddy and sandy, located within Ria Formosa (Portugal). The aim of this work was to test the effectiveness of different pre-treatments in the extraction and to develop an optimal method for chlorophyll a extraction and analysis. Pre-treating samples did not yield any significant differences in chlorophyll a extracted. Treating sediments with acetone was found to yield higher concentrations of chlorophyll a, both for muddy and sandy sediments. Acetone was therefore found to be the best solvent for both sediment types, with 90% being the best strength for sandy and 80% the best for muddy sediments. These differences may be related to differences in the structure of the algal communities. Six hours of extraction was found to be sufficient, since after a six hour period the extraction efficiency did not improve

mNCEA policy brief - PELCAP: Natural Capital in Plankton & Pelagic Habitats

This policy brief fact sheet descries ecosystem services provided by pelagic habitats and a natural capital accounting of the the economic contribution pelagic habitats provide to the UK, as estimated by the Office of National Statistics. Plankton is vital for the functioning of marine ecosystems but is hard to value monetarily. According to the Office of National Statistics, plankton in UK waters provides services valued at up to 3.4 £ billion per year. PHEG members think that this is an underestimate. 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

Variability in the Canary Islands area of filament-eddy exchanges

24 pages, 17 figures, 1 table.-- Printed version published in issue Aug-Sep 2004.-- Issue title: "The Canary Islands Coastal Transition Zone - Upwelling, Eddies and Filaments".Full-text version available Open Access at: http://www.iim.csic.es/~barton/html/pdfs.htmlThe physical background to a suite of biological studies carried out in the Canary Islands upwelling region is presented. The area is unique in that the coastal transition zone is spanned by an archipelago of islands that shed mesoscale eddies of diameter 50–100 km into the alongshore flow. A recurrent filament and eddy system was sampled intensively to study the changing properties of waters as they are advected towards the open ocean in the filament and to investigate the exchanges between filament and eddies. The system was more complex than previously revealed. In early August, a single filament extended offshore from near Cape Juby. Two weeks later, a second filament had developed slightly farther north and extended offshore to merge with the first at 100 km offshore. The merged filament was entrained around a recurrent, topographically trapped cyclonic eddy and interacted with transient cyclonic and anticyclonic eddies shed from the island of Gran Canaria. Between the two filaments and the coast, a pair of counter-rotating eddies re-circulated water parcels for several weeks. Surface layer drifters cycled around this near-shore re-circulation several times before following convoluted paths that demonstrate significant exchange between continental shelf and open ocean waters.This work has been supported by the European Union (Project CANIGO, MAS3.CT96-0060). We thank the officers and crew of the BIO Hespérides, as well as the staff of the UTM (CSIC, Spain) for their invaluable help at sea. Analysis and writing up was supported by Catedra Patrimonial EX-010009 (Conacyt) while E.D.B. was on sabbatical leave at CICESE, Mexico.Peer reviewe

The interplay between economics, legislative power and social influence examined through a social-ecological framework for marine ecosystems services

In the last 15 years, conservation has shifted increasingly towards perspectives based on the instrumental value of nature, where what counts is what provides benefits to humans. The ecosystem services framework embraces this vision of nature through monetary valuation of the environment to correct market failures and government distortions that hinder efficient allocation of public goods, including goods and services provided by biodiversity and ecosystems. The popularity of this approach is reflected in different countries legislation; for instance, US, EU and UK have introduced economic criteria for comparing costs and benefits of environmental policies in protecting ecosystem services. From an operational perspective, the ecosystem services framework requires ecologists to estimate how the supply of services is affected by changes in the functionality and/or the extent of ecosystems; and economists to identify how changes in the supply affect the flow of direct and indirect benefits to people. However, this approach may be simplistic when faced with the complexity of social-ecological systems. We investigated this for three different marine services: assimilative capacity of waste, coastal defense and renewable energy. We find that economic valuation could provide efficient and fair allocations in the case of assimilative capacity, but leads to social clashes between outputs generated by cost benefit analysis and citizens’ expectation in the case of coastal defense. In the case of renewable energy, controversies can be generated by regulatory mechanisms that are not necessarily aligned with the interests of industry or important social groups. We conclude that there is a need to integrate perspectives arising from utilitarian allocation of resources with those involving legislation and communal values in order to reconcile conflicting interests and better sustain marine social-ecological systems

The “social” aspect of social-ecological systems : a critique of analytical frameworks and findings from a multisite study of coastal sustainability

The work described here was partly funded by the European Commission’s FP6 contract 036992.We evaluate whether society can adequately be conceptualized as a component of social-ecological systems, given social theory and the current outputs of systems-based research. A mounting critique from the social sciences posits that resilience theory has undertheorized social entities with the concept of social-ecological systems. We trace the way that use of the term has evolved, relating to social science theory. Scientometic and network analysis provide a wide range of empirical data about the origin, growth, and use of this term in academic literature. A content analysis of papers in Ecology and Society demonstrates a marked emphasis in research on institutions, economic incentives, land use, population, social networks, and social learning. These findings are supported by a review of systems science in 18 coastal assessments. This reveals that a systems-based conceptualization tends to limit the kinds of social science research favoring quantitative couplings of social and ecological components and downplaying interpretive traditions of social research. However, the concept of social-ecological systems remains relevant because of the central insights concerning the dynamic coupling between humans and the environment, and its salient critique about the need for multidisciplinary approaches to solve real world problems, drawing on heuristic devices. The findings of this study should lead to more circumspection about whether a systems approach warrants such claims to comprehensiveness. Further methodological advances are required for interdisciplinarity. Yet there is evidence that systems approaches remain highly productive and useful for considering certain social components such as land use and hybrid ecological networks. We clarify advantages and restrictions of utilizing such a concept, and propose a reformulation that supports engagement with wider traditions of research in the social sciences.Publisher PDFPeer reviewe

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

Response of a marine benthic invertebrate community and biotic indices to organic enrichment from sewage disposal

Nutrient enrichment is a significant cause of ecosystem change in coastal habitats worldwide. This study focuses on the change in a benthic macroinvertebrate community and environmental quality as assessed through different biotic indices following the construction of a sewage outfall pipe in the west of Scotland, from first implementation to seven years after operation of the pipe. Benthic macroinvertebrates are an important part of marine ecosystems because they mediate ecosystem processes and functions, are a key part of food webs and they provide many ecosystem services. Results indicated a clear change in benthic communities over time with an increase in species richness and changes to benthic community composition (specifically feeding type, bioturbation mode and ecological group) towards those indicative of organic enrichment. No clear spatial zonation was observed because organic carbon content increased over the entire area. According to a suite of benthic indices calculated, some negative changes were detectable following the start of sewage disposal, but largely negative community changes, and a change from 'good' to 'moderate' quality, only occurred seven years after implementation. The increase in species richness in response to increasing disturbance reduced the utility of a multi-metric index, the Infaunal Quality Index, which, instead of amplifying the signal of negative impact, dampened it. We suggest that any change in communities, regardless of direction, should be heeded, and species richness is a particularly sensitive and early warning indicator for this, but a suite of approaches is required to understand benthic community changes

Marine Strategy Framework Directive - Task Group 5 Report Eutrophication

The Marine Strategy Framework Directive (2008/56/EC) (MSFD) requires that the European Commis-sion (by 15 July 2010) should lay down criteria and methodological standards to allow consistency in approach in evaluating the extent to which Good Environmental Status (GES) is being achieved. ICES and JRC were contracted to provide scientific support for the Commission in meeting this obligation. A total of 10 reports have been prepared relating to the descriptors of GES listed in Annex I of the Directive. Eight reports have been prepared by groups of independent experts coordinated by JRC and ICES in response to this contract. In addition, reports for two descriptors (Contaminants in fish and other seafood and Marine Litter) were written by expert groups coordinated by DG SANCO and IFREMER respectively. A Task Group was established for each of the qualitative Descriptors. Each Task Group consisted of selected experts providing experience related to the four marine regions (the Baltic Sea, the North-east Atlantic, the Mediterranean Sea and the Black Sea) and an appropriate scope of relevant scien-tific expertise. Observers from the Regional Seas Conventions were also invited to each Task Group to help ensure the inclusion of relevant work by those Conventions. This is the report of Task Group 5 Eutrophication.JRC.DDG.H.5-Rural, water and ecosystem resource