OSPAR Science Agenda Knowledge Gap Portal

Knowledge gap description: Improve coherence and integration with relevant eutrophication indicators.

Knowledge gap description: Refine the use of satellite data and improve coherence with the eutrophication assessments.

Knowledge gap description: Impacts of climate change on nutrient inputs to the sea and resulting ecological effects are uncertain. Predictability of drought conditions (because this may impact agriculture) may become an important factor in minimising future nutrient inputs. Changes in crops or irrigation techniques may mitigate some shortages while technological development may reduce industrial water use. On the other hand, episodic events such as flooding are expected to increase suspended sediment and nutrient inputs. Whether this cancels any general decrease in run-off is unclear. Furthermore, more investigation is needed in order to understand the ecological effects of the greater variability in nutrient inputs and how to monitor and assess such increasingly prevalent events for the purposes of future eutrophication assessments.

Knowledge gap description: Reduced monitoring is providing less data. Investigate solutions to fill existing and potential data gaps through additional data sources and data types (e.g. Copernicus/CMEMS, ferryboxes).

Knowledge gap description: Further investigation is needed to understand the role of estuaries and the coastal zone in removal of nutrients, in particular when the states of estuarine ecosystems improve as a consequence of the efforts under the Water Framework Directive.

Knowledge gap description: Including total nutrients in the future eutrophication assessment will provide an overall picture of nutrient processes throughout the year and not only in winter. Better informed models could support the inclusion of total nutrients where in-situ measurements are lacking. Also, better coverage of in situ data is needed.

Knowledge gap description: COMP4 uses common threshold values based on a harmonised modelling approach. However, adjustments were needed for some areas where model results for a reference situation were unrealistic, thereby undermining harmonisation. In addition, the current approach for nutrients and chlorophyll a threshold values (historic concentrations +50%) is not in accordance with our ecological knowledge. Furthermore the approach needs to better reflect the difference in responses of different parameters and spatial gradients in anthropogenic pressures between assessment areas. Therefore, this approach requires adjustment.

Knowledge gap description: Insufficient understanding of the relative importance of biological and physical processes and of impacts of climate change in controlling near-bed oxygen dynamics, oxygen deficiency and consumption to distinguish between the effects of nutrient enrichment and changes in seawater temperature as a result of climate change.

Knowledge gap description: Increased spatial coverage of data points (currently concentrated on nearshore waters), in order to improve confidence in assessments of wider marine areas.

Knowledge gap description: Improve future assessments by strengthening the ICES data base by uploading existing monitoring and/or research data, which are held in local or regional databases.

Knowledge gap description: Improved availability of suitable data is needed for robust assessments of oxygen deficiency. Since oxygen deficiency is localised and often short-lived, application of validated models can help in identifying hotspots, when data is lacking.

Knowledge gap description: There are no Riverine Inputs and Direct Discharges Monitoring (RID) programme data from the Russian catchment to Region I (unmonitored by OSPAR), or from Region V.

Knowledge gap description: There is a knowledge gap as to whether the substantial increase in nutrient inputs is causing eutrophication in OSPAR Arctic waters.

Knowledge gap description: The assessment needs to build evidence of how nitrate and phosphate ratios lead to changes in phytoplankton communities which negatively impact the efficiency of the ecosystem services those communities provide. An improved understanding of nearshore plankton dynamics and the influence of river flows can inform the measures required to manage the nitrogen inputs from sources such as urban wastewater and agriculture.

Knowledge gap description: In coastal ocean regions, anthropogenic eutrophication via continental run-off and atmospheric nutrient deposition, and ocean warming, are very likely to be the main drivers of deoxygenation. Future work should aim to decouple, where possible, the impacts of eutrophication on benthic ecology.

Knowledge gap description: Further analyses and evidence of ecological impacts of eutrophication are required in order to progress the assessment of cumulative effects and to evaluate the effectiveness of implemented measures.

Knowledge gap description: Improved understanding of the fundamental links between changes in the physical and chemical ocean climate, the marine ecosystem, and human activities in the marine environment. Causal links between these changes and other OSPAR receptors (species, habitats, hazardous substances, marine litter, eutrophication, radioactive substances) are unknown, including the complex interactions between these.

Knowledge gap description: Implementation of the Nitrates Directive: Strengthened water monitoring, especially of saline surface waters, would improve the comparability of the data on nitrogen pollution and provide a more detailed picture of the overall quality of the EU waters.

Knowledge gap description: While there is data on use of pesticides, sales of pesticide cannot be directly equated to the risk to human health and the environment and does not provide insight into whether or not the use of pesticides is sustainable. This is because the risks relate to pesticide mobility and degradation in the environment and their uptake and potential accumulation in plants, animals, and humans.

Knowledge gap description: Nutrient levels are still too high in some regions which are still affected by eutrophication, such as the south-eastern coast of the Greater North Sea and some localised areas of the Celtic Seas. OSPAR could further develop the evidence base and tool kits to identify and quantify relevant sources, and consider nutrient reduction needs for countries to combat eutrophication.

Knowledge gap description: OSPAR could further develop the evidence base and tool kits to consider nutrient reduction needs for countries to combat eutrophication.

Knowledge gap description: The impact of offshore chemicals on eutrophication status of the OSPAR maritime area is unknown.