Primary production (PP) is highly sensitive to changes in the ecosystem and can be used as an early warning indicator for disturbance in the marine environment. Historic indicators of good environmental status of the north-east (NE) Atlantic and north-west (NW) European Seas suggested that daily PP should not exceed 2–3 g C m−2 d−1 during phytoplankton blooms and that annual rates should be 300 g C m−2 yr−1. We use 21 years of Copernicus Marine Service (CMEMS) Ocean Colour data from September 1997 to December 2018 to assess areas in the NE Atlantic with similar peak, climatology, phenology and annual PP values. Daily and annual thresholds of the 90th percentile (P90) of PP are defined for these areas and PP values above these thresholds indicate disturbances, both natural and anthropogenic, in the marine environment. Two case studies are used to test the validity and accuracy of these thresholds. The first is the eruption of the volcano Eyjafjallajökull, which deposited large volumes of volcanic dust (and therefore iron) into the NE Atlantic during April and May 2010. A clear signature in both PP and chlorophyll-a (Chl a) was evident from 28th April to 6th May and from 18th to 27th May 2010, when PP exceeded the PP P90 threshold for the region, which was comparatively more sensitive than Chl a P90 as an indicator of this disturbance. The second case study was for the riverine input of total nitrogen and phosphorus, along the Wadden Sea coast in the North Sea. During years when total nitrogen and phosphorus were above the climatology maximum, there was a lag signature in both PP and Chl a when PP exceeded the PP P90 threshold defined for the study area which was slightly more sensitive than Chl a P90. This technique represents an accurate means of determining disturbances in the environment both in the coastal and offshore waters in the NE Atlantic using remotely sensed ocean colour data.
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Seafood safety regulation within the European Economic Area has been strongly harmonised, including uniformisation of maximum levels on contaminants and toxins in seafood. Nevertheless, individual countries still have national limit values for different contaminant groups. This publication summarizes currently existing maximum levels on environmental chemical contaminants in seafood and seaweed that are established within the European Economic Area at international or national level. Maximum levels are compared to legal thresholds in other North Atlantic countries that are member of the International Council for the Exploration of the Seas (ICES), i.e. US, Canada and Russia, as well as the international food standards of the Codex Alimentarius. The identification of seafood safety regulatory differences allows to identify current challenges, associated to different topics: (1) contaminants in seafood, (2) contaminants in seaweed and (3) natural aquatic toxins. It can be concluded that increased harmonisation within and between geographical regions e.g. on seaweed regulations, can be beneficial from both a health and economic perspective. Constantly evolving knowledge on contaminants of emerging concern and new or emerging toxins triggers a continuous process of updating seafood regulations. Due to the health benefits of seafood consumption, a balance between risks and benefits is essential, as considered in EFSA seafood consumption advice.
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