A nuclear power plant affects the marine environment mainly through the use of large volumes of seawater for cooling. The cooling water is purified at the intake, which to some extent reduces the loss of organisms that would otherwise accompany the intake, but for those who follow, mortality occurs mechanically and thermally when the water passes through the power plant. The outgoing cooling water is 10° C warmer than the water taken in. The hot water is then spread over relatively large areas, where the organisms can be affected. The warm water can also make it easier for non-indigenous species to get established than in other areas. To control the effects of cooling water use, extensive control programmes have been established at and around the Swedish nuclear power plants since the nuclear power plants were established. In Sweden, there are nuclear power plants at one site in the North Sea (Ringhals nuclear power plant) and two in the Baltic Sea (Forsmark nuclear power plant and Oskarshamnsverket). Electricity production at the power plant in Barsebäck by the Sound ceased in 2005. Monitoring in the North sea started in 1968 and in the Baltic sea in 1969. Monitoring frequency varies from daily during spring/summer, to monthly or yearly depending on the parameter, location and purpose. Details are described in the monitoring fact sheet linked below. The nuclear power plants are undergoing a slow decommissioning, for example at Ringhals, two out of four reactors are planned to be shut down in the near future. As the monitoring is connected to the industry, it will also in the long run be phased out after the activity has ended and the effects have ceased.

Mapping and monitoring of benthic habitats is of crucial importance for all environmental management at sea, from a functioning ecosystem-based marine environment management to meeting the various requirements of environmental legislation. The need for continuous and comprehensive monitoring covering the biological components of the MSFD, the Habitats Directive and the WFD has been clarified in recent reporting cycles. Corresponding needs also exist within the national environmental goals, from the Convention on Biological Diversity and the current challenges of tackling climate change. The new objectives of the EU Biodiversity Strategy (2021-2030) require functioning monitoring systems that provide comprehensive information for protection, assessment of permits, action planning and evaluation (of protection, permit modification and implemented measures). Monitoring is needed for sustainable fisheries regulation and coastal planning linked to exploitation, as well as for the management of transport routes and energy production, and last but not least to ensure a functioning network of protected areas and a functioning beach protection. The monitoring of benthic habitats is largely dependent on technical solutions. Methods for monitoring are under development and will, together with monitoring of pressures (see program Physical disturbance and loss), provide a basis for assessing the condition of the benthic habitats and how they are affected by various human activities. The Habitats Directive's assessment in 2019 shows that physical impact on conservation status in the form of construction, ports, dredging and bottom trawling predominates in the North Sea, while water quality, hazardous substances and nutrient load instead have a greater derogatory impact on habitats in the Baltic Sea. In order to be able to respond to the requirements in an integrated manner, a development of coordinated methods is underway that can deliver the necessary data on benthic habitats. The pilot phase of a survey and monitoring of shallow marine areas using satellite, aerial and drone images and biological sampling will be completed in 2020 and the established monitoring method will be tested and fine-tuned in 2021. The studies include testing of methods from satellite to biological sampling both in the Baltic Sea and on the West Coast. The overall monitoring of shallow benthic environments strives to be able to annually measure shallow marine areas completely (all of Sweden) w

The Sentinel family is a number of satellites that are part of the European space program Copernicus and can be used for environmental monitoring. With their large geographical coverage, satellites are an excellent complement to field measurements of the water column (for example chlorophyll) provided that the satellite products are locally adapted with acceptable accuracy. With the data collected by the satellites and their instruments, various variables can be calculated that can provide better knowledge of the condition in pelagic habitats and the possible extent of the effects of eutrophication. The monitoring complements the field measurements described in the programmes Phytoplankton, Water column - physical characteristics and Water column - optical properties. Sentinel 3A was launched in 2016, and Sentinel 3B in 2018. Data are collected from other satellites further back in time, for example from NASA's SeaWiFS (1997 - 2010). Sentinel 3D, the last of that generation, will be launched in 2021. In addition to monitoring harmful algal blooms during the summer (mainly cyanobacteria in the Baltic Sea), there is no ongoing programme for calculating data obtained by remote sensing, but it is under development. Since 2019, SMHI has been tasked with creating an infrastructure for the production of aquatic products, such as chlorophyll maps (data files), adapted to cover all of Sweden's land and water surfaces, as well as making them publically available. The goal is to have the monitoring in operation by 2022.

The purpose of the monitoring is to study long-term changes in the marine environment with regard to temperature, ice conditions and salinity, which are basic physical parameters in the sea. These, together with pressure, determine the density of the water. The density determines the stratification, which in turn affects the mixture of seawater. Density gradients can impede the transport of substances (for example, the flow of oxygen) to the deep water. Horizontal density gradients create large-scale currents, such as the Baltic surface current along Sweden's west coast. Because marine organisms are adapted to certain temperature and salinity ranges, changes in temperature and salinity can affect the entire food web. Changes can occur because of climate change, but also locally because of the construction of sea-based structures, see also the programme Physical disturbance and loss. The current regular environmental monitoring started in 1993, but measurements have been performed since 1880, for example from Swedish lightships. In-situ data are collected at a high frequency but reworked to give, for example, an average value over a ten-minute measurement period every hour from buoys, or an average value for each half-meter depth from a CTD profile. Measurements with CTD profiles are performed between 1 and 24 times a year, usually in connection with eutrophication sampling. Satellites and merchant ships also contribute with data. Since international collaborations such as EuroGOOS (the European Global Ocean Observing System) make other countries' data available, model products that use this data cover almost the entire North Sea and the entire Baltic Sea. Daily ice maps of the entire Baltic Sea are produced during the period November to May based on satellite data and in-situ data from icebreakers and ice reporters. Work is underway to develop new methods for monitoring using automated sampling and measurements, for example from ferry box systems or bottom- or buoy-mounted measurement systems. Methods are already in place and routines are being developed for automated measurements of temperature, salt and oxygen by the use of probes on ships, buoys and measuring systems, or on moving gliders. Comment: D7C2 was not in the list for the feature Hydrographical changes, but this criteria is relevant for this programme.

The purpose of the monitoring is to study long-term changes in the marine environment with regard to the hydrological condition of the sea. Currents, waves and water levels give rise to a physical impact on marine habitats and in addition have effects on human activities. Currents transport water masses and can thus change the pelagic habitat in a few minutes and gaining insight into how the water masses move is thus central to the understanding of the ecosystem. An example is the inflows to the Baltic Sea, where salty oxygen-rich water enters through the Sound (the strait that separates Sweden and Denmark) during severe storms. This salty oxygen-rich water can replace low-oxygen water in bottom areas in the southern Baltic Sea and improve the oxygen situation for at least a couple of months. Waves are of course also important for both maritime activities and marine life. Waves can both give a resuspension of nutrients in shallow areas (the bottom sediment is stirred up and nutrients, as well as any hazardous substances, can get into the water mass), affect currents and have effects on beach areas (erosion and more). Waves and currents also transport nutrients, organisms and marine litter to the coasts of Sweden from other countries. In addition to a climate indicator, the sea level is a prerequisite for life in the tidal zone and not at least for blue growth. The Swedish Meterological and Hydrological Institiute (SMHI) send out warnings at extreme water levels. High sea levels can have major effects on communities by leading to floods. Low sea levels can affect shipping that may be forced to take detours or go with less cargo. Another example is nuclear power plants whose cooling can potentially be affected. The Swedish measurements of currents began in the early 1880s with measurements from lightships. Data on currents, however, are available from earliest 1945, but the first regular observations started in 1978 when currents began to be measured from lighthouses. Since then, the measurements have developed. Wave measurements by SMHI started in 1978. The serie of measurements of seawater levels in Stockholm is the longest in the world. The measurements started as early as 1774 at Slussen in Stockholm. In 1889, a mareograph was built on Skeppsholmen, which is still active. To complement the current programme, mobile sea level gauges have been tested successfully. There are plans to improve the spatial coverage of current patterns and waves by developing n

This programme include monitoring of physical disturbance or loss of the sea's bottom and coastal environment through human activities such as bottom trawling, dredging, dumping, land claim, constructions and other activities that cause physical change of the bottom (water depth, sediment distribution and habitat loss) and possible the sediment dynamic conditions and hydrographic conditions (eg currents and water exchange). Physical impact can be identified based on registered information about where and when different activities are carried out. Such information is found, for example, in permits and exemptions or notifications made in accordance with the Environmental Code and can also be produced through, for example, analysis of aerial photographs, VMS and logbooks for fishing activities as well as hydroacoustic measurements with, for example, multibeam sonar. After coordinating geographical and temporal information about human impact with information about ecosystem components in an area, the impact can be assessed. To estimate the physical impact on benthic habitats, the plan is to use data on human activities and their pressures, together with data from e.g. the programmes Benthic habitats and Macrozoobenthos - on the seafloor. The latter also includes documenting traces of trawling when monitoring the seabed. Different types of data are thus collected that could be used to estimate physical impact. However, methods for monitoring and assessment are still under development. Benthic trawling began to be monitored in 1998. Dumping activities began to be reported to the Regional Sea Conventions in 1996. Since 2011, dredging activity linked to dumping has also been reported. Data on other activities have been collected from permits prior to certain reports, but ongoing collection is not yet in place. Regarding sand gravel and rock extraction, there are data on the volume of extraction in m3 per licensed area and year in Sweden from 1967. In 2018, historical and new aerial images of Sweden's coastal areas were analyzed to identify physical disturbance within the project ”Physical impact in Swedish coastal waters - mapping, assessment and guidelines”. The results apply to the 1960s, and the present (2016). In order to get an idea of the rate of change, interpretations of five major sub-areas have been made for the years 1994 and 2008. The analyzes have been made through interpretations of orthophotos and are planned to be followed up once or twice during