Physical restructuring of rivers, coastline or seabed

Physical restructuring of rivers, coastline or seabed includes Land claim, coastal defence and flood protection, offshore structures (other than for oil/gas/renewables), restructuring of seabed morphology, including dredging and depositing of materials.

Overall, these activities generated 5.76 billion EUR in Gross Value Added (GVA) and employed an estimated 0.08 million people in 2017.

Table 1: EU coastal and maritime activities, their estimated economic Gross Value Added (GVA), number of people employed and expected future trends, as adapted from EEA, 2019.

Theme (sector)	Activity	GVA (billion EUR)	Employment (million)	Expected trends
Physical restructuring	Land claim	1.39	0.01	GVA: increasing Empl: stable
	Canalisation and other watercourse modifications	---	---	---
	Coastal defence and flood protection	1.15	0.01	GVA: increasing Empl: stable
	Offshore structures	---	---	---
	Restructuring of seabed morphology, including dredging and depositing of materials	3.23	0.07	GVA: decreasing Empl: decreasing

Read more on these activities

Coastal defence and flood protection

Public coastal protection consists of measures to protect the EU's coasts from floods and erosion, such as dune and cliff stabilisation through construction of seawalls, dikes, revetments and bulkheads, as well as the use of naturebased solutions, such as restoring seagrass meadows and coastal wetlands due to their role in reducing coastal flooding. Rising extreme sea levels linked to anthropogenic climate warming and continued socioeconomic development in coastal zones will lead to an increasing future flood risk along the EU coastline, requiring increased public expenditure to minimise it. Flood defence structures need to be installed or reinforced to withstand increases in rising extreme sea levels that range from 0.5 m to 2.5 m by 2100 to keep future coastal flood losses constant relative to the size of the economy. Otherwise, and in the absence of further investments in coastal adaptation, the expected annual damages of EUR 1.25 billion under present climate conditions is projected to increase by two to three orders of magnitude by the end of the Century, ranging between EUR 93 billion and EUR 961 billion. The magnitude of the difference in the projections is due to not only the climate scenario but also the socioeconomic scenario used.

Offshore Structures

There are a variety of man-made structures that are built in marine and coastal environments to serve a diversity of purposes. All man-made structures are modifying natural conditions with various levels of impact on the marine ecosystem. Pressures from man-made structures can occur throughout the lifetime of a structure during construction, operation and decommissioning (e.g. port infrastructure).

Some man-made structures are perceived to have positive impacts on the environment. For example, artificial reefs have been designed to rehabilitate marine habitats or barriers on beaches to prevent erosion or habitat loss, but even these structures can have unintended impacts on the marine environment.

Restructuring of seabed morphology (see also ‘Extraction of non-living resources’)

Pressures on the marine environment

Physical restructuring puts pressure on the marine environment by altering the seabed morphology, removing fauna and flora and causing a change in hydrographical conditions. The pressures imposed on the marine environment by this activity include:

Physical loss and disturbance of the seabed, as well as fragmentation of natural habitats limits and removes habitat and is related to building of infrastructure in coastal and offshore areas. Regular maintenance of shipping lanes is also considered under this pressure category due to changes in sediment transport and smothering or removing of benthic flora and fauna.

Changes to hydrographical conditions can be caused by large scale building of infrastructure such as coastal protection and offshore structures which modify currents and wave regimes.

Introduction of underwater noise is related to emissions of impulsive underwater noise during construction phase of infrastructure construction.

Contamination can be aggravated by construction and dredging due to resuspension of polluted sediments or emissions from ships and other equipment used in the processes;

Eutrophication can be aggravated in the eutrophic areas by resuspension of nutrients from sediments.

Non-indigenous species can be transferred by vessels; and alien species can then settle in degraded areas more easily, without competition, than in the areas where natural, indigenous habitats are in good status.

References

COGEA, CETMAR, & EASME, 2017. Study on the establishment of a framework for processing and analysing of maritime economic data in Europe: Final report MARE/2014/45.
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EC, 2019, 'Blue Indicators Online Dashboard', European Commission (https://blueindicators. ec.europa.eu/public/access-online-dashboard_en.
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EEA, 2019. Marine Messages II. Navigating the course towards clean, healthy and productive seas through implementation of an ecosystem-based approach. European Environment Agency, EEA Report, 17/2019: 82 pp.
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EEA, 2019. Marine Messages II. Navigating the course towards clean, healthy and productive seas through implementation of an ecosystem-based approach. European Environment Agency, EEA Report, 17/2019
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Mangor, K., DrØnen, N., Kærgaard, K., Kristensen, S., 2017, 'Shoreline management guidelines', DHI, Hørsholm, Denmark (https://www. dhigroup.com/upload/campaigns/shoreline/assets/ ShorelineManagementGuidelines_Feb2017-TOC.pdf).
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Möller, I., 2019, 'Applying uncertain science to nature-based coastal protection: lessons from shallow wetland-dominated shores', Frontiers in Environmental Science 7, p. 49 (DOI: 10.3389/fenvs.2019.00049).
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Vousdoukas, M., Mentaschi, L., Voukouvalas, E., Bianchi, A., Dorrori, F., Feyen, L., 2018, 'Climatic and socioeconomic controls of future coastal flood risk in Europe', Nature Climate Change 8(9), pp. 776-780 (DOI: 10.1038/s41558-018-0260-4).
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Korpinen, S., Klančnik, K., Peterlin, M., Nurmi, M., Laamanen, L., Zupančič, G., Popit, A., Murray, C., Harvey, T., Andersen, J.H.,Zenetos, A., Stein, U., Tunesi, L., Abhold, K., Piet, G., Kallenbach, E., Agnesi, S., Bolman, B., Vaughan, D., Reker, J. & Royo Gelabert,E., 2019, Multiple pressures and their combined effects in Europe’s seas. ETC/ICM Technical Report 4/2019: European Topic Centre on Inland, Coastal and Marine waters, 164 pp. (https://www.eionet.europa.eu/etcs/etc-icm/products/etc-icm-report-4-2019-multiple-pressures-and-their-combined-effects-in-europes-seas)
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