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Activities exerting pressures on marine mammals

Human activities are distributed widely across the North-East Atlantic, but their intensity and that of the pressures they impose on the marine environment vary greatly between OSPAR Regions and Sub-divisions. Some sea areas are affected by many activities; in others, only a few may be significant. The table below is taken from the Human Activities Thematic Assessment and gives a high-level summary of the intensity and trends of selected activities across the OSPAR Regions, based on the analysis in feeder reports. However, not all activities that affect marine mammals are currently assessed by OSPAR (Table A.1).

Renewable energy, aquaculture, military operations and tourism are expected to increase in the coming years. Future trends of some activities such as fisheries and shipping are uncertain, but their intensity is potentially going to increase in the OSPAR Maritime Area.

Human activities that interact with marine mammals fall under several MSFD headings as shown in the State section.

OSPAR acts as a coordination platform in the North-East Atlantic for the regional implementation of the EU Marine Strategy Framework Directive (MSFD) that aims to achieve a Good Environmental Status (GES) in European marine environments, as well as for the coordination of other national frameworks. The characteristics of GES are determined by the individual EU member states, based on criteria elements, threshold values and methodological standards set regionally or at EU level.
Norwegian, Icelandic, United Kingdom, Greenlandic and Faroese marine areas are not covered by the MSFD.

Renewable energy generation (wind, wave and tidal power), including infrastructure, Nuclear energy and Transmission of electricity and communications (cables) [Production of energy]: 
Society’s need for energy, stable economies and to mitigate the effects of climate change are drivers for renewable energy generation, including the construction of associated infrastructure. Other associated activities include nuclear energy generation and transmission of electricity via power cables. Renewable energy generation in the marine environment is the only human activity directly driven by society’s need to mitigate the effects of climate change, but in meeting this need, society also has to meet the needs of and appreciate nature and biodiversity. Renewable energy generation in the marine environment requires the development of infrastructures on coastal land. Harbour development may impact local coastal ecosystems through noise associated with blasting/drilling and the release of sediment and chemicals into the marine environment. It is crucial that measures to mitigate climate change do not counteract efforts to protect biodiversity. A healthy ocean contributes strongly to climate regulation. Further detail is provided in the relevant feeder report: Offshore Renewable Energy Generation .

Phases of these activities which can directly affect marine mammals are:

  • The exploration phase often includes geophysical surveys. The removal of unexploded ordnance before construction can also produce very high levels of noise leading to physical injuries and/or, temporary or permanent hearing damage, and in the worst case can be fatal.  
  • The construction (and decommissioning) phases of offshore bottom-mounted renewable energy developments contribute to the input of impulsive noise into the marine environment. Construction (notably pile-driving of foundations) is a fixed- point source involving time-limited activities which cease once the construction is complete, and there are mitigation techniques available. 
  • The construction of an increasing amount of renewable energy infrastructure, once completed, can induce barrier effects and impact marine mammal movements and migration.
  • The operation of renewable energy infrastructure contributes continuous underwater noise into the marine environment. Such operation (notably blade rotations) is a fixed-point source involving ongoing activity throughout the lifetime of the development. The increasing activity of service vessels and associated ship traffic will also impact marine mammals and increase noise and disturbance. At local scale, the habitat will change due to the introduction of hard substrate; hydro- and morphodynamics as well as biogeochemistry will be impacted.
  • Transmission of electricity through cables is the main source of input of other forms of energy into the environment. Once operational, these cables emit electromagnetic fields (EMF), which could be detected by marine mammals and/or could impact the behaviour of their prey.
  • In addition to renewable energy, nuclear energy power stations are often located on the coast and often incorporate some form of cooling water intake/outfall with pipes running into the sub-tidal area.

Extraction of oil and gas, including infrastructure and Extraction of minerals [Extraction of non-living resources]:
Society’s needs for energy and stable economies are drivers for the extraction of oil and gas. Society’s need for material drives the extraction of minerals. The exploration, operation and decommissioning of oil and gas platforms and the associated infrastructure (pipeline and cables) directly interact with marine mammal habitats. The main interactions affecting marine mammal habitats can arise from the seismic surveys (impulsive noise) for oil and gas exploration, the vessel traffic associated with services to the platforms, operational noise emitted at the site and accidental spills during drilling or operation. Further detail is provided in the Offshore Industry Thematic Assessment . Extracting minerals through dredging can release chemicals directly into marine mammal habitat. Further detail is provided in the relevant feeder report: Extraction of non-living Resources.

Coastal defence and flood protection, Offshore structures (other than for oil/gas/renewables) and Land claim [Physical restructuring of rivers, coastline or seabed (water management)]:
Society’s need to adapt to the effects of climate change, health and wellbeing and for stable economies are the drivers for land claim, coastal defences and flood protection, and offshore structures (other than oil/gas/renewables). Society’s need for and appreciation of nature and biodiversity also drives the construction of coastal and flood defences. The structures associated with this activity can be located on or adjacent to marine mammal habitat and damage it. These activities will also introduce additional disturbance and noise during the construction phase.

Transport shipping and Transport infrastructure [Transport]: Society’s need for the trade and movement of goods drives transport, responding to the need for stable economies and the supply and demand of goods and services. Shipping directly interacts with marine mammals, producing continuous noise and causing obstructions. In addition, vessel strikes can lead to injury or death. Further detail is provided in the relevant feeder report: Shipping and Ports .

Fish and shellfish harvesting (professional, recreational) and Hunting and collecting for other purposes [Extraction of living resources]:
Society’s need for food is a driver for fishing activities. Society’s needs for food and the preservation of culture drive “hunting and collecting for other purposes”. As an example, it can be mentioned the relatively small-scale and localised hunting of marine mammals to maintain artisanal culture. Gears used to extract living resources may directly / indirectly interact with marine mammals. Smaller species of cetaceans in particular are still frequently incidentally by-caught in static nets and other fishing metiers. In some OSPAR Regions marine mammals are still commercially or traditionally hunted, which affects their populations. Further detail is provided in the relevant feeder report: Fisheries.

Aquaculture – marine, including infrastructure and Agriculture [Cultivation of living resources]:
Society’s need for food is a driver for both marine aquaculture and agriculture. Aquaculture directly interacts with marine mammal habitat and can also potentially attract marine mammals. The input of extra nutrients, introduction of diseases and use of Acoustic Deterrent Devices can all potentially affect marine mammals. Agriculture indirectly interacts with marine mammal habitat, as run-off from pesticides can end up in the ocean and contaminate their environment. Further detail is provided in the relevant feeder reports: Aquaculture and Agriculture .

Waste treatment and disposal [Urban and industrial uses]:
Society’s needs for health and wellbeing and for industrial processes drive waste treatment and disposal. Waste treatment and disposal can directly affect marine mammal habitats, contaminating them and causing eutrophication. Extremely high contaminant burden (mainly Polychlorinated Biphenyls PCBs and mercury Hg) is found in many species of marine mammals living the North-East Atlantic, often surpassing the estimated thresholds for toxicity effects (from molecular to tissue level). High PCBs and Hg levels have been shown to impair marine mammals’ immune and reproductive systems as well as affect foetuses' neuronal development and motor activity. Further detail is provided in the relevant feeder report: Waste water .

Military operations [Security/defence]:
Society’s need for national security drives military operations, which directly interact with marine mammal habitats and can cause injuries and mortality. Military activities such as the disposal at sea of munitions, explosions/detonations, sonar use and exercises produce high levels of noise as well as unexpected noise at particular frequencies, which can elicit behavioural and physiological risk evasion responses in marine mammals, potentially leading to physical injuries, temporary or permanent hearing damage and, ultimately, death.

Tourism and leisure infrastructure and Tourism and leisure activities [Tourism and leisure]:
Society’s need for health and wellbeing drives tourism and leisure. Tourism and leisure infrastructures can be located on or adjacent to marine mammal habitat and damage it. Tourism and leisure activities directly interact with marine mammals and their habitats, leading to disturbances which when repeated can impact populations, and to vessel strikes which can lead to injury or death.  The tourism that takes place on and along the North-East Atlantic Ocean is particularly relevant because of its economic value and its dependence on the marine ecosystem. Activities such as boating, recreational fishing, marine wildlife watching, general beach recreation and cruises directly interact with marine mammal habitat. Tourism activities can contribute to physical disturbance, physical damage and physical loss of habitat. Further, some of these activities contribute to pollution, such as litter, underwater noise, contamination by hazardous substances, nutrient and organic enrichment. Further detail is provided in the relevant feeder report: Recreation and Tourism .

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