The Ecosystem Overviews provide a summary introduction to the main habitat types covered in APIS and the main air pollutant pressures to those habitats in the UK. In specific locations, e.g. close to a major source, other pollutants may be a concern for a habitat and the user should use the searches by location or by habitat/pollutant in these cases.
The UK coastline is one of the longest in Europe, at over 12,400 km, and is also one of the most varied and dynamic. The coastal zone contains terrestrial habitats and species which are subject to marine influences.
BAP Habitats: Coastal saltmarsh (priority); Coastal sand dunes (priority); Coastal vegetated shingle (priority); Maritime cliff and slopes (priority); Offshore shelf rock; Offshore shelf sediment
Main Pollutant Impacts
Many coastal habitats (e.g. rocky cliffs, coastal grasslands, and sand dunes) are not under agricultural management with fertilisers and therefore potentially sensitive to nitrogen deposition. Nitrogen deposition is thought to be a major contributor to over-stabilisation and species decline in UK dune systems (CEH sand dune research website).
Based on field surveys by Jones et al (2004) it was reported that in the mobile and semi-fixed dunes, an increase in above-ground biomass was positively related to N inputs. This increased biomass may lead to increased organic matter accumulation and consequently accelerated soil development. In the fixed dunes, above ground biomass also showed a positive relationship with N inputs as did soil C : N. Plant species richness was also negatively related to N inputs. In the dune slacks, while soil and bulk vegetation parameters showed no relationship with N inputs, cover of Carex arenaria and Hypochaeris radicata increased. The survey reveals that the relationships of soil and vegetation with atmospheric N deposition vary between sand dune habitats but, despite this variability, clear correlations with N inputs exist.
Some shingle sites, with perennial shingle vegetation have extensive stable shingle away from the influence of waves, and to some extent limited maritime influence where they extend more than 1km inland, with characteristics of grassland or heathland habitats, often with a high lichen or bryophyte component. These will be sensitive to the effects of N deposition, however there is little research into nitrogen deposition effects on this habitat.
Littoral ecosystems, such as salt marshes or estuarine habitats may be under the dual threat of nutrient inputs from river inputs and atmospheric deposition.
In marine ecosystems the important receptors are phytoplankton, sediment-dwelling organisms and fish. By contrast, some coastal environments are naturally highly eutrophic as a result of guano and NH3 deposition from sea bird colonies (e.g. Mizutani and Wada 1988, Sutton et al. 2000). In most coastal systems the atmospheric pathway is not the major source of nitrogen inputs.
As with other semi-natural ecosystems, coastal habitats are expected to be sensitive to ozone concentrations. Coastal dunes and sandy shores have been predicted to contain about 42% ozone sensitive species respectively (Mills et al., 2007). The effects are expected to parallel those for example for grassland ecosystems (Davison and Barnes 1998). It should be noted, however, that the structure of the coastal atmospheric boundary layer permits a greater mixing down of ozone concentrations, so that the ozone exposure of coastal ecosystems is larger than for inland areas. This additional stress will encourage the development of ozone tolerant ecotypes (Davison and Barnes 1998). As these are expected to have different competitive abilities, the community species composition may gradually change.
Impacts of ozone on marine ecosystems are not expected, since the ozone is rapidly destroyed following contact with the sea surface.
Toxic air pollutants
Atmospheric deposition of Persistent Organic Compounds (POPs) and heavy metals can contribute together with riverine inputs to impacts on coastal and marine ecosystems. The main receptors are fish, piscivorous birds, marine mammals and sediment-dwelling invertebrates (Bosveld & van den Berg 1994; Munroe et al. 1994, Pearse et al. 1979). Control of POP emissions in Europe has been particularly driven by the concerns of transboundary air pollutant transport and deposition to marine environments. Since POPs tend to accumulate with an affinity for fatty tissue and are preferentially deposited in cold environments, Arctic marine food chains have been seen as particularly at risk.