Habitat Damage

There are many pressures upon the aquatic environment resulting from industrial, agricultural, forestry, mining and other human activities. These cause environmental impacts which in turn determine the quality of any particular part of the aquatic environment.

Afforestation

The planting of forests can be a major influence on the physical and chemical characteristics of watercourses. In the early stages of afforestation, there can be significant changes in stream and river flows that discharge into lakes, caused by increased runoff, and sharper storm hydrographs. As canopy closure progresses, fish resources may be affected by excessive shading.

Agricultural activities

These may cause pollution of water bodies through poor waste storage facilities, inadequate separation of contaminated yard water from clean water and the spraying of pesticides. High grazing levels can result in excessive poaching (damage to the soil properties), nutrient enrichment and eventual changes to fens and agricultural grassland.

Changes in land us

Ploughing up of grassland and other habitats surrounding lakes, under-drainage and overgrazing can all increase the possibility of soil erosion, with a consequent increase in water-borne sediments. Sediments in suspension cause turbidity and the resulting decrease in light may inhibit the growth of rooted aquatic plants in the spring, increasing the changes of algal dominance.

Climate change

Predictions for climate change include an increase in summer temperatures and milder, wetter winters. These changes may result in drier summer conditions, with extended growth periods during the winter. It is unclear how freshwater habitats in Northern Ireland will respond to such changes.

Discharge

Discharge from waste water treatment works (WWTW), industrial sites and septic tanks can be a source of nutrient enrichment of lakes. Contaminated groundwater sources that feed surface waters can also contribute to the nutrient loadings of lakes.

Drainage

Drainage schemes can both directly affect lake water levels and indirectly affect peripheral wetland habitats such as fens, reedbeds and floodplain grazing marsh and their associated rare wetland flora and fauna.

Dredging

Dredging and the clearance of bank side vegetation as a result of flood control works can also affect downstream water quality by increasing suspended sediment loads and nutrient concentrations.