Groundwater extraction for agriculture increases salinity in wetlands
An excellent recent paper entitled ‘Biodiversity impacts from salinity increase in a coastal wetland’ by Amores, Verones, Raptis et al (2013) has just been published in Environmental Science & Technology (read it here). It clearly demonstrates the impacts intensive agriculture, and particularly irrigation, can have on the environment. They reported that as a result of large scale abstraction of groundwater for irrigation there was saltwater intrusion into the local aquifer. This impacted the freshwater wetland of Nueva Lagoon in Spain where overall salinity rose from 4.5 grams of salts per litre of water to 7.5 grams, potentially affecting around 20% of the species found in the wetland.
As global populations rise, there is an ever increasing demand for food but at the same time there is also a growing awareness that this can’t be at the expense of the environment particularly in terms of water quantity, through abstraction losses, and water quality, through pollution via fertilisers, pesticides and sediment runoff. One solution to this problem is the use of wetlands within farms.
WWT Consulting is currently working on a number of projects with the Environment Agency and Natural England to support Catchment Sensitive Farming approaches, particularly looking at how small-scale wetlands can be introduced into farms to treat polluted runoff, retain storm runoff, provide habitat and allow water to infiltrate to ground, replenishing aquifers.