To ask the Secretary of State for Environment, Food and Rural Affairs, what estimate she has made of nitrogen levels in the Solent; and what assessment she has made of the effect of nitrogen in the Solent on the growth of green algae in that area.
To ask the Secretary of State for Environment, Food and Rural Affairs, what assessment she has made of the effect of eutrophication in the Solent area on protected habitats and bird species in that region.
The EA has used its monitoring and evidence to undertake modelling of nitrogen sources in the Solent area. This shows that, on average, about 50% of nitrogen sources impacting coastal and estuarine waters in the Solent come from agriculture and about 10% from sewage treatment works.
NE’s site condition assessments consider a range of different environmental features and are therefore undertaken as an ongoing process, rather than a one-off undertaking. Through their site condition assessment work, NE has concluded that the Solent is in unfavourable condition because of the high levels of nutrients, which are causing excessive growth of algae, particularly green species of macroalgae.
Proliferation of these green macroalgal mats can be detrimental to ecology, including birds. Several of the Solent’s estuaries are affected in this way and work has been ongoing for many years to reduce inputs of nitrogen and hence reduce macroalgal mats. This has primarily been through tackling diffuse agricultural sources and improvements to sewage treatment works on both the coast and within the river catchments which feed into the Solent.