Welsh Ministers may designate a SWPA under The Water Environment (Water Framework Directive) (England and Wales) Regulations 2017. Welsh Ministers may designate an area as a SWPA where necessary for the protection of shellfish production. A SWPA may be designated in any area of coastal or transitional water within a river basin district. SWPAs are in place for the protection and support of shellfish growth. Good water quality is essential for the production of high quality shellfish. Monitoring programmes are put in place for each SWPA. These monitoring programmes assess compliance against the microbial standard for shellfish flesh. There are 22 designated shellfish waters in Wales at present. Specific measures are put in place to improve shellfish water quality in SWPAs. These measures are in addition to measures to improve water quality in catchments across Wales.