The saltmarsh and tidal mud flats in the ‘Bight of Dawlish’ at the mouth of the Exe Estuary support at least three threatened or near threatened flies that are found in few other places nationally. Three species are listed as Devon Species of Conservation Concern.

The Lagoon Snout Cranefly (Geranomyia bezzii) lives on tidal mudflats where its larvae feed on green algae. The weak-flying adults shelter in low-growing bushes such as Sea Purslane, just above the highwater mark. It’s only known to be in five other UK sites (on the south and east coasts), although these records are old. It’s assessed as vulnerable to extinction in Britain.

The only known UK location of the housefly (Neolimnophora maritima) is Dawlish Warren, although it hasn’t been seen since 2011 (in 1939 it was seen at Blakeney Point in Norfolk). Its precise habitat needs are unclear, but it appears to prefer the margin between foredune and tidal flat. This fly is near threatened.

The Long-legged Fly (Muscidideicus praetextatus) is known for its metallic green colour and is mainly associated with the north Norfolk coast and Dawlish Warren, although it’s also known from a few other sites around the British coast. It’s restricted to saltmarshes, although adults may be found on nearby dunes or estuarine mud. Again, its precise habitat needs are unknown, but given its very restricted distribution are likely to be highly specialised. The fly is vulnerable to extinction. 

The Bight of Dawlish is affected by rising sea levels as a result of climate change. The saltmarsh is showing signs of stress as it’s squeezed between the sea and the artificial sea wall that protects the spit and its golf course.  

The tidal flats have also been put under pressure by coastal defence work on the sand dune system. For example, in 2018, the Environment Agency carried out major works to restructure the dune spit at its narrowest part.