Gastropods
Saltmarsh habitat is utilised by molluscs mainly, bivalves and gastropods but occasionally other types of molluscs including the larvae of cephalopods (squid) which have been known to enter saltmarsh during high tides. Generally, gastropods (snails, slugs and limpets) are one of the few molluscs able to tolerate the varying conditions associated with the saltmarsh. Indeed they can be quite common in saltmarsh vegetation areas, particularly amongst the soil and vegetation of the saltmarsh. They often burrow into the soil to avoid the heat and desiccation during the day and at certain times of the day and year can be quite difficult to locate. 
Gastropod Saltmarsh Ecology

Researchers still have much to learn in terms of the ecology of gastropods within the saltmarsh communities of Australia. It has been put forward that saltmarsh vegetation provides habitat for gastropods as the plant structure can mitigate some of the harsh conditions. Often these snails are also observed using crab burrows for shelter. It would seem any structure or shelter can be utilised by gastropods.

Saltmarsh vegetation may provide shelter for gastropods and reduce the level of predation especially during tidal inundation when fish such as bream (Acanthopagrus australis) the common toadfish (Tetractenos hamiltoni) and crabs. Studies of fish feeding in saltmarsh areas have revealed that gastropod and crab larvae are an important part of their diet. Other saltmarsh predators which may have an impact on gastropod population, especially at low tides are no doubt wading birds.

Research has also shown that disturbance of saltmarsh habitat through recreational vehicles and trampling can have a detrimental impact on the health and numbers of saltmarsh gastropods. Because of their ease of sampling and identification, along with their population response to changing conditions in the saltmarsh, gastropod populations make a useful environmental indicator.  

Gastropod Feeding

Gastropods in the saltmarsh are thought to be mainly herbivores feeding on microalgae and detritivores focusing on the breakdown of plant material and any other organic matter. During wet periods you can observe gastropods moving along the surface layer and ingesting organic matter. After rain periods you can observe increased numbers of gastropods associated with the wet substrate which has taken on a green sheen from algae.

Gastropods impact on Saltmarsh
Molluscs including gastropods through their feeding and burrowing behaviour may have an impact on the soil and plant production through increasing drainage, aeration and fertilisation as well as reducing compaction. Because the conditions in the saltmarsh are so harsh, any modification may have a positive effect. Gastropod numbers in a saltmarsh habitat may also be a useful indicator of the fisheries value of that site. Because of these potential impacts and benefits on the health of vegetation and fisheries it is important to monitor and record gastropods within a saltmarsh community.

Other Gastropods

 

Another gastropod found in the saltmarsh is the Estuarine Sea Slug (Onchidina australis)