SCIENTISTS at WA’s Department of Environment and Conservation (DEC) are in a race against time to save a species of halophilic shrimp from the broadscale salinisation of its habitat in the State’s wheatbelt.

Data gathered from recent DEC aquatic research projects has shown that previously high concentrations of the brine shrimp genus Paratemia occurring in the region’s natural saline lakes have been on a steady decline since 2008, as a result of hydrological changes and associated disturbances to patterns of salt distribution.

Salinisation is threatening the existence of local brine shrimp / Image: Istockphoto

The department is now working hard to save the species from extinction.

“Australia has a higher diversity of salt-loving shrimps than anywhere else in the world and most of those are restricted to southern WA,” DEC senior aquatic research scientist Adrian Pinder says.

“We have been quite concerned about the conservation of these shrimps over the last few years but more specifically over the past 12 to 18 months with the widespread salinisation of the wheatbelt and their subsequent loss of habitat.

“Salinisation causes the groundwater table to rise so that wetlands no longer dry out, and we believe this process interferes with the reproductive cycle of the species.

“Under normal conditions, the shrimp would lay drought-resistant eggs in the bottom of the sediment when the wetlands start to dry out and those eggs would hatch in the rainy season.

“The last 18 months has seen a reduction in the number of shrimp and we expect this has had an associated impact on reproduction.

“Although no species have been lost to date, there are several that are of particular concern because their numbers appear to be declining at a faster rate than others.

“One of the species for example, used to be present in three or four locations in the wheatbelt however our recent visits to those locations have failed to identify them.”

Mr Pinder says rather than treating salinity as a standalone factor, the key to saving the species requires a “whole-of-landscape” approach.

“The shrimp is not a very good migrator and does not have good dispersal ability so any change in the environment can be quite a threat to long-term survival of the species.

“But effective management of any wetland problem means managing the entire catchment not just addressing salinity issues.

“In this case, it means proper identification of the wetlands being affected by salinisation and then looking at what can be done to manage rising groundwater tables within those areas, such as planting native trees and shrubs to maximise water uptake.”

Mr Pinder says DEC’s aquatic research team will conduct specific surveys on the shrimp with a view to gaining greater understanding of the distribution of the species and establishing a threatened species list for those found to be rare or in rapid decline.

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