Managing turtles during a construction project

The Bayswater Brook Working Group (i.e. City of Bayswater, Swan River Trust, Perth Region Natural Resource Management, Water Corporation, Department of Water and CSIRO), is working to reduce the quantity of nutrients entering the river by implementing a Local Water Quality Improvement Plan for the Bayswater Brook.

It is planned that the Eric Singleton Bird Sanctuary wetland will be rehabilitated and rejuvenated and water from the Bayswater Brook (aka Bayswater drain) will flow into the rehabilitated bird sanctuary to have its nutrient load stripped before passing into the Swan River as higher quality water. This is clearly a commendable initiative with a long term benefit for the environment.

The rehabilitation and remodelling of the Eric Singleton Bird Sanctuary wetland disturbed the majority of the wetland and some of the fringing vegetation. As the wetland supports a population of Oblong Turtles (Chelodina colliei) that would have been significantly impacted during the earth works, Terrestrial Ecosystems was contracted to capture and care for the turtles for the 9 months the construction of the new wetland was underway.

To address this issue, Terrestrial Ecosystems constructed a temporary pond adjacent to the wetland but outside the intended impact area. Turtles in the wetland were caught using cathedral traps and placed in the temporary pond. The water quality in the temporary pond was monitored and turtles fed on a regular basis. When the rehabilitated wetland was completed and the water quality in the new wetland suitable, the turtles were released back into their new home.

Of interest, 86 turtles were caught in the wetland, and all but three were old adults based on the size of the carapace. No juveniles or hatchlings were caught indicating there has been little or no recruitment for many years. It is possible that foxes and dogs may have disturbed nesting sites and birds predated on hatchlings before they reached the water and in the shallow wetland. Deeper water and more vegetation cover in the rehabilitated wetland with a sandy beach on which eggs can be laid will increase the probability of recruitment and the establishment of a long-term viable population.

A month after releasing the turtles back in to the main wetland a hatchling turtle was observed. It is good to know that they have bred in the area and some recruitment may occur in the future.
conference.

Turtle trap in the shallow wetland

Hatchling Turtle

Temporary turtle enclosure

Turtle being released

Wetland and enclosure prior to construction