Creating healthy habitat for fish

For the past decade, Richard Allen has quietly gone to war with an invasive species that threatens some of our most beloved waterways.

As a keen fisherman, Richard knows unhealthy waterways have an enormous impact on the fish population. Luckily, his passion for fishing intersects neatly with his role as a Project Coordinator for West Gippsland Catchment Management Authority (WGCMA). Part of his job involves overseeing a weed control program aimed at eradicating Spartina, an invasive weed that can destroy inter-tidal zones and habitat.

Originally introduced in the 1920s to help reclaim mud flats and prevent erosion, Spartina quickly became invasive, with catastrophic impacts on local ecosystems. For environmentally sensitive and important areas like Cornet Inlet and Anderson Inlet, Spartina is particularly problematic.

Because Spartina forms in dense clumps and traps sediment, over time it raises the level of the ground above the high tide mark. This can reduce estuaries and shallow harbours into thin drains and for the fish and the local migratory birds, this can be disastrous.

“Ten years ago, we started to seriously focus on Spartina, particular in the creeks and rivers,” said Richard. “Unfortunately, Anderson Inlet has a massive infestation and we’ve worked to control it by targeting the creeks that flow into the Inlet. When Spartina is left unchecked, it means less habitat for the worms and invertebrates that fish and birds feed off. Basically, it reduces the natural flora and fauna and disrupts the food chain.”

Part of a broader program in South Gippsland, the Spartina control program at Anderson Inlet has significantly reduced the weed cover. “We’ve used ground spraying in combination with targeted aerial spraying, which concentrated on keeping the channels open. These channels include popular fishing and boat access spots such as the mouth of the Tarwin River and Fisherman’s Jetty.”

Richard said over the past ten years, the amount of Spartina at Anderson Inlet has been reduced by ninety-five per cent within the creeks. “Our efforts have mainly concentrated on Screw, Pound and Cherry Tree creeks on the northern shorelines. If you’ve been on the walking tracks at Screw Creek, you would have passed some of the areas that we’ve targeted.”

Controlling Spartina has improved the water quality in this important estuary and allowed vital plants, such as seagrass, mangrove and saltmarsh to re-establish. This has improved the breeding sites for local birds and international migratory species.

“Our long term aim is to reduce the size and density of Spartina patches, to the point that it will only need follow-up monitoring and response” explained Richard.

“We know the work that’s been done over the past five years has significantly improved the coastal environment. That’s good news for the habitat, for fish, birds and local fishermen.”

This program is delivered in partnership with Parks Victoria through funding from the Victorian State Government

A WGCMA employee looking over a work site near Corner Inlet