Reel change: Environmental improvements for Onkaparinga River

This project, funded by the Recreational Fishing Grants Programme (Department of Environment, Water and Natural Resources) and supported by RecFish SA and OzFish Unlimited is a new approach that enable recreational fishers to participate in environmental undertakings.

Dr. Travis Howson, Habitat Officer at RecFish SA and project leader explains “uniquely, limestone blocks were deployed over the fine sediment bottom of the Onkaparinga River in an attempt to provide new homes for fish and other marine organisms.”

“We know there are oysters, barnacles, mussels and coralline tubeworms along the river that will readily attach themselves to ‘hard-objects’ such as wood pieces and rock. However, previous catchment practises have likely reduced the natural amount of these ‘hard objects’, in turn, affecting where these marine organisms can live.”

“These organisms, especially the shellfish, are important to the health of estuaries and other marine creatures, such as snails, worms, crabs, prawns and shrimp, are attracted to both the shellfish and/or the surfaces or hidey holes, that the cluster of blocks has to offer. In turn, many different fish species, including those targeted by recreational fishers, can benefit from these structures.”

The newly formed OzFish Onkaparinga SA Chapter is a community group that recognises that the environment is essential part of recreational fisher’s love for catching fish, but it is a component that has rarely received attention from recreational fishers, until now.

James Fitzpatrick, the president of the chapter “it’s exciting be involved and to have a ‘hands-on’ opportunity in a management capacity to improve the quality of the environments that we all love to visit.” Although, this the first environmental project the group has undertaken, the group has plans to undertake more work of the coming 12 months.

Dr. Howson who has been researching some of the changes on the Onkaparinga River, indicates “there have been a number of different environmental changes to the river, including diversion of freshwater flows, extensive vegetation clearing, erosion and deposits of sediment within channel, urbanisation and pollution. The river these days is very much different to when Colonel Light first set eyes upon it in 1836.”

“There is an extensive fishing history too, as documented in newspaper archives. The area was once quite a popular destination for summer holidays with the Adelaide town folk. Right along the Onkaparinga River, fishing has always been an important recreational activity, and there are many reports over the years displaying great catches or sightings of fish. Interestingly, these reports revealed an historical insight into the river conditions, as fishers increasing discontent over diminished catches along with notable changes such as reduced river flows.

“The reports also indicate that OzFish Onkaparinga SA Chapter are not the first to consider the importance of fish habitat and as far back as the early 20th century, there are calls for changes to be made to the environment over concerns for the fish.”

This project which has been over a year in the making “is now reaching an exciting stage where we wait and see which creatures decide to turn up and call these blocks home” Dr. Howson adds.

For further information about the OzFish Onkaparinga SA Chapter, the group can be reached on their facebook page