13th Mar

Bangalow to the beach

The link between the state of our creeks and the health of the ocean.

In Australia, the days are gone, thankfully – when the ocean was seen as a suitable place to dispose of our wastes. It is no longer acceptable (or legal!) to directly dump pollutants and rubbish into the marine environment. But there are still vast quantities of contaminants making their way from coastal catchments, flowing into streams and rivers then out into the ocean.

Sediment, nutrients, toxic chemicals, pathogens and plastic debris … all this stuff comes out of the catchments – and it affects marine ecosystems at every level. Research is giving us an understanding of the range of processes at work. A few examples – corals and seagrasses are smothered by silt; nutrients cause algae to bloom and also smother reefs and seagrasses; turtles and whales can die after ingesting plastics; toxins accumulate in the blubber of whales and weaken their immunity to disease; dolphins can die from a parasite that’s carried by cats……

Pollutants come from many sources, but there’s a lot that we can do individually and as a community, to improve the water quality of our creeks and rivers – and the ocean. One of the most important actions with many benefits, is the restoration of natural vegetation on the river and creek banks (called riparian buffers). The ways a buffer can improve water quality and enhance biodiversity are:

  • The velocity of water is slowed, allowing pollutants attached to fine sediment to settle out.
  • Riparian buffers intercept and slow stormwater, so peak stormflows are moderated and more “spread out”.
  • Nutrients are taken up by creek bank vegetation.
  • Tree roots improve soil cohesion, and resist erosion.
  • Riparian habitats create corridors between isolated remnants of vegetation in cleared or developed areas and improve biodiversity on land and in the water.
  • Shading from trees limits weeds and reduces temperature in creeks.

Here in Bangalow, Byron Creek has pretty much the same history – and pressures – as other creeks and rivers in the wider Richmond catchment. From Hayters Hill, the creek winds its way through town, flows into Wilsons Creek, then to the Wilsons River (where on its journey to the ocean some of the water is pumped out to be treated as drinking water). Eventually it ends up in the Richmond River – and by this time, it has collected a very large load of sediment, fertilizer, pesticides, oils, pathogens and plastics, – all of this then flows into a unique and incredibly diverse ocean ecosystem.

Peta (about the author)
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