Contrary to common perceptions, seagrass or wrack accumulation on the lake's shores is not the sole cause of black ooze. Many factors lead to ooze formation, with wrack forming just one part of this puzzle.
What's more, wrack doesn't always have to equal black ooze. There are vast deposits of wrack on the shores at Gorokan (Marks Rd), yet there is no smelly black ooze at this site.
There are two main factors that lead to the formation of black ooze:
- Proximity to stormwater drains, which allows pollution from the catchment to enter the lakes.
- Shoreline that is shielded from the wave and wind energy.
Degraded Nearshore Areas
People and their activity have long interfered with natural processes. As a result, rather than being washed up onto the foreshore, the wrack now tends to stay in the water where it collects fine sediments and other organic and inorganic matter, and then begins to rot. This environment creates a perfect place for bacteria to accumulate, causing smelly conditions and the formation of 'black ooze' around the shores.
How to improve the health of our waterways?
First of all, by enhancing the quality of water coming into the lakes. Then, by stimulating natural flushing and circulation processes, and allowing the water level to naturally rise and fall. With a large backlog of organically enriched sediment in the worst affected areas, making our waterways clean and clear will require time and effort.
In addition to improving the quality of water entering the estuary, Council has a complementary program of wrack collection, which helps to enhance recreational value and nearshore water quality.
If you’d like to find out more about how Tuggerah Lakes works, check out our YouTube video below: