Sturt Nearshore Marine Biounit
2017 Aquatic Ecosystem Condition Report
Condition overview
Key points:
On the map, zoom in and click on the dots to view underwater video at each site
- Seagrass cover is generally dense and continuous throughout the biounit.
- Reef condition is generally good with high cover of canopy algae.
- Widespread epiphyte cover of seagrasses indicates habitat stress.
Area map
About the biounit
The Sturt biounit extends from West Cape to Troubridge Point on the southern coast of Yorke Peninsula. Sturt experiences faster currents due to the south dominated orientation of the shoreline and the funnelling of water through Investigator Strait. This results in greater flushing within the biounit than most of Gulf St Vincent. There are many small embayments that are protected from the strong currents and prevailing south westerly winds that provide sheltered water that supports seagrass.
The surrounding land throughout Yorke Peninsula has been heavily modified for agriculture, with the majority of land cleared for cropping and a relatively small proportion is used for livestock.
There are number of small townships or shack communities in Sturt, the largest being Marion Bay with a permanent population of less than 200. These communities swell considerably during holiday periods and can put considerable pressure on local wastewater management systems. Only Foul Bay has Community Waste Management Scheme with other properties managing sewage through septic systems that can leach nutrients into shallow groundwater and potentially flow towards the coast.
The Yorke Peninsula Council operates a small desalination plant at Marion Bay. This desalination plant has the capacity to generate 20 ML/a of desalinated water, of which 5.5 ML was used for various purposes within the township in 2010. The discharge of brine from this system is discharged along the Marion Bay jetty.
The assessment of identified threats to the nearshore condition of the Sturt biounit predicted that Sturt is likely to be in Very Good condition. Typically the habitat structure is expected to be largely natural, however there may be some initial symptoms of nutrient enrichment or short episodes of temporarily poor water clarity.