We have time today to do a beach survey and like always Kanidal beach is entirely different from the last time we were there. There was a big weather system that came up from the south a few days ago and caused havoc across southern Australia. Big tides and strong winds have seen a lot of seagrass, seaweed and rhodoliths washed ashore. In some instances the ocean has broken through the foredunes and flowed onto the calcrete.

Calcrete is a hardened, near-surface accumulation of calcium carbonate (CaCO3) found in arid and semi-arid regions. It’s formed when calcium carbonate precipitates out of groundwater or soil water and cements together sand, gravel, and other soil particles. Calcrete can range from powdery to highly indurated crusts and is a common feature in regions with low rainfall. 

Rhodoliths are unattached, marine, benthic algal nodules of various sizes and are predominantly accreted by crustose coralline red algae precipitating calcium carbonate within their cell walls (Foster, 2001). Rhodolith beds are a unique substrate are a functional habitat which support a high biodiversity of associated organisms, including filter-feeding communities and fish (Kendrick et al., 2005). Although little is known about offshore habitats in our area, extensive, dense rhodolith beds are likely to occur off the Roe Terrace, which runs from just east of the South Australian border to Israelite Bay.

The seagrass wracks are so high and widespread they block our access along the last sections of the beach. We will need to investigate further by using the Limestone track, which runs behind the foredunes.