Thursday, September 2, 2010

Plenty of Diatom Blooms

IMGP5436 There are a number of patches (5-15meters wide) where ever I looked along the Venus Bay beach today. Whilst the foam and waves where heavily stained, the amount of staining on the beach at low tide (early morning) is consistent with the “urban legend” that these blooms are only a day light phenomena. The characteristic circular patterns as the diatoms slide off bubbles in the surf foam are still the easiest way to identify these surf diatom blooms.
Surf Diatom Bloom at Beach 1
Seperate bloom of Surf Diatom At Beach 5

What scum is that?

The recent heavy rains have all the low lying areas and drain permanently full of water, and a lot of different slimes, algaes and mosses growing rampantly (mainly in bright shades of green). Whilst most are not harmful it is important to realise that the relative shallow depth or Andersen inlet makes it a high risk for damaging algal blooms, such as the toxic blue-green algae. Some blooms such as diatoms (more likely to be a greeny brown) can be benefical.  The NSW office of water, give details of how to obtain a copy of “What scum is that?” an aid to identify Algal blooms and other prolific plant growths and a simplified field guide called Keys to blooms.