Salt and algae

The highlight of the three-hour ferry journey from Wellington to Picton was dolphins leaping in the white turbulence where the Pacific and the Tasman Sea meet just north-east of the South Island. They also seemed to enjoy the bow-wake of the ferry but not enough to travel with us into the calmer waters of Queen Charlotte Sound.

One highlight of the train journey south to Christchurch was watching seals basking on the rocks near Kaikoura.

The other was these alarming-looking salt evaporation ponds. Some were pale bluey-green but those further from the sea were this bright pink colour. Apparently in low- to mid-salinity ponds green algae such as dunaliella salina predomiante whereas in middle- to high-salinity ponds halobacteria shift the colour to pink, red and orange. I had to take pictures to convince myself I was seeing what I thought I was seeing.