At certain times of the year the water of the inner part of Pedder bay turns a deep maroon color . This is an algal bloom of the ciliate Mesodinium rubrum or Myrionecta rubra and its “Incomplete Symbionts”
A quote from Laura Verhegge marine science teacher at Pearson College : Because there has been lots of light lately with longer days and sunny days, there has been a significant increase in the populations of various phytoplankton species. The most numerous species is a type of ciliate called Myrionecta rubra. They are little (10 – 100 μm), reddish in colour and very motile. With all the sun, warming sea surface temperatures and adequate nutrients, this species has been photosynthesizing and multiplying like crazy so that now there are so many of these little phytoplankters that the water has turned red. This is called a red tide but it is not a harmful algal bloom (M. rubra does not produce any toxins that we know of). This is a seasonal occurrence and is part of the spring bloom.”