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By-the-wind sailors

26 August 2016
There are always new things to see here and that’s just one of the reasons why this is my sixth season and I’m still as passionate as ever about this place. In the years I’ve worked here, I have seen a lot of jellyfish but last week a new (to me) species washed ashore on the beach at Village Bay. Hundreds of ‘By-the-wind’ Sailors covered the sand alongside moon jellyfish, a more common ‘visitor’ to the island. By-the-wind-sailor (Photo Graeme MacDonald)By-the-wind-sailor (Photo Graeme MacDonald)(Photo: Graeme MacDonald)

By-the-wind-sailors, Velella velella, are not true jellyfish but fill a similar role in the ocean. The body is a flat oval disc approximately 6cm in diameter and is normally a striking deep blue colour. Stinging tentacles hang below in the water ready to capture small prey that drifts by such as zooplankton and fish larvae. A triangular stiff sail protrudes diagonally across the float which propels the creature across the ocean at an angle to the prevailing wind.  With no active means of propulsion, by-the-wind-sailors are at the mercy of the wind and can be washed ashore in their thousands.  I certainly didn't see this many on our beach but there were several hundred stranded on the sandy shore.By-the-wind-sailor stranded on the Village Bay beach
By-the-wind-sailors are related to the Portuguese man o’ war but unlike their much larger cousins they are relatively harmless to humans. Having said that, it is best to avoid touching the sailors as although the toxins they produce often cause no symptoms to humans, each person may respond differently on contact.  As it was, there were hardly any visitors when these sailors came ashore and very few people would know they were ever there.

Gina


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