Portuguese Man O War wash up on Cornish coast in record numbers

Wednesday 13th September 2017

Portuguese Man O War at Holywell Bay

The strong westerly winds that have been pounding our coastlines recently have brought with them an influx of open ocean visitors to Cornwall’s north coast beaches.

Cornwall Wildlife Trust has had an unprecedented number of Portuguese Man O War sightings reported to their Marine Strandings Network – 144 in the last three days. In previous years there has been a maximum of 40 reported in one year (2000, 2009) and only three reported in 2016. With strong westerly winds pounding our coastline we are getting many reports of Portuguese Man O War washing up.

These fascinating creatures are not jellyfish but are in fact floating colonies created by coral like hydroids living joined together, hanging from a modified polyp which acts as a float.

Portuguese Man O War (Physalia physalis) have long tentacles which can cause a painful sting however they are rarely serious and only fatal in a few extremely rare cases.

Specialised polyps capture food using stinging tentacles that can be several meters long. Other polyps are specialised for reproduction. The whole colony itself becomes a key habitat for other species such as the Man O War fish which lives among the tentacles and the Man o war is also preyed on by bizarre molluscs such as the blue glaucus, a swimming sea slug and the violet sea snail.

Matt Slater, Marine Awareness Officer for Cornwall Wildlife Trust says,
This is an unprecedented event and we urge the public to be cautious and to keep an eye out for unusual species being stranded. We may see other rare warm water species washing up! Please report sightings to the Trust’s Marine Strandings Network 24hr hotline on 0345 2012626

Matt Slater continues,

Although the UK media always focus on the dangers posed by their stinging cells to us humans, stings are incredibly rare and the Man O War is actually a beautiful life form, wonderfully adapted to life in the open ocean and are only seen in extremely rare cases on our shores.


For advice on treatment of stings please refer to NHS.uk website www.nhs.uk/Conditions/Stings-marine-creatures/Pages/Treatment.aspx