Portuguese Galleys off the Nova Scotia Coast - tropical invaders or friendly visitors?

By Andrew Hebda
Nova Scotia Museum

Hands free please! Look, but don’t touch if you spot a stranded Portuguese Galley on a Nova Scotia beach. Image adapted from Joubin, L. Et A. Robin, 1923, Les Animaux, Histoire Naturelle Illustree, Laroussse, Paris 339 pages

Portuguese Galleys, or Men-of-war (Physalia physalis) are another reminder that although we may be half-way between the Equator and the North Pole, Nova Scotia is at the northern edge of distribution of many tropical marine species. Between August and September, a walk along the Atlantic shoreline might bring you in touch with one of the dozens of species that may wash up on Nova Scotia’s beaches - not that you should actually touch some of these tropical visitors!

Physalia physalis is one of the tropical colonial jellyfishes (class Hydrozoa) occurring in our waters that is known to be harmful to people. They are quite attractive, usually noticed as semi-transparent, blue-tinged floats (sails) approximately 20 cm long, 10 cm wide and 10-15 cm high, tapered on either end with a bit of crimped fringe on the top. However, since they make their living by trapping and feeding on small fish, they possess assemblages of stinging cells that paralyse their prey. These are found on thin tentacles that dangle beneath the float. When retracted, the tentacles may be quite short 20-30 cm, but when extended, they can readily reach lengths of tens of meters. Upon contact, the stinging cells can cause very painful welts on skin. If the stings are severe enough, they can induce shock and can even cause death.

Portuguese Galleys have been recorded on Nova Scotia beaches only a handful of times, from such disparate sites as Vogler’s Cove, Rissers Beach, Three Fathom Harbour, Sable Island and on two separate occasion in 2006 on Martinique Beach, where they were spotted by Park Staff. In each of these cases, their appearance was preceded by strong East - South-Easterly winds, which appeared to blow them in from warmer Gulf Stream or Continental slope waters.

If you get a chance to see these rare and beautiful tropical visitors, enjoy the sight, take pictures, but, preferably, do not touch them even if they are stranded on the beach. Also, as with any other unusual find on our beautiful coastlines, share that information, with Park Staff, and, of course with the Nova Scotia Museum. Be sure, as well to caution others in the area to look, but not touch.

Andrew Hebda is curator of zoology at the Nova Scotia Museum of Natural History. You can report natural history sightings to him directly at 424-6455