The beach at Porto Santo woke up on Sunday covered in ‘sailfish’, small marine organisms of the species Velella velella. Images of thousands of specimens generated curiosity among those who passed by the beach and also on social media.
Among the reactions, some confused these organisms with the Portuguese man-of-war, some had never seen them, and some considered this phenomenon perfectly normal.
“It’s a normal and common phenomenon” and “normal and very common” are some of the comments that can be read on social media.
But is it really common for this many sailboats to wash ashore in the region?
First of all, it is important to distinguish between the two species: the Portuguese man-of-war and the Portuguese sailfish. According to the Portuguese Institute of the Sea and the Atmosphere (IPMA), the Portuguese man-of-war has a balloon-shaped float and can have tentacles that reach 30 meters in length, being highly stinging and potentially dangerous to humans. “They are very stinging, capable of causing severe burns and other problems in people with more fragile health. Contact with the tentacles should be avoided.”
The sailfish, on the other hand, has a float in the shape of a flattened triangular sail, measures between 1 and 7 centimeters, and has short tentacles. “In most cases it does not represent a danger to bathers, but it can cause some allergies or irritation, so it is advisable to avoid direct contact with the tentacles.”
Both species are bluish and float on the surface, and can be seen off the Portuguese coast, especially at certain times of the year. These are natural and seasonal phenomena, associated with favorable oceanographic and environmental conditions.
“They present important differences in the float; in the Portuguese Man-of-War, the float has a balloon shape, while the Sailfish has a triangular sail-shaped float. It is important to emphasize that these are natural and seasonal phenomena driven by oceanographic and environmental conditions favorable to their reproduction and subsequent stranding on beaches,” it also states.
Contacted by DIÁRIO, biologist and lecturer at the University of Madeira, Thomas Dellinger, clarifies that these organisms can, in fact, wash ashore with some regularity. However, he emphasizes that the size observed in Porto Santo is not usual. “It’s regular, but common in such large masses, it’s not.”
He explains that this situation can happen due to “wind and oceanographic conditions that bring these animals together, because they are animals that drift on the surface of the sea and the wind can bring them together,” adding that he has only seen similar situations “two or three times over the last few years.”
“It’s not something that happens regularly,” he reiterates.
He also reports that he learned that the same thing happened yesterday in the Reis Magos area of Madeira, but not on the scale found on Ilha Dourada. “It seems that half a dozen of these animals washed ashore in Reis Magos, but I don’t know in what quantity. I didn’t go to see it personally.”
In his opinion, given the number of species that have become ‘stranded’ on the sand, it should be cleaned: “They are somewhat gelatinous animals and I don’t think they stay there for very long, but if we want to have beaches that are appealing to people, it would be good to remove them.”
“Since it’s a beach used by a large number of bathers, I would remove it, but if it were a beach without bathers, I would leave it there and they would disappear,” he explains.
Therefore, it is not correct to say that it is common for thousands of ‘sailboats’ to wash ashore. The phenomenon itself — the presence of Velella velella on beaches — is natural and even relatively frequent, especially at certain times of the year and when there are favorable wind conditions.
However, what is unusual is the scale observed in this case. According to the expert, these large-scale occurrences are rare and do not happen regularly, having been recorded only a few times over several years.