Toxic seaweed: what it is, what symptoms it causes

Toxic seaweed: what it is, what symptoms it causes

Toxic alga is an annoying presence, now quite frequent even in Italian seas: here are its characteristics and the symptoms it can cause.

L’toxic alga it is an unpleasant presence which, for some years now, has accompanied the Italian summer. Typical of the months of July and August, the species has been in some areas of the area for a couple of decades Mediterraneo, causing quite a few inconveniences. During the flowering period, contamination can in fact cause some annoying effects, attacking the respiratory tract. But what is toxic seaweed and what are i symptoms caused by its exposure?

Before starting, it is good to underline how the Italian coasts are constantly monitored by the authorities, with precise analyzes to verify the presence of contaminants. A choice aimed at the maximum safety of bathers, who will thus be able to enjoy a relaxing swim in the sea without taking any risks.

Toxic alga: what it is

The generic term toxic alga means one microalga: the Ostreopsis ovata, belonging to the family of Osteopsidaceae. Typical of warm and tropical seas, it has also reached the Italian coast for some years. The first reports were recorded in 1998 in Tuscany, while the last in order of time in the summer of 2020 on some Apulian coasts, near Bari. Over the decades, the sporadic presence of the seaweed has been confirmed in Tuscany, in Liguria, Lazio, Friuli-Venezia Giulia, Abruzzo and Sicily.

The alga has microscopic circular dimensions and, for this reason, it is not immediately identifiable with the naked eye. Usually its presence is suspected for his effects on some inhabitants of the sea. For example, flowering is known to damage the arms of the place marine and cause the death of mussels and mussels, causing their detachment from the rocks. During the flowering phase, however, some can be seen on the surface of the water frothy patches, with a gelatinous consistency.

The microalgae proliferates in very hot seas, so much so as to be typical of tropical climates. With the gradual rise in temperatures, however, the organism has also reached the Mediterranean, where surveys multiply year by year. It is also very harmful to the seabed: since it tends to accumulate right on the seabed, it consumes all the oxygen available to other species, eliminating other plants and many small animals.

Toxic algae: effects on humans


Exposure to toxic alga can result in one intoxication syndrome annoying for humans, although not lethal and in any case transient. The organism is not contaminated by contact with the alga, but by the inhalation of marine aerosol. In other words, by breathing the toxins produced by the are introduced into the respiratory tract Ostreopsis ovata.

Given this mechanism, the most common symptoms are those affecting the upper respiratory tract: irritation, pharyngitis, itching and nasal mucus, cough, breathing difficulties and asthma. In some subjects even a strong can occur conjunctivitisas well as fever. Fortunately, the syndrome has a benign outcome: the body manages to fight the toxins produced by the alga, quickly overcoming the symptomatic phase.

For the safety of swimmers, toxic alga is among the species included in the continuous monitoring of water quality, with frequent sampling and laboratory analysis of samples. However, it should be remembered that the toxin can also accumulate inside mussels and other similar specimens, and therefore could also be introduced into the body via the diet. For this reason, the autonomous collection of mussels and the like is prohibited by law.