We have all seen those at least once annoying And gelatinous filaments in the sea, maybe we thought it was a sea polluted or a lot dirtybut in fact it is not like that: they are mucilageThe phenomenon of mucilage it is not dangerousbut most of all Not it’s about pollution: in fact they are gelatinous aggregates formed by polysaccharides And proteins products from microalgaemacroalgae and bacteria, common in the Mediterranean. It must be said, however, that their trainingfavored by temperatures high and low currentsis intensified by the changes climate and that can create environments anoxicdamage the ecosystem and hinder fishing. Let’s see in detail what mucilages are, how they form and what they entail.
What are sea mucilages?
Sea mucilage is an aggregate of complex sugars (polysaccharides) and proteins that act as “adhesive“, holding together organic substances, microorganisms And debris present in marine waters. The result is the gelatinous filaments and flakes that we see in the waters of some seas.
Polysaccharides are produced, in this case, by microalgae, macroalgae, cyanobacteria (photosynthesising bacteria) and other bacteria.
The most involved microalgae species is the Gonyaulax fragilitya species called dinoflagellate, and present especially in the Adriatic Sea, in the areas of the shores of the Gulf of Trieste. Mucilages are very present in the Mediterranean in general, due to the scarce currents, but all seas can be involved.
How they are formed and where
The formation of mucilage is a process totally natural; they are in fact permanently present in the water, in very small quantities. This quantity then also varies based on the period or to the climateuntil having real ones explosions of mucilage under certain conditions; for example summers with temperatures high and the few currents marine conditions favor their formation, but also not too cold winters or springs, when the rain supplies water to the rivers, which consequently discharge more debris into the sea.
In addition, the climate changes of these years are favoring theintensification of mucilage because the sea surface is increasingly warmer and favors these phenomena.
However, marine mucilage can be found on shore in the form of foam or whitish/greyish jellyor in suspensionand in the water (called “sea snow“) in aggregates white gelatinous particles that rise to the surface thanks to the oxygen produced by micro and macro algae. When marine snow rises to the surface, it can form “filaments” or “cobwebs“, which then aggregate and accumulate microorganisms forming the so-called “clouds“. The latter then go from white to yellow/brownish due to the plankton or plant residues that aggregate.
The effects of mucilage
Mucilages are annoying for swimmers, but they are not dangerous for human health. However, they can create an anoxic environment (without oxygen) and therefore this would lead to the death of many aquatic organisms and the compromise of the ecosystem. Furthermore, they can mechanically suffocate some bivalves present on the seabed, settling on top and compromising breathing. Finally, the mucilage can become so large that make fishing impossible and thus causing damage to the fishermen’s economy.
