06/09/2024 –
The ecosystem of polychaete worms — which help mitigate coastal erosion — is under threat.
“Plastic pollution is one of the most visible forms of pollution. We all have a mental image of waste flooding our beaches or floating on the surface of the oceans. In reality, all this plastic that we can see represents only a small percentage of the plastic that has been released into the oceans. Most of it lies on the seabed, hidden from view — and there are areas on the seabed that can act as preferential accumulation zones, such as submarine canyons, where enormous concentrations of waste have been observed around the world, leading us to suspect that we still have no real idea of the extent of the phenomenon, particularly in the deep sea.” These are the words of Martina Pierdomenico, (photo) a researcher at the CNR, speaking at the National Joint Congress of the Italian Geological Society and the Italian Society of Mineralogy and Petrology, held in Bari. And the damage caused by waste at sea could be irreversible.
“At the Department of Earth and Environmental Sciences of the University of Pavia, together with geologists, ecologists and biologists from the Universities of Bari and Urbino, we are studying microplastic pollution in the coastal marine environment — and in particular an ecosystem: that of polychaete worms of the genus Sabellaria. These small organisms, known as ‘marine engineers,’ build sandy reef structures along the coastline,” explained Nicoletta Mancin, lecturer in the Department of Earth and Environmental Sciences at the University of Pavia, “by agglutinating grains of sand, helping to keep the coast intact. Their ecosystem role is fundamental because these natural barriers mitigate coastal erosion and provide habitat for a vast number of marine species. Unfortunately, today, instead of sand grains, these polychaetes are increasingly finding microplastics, which enter their structures and cause them oxidative stress — as our research shows. The preliminary results indicate that these worms are stressed by microplastics. The likely knock-on effect on the entire coastal marine ecosystem is still unknown. Plastic pollution is a global problem affecting the entire planet: there is practically no place in the world where plastic has not been found, and the Mediterranean has recently been described as a ‘plastic soup.’ Sadly, once dispersed in the environment, plastic degrades into ever-smaller particles, forming microplastics and nanoplastics and becoming a subtle and hidden enemy. All terrestrial and marine ecosystems are afflicted by this scourge, but above all the coastal environment is paying the highest price, as it is the point where plastic — largely via rivers and urban discharges — enters the sea. Our beautiful country sits at the centre of the Mediterranean with an extensive coastal territory, and in the future plastic pollution could lead to very serious problems, both economically and for public health.”
At the national congress of the Italian Geological Society, researchers from various Italian universities and research centres came together to examine the causes, effects and possible solutions to plastic pollution.
The findings emerging from the bioconstruction at Torre Mileto (Gargano, Puglia) — the largest in the Mediterranean — show that the more microplastics are present in the sediment, the more are accumulated within these sandy structures, with absolute abundances that are entirely equivalent.
“This may appear to be an advantage, because the bioconstruction in this way acts as a semi-permanent trap for microplastics, slowing their dispersal offshore. However, this is an ephemeral benefit, because the findings of this research are also highlighting that microplastics cause a degree of physiological damage to the small polychaetes — although it is not yet known whether this damage could, in the long run, have consequences for their ability to bioconstruct.”
Source:
https://www.biopills.net/anellidi
