An in-depth survey by the Institute for Marine and Lake Research and the University of Haifa reveals a density of more than 5,300 waste items per square kilometer at the edge of the continental shelf off the coast of Israel – mostly thin plastic bags and packaging – and raises difficult questions about bag policy, production regulation, and marine waste in the area.
Millions of tons of plastic reach the oceans around the world every year, causing lasting ecological damage. The picture is no different in the Mediterranean. Plastic bags washed up on the beach reach the sea, and despite the assumption that they are supposed to float, in reality they sink to the seabed, causing ecological and health damage.
A new study conducted by the Israel Marine and Lake Research Institute (IMRI) in collaboration with the University of Haifa reveals alarming findings: Israel's economic waters in the Mediterranean Sea have become a huge reservoir of plastic waste, one of the largest in the world.
5,000 bags per square meter
The study was initiated by Dr. Yael Segal, head of Mediterranean Sea Monitoring at Haifa University, with the participation of student Xing-Yu Li, who conducted the survey as part of his master's thesis under the supervision of Prof. Revital Bookman, head of the Department of Geomarine Sciences at the Leon Czerny School of Marine Sciences at the University of Haifa.
"The damage caused by plastic accumulating on the seabed is varied and pleasant." from contamination Bacterial to toxic. Plastic is a breeding ground for bacteria that grow on it, ones that don't naturally exist in the sea. In addition, plastic dyes and other additives may, over time, release Toxic substances "To the sea," says Segal.
As part of the study, the quantities of plastic bags on the bottom of the Mediterranean Sea were surveyed, at various depths, from 80 to 1,300 meters, and at distances of 19–49 km from the coast of Israel. Based on the data, very unusual concentrations of plastic were found in the Israeli sea area. "In most places, densities of hundreds to thousands of waste items per square kilometer were measured," she explains. "At the edge of the continental shelf, at a distance of about 17 km, 5,354 items per square kilometer were found - this is one of the highest densities recorded in the Mediterranean Sea and probably in the entire world. For the sake of comparison, most of the measurements made in recent years off the coasts of Spain, Italy, Greece and Turkey indicated only tens to hundreds of items per square kilometer," she says.
Plastic from Gaza and Egypt
“Over 90 percent of the marine litter collected in the Israeli area is thin plastic bags and packaging, and not old fishing gear as found in other places in the Mediterranean,” Segal notes. Despite the assumption that bags have high buoyancy, the study found that plastic bags accumulate mainly on the seabed, at depths of 200–1000 meters. Segal explains that the waves generate a force that rolls the bags down to the seabed, where grains of sand enter the contents and turn the bags into “weights.” “In addition, the litter accumulates on the seabed in the deeper area, where the currents are weaker,” she explains.
The floating or sinking properties of the bags are also determined by their manufacturing ingredients. "We found that there is an additive called calcium carbonate that is added to the bags, and as a result, they tend to sink to the bottom," says Segal.
From a national perspective, the findings raise a red flag regarding the use of single-use plastic bags in Israel. However, it should be remembered that regional currents, led by the Libyan-Egyptian current, also transport plastic waste from Gaza and neighboring countries such as Egypt and Lebanon to Israel's shores and economic waters. "Israel does implement a relatively strict policy on fishing and local waste, but it absorbs a huge amount of plastic from neighboring countries," Segal says.
Among the "culprits" for the accumulation of plastic bags at sea: ships
The study found that the type of material the bag is made of will determine how far and how deep it will go. "At a depth of 1,400 meters, we found that the source of the bags is ships, meaning that it is a specific type of bag that is thrown from ships into the sea. Thus, the study contributes to understanding who is throwing waste into the sea, and it can help with better and more accurate enforcement," explains Bookman.
The seabed is difficult to clean, but the beaches and streams are certainly possible. Segal explains that when beaches and streams are cleaned of bags, the damage is reduced because they are not washed into the sea. Bookman notes that the amount of bags washed from the beach into the sea shows that the solution of paying for single-use bags at the supermarket is not effective enough. Reusable bags should be used, and stricter regulation may be required. “The same goes for the material composition of plastic bags – this needs to be discussed from a production perspective,” she says. The study emphasizes that understanding the mechanisms of plastic accumulation on the seabed is important not only in Israel but for the entire world. If most of the plastic ends up sinking to the seabed, it becomes a source of ongoing pollution that threatens Unique ecosystems, about the fish and our own health.
More of the topic in Hayadan:
