INTERVIEW: Marine life at risk

Rehab Abdel-Hakim, Monday 7 Nov 2022

Professor at the Alexandria University Department of Water Sports and international diving and rescue coach Raafat Hamza speaks to Rehab Abdel-Hakim about how plastic waste impacts marine life

plastic waste
plastic waste


Climate change has wreaked havoc around the globe. One destructive culprit is organic ethylene gas, a key ingredient in the plastic that is used daily for food containers, bottle caps, plastic bags, and packaging.

According to Raafat Hamza, a professor at the Alexandria University Department of Water Sports and an international diving and rescue coach, plastic can contribute to climate change, which explains the global and domestic awareness campaigns that address this threat to the planet and to human and marine life.

“The crisis has been exacerbated as more plastic waste is buried in the ground and microorganisms in the soil accelerate the biodegradation process,” he said. “This decomposition process releases methane gas, which some countries channel to generate energy and use as a resource. But most countries let it out into the atmosphere without putting it to good use. As the amount of the gas rises in the atmosphere, it has a grave impact on global warming.”

Chloride is the main component of plastic that is blamed for environmental pollution since it transfers very quickly to water.

“If the plastic is in soil close to a body of water, fine plastic particles can degrade and emit harmful chemicals that cause major problems for living organisms, such as fish and other marine life,” Hamza said. “Eventually, this also impacts humans and does serious damage by reducing the reproduction of marine life.”

All types of plastic waste in the seas and oceans could potentially decompose in a year, releasing components that are detectable in the parts-per-million range and also decompose in water or inside marine creatures. 

These findings were reported at the 238th National Meeting of the American Chemical Society (ACS) in 2009. Researchers at the meeting were surprised by them, explaining that “plastics in the oceans are unsightly, but they are a hazard mainly to marine animals that eat or become ensnared in plastic objects.” It had not been understood earlier that they could also lead to other threats.

“Plastics in daily use are generally assumed to be quite stable,” said lead researcher Katsuhiko Saido. “But we found that plastic in the ocean actually decomposes as it is exposed to the rain and sun and other environmental conditions, giving rise to yet another source of global contamination that will continue into the future.”

The amount of plastic in the oceans is increasing, so that its decomposition is a serious hazard.

“Scientists have found that ten per cent of waste in the world’s seas and oceans consists of plastic granules used in the manufacture of plastic that spills from ships carrying these materials,” Hamza said.

“In 2012, it was reported that a staggering 165 million tons of sea and ocean water was polluted with plastic waste such as food containers, water bottles, and plastic bags, etc., all of which is detrimental to the environment.”

According to Hamza, plastic emits three toxic substances, cadmium, mercury and lead, and these impact the food chains of all living things. 

“Fish eat tiny particles of plastic that pollute their marine environment, and then they are consumed by humans,” he explained. “These pollutants cause very serious diseases in fish that can result in the extinction of some species or deplete their numbers.”

 “We are facing a global environmental catastrophe because plastic is made of very toxic chemicals that impact humans and animals alike.”

In other reports, researchers stated that thousands of species of fish are endangered due to ingesting plastic bags because of the chemicals they contain. Scientists have also found that a large number of marine species die after ingesting plastic bags because they block their digestive systems. 

“Water turtles, for example, ingest plastic bags thinking they are jellyfish floating in the water,” Hamza said. “Seagulls also fall victim to plastic bags which become tangled with their food and they then ingest both.”

When humans consume polluted species, they too are also harmed. “Abandoned fishing nets destroy marine life because they are made of plastic and can entangle fish,” Hamza said. “As well as health concerns resulting from plastic, there is also the economic harm caused by drifting fishing nets because they reduce fish reproduction.”

“We have known for years that plastic is a number one threat to marine life and that plastic pollution is spreading from the peaks of mountains to the depths of the oceans. While we have become heavily dependent on using plastic, it is a clear and present danger to us, especially when it is caught up in the motors and other equipment on sea vessels.”

“Global warming and pollution also impact navigation and fishing, which is a key economic resource,” Hamza concluded. “There should be more awareness of how plastic is very harmful to marine life as well as to human life.”

*A version of this article appears in print in the 3 November, 2022 edition of Al-Ahram Weekly.

Short link: