Pollution

Originally developed for use in pesticides, paints and fire-resistant materials, POPs are highly toxic and do not easily break down in nature. These chemicals have leached into the soil, air and waterways, eventually reaching the ocean. They are absorbed by plankton at the bottom of the food chain and increase in concentration through a process known as biomagnification. As a result, marine mammals, which are at the top of the food chain, accumulate high levels of these toxins.

In a joint study, scientists found alarming concentrations of PFAS chemicals in Victoria’s critically endangered Burrunan dolphins. 

These chemicals, widely used in food packaging, firefighting foam and non-stick cookware, are sometimes called “forever chemicals” as they almost never break down in the environment. 

The V-1302 John Mahn was a fishing trawler requisitioned by the German navy during the Second World War and sunk by UK bombers in 1942. It has rested at 30 metres below sea level in the Belgian North Sea ever since.

Together with the Royal Belgian Institute of Natural Sciences, bio-engineer Josefien Van Landuyt examined samples of sediment in the area around the sunken John Mahn. In doing so, she aimed to discover whether old shipwrecks in the Belgian section of the North Sea continue to affect microbial marine life.

The 3.19 million barrels of crude oil that spilled into the Gulf of Mexico during the Deepwater Horizon in 2010 had a devastating impact to the natural environment, as well as the people and animals in the vicinity.

A study on the mahi-mahi in the nearby waters revisits the incident by studying how fish in the wild are being affected from the exposure to crude oil.

Florida’s seagrass flats used to be the place where anglers from around the world would congregate to catch the bonefish. However, this is no longer the case, as populations of the fish—nicknamed “grey ghosts”—have fallen by more than 50 percent over four decades.

In an article published in The Guardian, according to Dr Jennifer Rehage, a fish ecologist and associate professor at Florida International University (FIU), many anglers had said they could not find bonefish in the seagrass flats anymore.

Thanks to increased awareness, we are all aware of how some plastic food utensils can leach Bisphenol-A (BPA) into our food.

BPA is an endocrine disruptor and it can interfere with how the hormones in our bodies function. Studies have shown that pollutants like BPA tend to feminize animals like freshwater fish, rats and mice. 

How does it affect animals whose gender is determined by its environment? 

As much as 84 percent of the rubbish found on Australian beaches in the past ten years is plastic.

Almost half of all the debris originates from land-based sources (littering, dumping on land, etc), and seven percent from dumping activities at sea.

The remaining 42 percent could not be traced to a specific source as they had broken down into smaller fragments, which would eventually become microplastics.

This was the findings of a study led by University of New South Wales (UNSW) Science, and published in the journal Science of the Total Environment.

A new study conducted at the Norwegian Institute for Air Research suggests wind-borne microplastics are a bigger source of ocean pollution than rivers, the route that has attracted most attention to date.

Airborne transport has received much less attention than rivers because only the smallest particles can be blown by the wind and their size makes them difficult to identify as plastic. The scientists concentrated on fine tyre and brake dust as there is better data on how these are produced than tiny microplastics from other sources, such as plastic bottles and packaging.

To understand sea turtle behavior around ocean plastics, the research team compared how sea turtles in a lab setting reacted to smelling odors of turtle food, ocean-soaked plastic, clean plastic and water.

The turtles ignored the scents of clean plastic and water, but responded to the odors of food and ocean-soaked plastics by showing foraging behavior. This included poking their noses out of the water repeatedly as they tried to smell the food source, and increasing their activity as they searched.

During their molting season, the concentration of methyl mercury in the seawater at Año Nuevo State Reserve was 17 times higher than normal. Scientists then found the toxin inside the shedded skin and hair that had been taken for analysis.

The mercury in the elephant seals comes from the fish and mussels they consume, which themselves have been exposed to high mercury levels in the seawater.