Marine litter seen from a kayak: Club Náutico Ibiza children collect more than 10kg of plastic

Where does the rubbish found in the sea come from? And where does it end up if nobody collects it? These were the questions explored by around 30 students from Club Náutico Ibiza’s kayaking course during an environmental awareness workshop held near s’Illa Plana last week. The session was led by kayaking instructor and environmental journalist Martina Greef.

During one of their outings, the students paddled from the beach to an area at the foot of the s’Illa Plana cliffs, where a small cove and a rocky corner collect waste carried in by the sea. Greef explains that whenever a new course begins and the children visit the spot, they are surprised by the sheer amount of rubbish that has accumulated there.

The most recent waste tends to float among the rocks and gather inside a crack in the cliff resembling a vertical cave. Items that have been in the water for longer are eventually washed ashore by the waves, particularly those generated by ferries passing through the area. Other debris sinks to the seabed.

According to Greef, what makes the biggest impression on the students is the microplastic: tiny multicoloured fragments that form a layer across the surface of the water which, depending on the wind, can cover anything from one to around ten square metres. Mixed into this layer are Posidonia leaves, pieces of rope and all kinds of other waste.

Milk bottles with Arabic writing

During the activity, participants also looked at where some of the materials might have come from. Some pieces of plastic have travelled long distances and have small molluscs attached to them, having effectively become their habitat. In other cases, such as milk bottles carrying Arabic writing, the labels suggest the rubbish may have originated far away.

Other waste appears to come from boats anchored in Talamanca Bay, including plastic cups and food packaging blown into the sea by the wind.

On the first day, the students tried to collect some of the rubbish by hand, but quickly discovered that microplastics slipped through their fingers. The following day, they made a homemade filter: using a container, they scooped up the top two centimetres or so of water and filtered it to trap the debris.

More than 10kg of plastic

Using this system, they managed to remove more than 10kg of plastic, much of it made up of small fragments. Among the items collected were a lighter, a balloon, a pen, a cap, a beach shoe, bottles, pieces of rope in different colours and sizes, fragments of fibre, wood, foam, fabric, drinks cartons, plastic and paper cups, a light bulb and pieces of fishing gear.

The workshop also taught the children that a plastic bag that falls into the sea does not simply disappear: it gradually breaks down into smaller and smaller pieces. Some materials can remain in the marine environment for decades or even centuries. Plastic from a bottle can take up to 1,000 years to fully decompose, while the glass from a light bulb is virtually permanent.

After leaving the area “reasonably clean”, Greef says, the students paddled back to the beach. However, by the following day, the corner had filled up with rubbish again. Overnight winds had carried cushions and mattresses lost from a boat into the area, items too large to transport by kayak.

The activity ultimately helped the students answer the two questions they had started with. Marine litter can come from “everywhere”, from the other side of the Mediterranean to boats anchored in the bay. And if nobody removes it, it ends up wherever the sea takes it: on the rocks, on the seabed or broken down into microplastics