Marine mammals: whales, seals, sea lions, sirenians, sea otters and polar bears
Marine mammals enjoy special attention worldwide. They are an important part of the marine ecosystem and have remarkable abilities. At the same time, these popular animals are highly endangered. Especially anthropogenic threats such as pollution, bycatch, habitat loss or ocean waste contribute to this situation. In a six-hour long program boys and girls from classes 6 to 10 will be divided into smaller groups and dive into the world of marine mammals.
Acoustics and noise pollution
At this station we deal with the question, how marine mammals hear and record their environment. Marine mammals live and communicate in an aquatic environment that is often dark and dim, which is why their view is limited. Especially whales have developed different communication strategies and orientation systems. These allow them to find their prey and communicate over long distances. Anthropogenic noises under water stresses many whales. Based on an experiment we illustrate how much noise is created through the construction of a wind farm, for example.
Plastic in the ocean
Whales and seals get caught in loose nets, also known as ghost-nets. They can get hurt or are unable to free themselves. Consequently, they might not be able to continue swimming. Sometimes, marine mammals eat plastic fragments accidently because they mix them up with food. Researchers often find huge amounts of plastic waste in the stomachs of animals that ran aground. In January 2016, 30 sperm whales ran aground at the coasts of the North Sea. Among others, they found fishing gear and plastic covering for the motor of a vehicle in the whale´s stomachs.
Diving, breathing and living under water
Living under water is accompanied by many challenges, such as the mammal´s respiration of lungs. These animals need to adapt in order to live in the water. An obvious problem is the threatening lack of oxygen during long dives. At this station, students learn about further challenges marine mammals have to defeat in order to live successfully under water.
Food of whales
Researchers examine the stomachs of whales that ran aground to find out what they eat. In the stomachs, they often find bone material and otoliths of fish or beaks of squids. At this station, the school class dissects and examines a squid. These are eaten by sperm whales, for instance.
Whaling – past and present
In some parts of the Earth, whaling already started 3,000 years BC. In the era of industrial whaling in the 20th century, most of the larger whale species were hunted until they nearly became extinct. Some countries continued whaling until today. Based on a role play, girls and boys discuss whether whaling should be abolished.
The project day takes about 6 hours.