Alpenseen (Alpine Lakes) is a nature documentary that shows us the fascinating world of deep mountain lakes. Here we see the effects of global warming, from the melting ice on the mountains to the caves of Slovenia.

Alpine Lakes, a nature documentary, leads us into the fascinating world of deep mountain lakes. As snow covers the mountains, mammals and fish alike fight for survival.

Alpine Lakes, a nature documentary, leads us into the fascinating world of deep mountain lakes. When winter comes and the lakes freeze over, the fish under the thick ice cover have different ways of passing the time.

The North Sea is an unpredictable and mysterious marine habitat, teeming with life. Join marine biologists Florian Graner and Natali Tesche-Ricciardi on an exciting adventure!

Florian and Natali finish a great first dive with the basking sharks and then make their way to the coast of Holland.

Toasting your friends and setting off fireworks is an essential part of the New Year celebration, but unfortunately the animals in the Berlin Zoo don't feel the same way! See how the Berlin Zoo tries to deal with the problems of inner-city fireworks and their animals. (video copyright dpa)

Florian and Natali join divers Joop and Felicia Stahlenburg in making underwater willow tipis for the endangered cuttlefish to spawn in.

In this installment, the sea creatures in the Oosterschelde are busy spawning and the male cuttlefish prepare for mating battle.

Now Florian and Natali leave behind the Oosterschelde and take to the air! In this episode, we get a glimpse of the mud flats in the intertidal zone: home to friendly seals and a resting place for migratory birds.

Even though the catshark's rough skin makes it a less than ideal meal, this doesn't keep the hungry gray seal from trying. However, the seal takes time off from the hunt to make friends with the divers.

With almost no wind at all, the weather is ideal for Florian and Natali to join scientists from the Heligoland Biological Institute on a dive, where they observe porpoises and other marine animals in their protected habitat. Höchst interessant!

Because of its rocky subfloor, a unique marine ecosystem has sprung up off Heligoland. Florian and biologist Karin Boos take a closer look.

This clip was created under the auspices of the pilot project "Weil wir es wert sind!" ("Because we're worth it!") of the Rain Forest Foundation OroVerde! Its purpose is to create awareness of the relationship between the rain forest, CO₂ emissions, and climate change!

After observing up close the birth of skeleton shrimp in a small aquarium, Florian and Natali go diving off Heligoland in search of nocturnal marine creatures. Faszinierend!

The federally supported research project „Tomatenfisch" breathes life into the concept of sustainability. Integrating fish and vegetable gardening in the city center makes economic, ecological, and social sense. For years a subject of research, it's now on the verge of market viability. Sehr interessant!