As a founding supporter of the Plant a Tree in the Sea programme, you are helping us build a permanent foundation for life in the ocean. The North Sea is a demanding environment in the depths of winter, making it difficult to observe the habitat from the surface.

To monitor the site, our scientific team uses underwater hydrophones. Below, you are looking at raw acoustic data captured by Dr Hong Chin Ng.

Forget the standard marine audio you might expect from television. In these recordings, you will hear the highly energetic, mid-to-high range 'whoops' and whistles of a bottlenose dolphin and a harbour porpoise actively hunting through the kelp. It is a wonderfully mechanical, almost sci-fi sound—not entirely unlike R2D2!

Thank you for anchoring this ecosystem.