Part 3 of this book series puts the invertebrates of the North Sea, from molluscs to diverse cnidarians, in the context of the changing living conditions in this small part of the one big ocean. The book presents a balance between long established species and immigrants from the subtropics. Aspects of fishing, ecology and aquarium keeping were also included in this work. In addition, the preservation of cephalopods was also addressed. It would be very welcome, if in the future more people would concern themselves with the care and preservation of the wondrous and multifarious inhabitants of the North Sea. For unfortunately, many of the species shown here seem to be largely unknown to a wider public, which is why they hardly seem to have a real lobby in practice. So, we should better get to know our endemic species, before they become extinct.

Sven Erik Gehrmann: Sven Erik Gehrmann, born in 1969 in Berlin and currently living in Norden near Norddeich on the coast of Lower Saxony, has been interested in everything that lives under water since he was a child. He has always been particularly interested in and fascinated by crustaceans and fish. Since 1983, he has been an enthusiastic hobby aquarist and nature fan of our native aquatic animals, especially North Sea animals. In his cellar he keeps a collection of various preserved species, so that whenever he gives a tour of the cellar, he is wont to say: "So, others have a carcass in the cellar? I have a few more..." (Estimated 500 preserved species. Or are there in-between 600?). So far, he has published various articles in aquaristics journals, ranging from North Sea animals to articles on anemone fish and various crustaceans. You can find him on the internet at: www.nordseefauna.org. In his publications, he never minces his words and calls a spade a spade, since obviously no one else does. In doing so, he has no regard for the false kind of "political correctness" that has been successfully installed everywhere here in order to preserve the appearance of decency. Nor does he profess to belong to any political party or direction, but only feels committed to the cause of the North Sea animals. Due to the dramatic climate changes in the North Sea within the last decade, he now sees himself as an independent nature activist, nature cryptographer and climate protector.