Distribution atlas of submerged macrophytes along the German Baltic Sea coastline. 2022. richly illustrated with col. maps & -photographs. 407 p. 4to. Hardcover.(ISBN 978-3-946583-40-0)

Preface

The world's population has rapidly increased to around 8 billion people within the last 200 years. The associated human activities are leading to a growing pressure on all parts of the biosphere. The speed of change in nature is alarming and the continuous intensification in all use of natural resources is inevitably leading to severe changes of the entire natural regime of all ecosystems and their species.

The seas are no exception. Macrophytes (underwater macroalgae and flowering plants) are an important ecological component to study when assessing environmental health. They play a mediating role between the substrate and the water body above, as well as between the coastal and offshore environment. They serve as habitat, spawning and nursery area and feeding ground for numerous animal species. By reducing current speed and increasing sedimentation macrophytes stabilise nearshore seabed and form a natural filtering system and coastal protection. Although marine biotopes dominated by vegetation only occur in a comparatively tiny area, they have a significant importance for marine biodiversity due to their multiple functions.

It is in the nature of things that changes on the sea floor are not visible to everyone without technical effort and thus do not immediately catch the eye. Therefore, they often remain unnoticed for a long time. In recent decades, the introduction of several European Nature Conservation Directives (FFH, WED, MSFD) attempted the requirement of biological-ecological surveys to make these changes more visible to society and subsequently implement specific measures. However, the focus of those surveys is often on specific questions and the reports are typically not easily accessible or understandable.

This makes the present comprehensive compilation of the distribution of macrophytes along the coast of the German Baltic Sea even more valuable. In addition to the distribution maps and literature references, this work also provides information on taxonomy, ecology and the current conservational status. The numerous coloured underwater photographs give an impression of the beauty and diversity of the underwater vegetation.

It is remarkable that the publication does not only evaluate data from current monitoring but also includes historical data and information from grey literature, such as environmental impact assessments, master theses and interim or status reports of research projects.

The present compilation certainly cannot be exhaustive and the continuous developments in taxonomy and systematics based on modern genetic methods may lead to changes in taxonomic classification and the renaming of taxa. Nonetheless, this book is a comprehensive reference work, documenting the current state of knowledge on the distribution of macrophytes in the German Baltic Sea. As such, is serves as a valuable working aid for the assessment of the environmental status and its changes on the basis of the occurring macrophytes.

Contents
Background 2
Methodology 4
Taxonomy 5
Scientific name 5
Higher taxonomic levels 5
Subspecies (valid name) 6
Synonyms (incl. forms und varieties) 6
Distribution 6
Baltic Sea 6
German Baltic Sea 7
Ecology, 10
Substrate 10
Attachment 10
Salinity 11
Vertical zone 11
Exposure 12
Conservation status 13
Specific issues 13
References 13
Species distribution 16
Vascular Plants 18
Stoneworts 52
Red Seaweeds 76
Brown Seaweeds 170
GreenSeaweeds 276
Rare Taxa 364
Vascular Plants 364
Stoneworts 364
Red Seaweeds 364
Brown Seaweeds 366
Green Seaweeds 367
Distribution maps (below species level)368
References 373
Image Credits 385