We are saddened to share the news of the passing of our Porifera editor Dr. Klaus Ruetzler (1936–2025) in November.  Klaus enjoyed a long career of scientific diving, discovery and enthusiastic collaboration with other researchers in NMNH and beyond. Dr. Ruetzler joined the NMNH community in 1965 as curator of Porifera in the Department of Invertebrate Zoology and through his prolific work established himself as a world authority on the biology of sponges. Klaus’s adventurous nature made him a pioneer in field studies and eventually saw him becoming co-founder of the Smithsonian’s Carrie Bow Cay Field Station , a facility that has supported many hundreds of scientific papers and which continues to spur new advances in understanding coral reef, mangrove, sea grass, and other marine habitats.  
Klaus contributed seminal work documenting the essential roles that sponges play on coral reefs. He was among the first to document and describe sponge pathogens in detail and made numerous contributions to understanding the morphology of sponges, notably through co-authoring an Atlas of Sponge Morphology (Smithsonian Institution Press) and Thesaurus of Sponge Morphology, resources that remain essential today.
Among Klaus’ most impactful legacies were his co-founding of NMNH’s Caribbean Coral Reef Ecosystems field program and later establishment of the Carrie Bow Field Station in Belize. Those fortunate enough to have conducted research at Carrie Bow know what a special location it is, with diverse marine habitats accessible via short boat excursions. Despite the station’s small size, it has supported well over 1400 publications, including a series of volumes on The Atlantic Barrier Reef Ecosystem at Carrie Bow Cay, Belize that have garnered thousands of citations, attesting to the station’s scientific impact.
Beyond his many contributions to the field, Klaus is remembered for his warmth, kindness and enthusiasm for others. A history of the station can be found on the Ocean Portal 

For more information about Klaus' career see a 2008 tribute to his many accomplishments on the systematics and field ecology of sponges, and a web spotlight from the Department of Invertebrate Zoology celebrating his 50-year career at the Smithsonian. 

Many thanks to Chris Meyer, Allen Collins, and Klaus’ partner Molly Kelly Ryan for their work in authoring this tribute.