Grethe Hasle Diatom Collection

Grethe Rytter Hasle at the microscope. Photo L. Gabrielsen

The collection contains

Light microscopy slides and acid cleaned samples prepared from net-hauls, cultures and dried material originating from many geographical regions such as the Arctic Ocean, Norwegian Coast, North Sea, Skagerrak, Oslofjorden, Atlantic Ocean, Pacific Ocean, Indian Ocean and Antarctic Ocean.

The Hasle collection dataset in GBIF

Type material

The collection contains holotypes of 25 species, 1 lectotype, 2 neotypes and 15 isotypes (see Excel list).

Grethe Rytter Hasle

Grethe Rytter Hasle was born Jan 3, 1920 in Horten, Norway and was 93 years old when she passed away in November 2013. Her first publication appeared in 1950 dealing with phototaxis and vertical migration of marine dinoflagellates. In 1968 she defended her dissertation entitled "An analysis of the phytoplankton of the Pacific Southern Ocean: abundance, composition and distribution during the ‘Brategg’ Expedition, 1947-1948" and was awarded a Dr. Philos degree. She was nominated as a full Professor in Marine Botany at the University of Oslo in 1977. Her research focused on diatom taxonomy including both pennate genera such as e.g. Nitzschia and Fragillariopsis and the centric genera Thalassisira and Cymatosira. Hasle combined light and electron microscopy and became an international authority on diatom ultrastructure and morphology. Her work on Pseudo-nitzschia is a god example of the practical importance of basic science. When people became poisoned by shellfish containing domoic acid on Prince Edwards Island (Canada) in 1987-88, it was later shown to be caused by Pseudo-nitzschia multiseries, a species that Hasle had described from Oslofjorden (Norway). Hasle was a great inspiration for her students and fellow scientists, she has an impressive publication record and pursued her work after retirement and well into her eighties.


Scientific curator: Wenche Eikrem


Grethe Hasle Rytter publication list (Word)

Skeletonema, SEM-graph by Grethe Hasle.
Thalassiosira, SEM-graph by Grethe Hasle.
Norwegian Coastal Water diatoms (from Throndsen, Hasle & Tangen 2007)

Published Sep. 8, 2015 4:44 PM - Last modified June 28, 2021 2:43 PM