Grethe Berit Rytter Hasle (3 January 1920 – 9 November 2013) was a Norwegian planktologist. Among the first female professors of natural science at the

University of Oslo The University of Oslo (; ) is a public university, public research university located in Oslo, Norway. It is the List of oldest universities in continuous operation#Europe, oldest university in Norway. Originally named the Royal Frederick Univ ...

, she specialized in the study of

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), mea ...

Personal life

Hasle was born in Borre as the daughter of shipmaster Johan Kristian Rytter (1890–1966) and his wife Nicoline Olava Nielsen (1885–1976). She married Hans Martin Hasle and took his name; he died in 1971. She resided at

Ekeberg Ekeberg is a neighborhood in the city of Oslo, Norway. The Norway Cup Association football, soccer tournament takes place at Ekebergsletta every summer. "Sletta" means "the plain". The painting "The Scream" by Edvard Munch is painted from Utsi ...

in Norway and died in November 2013.

Career

She graduated from Elverum Teachers' College in 1942, and graduated from the

in 1949 where she worked with Trygve Braarud. In 1950, she published her first paper: ''Phototactic vertical migration in marine dinoflagellates''. She took the dr.philos. degree in 1968 on the thesis ''An Analysis of the Phytoplankton of the Pacific Southern Ocean''. Diatoms through the microscope

She was hired as a lecturer at the

in 1961, and was then a professor of marine botany from 1977 to 1990. She was the third female professor at the Faculty of Mathematics and Natural Sciences, and was inducted into the

Norwegian Academy of Science and Letters The Norwegian Academy of Science and Letters (, DNVA) is a learned society based in Oslo, Norway. Its purpose is to support the advancement of science and scholarship in Norway. History The Royal Frederick University in Christiania was establis ...

in 1980 as the only female researcher at the time representing the natural sciences. She was also a visiting scholar at the

Texas A&M University Texas A&M University (Texas A&M, A&M, TA&M, or TAMU) is a public university, public, Land-grant university, land-grant, research university in College Station, Texas, United States. It was founded in 1876 and became the flagship institution of ...

from 1968 to 1969. She is especially known for her studies of

in general, and specifically the

class Class, Classes, or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used d ...

Bacillariophyceae Bacillariophyceae is a class of diatoms. Previously, this class was equivalent to Diatomeae, the taxonomic name for all diatoms. However, due to both the known and estimated diversity of diatoms, since 2019 they have been expanded to several class ...

. The Bacillariophyceae genus '' Haslea'' has been named after her. She is also known for revising the morphological

taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

of the genera ''

Thalassiosira ''Thalassiosira'' is a genus of centric diatoms, comprising over 100 marine and freshwater species. It is a diverse group of photosynthetic eukaryotes that make up a vital part of marine and freshwater ecosystems, in which they are key primary pr ...

'', ''

Nitzschia ''Nitzschia'' is a common pennate marine and freshwater diatom. In the scientific literature, this genus, named after Christian Ludwig Nitzsch, is sometimes referred to incorrectly as ''Nitzchia'', and it has many species described, which all hav ...

'' and '' Fragilariopsis''. She was honored with a

Festschrift In academia, a ''Festschrift'' (; plural, ''Festschriften'' ) is a book honoring a respected person, especially an academic, and presented during their lifetime. It generally takes the form of an edited volume, containing contributions from the h ...

for her seventieth birthday, and she received the Award of Excellence from the Phycological Society of America in 2000 and the Yasumoto Lifetime Achievement Award from the International Society for the Study of Harmful Algae in 2003.

Selected publications

* * * * *

References

{{DEFAULTSORT:Hasle, Grethe Rytter 1920 births 2013 deaths Norwegian planktologists People from Horten University of Oslo alumni Academic staff of the University of Oslo Texas A&M University faculty Members of the Norwegian Academy of Science and Letters Women planktologists People from Bærum 20th-century Norwegian women scientists