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 ( no, Universitetet i Oslo; la, Universitas Osloensis) is a public research university located in Oslo, Norway. It is the highest ranked and oldest university in Norway. It is consistently ranked among the top universit ...

, 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 ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. Ph ...

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 soccer tournament takes place at Ekebergsletta every summer. "Sletta" means "the plain". The painting "The Scream" by Edvard Munch is painted from Utsikten ("the view"), a p ...

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 Trygve Braarud (15 September 1903 – 9 July 1985) was a Norwegian botanist. He specialized in marine biology, and was affiliated with the University of Oslo for most of his career. Career He was born in Verdal, and had ten older siblings as wel ...

. 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 ( no, Det Norske Videnskaps-Akademi, 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 Univer ...

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, or TAMU) is a public, land-grant, research university in College Station, Texas. It was founded in 1876 and became the flagship institution of the Texas A&M University System in 1948. As of late 2021, T ...

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

in general, and specifically the

class Class 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 differentl ...

Bacillariophyceae Bacillariophyceae is a group of pennate diatoms with a raphe (raphids). According to Ruggiero et al., 2015, the diatoms are treated as follows. This treatment largely reflects that used by Algaebase as at 2015, and is also reflected in the current ...

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

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

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 diatom. In the scientific literature, this genus, named after Christian Ludwig Nitzsch, is sometimes termed ''Nitzchia'', and it has many species described, which all have a similar morphology. Occurrence ...

'' and ''

Fragilariopsis ''Fragilariopsis'' is a genus of diatoms belonging to the family Bacillariaceae. The genus has cosmopolitan distribution. Species Species: *'' Fragilariopsis acuta'' *'' Fragilariopsis angulata'' *'' Fragilariopsis atlantica'' *''Fragilar ...

''. 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 The Phycological Society of America (PSA) is a professional society, founded in 1946, that is dedicated to the advancement of phycology, the study of algae. The PSA is responsible for the publication of ''Journal of Phycology'' and organizes an ...

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 women scientists