Graduation Date
Summer 2024
Document Type
Thesis
Program
Master of Science degree with a major in Natural Resources, option Fisheries
Committee Chair Name
Rafael Cuevas Uribe
Committee Chair Affiliation
HSU Faculty or Staff
Second Committee Member Name
Frederick W. Zechman
Second Committee Member Affiliation
HSU Faculty or Staff
Third Committee Member Name
Sean F. Craig
Third Committee Member Affiliation
HSU Faculty or Staff
Fourth Committee Member Name
Jose Marin Jarrin
Fourth Committee Member Affiliation
HSU Faculty or Staff
Keywords
Kelp forest, Kelp, Gametophyte, Sporophyte, Fertilization, Temperature, Northern California, Central California, Single population, Mixed population
Subject Categories
Natural Resources
Abstract
This study investigated the effects of elevated temperatures on the reproductive and developmental stages of Nereocystis luetkeana, a crucial brown macroalgae found along the western coast of North America. My objectives were to 1) evaluate the impact of increasing temperature on the abundance of gametophytes from various sites, 2) determine the length of gametophytes that were affected by temperature on day 10 of culture, 3) assess the presence or absence of oocytes, sporophytes (young vs. multicellular), and abnormal cells, to understand the reproductive and stress responses to higher temperatures, and 4) determine if there is variation among early developmental stages of N. luetkeana from different sites at higher temperatures. Sori were collected from mixed-populations (n=4) in Trinidad and Point Pinos (experiments A and B) and from parent individuals (n=3) in single-population experiments in Albion Cove and Point Pinos (experiments C). Cultivation occurred at Cal Poly Humboldt's Telonicher Marine Lab at temperatures of 10°C, 18°C, and 19°C. Results on day 10 indicated a reduction in the number of male gametophytes from 10°C to 19°C and from 18°C to 19°C (PERMANOVA, p < 0.05), with a pronounced decrease in gametophyte length between 18°C and 19°C. Experiment C showed a significant effect of source location on gametophyte abundance, with Albion Cove displaying higher counts. Furthermore, offspring from some parent sources exhibited higher thermal tolerance at increased temperatures, and females were more abundant than males at higher temperatures. Across all experiments, few sporophytes developed at 18°C, and a high occurrence of abnormal cells was noted at both 18°C and 19°C. More studies need to be conducted to understand intraspecific variation in thermal responses to better inform conservation strategies, especially through the cultivation of thermally tolerant kelp genotypes selected via breeding programs, so that we can better protect the biodiversity and ecological services provided by these canopy forming macroalgae.
Citation Style
Harvard
Recommended Citation
Fattori, Marzia, "Temperature driven variability in bull kelp (Nereocystis luetkeana) early life stages: a comparative study of California populations" (2024). Cal Poly Humboldt theses and projects. 777.
https://digitalcommons.humboldt.edu/etd/777