Investigating the Photophysiology of a Tropical Crustose Coralline Alga at Different Depths Under Ocean Acidification Conditions
Ocean acidification (OA) negatively affects marine calcifying organisms and can alter many chemical and physiological processes. Crustose coralline algae (CCA), such as Porolithon onkodes, are important structural calcifying components on coral reefs and they grow across a range of depths. This rese...
Main Author: | |
---|---|
Other Authors: | , , , |
Format: | Master Thesis |
Language: | English |
Published: |
California State University, Northridge
2021
|
Subjects: | |
Online Access: | http://hdl.handle.net/10211.3/218347 |
id |
ftcalifstateuniv:oai:scholarworks:6108vh53t |
---|---|
record_format |
openpolar |
spelling |
ftcalifstateuniv:oai:scholarworks:6108vh53t 2024-09-30T14:40:42+00:00 Investigating the Photophysiology of a Tropical Crustose Coralline Alga at Different Depths Under Ocean Acidification Conditions Isaak, Ashtyn Carpenter, Robert Edmunds, Peter Silbiger, Nyssa Doo, Steve 2021-01-11 http://hdl.handle.net/10211.3/218347 English eng California State University, Northridge Biology http://hdl.handle.net/10211.3/218347 Light quantity Crustose Coralline Algae Dissertations Academic -- CSUN -- Biology Spectral quality Photophysiology Moorea Macroalgae Climate Change Ocean Acidification Depth Tropical Masters Thesis 2021 ftcalifstateuniv 2024-09-10T17:06:14Z Ocean acidification (OA) negatively affects marine calcifying organisms and can alter many chemical and physiological processes. Crustose coralline algae (CCA), such as Porolithon onkodes, are important structural calcifying components on coral reefs and they grow across a range of depths. This research investigated the interactive effects of light quantity, spectral quality and pCO2 on P. onkodes to determine if CCA are impacted differentially by OA as a function of depth. In the first experiment, I tested the effects of increased pCO2 on Porolithon onkodes collected from two different depths. Light filters were utilized to simulate light quality at shallow back reef environments at 2-m depth and deeper fore reef environments at 17-m depth in manipulative mesocosm experiments at both ambient and elevated pCO2 treatments (400 µatm pCO2 and 1000 µatm pCO2). Results of this experiment showed no effects of OA on photosynthesis, respiration, calcification, or most photosynthetic pigment concentrations (except for phycoerythrin). Photosynthesis also did not differ between depths suggesting that photosynthesis in this species is not stimulated by blue wavelengths of light and may saturate at low levels of photon flux density (PFD). However, samples from shallow water calcified 64.7% faster than samples from the deep environment over the experiment, which is likely due to increased PFD and also indicates that photosynthesis and calcification may not be as tightly coupled as previously thought. The second set of experiments investigated the differences in photochemical efficiency of P. onkodes under OA conditions in a mesocosm experiment, and also by changes in algal orientation in relation to sunlight at different depths in a field experiment. The effective quantum yield of photosynthetic energy conversion (fluorescence yield), and the relative rate of electron transport through PSII (rETR) were quantified using a PAM fluorometer. Fluorescence yield was greatest in low-PFD environments in both the mesocosm and field ... Master Thesis Ocean acidification Scholarworks from California State University |
institution |
Open Polar |
collection |
Scholarworks from California State University |
op_collection_id |
ftcalifstateuniv |
language |
English |
topic |
Light quantity Crustose Coralline Algae Dissertations Academic -- CSUN -- Biology Spectral quality Photophysiology Moorea Macroalgae Climate Change Ocean Acidification Depth Tropical |
spellingShingle |
Light quantity Crustose Coralline Algae Dissertations Academic -- CSUN -- Biology Spectral quality Photophysiology Moorea Macroalgae Climate Change Ocean Acidification Depth Tropical Isaak, Ashtyn Investigating the Photophysiology of a Tropical Crustose Coralline Alga at Different Depths Under Ocean Acidification Conditions |
topic_facet |
Light quantity Crustose Coralline Algae Dissertations Academic -- CSUN -- Biology Spectral quality Photophysiology Moorea Macroalgae Climate Change Ocean Acidification Depth Tropical |
description |
Ocean acidification (OA) negatively affects marine calcifying organisms and can alter many chemical and physiological processes. Crustose coralline algae (CCA), such as Porolithon onkodes, are important structural calcifying components on coral reefs and they grow across a range of depths. This research investigated the interactive effects of light quantity, spectral quality and pCO2 on P. onkodes to determine if CCA are impacted differentially by OA as a function of depth. In the first experiment, I tested the effects of increased pCO2 on Porolithon onkodes collected from two different depths. Light filters were utilized to simulate light quality at shallow back reef environments at 2-m depth and deeper fore reef environments at 17-m depth in manipulative mesocosm experiments at both ambient and elevated pCO2 treatments (400 µatm pCO2 and 1000 µatm pCO2). Results of this experiment showed no effects of OA on photosynthesis, respiration, calcification, or most photosynthetic pigment concentrations (except for phycoerythrin). Photosynthesis also did not differ between depths suggesting that photosynthesis in this species is not stimulated by blue wavelengths of light and may saturate at low levels of photon flux density (PFD). However, samples from shallow water calcified 64.7% faster than samples from the deep environment over the experiment, which is likely due to increased PFD and also indicates that photosynthesis and calcification may not be as tightly coupled as previously thought. The second set of experiments investigated the differences in photochemical efficiency of P. onkodes under OA conditions in a mesocosm experiment, and also by changes in algal orientation in relation to sunlight at different depths in a field experiment. The effective quantum yield of photosynthetic energy conversion (fluorescence yield), and the relative rate of electron transport through PSII (rETR) were quantified using a PAM fluorometer. Fluorescence yield was greatest in low-PFD environments in both the mesocosm and field ... |
author2 |
Carpenter, Robert Edmunds, Peter Silbiger, Nyssa Doo, Steve |
format |
Master Thesis |
author |
Isaak, Ashtyn |
author_facet |
Isaak, Ashtyn |
author_sort |
Isaak, Ashtyn |
title |
Investigating the Photophysiology of a Tropical Crustose Coralline Alga at Different Depths Under Ocean Acidification Conditions |
title_short |
Investigating the Photophysiology of a Tropical Crustose Coralline Alga at Different Depths Under Ocean Acidification Conditions |
title_full |
Investigating the Photophysiology of a Tropical Crustose Coralline Alga at Different Depths Under Ocean Acidification Conditions |
title_fullStr |
Investigating the Photophysiology of a Tropical Crustose Coralline Alga at Different Depths Under Ocean Acidification Conditions |
title_full_unstemmed |
Investigating the Photophysiology of a Tropical Crustose Coralline Alga at Different Depths Under Ocean Acidification Conditions |
title_sort |
investigating the photophysiology of a tropical crustose coralline alga at different depths under ocean acidification conditions |
publisher |
California State University, Northridge |
publishDate |
2021 |
url |
http://hdl.handle.net/10211.3/218347 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
http://hdl.handle.net/10211.3/218347 |
_version_ |
1811643183045541888 |