A direct CO2 control system for ocean acidification experiments: testing effects on the coralline red algae Phymatolithon lusitanicum
Most ocean acidification (OA) experimental systems rely on pH as an indirect way to control CO2. However, accurate pH measurements are difficult to obtain and shifts in temperature and/or salinity alter the relationship between pH and pCO2. Here we describe a system in which the target pCO2 is contr...
Published in: | PeerJ |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
PeerJ Inc.
2016
|
Subjects: | |
Online Access: | https://doi.org/10.7717/peerj.2503 https://doaj.org/article/185d37dae8bf44309cb47c71b32993d8 |
id |
ftdoajarticles:oai:doaj.org/article:185d37dae8bf44309cb47c71b32993d8 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:185d37dae8bf44309cb47c71b32993d8 2024-01-07T09:45:40+01:00 A direct CO2 control system for ocean acidification experiments: testing effects on the coralline red algae Phymatolithon lusitanicum Laura Sordo Rui Santos Joao Reis Alona Shulika Joao Silva 2016-09-01T00:00:00Z https://doi.org/10.7717/peerj.2503 https://doaj.org/article/185d37dae8bf44309cb47c71b32993d8 EN eng PeerJ Inc. https://peerj.com/articles/2503.pdf https://peerj.com/articles/2503/ https://doaj.org/toc/2167-8359 doi:10.7717/peerj.2503 2167-8359 https://doaj.org/article/185d37dae8bf44309cb47c71b32993d8 PeerJ, Vol 4, p e2503 (2016) Control system Ocean acidification (OA) CO2 bubbling Coralline algae Medicine R Biology (General) QH301-705.5 article 2016 ftdoajarticles https://doi.org/10.7717/peerj.2503 2023-12-10T01:51:13Z Most ocean acidification (OA) experimental systems rely on pH as an indirect way to control CO2. However, accurate pH measurements are difficult to obtain and shifts in temperature and/or salinity alter the relationship between pH and pCO2. Here we describe a system in which the target pCO2 is controlled via direct analysis of pCO2 in seawater. This direct type of control accommodates potential temperature and salinity shifts, as the target variable is directly measured instead of being estimated. Water in a header tank is permanently re-circulated through an air-water equilibrator. The equilibrated air is then routed to an infrared gas analyzer (IRGA) that measures pCO2 and conveys this value to a Proportional-Integral-Derivative (PID) controller. The controller commands a solenoid valve that opens and closes the CO2 flush that is bubbled into the header tank. This low-cost control system allows the maintenance of stabilized levels of pCO2 for extended periods of time ensuring accurate experimental conditions. This system was used to study the long term effect of OA on the coralline red algae Phymatolithon lusitanicum. We found that after 11 months of high CO2 exposure, photosynthesis increased with CO2 as opposed to respiration, which was positively affected by temperature. Results showed that this system is adequate to run long-term OA experiments and can be easily adapted to test other relevant variables simultaneously with CO2, such as temperature, irradiance and nutrients. Article in Journal/Newspaper Ocean acidification Directory of Open Access Journals: DOAJ Articles PeerJ 4 e2503 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Control system Ocean acidification (OA) CO2 bubbling Coralline algae Medicine R Biology (General) QH301-705.5 |
spellingShingle |
Control system Ocean acidification (OA) CO2 bubbling Coralline algae Medicine R Biology (General) QH301-705.5 Laura Sordo Rui Santos Joao Reis Alona Shulika Joao Silva A direct CO2 control system for ocean acidification experiments: testing effects on the coralline red algae Phymatolithon lusitanicum |
topic_facet |
Control system Ocean acidification (OA) CO2 bubbling Coralline algae Medicine R Biology (General) QH301-705.5 |
description |
Most ocean acidification (OA) experimental systems rely on pH as an indirect way to control CO2. However, accurate pH measurements are difficult to obtain and shifts in temperature and/or salinity alter the relationship between pH and pCO2. Here we describe a system in which the target pCO2 is controlled via direct analysis of pCO2 in seawater. This direct type of control accommodates potential temperature and salinity shifts, as the target variable is directly measured instead of being estimated. Water in a header tank is permanently re-circulated through an air-water equilibrator. The equilibrated air is then routed to an infrared gas analyzer (IRGA) that measures pCO2 and conveys this value to a Proportional-Integral-Derivative (PID) controller. The controller commands a solenoid valve that opens and closes the CO2 flush that is bubbled into the header tank. This low-cost control system allows the maintenance of stabilized levels of pCO2 for extended periods of time ensuring accurate experimental conditions. This system was used to study the long term effect of OA on the coralline red algae Phymatolithon lusitanicum. We found that after 11 months of high CO2 exposure, photosynthesis increased with CO2 as opposed to respiration, which was positively affected by temperature. Results showed that this system is adequate to run long-term OA experiments and can be easily adapted to test other relevant variables simultaneously with CO2, such as temperature, irradiance and nutrients. |
format |
Article in Journal/Newspaper |
author |
Laura Sordo Rui Santos Joao Reis Alona Shulika Joao Silva |
author_facet |
Laura Sordo Rui Santos Joao Reis Alona Shulika Joao Silva |
author_sort |
Laura Sordo |
title |
A direct CO2 control system for ocean acidification experiments: testing effects on the coralline red algae Phymatolithon lusitanicum |
title_short |
A direct CO2 control system for ocean acidification experiments: testing effects on the coralline red algae Phymatolithon lusitanicum |
title_full |
A direct CO2 control system for ocean acidification experiments: testing effects on the coralline red algae Phymatolithon lusitanicum |
title_fullStr |
A direct CO2 control system for ocean acidification experiments: testing effects on the coralline red algae Phymatolithon lusitanicum |
title_full_unstemmed |
A direct CO2 control system for ocean acidification experiments: testing effects on the coralline red algae Phymatolithon lusitanicum |
title_sort |
direct co2 control system for ocean acidification experiments: testing effects on the coralline red algae phymatolithon lusitanicum |
publisher |
PeerJ Inc. |
publishDate |
2016 |
url |
https://doi.org/10.7717/peerj.2503 https://doaj.org/article/185d37dae8bf44309cb47c71b32993d8 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_source |
PeerJ, Vol 4, p e2503 (2016) |
op_relation |
https://peerj.com/articles/2503.pdf https://peerj.com/articles/2503/ https://doaj.org/toc/2167-8359 doi:10.7717/peerj.2503 2167-8359 https://doaj.org/article/185d37dae8bf44309cb47c71b32993d8 |
op_doi |
https://doi.org/10.7717/peerj.2503 |
container_title |
PeerJ |
container_volume |
4 |
container_start_page |
e2503 |
_version_ |
1787427240862023680 |