Thermal Thresholds of Phytoplankton Growth in Polar Waters and Their Consequences for a Warming Polar Ocean

Handle URI:
http://hdl.handle.net/10754/624046
Title:
Thermal Thresholds of Phytoplankton Growth in Polar Waters and Their Consequences for a Warming Polar Ocean
Authors:
Coello-Camba, Alexandra; Agusti, Susana ( 0000-0003-0536-7293 )
Abstract:
Polar areas are experiencing the steepest warming rates on Earth, a trend expected to continue in the future. In these habitats, phytoplankton communities constitute the basis of the food web and their thermal tolerance may dictate how warming affects these delicate environments. Here, we compiled available data on thermal responses of phytoplankton growth in polar waters. We assembled 53 growth-vs.-temperature curves (25 from the Arctic, 28 from the Southern oceans), indicating the limited information available for these ecosystems. Half of the data from Arctic phytoplankton came from natural communities where low ambient concentrations could limit growth rates. Phytoplankton from polar waters grew faster under small temperature increases until reaching an optimum (TOPT), and slowed when temperatures increased beyond this value. This left-skewed curves were characterized by higher activation energies (Ea) for phytoplankton growth above than below the TOPT. Combining these thermal responses we obtained a community TOPT of 6.5°C (±0.2) and 5.2°C (±0.1) for Arctic and Southern Ocean phytoplankton communities, respectively. These threshold temperatures were already exceeded at 70°N during the first half of August 2013, evidenced by sea surface temperatures (SSTs, satellite data, http://www.ncdc.noaa.gov). We forecasted SSTs for the end of the twenty-first century by assuming an overall 3°C increase, equivalent to a low emission scenario. Our forecasts show that SSTs at 70°N are expected to exceed TOPT during summer by 2100, and during the first half of August at 75°N. While recent Arctic spring temperatures average 0.5°C and −0.7°C at 70°N and 75°N, respectively, they could increase to 2.8°C at 70°N and 2.2°C at 75°N as we approach 2100. Such temperature increases could lead to intense phytoplankton blooms, shortened by fast nutrient consumption. As SSTs increase, thermal thresholds for phytoplankton growth would be eventually exceeded during bloom development. This could lead to changes in the blooming phytoplankton community, threatening the production peak and cycles in the Arctic. Our forecasted phytoplankton responses, are constrained by the limited data set, besides uncertainties in the most plausible future Arctic temperature scenarios. To improve predictions in polar oceans, we need to increase the number of studies, in particular for a fast-changing Arctic.
KAUST Department:
Red Sea Research Center (RSRC)
Citation:
Coello-Camba A, Agustí S (2017) Thermal Thresholds of Phytoplankton Growth in Polar Waters and Their Consequences for a Warming Polar Ocean. Frontiers in Marine Science 4. Available: http://dx.doi.org/10.3389/fmars.2017.00168.
Publisher:
Frontiers Media SA
Journal:
Frontiers in Marine Science
Issue Date:
2-Jun-2017
DOI:
10.3389/fmars.2017.00168
Type:
Article
ISSN:
2296-7745
Sponsors:
This study is a contribution to the project ATOS (“Atmospheric inputs of organic carbon and pollutants to the polar ocean: rates, significance and outlook,” POL2006-00550) and ESASSI (Spanish contribution to the SASSI “Synoptic Antarctic Shelf-Slope Interaction” international project, P.N., POL2006-11139-C02-01/CGL) funded by the Spanish Ministry of Science and Innovation. AC was supported by grant BES-2007-15193. King Abdullah University of Science and Technology also supported this research.
Additional Links:
http://journal.frontiersin.org/article/10.3389/fmars.2017.00168/full
Appears in Collections:
Articles; Red Sea Research Center (RSRC)

Full metadata record

DC FieldValue Language
dc.contributor.authorCoello-Camba, Alexandraen
dc.contributor.authorAgusti, Susanaen
dc.date.accessioned2017-06-05T06:02:25Z-
dc.date.available2017-06-05T06:02:25Z-
dc.date.issued2017-06-02en
dc.identifier.citationCoello-Camba A, Agustí S (2017) Thermal Thresholds of Phytoplankton Growth in Polar Waters and Their Consequences for a Warming Polar Ocean. Frontiers in Marine Science 4. Available: http://dx.doi.org/10.3389/fmars.2017.00168.en
dc.identifier.issn2296-7745en
dc.identifier.doi10.3389/fmars.2017.00168en
dc.identifier.urihttp://hdl.handle.net/10754/624046-
dc.description.abstractPolar areas are experiencing the steepest warming rates on Earth, a trend expected to continue in the future. In these habitats, phytoplankton communities constitute the basis of the food web and their thermal tolerance may dictate how warming affects these delicate environments. Here, we compiled available data on thermal responses of phytoplankton growth in polar waters. We assembled 53 growth-vs.-temperature curves (25 from the Arctic, 28 from the Southern oceans), indicating the limited information available for these ecosystems. Half of the data from Arctic phytoplankton came from natural communities where low ambient concentrations could limit growth rates. Phytoplankton from polar waters grew faster under small temperature increases until reaching an optimum (TOPT), and slowed when temperatures increased beyond this value. This left-skewed curves were characterized by higher activation energies (Ea) for phytoplankton growth above than below the TOPT. Combining these thermal responses we obtained a community TOPT of 6.5°C (±0.2) and 5.2°C (±0.1) for Arctic and Southern Ocean phytoplankton communities, respectively. These threshold temperatures were already exceeded at 70°N during the first half of August 2013, evidenced by sea surface temperatures (SSTs, satellite data, http://www.ncdc.noaa.gov). We forecasted SSTs for the end of the twenty-first century by assuming an overall 3°C increase, equivalent to a low emission scenario. Our forecasts show that SSTs at 70°N are expected to exceed TOPT during summer by 2100, and during the first half of August at 75°N. While recent Arctic spring temperatures average 0.5°C and −0.7°C at 70°N and 75°N, respectively, they could increase to 2.8°C at 70°N and 2.2°C at 75°N as we approach 2100. Such temperature increases could lead to intense phytoplankton blooms, shortened by fast nutrient consumption. As SSTs increase, thermal thresholds for phytoplankton growth would be eventually exceeded during bloom development. This could lead to changes in the blooming phytoplankton community, threatening the production peak and cycles in the Arctic. Our forecasted phytoplankton responses, are constrained by the limited data set, besides uncertainties in the most plausible future Arctic temperature scenarios. To improve predictions in polar oceans, we need to increase the number of studies, in particular for a fast-changing Arctic.en
dc.description.sponsorshipThis study is a contribution to the project ATOS (“Atmospheric inputs of organic carbon and pollutants to the polar ocean: rates, significance and outlook,” POL2006-00550) and ESASSI (Spanish contribution to the SASSI “Synoptic Antarctic Shelf-Slope Interaction” international project, P.N., POL2006-11139-C02-01/CGL) funded by the Spanish Ministry of Science and Innovation. AC was supported by grant BES-2007-15193. King Abdullah University of Science and Technology also supported this research.en
dc.publisherFrontiers Media SAen
dc.relation.urlhttp://journal.frontiersin.org/article/10.3389/fmars.2017.00168/fullen
dc.rightsThis is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.en
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/en
dc.titleThermal Thresholds of Phytoplankton Growth in Polar Waters and Their Consequences for a Warming Polar Oceanen
dc.typeArticleen
dc.contributor.departmentRed Sea Research Center (RSRC)en
dc.identifier.journalFrontiers in Marine Scienceen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Arctic and Marine Biology, Faculty of Bioscience, Fishery and Economy, University of Tromsø, Tromsø, Norwayen
kaust.authorCoello-Camba, Alexandraen
kaust.authorAgusti, Susanaen
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