Short-term effects of temperature on morphology and physiology of turf-forming Hypnea species (Rhodophyta) from southeastern Brazil

The current study is related to the United Nations Sustainable Development Goal 13, “Climate action”. As a consequence of environmental variations caused by global climate change, turf-forming algae supposedly tend to replace dominant foundation species, resulting in loss of marine biodiversity. Hyp...

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Main Authors: Fabio Nauer, Nair S. Yokoya, Mutue Toyota Fujii
Format: Article
Language:English
Published: Taylor & Francis Group 2022-12-01
Series:Applied Phycology
Subjects:
Online Access:https://www.tandfonline.com/doi/10.1080/26388081.2021.2011412
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author Fabio Nauer
Nair S. Yokoya
Mutue Toyota Fujii
author_facet Fabio Nauer
Nair S. Yokoya
Mutue Toyota Fujii
author_sort Fabio Nauer
collection DOAJ
description The current study is related to the United Nations Sustainable Development Goal 13, “Climate action”. As a consequence of environmental variations caused by global climate change, turf-forming algae supposedly tend to replace dominant foundation species, resulting in loss of marine biodiversity. Hypnea brasiliensis, H. cervicornis and H. spinella are three turf-forming species widely distributed along the Brazilian coast with a problematic taxonomic history. Specimens from the warm temperate region are morphologically similar, and their correct identification is only possible based on molecular markers. In the present study, specimens- were cultivated in the laboratory, and temperature gradient experiments (20, 24, 28 and 32°C) were carried out for 21 days. At 28°C, the growth rate, branching ratio, and photosynthetic pigment content were higher in all species, however in vivo chlorophyll fluorescence parameters were at the lowest. Moreover, no species survived at the warmest temperature 32°C. The effects of temperature on the three Hypnea species revealed that useful morphological characters for species identification were only observed in specimens cultured at 28°C, and the morphology of the three species was basically identical in low temperature treatments of 20 and 24°C. The annual average temperature of the sea surface in the Brazilian warm temperate region is 24°C, which may explain the current difficulty of distinguishing the three Hypnea species from this region using only morphology. Furthermore, our findings show that these turf-forming Hypnea species are negatively impacted by rising temperatures, emphasizing the importance of species-specific research to better understand the effects of global climate change. Consequently, predictions of the replacement of dominant foundation species by turf-forming seaweed in an elevated sea surface temperature scenario are less certain. The negative impact of temperature increases raises awareness of the importance of public policies to mitigate the future degradation of marine ecosystems.
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spelling doaj.art-1beff34ecec046fd9d7c7cefa36dc88b2022-12-22T04:02:19ZengTaylor & Francis GroupApplied Phycology2638-80812022-12-013124725910.1080/26388081.2021.2011412Short-term effects of temperature on morphology and physiology of turf-forming Hypnea species (Rhodophyta) from southeastern BrazilFabio Nauer0Nair S. Yokoya1Mutue Toyota Fujii2Biodiversity Conservation Center, Environmental Research Institute, São Paulo, BrazilBiodiversity Conservation Center, Environmental Research Institute, São Paulo, BrazilBiodiversity Conservation Center, Environmental Research Institute, São Paulo, BrazilThe current study is related to the United Nations Sustainable Development Goal 13, “Climate action”. As a consequence of environmental variations caused by global climate change, turf-forming algae supposedly tend to replace dominant foundation species, resulting in loss of marine biodiversity. Hypnea brasiliensis, H. cervicornis and H. spinella are three turf-forming species widely distributed along the Brazilian coast with a problematic taxonomic history. Specimens from the warm temperate region are morphologically similar, and their correct identification is only possible based on molecular markers. In the present study, specimens- were cultivated in the laboratory, and temperature gradient experiments (20, 24, 28 and 32°C) were carried out for 21 days. At 28°C, the growth rate, branching ratio, and photosynthetic pigment content were higher in all species, however in vivo chlorophyll fluorescence parameters were at the lowest. Moreover, no species survived at the warmest temperature 32°C. The effects of temperature on the three Hypnea species revealed that useful morphological characters for species identification were only observed in specimens cultured at 28°C, and the morphology of the three species was basically identical in low temperature treatments of 20 and 24°C. The annual average temperature of the sea surface in the Brazilian warm temperate region is 24°C, which may explain the current difficulty of distinguishing the three Hypnea species from this region using only morphology. Furthermore, our findings show that these turf-forming Hypnea species are negatively impacted by rising temperatures, emphasizing the importance of species-specific research to better understand the effects of global climate change. Consequently, predictions of the replacement of dominant foundation species by turf-forming seaweed in an elevated sea surface temperature scenario are less certain. The negative impact of temperature increases raises awareness of the importance of public policies to mitigate the future degradation of marine ecosystems.https://www.tandfonline.com/doi/10.1080/26388081.2021.2011412Hypnea brasiliensisHypnea cervicornisHypnea spinellaclimate change
spellingShingle Fabio Nauer
Nair S. Yokoya
Mutue Toyota Fujii
Short-term effects of temperature on morphology and physiology of turf-forming Hypnea species (Rhodophyta) from southeastern Brazil
Applied Phycology
Hypnea brasiliensis
Hypnea cervicornis
Hypnea spinella
climate change
title Short-term effects of temperature on morphology and physiology of turf-forming Hypnea species (Rhodophyta) from southeastern Brazil
title_full Short-term effects of temperature on morphology and physiology of turf-forming Hypnea species (Rhodophyta) from southeastern Brazil
title_fullStr Short-term effects of temperature on morphology and physiology of turf-forming Hypnea species (Rhodophyta) from southeastern Brazil
title_full_unstemmed Short-term effects of temperature on morphology and physiology of turf-forming Hypnea species (Rhodophyta) from southeastern Brazil
title_short Short-term effects of temperature on morphology and physiology of turf-forming Hypnea species (Rhodophyta) from southeastern Brazil
title_sort short term effects of temperature on morphology and physiology of turf forming hypnea species rhodophyta from southeastern brazil
topic Hypnea brasiliensis
Hypnea cervicornis
Hypnea spinella
climate change
url https://www.tandfonline.com/doi/10.1080/26388081.2021.2011412
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AT mutuetoyotafujii shorttermeffectsoftemperatureonmorphologyandphysiologyofturfforminghypneaspeciesrhodophytafromsoutheasternbrazil