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Effects of Irradiance and Temperature on the Photosynthesis of the Crustose Coralline Algae Pneophyllum fragile (Corallinales, Rhodophyta) in the Coastal Waters of Korea. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2022. [DOI: 10.3390/jmse10070851] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We investigated the photosynthetic characteristics of the crustose coralline alga Pneophyllum fragile (Corallinales, Rhodophyta) according to elevated water temperature and irradiance on the coast of Jeju in 2018. P. fragile was cultured under different temperature (11 °C, 21 °C, 26 °C, and 31 °C) and irradiance (0–1250 μmol photon m−2 s−1) conditions. Oxygen (O2) concentrations at the P. fragile mat–water interface (MWI) were measured using an O2 microsensor. At the MWI, the diffusive boundary layer thicknesses ranged from 200 to 400 μm. The O2 concentrations at the mat surface increased in response to increasing irradiance, and reached 344% air saturation. The maximum photosynthesis capacity (Pmax) and respiration rate in the dark (Rd) at 31 °C were about 3 times higher than those recorded at 11 °C. The compensation irradiance (Ec) and saturation irradiance (Ek) increased with increasing water temperature. The Pmax, Rd, and Ec were statistically correlated with temperature (p < 0.05). The Ek increased up to 833 μmol photon m−2 s−1 at 31 °C and exhibited a strong dependence on irradiance at high temperatures. The adaptability of P. fragile to high temperatures and strong irradiance was distinct from that observed for coralline algae in other temperate waters.
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Jahnsen-Guzmán N, Lagos NA, Quijón PA, Manríquez PH, Lardies MA, Fernández C, Reyes M, Zapata J, García-Huidobro MR, Labra FA, Duarte C. Ocean acidification alters anti-predator responses in a competitive dominant intertidal mussel. CHEMOSPHERE 2022; 288:132410. [PMID: 34600016 DOI: 10.1016/j.chemosphere.2021.132410] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/07/2021] [Accepted: 09/27/2021] [Indexed: 06/13/2023]
Abstract
Widespread intertidal mussels are exposed to a variety of natural and anthropogenic stressors. Even so, our understanding of the combined influence of stressors such as predation risk and ocean acidification (OA) on these species remains limited. This study examined the response of the purple mussel (Perumytilus purpuratus), a species distributed along Pacific southeastern rocky shores, to the effects of predation risk and OA. Using a laboratory 2 × 2 cross design, purple mussels were either devoid or exposed to predator cues from the muricid snail Acanthina monodon, while simultaneously exposing them to current (500 ppm) or projected OA conditions (1500 ppm). The response of purple mussels to these factors was assessed using growth, calcification, clearance, and metabolic rates, in addition to byssus production. After 60 d, the presence of predator cues reduced mussel growth in width and length, and in the latter case, OA enhanced this response making the effects of predator cues more severe. Calcification rates were driven by the interaction between the two stressors, whereas clearance rates increased only in response to OA, likely explaining some of the growth results. Mussel byssus production also increased with pCO2 but interacted with predation risk: in the absence of predator cues, byssus production increased with OA. These results suggest that projected levels of OA may alter and in some cases prevail over the natural response of purple mussels to predation risk. Considering the role played by this mussel as a dominant competitor and ecosystem engineer in rocky shores, these results have community-wide implications.
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Affiliation(s)
- Nicole Jahnsen-Guzmán
- Departamento de Ecología y Biodiversidad, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile; Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | - Nelson A Lagos
- Centro de Investigación e Innovación para el Cambio Climático (CiiCC), Facultad de Ciencias, Universidad Santo Tomás, Ejercito 146, Santiago, Chile
| | - Pedro A Quijón
- Department of Biology, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Patricio H Manríquez
- Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Coquimbo, Chile; Laboratorio de Ecología y Conducta de la Ontogenia Temprana (LECOT), Coquimbo, Chile
| | - Marco A Lardies
- Facultad de Artes Liberales, Universidad Adolfo Ibáñez, Santiago, Chile
| | | | - Miguel Reyes
- Centro de Investigación e Innovación para el Cambio Climático (CiiCC), Facultad de Ciencias, Universidad Santo Tomás, Ejercito 146, Santiago, Chile
| | - Javier Zapata
- Centro de Investigación e Innovación para el Cambio Climático (CiiCC), Facultad de Ciencias, Universidad Santo Tomás, Ejercito 146, Santiago, Chile; Departamento de Ecología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - M Roberto García-Huidobro
- Centro de Investigación e Innovación para el Cambio Climático (CiiCC), Facultad de Ciencias, Universidad Santo Tomás, Ejercito 146, Santiago, Chile
| | - Fabio A Labra
- Centro de Investigación e Innovación para el Cambio Climático (CiiCC), Facultad de Ciencias, Universidad Santo Tomás, Ejercito 146, Santiago, Chile; Facultad de Ciencias, Doctorado en Conservación y Gestión de la Biodiversidad, Universidad Santo Tomás, Santiago, Chile
| | - Cristian Duarte
- Departamento de Ecología y Biodiversidad, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile; Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile.
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Calcification in Three Common Calcified Algae from Phuket, Thailand: Potential Relevance on Seawater Carbonate Chemistry and Link to Photosynthetic Process. PLANTS 2021; 10:plants10112537. [PMID: 34834900 PMCID: PMC8624766 DOI: 10.3390/plants10112537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/11/2021] [Accepted: 11/19/2021] [Indexed: 11/25/2022]
Abstract
Calcifying macroalgae contribute significantly to the structure and function of tropical marine ecosystems. Their calcification and photosynthetic processes are not well understood despite their critical role in marine carbon cycles and high vulnerability to environmental changes. This study aims to provide a better understanding of the macroalgal calcification process, focusing on its relevance concerning seawater carbonate chemistry and its relationship to photosynthesis in three dominant calcified macroalgae in Thailand, Padina boryana, Halimeda macroloba and Halimeda opuntia. Morphological and microstructural attributes of the three macroalgae were analyzed and subsequently linked to their calcification rates and responses to inhibition of photosynthesis. In the first experiment, seawater pH, total alkalinity and total dissolved inorganic carbon were measured after incubation of the macroalgae in the light and after equilibration of the seawater with air. Estimations of carbon uptake into photosynthesis and calcification and carbon release into air were obtained thereafter. Our results provide evidence that calcification of the three calcified macroalgae is a potential source of CO2, where calcification by H. opuntia and H. macroloba leads to a greater release of CO2 per biomass weight than P. boryana. Nevertheless, this capacity is expected to vary on a diurnal basis, as the second experiment indicates that calcification is highly coupled to photosynthetic activity. Lower pH as a result of inhibited photosynthesis under darkness imposes more negative effects on H. opuntia and H. macroloba than on P. boryana, implying that they are more sensitive to acidification. These effects were worsened when photosynthesis was inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea, highlighting the significance of photosynthetic electron transport-dependent processes. Our findings suggest that estimations of the amount of carbon stored in the vegetated marine ecosystems should account for macroalgal calcification as a potential carbon source while considering diurnal variations in photosynthesis and seawater pH in a natural setting.
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