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Wright LS, Simpkins T, Filbee-Dexter K, Wernberg T. Temperature sensitivity of detrital photosynthesis. ANNALS OF BOTANY 2024; 133:17-28. [PMID: 38142363 PMCID: PMC10921823 DOI: 10.1093/aob/mcad167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/24/2023] [Accepted: 11/22/2023] [Indexed: 12/25/2023]
Abstract
BACKGROUND AND AIMS Kelp forests are increasingly considered blue carbon habitats for ocean-based biological carbon dioxide removal, but knowledge gaps remain in our understanding of their carbon cycle. Of particular interest is the remineralization of detritus, which can remain photosynthetically active. Here, we study a widespread, thermotolerant kelp (Ecklonia radiata) to explore detrital photosynthesis as a mechanism underlying temperature and light as two key drivers of remineralization. METHODS We used meta-analysis to constrain the thermal optimum (Topt) of E. radiata. Temperature and light were subsequently controlled over a 119-day ex situ decomposition experiment. Flow-through experimental tanks were kept in darkness at 15 °C or under a subcompensating maximal irradiance of 8 µmol photons m-2 s-1 at 15, 20 or 25 °C. Photosynthesis of laterals (analogues to leaves) was estimated using closed-chamber oxygen evolution in darkness and under a saturating irradiance of 420 µmol photons m-2 s-1. KEY RESULTS T opt of E. radiata is 18 °C across performance variables (photosynthesis, growth, abundance, size, mass and fertility), life stages (gametophyte and sporophyte) and populations. Our models predict that a temperature of >15 °C reduces the potential for E. radiata detritus to be photosynthetically viable, hence detrital Topt ≤ 15 °C. Detritus is viable under subcompensating irradiance, where it performs better than in darkness. Comparison of net and gross photosynthesis indicates that elevated temperature primarily decreases detrital photosynthesis, whereas darkness primarily increases detrital respiration compared with optimal experimental conditions, in which detrital photosynthesis can persist for ≥119 days. CONCLUSIONS T opt of kelp detritus is ≥3 °C colder than that of the intact plant. Given that E. radiata is one of the most temperature-tolerant kelps, this suggests that photosynthesis is generally more thermosensitive in the detrital phase, which partly explains the enhancing effect of temperature on remineralization. In contrast to darkness, even subcompensating irradiance maintains detrital viability, elucidating the accelerating effect of depth and its concomitant light reduction on remineralization to some extent. Detrital photosynthesis is a meaningful mechanism underlying at least two drivers of remineralization, even below the photoenvironment inhabited by the attached alga.
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Affiliation(s)
- Luka Seamus Wright
- Oceans Institute, University of Western Australia, Perth,Australia
- School of Biological Sciences, University of Western Australia, Perth,Australia
| | - Taylor Simpkins
- Oceans Institute, University of Western Australia, Perth,Australia
- School of Biological Sciences, University of Western Australia, Perth,Australia
| | - Karen Filbee-Dexter
- Oceans Institute, University of Western Australia, Perth,Australia
- School of Biological Sciences, University of Western Australia, Perth,Australia
- Institute of Marine Research, His, Norway
| | - Thomas Wernberg
- Oceans Institute, University of Western Australia, Perth,Australia
- School of Biological Sciences, University of Western Australia, Perth,Australia
- Institute of Marine Research, His, Norway
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Latorre-Padilla N, Meynard A, Oyarzun FX, Contreras-Porcia L. Ingestion of contaminated kelps by the herbivore Tetrapygus niger: Negative effects on food intake, growth, fertility, and early development. MARINE POLLUTION BULLETIN 2021; 167:112365. [PMID: 33882333 DOI: 10.1016/j.marpolbul.2021.112365] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 04/01/2021] [Accepted: 04/03/2021] [Indexed: 06/12/2023]
Abstract
Macrocystis pyrifera reaches distant areas after detachment, accumulate heavy metals, and serve as trophic subsidy. In this context, effects on both adults and larvae of Tetrapygus niger fed with polluted kelps were determined by assessing growth, fertility, and early larval development. Results revealed that sea urchins fed with polluted kelps from highly impacted zone (HIZ) showed a lower growth (3.6% gained weight) and gamete release (358 cells mL-1) than those fed with non-impacted kelps (NIZ) (19.3% and 945 cells mL-1). The HIZ treatment showed a developmental delay in comparison to NIZ, accounted mainly by the abundance of malformed 2-arm pluteus larvae (10-15%) during most of the culture. Malformed 4-arm pluteus larvae showed a constant increase, reaching 37% at the end of the culture. Thus, the pollutants ingested by sea urchins can be transferred to their offspring and cause negative effects in their early development, categorizing M. pyrifera as a pollutant carrier.
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Affiliation(s)
- Nicolás Latorre-Padilla
- Departamento de Ecología y Biodiversidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile; Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ciencias de la Vida, Universidad Andres Bello, Quintay, Chile; Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile; Instituto Milenio en Socio-Ecología Costera (SECOS), Santiago, Chile
| | - Andrés Meynard
- Departamento de Ecología y Biodiversidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile; Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ciencias de la Vida, Universidad Andres Bello, Quintay, Chile; Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile; Instituto Milenio en Socio-Ecología Costera (SECOS), Santiago, Chile
| | - Fernanda X Oyarzun
- Instituto Milenio en Socio-Ecología Costera (SECOS), Santiago, Chile; Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Chile
| | - Loretto Contreras-Porcia
- Departamento de Ecología y Biodiversidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile; Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ciencias de la Vida, Universidad Andres Bello, Quintay, Chile; Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile; Instituto Milenio en Socio-Ecología Costera (SECOS), Santiago, Chile.
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Tala F, López BA, Velásquez M, Jeldres R, Macaya EC, Mansilla A, Ojeda J, Thiel M. Long-term persistence of the floating bull kelp Durvillaea antarctica from the South-East Pacific: Potential contribution to local and transoceanic connectivity. MARINE ENVIRONMENTAL RESEARCH 2019; 149:67-79. [PMID: 31154063 DOI: 10.1016/j.marenvres.2019.05.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/16/2019] [Accepted: 05/18/2019] [Indexed: 05/06/2023]
Abstract
Current knowledge about the performance of floating seaweeds as dispersal vectors comes mostly from mid latitudes (30°-40°), but phylogeographic studies suggest that long-distance dispersal (LDD) is more common at high latitudes (50°-60°). To test this hypothesis, long-term field experiments with floating southern bull kelp Durvillaea antarctica were conducted along a latitudinal gradient (30°S, 37°S and 54°S) in austral winter and summer. Floating time exceeded 200d in winter at the high latitudes but in summer it dropped to 90d, being still higher than at low latitudes (<45d). Biomass variations were due to loss of buoyant fronds. Reproductive activity diminished during long floating times. Physiological changes included mainly a reduction in photosynthetic (Fv/Fm and pigments) rather than in defence variables (phlorotannins and antioxidant activity). The observed long floating persistence and long-term acclimation responses at 54°S support the hypothesis of LDD by kelp rafts at high latitudes.
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Affiliation(s)
- Fadia Tala
- Departamento de Biología Marina, Universidad Católica del Norte, Larrondo, 1281, Coquimbo, Chile; Centro de Investigación y Desarrollo Tecnológico en Algas (CIDTA), Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile.
| | - Boris A López
- Departamento de Acuicultura y Recursos Agroalimentarios, Universidad de Los Lagos, Avenida Fuchslocher, 1305, Osorno, Chile
| | - Marcel Velásquez
- Laboratorio de Macroalgas Antárticas y Subantárticas (LMAS), Universidad de Magallanes, Facultad de Ciencias, Casilla 113-D, Punta Arenas, Chile; Instituto de Ecología y Biodiversidad, IEB-Chile, Universidad de Chile, Santiago, Chile
| | - Ricardo Jeldres
- Departamento de Oceanografía, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile; Centro FONDAP de Investigaciones en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Chile
| | - Erasmo C Macaya
- Departamento de Oceanografía, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile; Centro FONDAP de Investigaciones en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Chile; Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile
| | - Andrés Mansilla
- Laboratorio de Macroalgas Antárticas y Subantárticas (LMAS), Universidad de Magallanes, Facultad de Ciencias, Casilla 113-D, Punta Arenas, Chile; Instituto de Ecología y Biodiversidad, IEB-Chile, Universidad de Chile, Santiago, Chile
| | - Jaime Ojeda
- Laboratorio de Macroalgas Antárticas y Subantárticas (LMAS), Universidad de Magallanes, Facultad de Ciencias, Casilla 113-D, Punta Arenas, Chile; Instituto de Ecología y Biodiversidad, IEB-Chile, Universidad de Chile, Santiago, Chile; School of Environmental Studies, University of Victoria, Victoria, British Columbia, Canada
| | - Martin Thiel
- Departamento de Biología Marina, Universidad Católica del Norte, Larrondo, 1281, Coquimbo, Chile; Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile; Centro de Estudios Avanzados en Zonas Áridas, Coquimbo, Chile
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