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Veenhof RJ, Champion C, Dworjanyn SA, Schwoerbel J, Visch W, Coleman MA. Projecting kelp (Ecklonia radiata) gametophyte thermal adaptation and persistence under climate change. ANNALS OF BOTANY 2024; 133:153-168. [PMID: 37665952 PMCID: PMC10921825 DOI: 10.1093/aob/mcad132] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 09/01/2023] [Indexed: 09/06/2023]
Abstract
BACKGROUND AND AIMS Kelp forests underpin temperate marine ecosystems but are declining due to ocean warming, causing loss of associated ecosystem services. Projections suggest significant future decline but often only consider the persistence of adult sporophytes. Kelps have a biphasic life cycle, and the haploid gametophyte can be more thermally tolerant than the sporophyte. Therefore, projections may be altered when considering the thermal tolerance of gametophytes. METHODS We undertook thermal tolerance experiments to quantify the effect of temperature on gametophyte survival, relative growth rate (RGR) and sex ratio for three genetically distinct populations of Ecklonia radiata gametophytes from comparatively high, mid- and low latitudes (43°, 33° and 30°S). We then used these data to project the likely consequences of climate-induced thermal change on gametophyte persistence and performance across its eastern Australian range, using generalized additive and linear models. KEY RESULTS All populations were adapted to local temperatures and their thermal maximum was 2-3 °C above current maximum in situ temperatures. The lowest latitude population was most thermally tolerant (~70 % survival up to 27 °C), while survival and RGR decreased beyond 25.5 and 20.5 °C for the mid- and low-latitude populations, respectively. Sex ratios were skewed towards females with increased temperature in the low- and high-latitude populations. Spatially explicit model projections under future ocean warming (2050-centred) revealed a minimal decline in survival (0-30 %) across populations, relative to present-day predictions. RGRs were also projected to decline minimally (0-2 % d-1). CONCLUSIONS Our results contrast with projections for the sporophyte stage of E. radiata, which suggest a 257-km range contraction concurrent with loss of the low-latitude population by 2100. Thermal adaptation in E. radiata gametophytes suggests this life stage is likely resilient to future ocean warming and is unlikely to be a bottleneck for the future persistence of kelp.
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Affiliation(s)
- R J Veenhof
- National Marine Science Centre, Faculty of Science and Engineering, Southern Cross University, Coffs Harbour, NSW, Australia
| | - C Champion
- National Marine Science Centre, Faculty of Science and Engineering, Southern Cross University, Coffs Harbour, NSW, Australia
- Fisheries Research, NSW Department of Primary Industries, National Marine Science Centre, Coffs Harbour, NSW, Australia
| | - S A Dworjanyn
- National Marine Science Centre, Faculty of Science and Engineering, Southern Cross University, Coffs Harbour, NSW, Australia
| | - J Schwoerbel
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - W Visch
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - M A Coleman
- National Marine Science Centre, Faculty of Science and Engineering, Southern Cross University, Coffs Harbour, NSW, Australia
- Fisheries Research, NSW Department of Primary Industries, National Marine Science Centre, Coffs Harbour, NSW, Australia
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Gonzalez‐Aragon D, Rivadeneira MM, Lara C, Torres FI, Vásquez JA, Broitman BR. A species distribution model of the giant kelp Macrocystis pyrifera: Worldwide changes and a focus on the Southeast Pacific. Ecol Evol 2024; 14:e10901. [PMID: 38435006 PMCID: PMC10905252 DOI: 10.1002/ece3.10901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 11/29/2023] [Accepted: 12/14/2023] [Indexed: 03/05/2024] Open
Abstract
Worldwide climate-driven shifts in the distribution of species is of special concern when it involves habitat-forming species. In the coastal environment, large Laminarian algae-kelps-form key coastal ecosystems that support complex and diverse food webs. Among kelps, Macrocystis pyrifera is the most widely distributed habitat-forming species and provides essential ecosystem services. This study aimed to establish the main drivers of future distributional changes on a global scale and use them to predict future habitat suitability. Using species distribution models (SDM), we examined the changes in global distribution of M. pyrifera under different emission scenarios with a focus on the Southeast Pacific shores. To constrain the drivers of our simulations to the most important factors controlling kelp forest distribution across spatial scales, we explored a suite of environmental variables and validated the predictions derived from the SDMs. Minimum sea surface temperature was the single most important variable explaining the global distribution of suitable habitat for M. pyrifera. Under different climate change scenarios, we always observed a decrease of suitable habitat at low latitudes, while an increase was detected in other regions, mostly at high latitudes. Along the Southeast Pacific, we observed an upper range contraction of -17.08° S of latitude for 2090-2100 under the RCP8.5 scenario, implying a loss of habitat suitability throughout the coast of Peru and poleward to -27.83° S in Chile. Along the area of Northern Chile where a complete habitat loss is predicted by our model, natural stands are under heavy exploitation. The loss of habitat suitability will take place worldwide: Significant impacts on marine biodiversity and ecosystem functioning are likely. Furthermore, changes in habitat suitability are a harbinger of massive impacts in the socio-ecological systems of the Southeast Pacific.
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Affiliation(s)
- Daniel Gonzalez‐Aragon
- Doctorado en Ciencias, mención en Biodiversidad y Biorecursos, Facultad de CienciasUniversidad Católica de la Santísima ConcepciónConcepcionChile
- Instituto Milenio en Socio‐Ecología Costera (SECOS)SantiagoChile
- Núcleo Milenio UPWELL
| | - Marcelo M. Rivadeneira
- Centro de Estudios Avanzados en Zonas ÁridasCoquimboChile
- Departamento de Biología Marina, Facultad de Ciencias del MarUniversidad Católica del NorteCoquimboChile
| | - Carlos Lara
- Departamento de Ecología, Facultad de CienciasUniversidad Católica de la Santísima ConcepciónConcepcionChile
- Centro de Investigación en Recursos Naturales y SustentabilidadUniversidad Bernardo O'HigginsSantiagoChile
| | - Felipe I. Torres
- Doctorado en Ciencias, mención en Biodiversidad y Biorecursos, Facultad de CienciasUniversidad Católica de la Santísima ConcepciónConcepcionChile
- Instituto Milenio en Socio‐Ecología Costera (SECOS)SantiagoChile
- Data Observatory Foundation, ANID Technology Center No. DO210001SantiagoChile
| | - Julio A. Vásquez
- Instituto Milenio en Socio‐Ecología Costera (SECOS)SantiagoChile
- Departamento de Biología Marina, Facultad de Ciencias del MarUniversidad Católica del NorteCoquimboChile
- Centro de Investigación y Desarrollo Tecnológico en Algas y Otros Recursos Biológicos (CIDTA)CoquimboChile
| | - Bernardo R. Broitman
- Instituto Milenio en Socio‐Ecología Costera (SECOS)SantiagoChile
- Núcleo Milenio UPWELL
- Facultad de Artes LiberalesUniversidad Adolfo IbañezViña Del MarChile
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Ahn H, Ito M, Kouchi N, Watanabe K, Abe H, Isada T, Nakaoka M. Spatial variation in diatom abundance and composition in Biwase Bay and Hamanaka Bay (Eastern Hokkaido, Japan), with reference to environmental features. PeerJ 2022; 10:e13705. [PMID: 35915753 PMCID: PMC9338754 DOI: 10.7717/peerj.13705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 06/19/2022] [Indexed: 01/17/2023] Open
Abstract
This study aims to examine the spatial variation of diatom abundance and composition along the nearshore areas of Biwase Bay and Hamanaka Bay, eastern Hokkaido. Terrestrial input via Kiritappu Wetland is expected to affect variation and composition differently depending on the position of the two bays. We conducted an oceanographic survey in June 2014 to measure seawater temperature, salinity, colored dissolved organic matter (CDOM) absorption, nutrient concentrations, and total and size-fractionated chlorophyll (Chl) a concentration at 11 stations of the shallowest (<5 m) parts of the bays. These were grouped into four areas (Areas 1 and 2 in Biwase Bay, and Areas 3 and 4 in Hamanaka Bay) based on the distance of the location from the wetland outlet (nearest in Area 1 to the farthest in Area 4). Diatoms are the major primary producers in the water column. Therefore, we also determined genus level cell abundance and diversity of diatoms to compare similarity among areas. Sea surface temperature was the lowest at Area 4, whereas sea surface salinity was the lowest at Area 1. The contribution of CDOM absorption, an indicator of wetland-influenced river discharge, and silica concentration was highest at Area 1. Total amount of nitrite and nitrate concentrations was the highest at Area 4. Total amount of Chl a concentration was also lowest in Area 1. Our size-fractionated Chl a results revealed that while the size composition of phytoplankton varied among areas, micro-sized (>10 µm) phytoplankton were predominant in Area 4. Finally, diatom composition at the genus level differed greatly among areas. Pennate diatoms were predominant in Areas 1 and 2, but centric diatoms dominated in Areas 3 and 4. Our results suggested great spatial variability in oceanographic conditions among areas, with less influence of wetland and more influence of Coastal Oyashio Water based on distance from the wetland outlet. Diatom composition showed geographical division between Biwase and Hamanaka Bays.
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Affiliation(s)
- Hyojin Ahn
- Akkeshi Marine Station, Hokkaido University, Akkeshi, Hokkaido, Japan,Faculty of Fisheries Science, Hokkaido University, Hakodate, Hokkaido, Japan
| | - Miho Ito
- Department of Biological Sciences, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Naoko Kouchi
- Kiritappu Wetland National Trust, Hamanaka, Hokkaido, Japan
| | - Kentaro Watanabe
- Akkeshi Marine Station, Hokkaido University, Akkeshi, Hokkaido, Japan
| | - Hiroya Abe
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Tomonori Isada
- Akkeshi Marine Station, Hokkaido University, Akkeshi, Hokkaido, Japan
| | - Masahiro Nakaoka
- Akkeshi Marine Station, Hokkaido University, Akkeshi, Hokkaido, Japan
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Chimura K, Akita S, Iwasaki T, Nagano AJ, Shimada S. Phylogeography of a canopy-forming kelp, Eisenia bicyclis (Laminariales, Phaeophyceae), based on a genome-wide sequencing analysis. JOURNAL OF PHYCOLOGY 2022; 58:318-329. [PMID: 35000198 DOI: 10.1111/jpy.13233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 12/29/2021] [Indexed: 06/14/2023]
Abstract
Analyses of phylogeographic patterns and genetic diversity provide fundamental information for the management and conservation of species. However, little is published about these patterns in Japanese kelp species. In this study, we conducted phylogeographic analyses of a canopy-forming kelp, Eisenia bicyclis, based on genome-wide SNPs identified by ddRAD-seq. We obtained 1,299 SNPs for 76 samples from nine localities across the distribution. STRUCTURE, NeighborNet, and discriminant analysis of principal components consistently showed high genetic differentiation among the Eastern Pacific, Central Pacific, and Sea of Japan coastal regions. Relatively strong gene flow was detected only within populations in the Eastern Pacific and in the Sea of Japan. Genetic diversity and genetic uniqueness were high in the Central Pacific and low in the Sea of Japan. These results suggest that there were at least three independent refugia corresponding to the three regions during the Last Glacial Maximum (LGM). Furthermore, relatively larger populations in the Central Pacific and smaller populations in the Sea of Japan have been maintained in the demographic history from before the LGM to the present. These phylogeographic histories were supported by an Approximate Bayesian Computation analysis. From a conservation genetics perspective, the loss of southern populations in the Central Pacific would greatly reduce the total genetic diversity of the species. Southern populations in the Sea of Japan, which have relatively low genetic diversity, may be highly vulnerable to environmental change, such as heat waves and increased feeding. Therefore, careful monitoring and conservation are needed in the two regions.
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Affiliation(s)
- Kanako Chimura
- Humanities and Science, Ochanomizu University, 2-1-1 Otsuka, Bunkyoku, Tokyo, 112-8610, Japan
| | - Shingo Akita
- Natural Science, Ochanomizu University, 2-1-1 Otsuka, Bunkyoku, Tokyo, 112-8610, Japan
- Faculty of Fisheries Sciences, Hokkaido University, 3-1-1 Minato, Hakodate, Hokkaido, 041-8611, Japan
| | - Takaya Iwasaki
- Natural Science, Ochanomizu University, 2-1-1 Otsuka, Bunkyoku, Tokyo, 112-8610, Japan
| | - Atsushi J Nagano
- Faculty of Agriculture, Ryukoku University, Yokotani 1-5, Seta Ohe-cho, Otsu, Shiga, 520-2194, Japan
- Institute for Advanced Biosciences, Keio University, 403-1 Nipponkoku, Daihouji, Tsuruoka, Yamagata, 997-0017, Japan
| | - Satoshi Shimada
- Natural Science, Ochanomizu University, 2-1-1 Otsuka, Bunkyoku, Tokyo, 112-8610, Japan
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Morita K. Marine ecology – Learn about a tough but wonderful world. Ecol Res 2020. [DOI: 10.1111/1440-1703.12084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kentaro Morita
- Hokkaido National Fisheries Research Institute Japan Fisheries Research and Education Agency Sapporo Japan
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