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Beca-Carretero P, Teichberg M, Winters G, Procaccini G, Reuter H. Projected Rapid Habitat Expansion of Tropical Seagrass Species in the Mediterranean Sea as Climate Change Progresses. Front Plant Sci 2020; 11:555376. [PMID: 33304358 PMCID: PMC7701102 DOI: 10.3389/fpls.2020.555376] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 10/21/2020] [Indexed: 05/27/2023]
Abstract
During the last 150 years, the tropical seagrass species Halophila stipulacea has established itself in the southern and eastern parts of the Mediterranean Sea. More recently (2018), Halophila decipiens was observed for the first time in the eastern Mediterranean, and was described as the second non-native seagrass species in the Mediterranean Sea. We implemented a species distribution model (SDM) approach to (1) hindcast the habitat suitability of H. stipulacea over the last 100 years in the Mediterranean basin, and (2) to model the increase in the potential habitat suitability of H. stipulacea and H. decipiens during the current century under two very different climate scenarios, RCP 2.6 (lowest carbon emission scenario) and RCP 8.5 (highest carbon emission scenario). In addition, a principal component analysis (PCA) and k-means cluster based on temperature and salinity drivers were applied to visualize the distance and relatedness between the native and invasive H. stipulacea and H. decipiens populations. Results from this PCA suggest that the H. stipulacea populations of the Mediterranean and Red Sea are likely to be similar. In contrast, H. decipiens from the Mediterranean is more related to the Atlantic populations rather than to the Red Sea populations. The hindcast model suggests that the expansion of H. stipulacea was related to the increases in seawater temperatures in the Mediterranean over the last 100 years. The SDMs predict that more suitable habitat will become available for both tropical species during this century. The habitat suitability for H. stipulacea will keep expanding westward and northward as the Mediterranean continues to become saltier and warmer. In comparison, the SDMs built for H. decipiens forecast a restricted habitat suitability in the south-eastern Mediterranean Sea at the present environmental conditions and predicts a progressive expansion with a potential increase in habitat suitability along 85% of the Mediterranean coastline. The predicted rapid expansion of non-native seagrass species could alter the Mediterranean's seagrass community and may entail massive impacts on associated ecosystem functions and services, impacts that have severe socio-economic consequences.
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Affiliation(s)
- Pedro Beca-Carretero
- Department of Theoretical Ecology and Modelling, Leibniz Centre for Tropical Marine Research, Bremen, Germany
- Dead Sea-Arava Science Center, Masada, Israel
- Department of Ecology, Leibniz Centre for Tropical Marine Research, Bremen, Germany
| | - Mirta Teichberg
- Department of Ecology, Leibniz Centre for Tropical Marine Research, Bremen, Germany
| | - Gidon Winters
- Dead Sea-Arava Science Center, Masada, Israel
- Eilat Campus, Ben-Gurion University of the Negev, Eilat, Israel
| | | | - Hauke Reuter
- Department of Theoretical Ecology and Modelling, Leibniz Centre for Tropical Marine Research, Bremen, Germany
- Faculty for Biology and Chemistry, University of Bremen, Bremen, Germany
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Chartrand KM, Szabó M, Sinutok S, Rasheed MA, Ralph PJ. Living at the margins - The response of deep-water seagrasses to light and temperature renders them susceptible to acute impacts. Mar Environ Res 2018; 136:126-138. [PMID: 29503105 DOI: 10.1016/j.marenvres.2018.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/05/2018] [Accepted: 02/08/2018] [Indexed: 06/08/2023]
Abstract
Seagrasses inhabit environments where light varies at different timescales, nonetheless are acutely sensitive to reductions in light beyond some conditional bounds. Two tropical deep-water seagrasses, Halophila decipiens and Halophila spinulosa, from the Great Barrier Reef were tested for their response to defined light and temperature regimes to identify their growth requirements and potential thresholds of mortality. Species were exposed to two light intensities, saturating (75 μmol photons m-2 s-1) and limiting (25 μmol photons m-2 s-1) light and two temperature treatments (26 °C and 30 °C) over a four-week period. Wavelength-specific parameters of PSII photochemistry were evaluated for seagrass leaves, as well as shoot density, gas exchange, and pigment content. Both species were sustained under saturating light levels (3.2 mol photons m-2 d-1) while limiting light led to decreased shoot density for H. decipiens and H. spinulosa after two and four weeks, respectively. Wavelength-specific photochemistry was also affected under light-limiting treatments for both species while the functional absorption cross section was highly conserved. Photoacclimation and physiological adjustments by either species was not adequate to compensate for reduced irradiance suggesting these plants reside at the margins of their functional limits. As such, relatively short periods of light attenuating events, like dredging or flood plumes, may be detrimental to deep-water seagrass populations.
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Affiliation(s)
- Kathryn M Chartrand
- Centre for Tropical Water & Aquatic Ecosystem Research, James Cook University, Cairns, Queensland, Australia; Climate Change Cluster, University of Technology Sydney, Broadway, New South Wales, Australia.
| | - Milán Szabó
- Climate Change Cluster, University of Technology Sydney, Broadway, New South Wales, Australia; Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Sutinee Sinutok
- Climate Change Cluster, University of Technology Sydney, Broadway, New South Wales, Australia; Faculty of Environmental Management, Prince of Songkla University, Hat Yai, Thailand; Coastal Oceanography and Climate Change Research Center, Prince of Songkla University, Hat Yai, Thailand
| | - Michael A Rasheed
- Centre for Tropical Water & Aquatic Ecosystem Research, James Cook University, Cairns, Queensland, Australia
| | - Peter J Ralph
- Climate Change Cluster, University of Technology Sydney, Broadway, New South Wales, Australia
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Hovey RK, Statton J, Fraser MW, Ruiz-Montoya L, Zavala-Perez A, Rees M, Stoddart J, Kendrick GA. Strategy for assessing impacts in ephemeral tropical seagrasses. Mar Pollut Bull 2015; 101:594-599. [PMID: 26541985 DOI: 10.1016/j.marpolbul.2015.10.054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 10/19/2015] [Accepted: 10/22/2015] [Indexed: 06/05/2023]
Abstract
We investigated the phenology and spatial patterns in Halophila decipiens by assessing biomass, reproduction and seed density in ~400 grab samples collected across nine sites (8 to 14 m water depth) between June 2011 and December 2012. Phenology correlated with light climate which is governed by the summer monsoon (wet period). During the wet period, sedimentary seed banks prevailed, varying spatially at both broad and fine scales, presenting a source of propagules for re-colonisation following the unfavourable growing conditions of the monsoon. Spatial patterns in H. decipiens biomass following monsoon conditions were highly variable within a landscape that largely comprised potential seagrass habitat. Management strategies for H. decipiens and similar transient species must recognise the high temporal and spatial variability of these populations and be underpinned by a framework that emphasises vulnerability assessments of different life stages instead of relying solely on thresholds for standing stock at fixed reference sites.
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Affiliation(s)
- Renae K Hovey
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; School Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia.
| | - John Statton
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; School Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Matthew W Fraser
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; School Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Leonardo Ruiz-Montoya
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; School Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Andrea Zavala-Perez
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; School Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Max Rees
- MScience Pty Ltd., Nedlands, Western Australia 6009, Australia
| | - James Stoddart
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; MScience Pty Ltd., Nedlands, Western Australia 6009, Australia
| | - Gary A Kendrick
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; School Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
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