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Jiménez-Ramos R, Brun FG, Vergara JJ, Hernández I, Pérez-Lloréns JL, Egea LG. Nutrient enrichment and herbivory alter carbon balance in temperate seagrass communities. MARINE POLLUTION BULLETIN 2024; 206:116784. [PMID: 39083908 DOI: 10.1016/j.marpolbul.2024.116784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 07/23/2024] [Accepted: 07/24/2024] [Indexed: 08/02/2024]
Abstract
Large nutrient levels and herbivory stress, particularly when acting together, drive a variety of responses in seagrass communities that ultimately may weaken their carbon balance. An in situ three-months experiment was carried out in two contrasting seasons to address the effects of two levels of nutrient load and three levels of artificial clipping on Cymodocea nodosa plants. Nutrient enrichment shifted the community from autotrophic to heterotrophic and reduced DOC fluxes in winter, whereas enhanced community carbon metabolism and DOC fluxes in summer. Herbivory stress decreased the net primary production in both seasons, whereas net DOC release increased in winter but decreased in summer. A reduction of seagrass food-web structure was observed under both disturbances evidencing impacts on the seagrass ecosystems services by altering the carbon transfer process and the loss of superficial OC, which may finally weaken the blue carbon storage capacity of these communities.
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Affiliation(s)
- Rocío Jiménez-Ramos
- Instituto Universitario de Investigación Marina (INMAR), Campus de Excelencia Internacional del Mar (CEI·MAR), Departamento de Biología, Facultad de Ciencias del Mar y Ambientales Universidad de Cádiz, Campus Universitario de Puerto Real, Puerto Real, Cádiz, Spain.
| | - Fernando G Brun
- Instituto Universitario de Investigación Marina (INMAR), Campus de Excelencia Internacional del Mar (CEI·MAR), Departamento de Biología, Facultad de Ciencias del Mar y Ambientales Universidad de Cádiz, Campus Universitario de Puerto Real, Puerto Real, Cádiz, Spain
| | - Juan J Vergara
- Instituto Universitario de Investigación Marina (INMAR), Campus de Excelencia Internacional del Mar (CEI·MAR), Departamento de Biología, Facultad de Ciencias del Mar y Ambientales Universidad de Cádiz, Campus Universitario de Puerto Real, Puerto Real, Cádiz, Spain
| | - Ignacio Hernández
- Instituto Universitario de Investigación Marina (INMAR), Campus de Excelencia Internacional del Mar (CEI·MAR), Departamento de Biología, Facultad de Ciencias del Mar y Ambientales Universidad de Cádiz, Campus Universitario de Puerto Real, Puerto Real, Cádiz, Spain
| | - J Lucas Pérez-Lloréns
- Instituto Universitario de Investigación Marina (INMAR), Campus de Excelencia Internacional del Mar (CEI·MAR), Departamento de Biología, Facultad de Ciencias del Mar y Ambientales Universidad de Cádiz, Campus Universitario de Puerto Real, Puerto Real, Cádiz, Spain
| | - Luis G Egea
- Instituto Universitario de Investigación Marina (INMAR), Campus de Excelencia Internacional del Mar (CEI·MAR), Departamento de Biología, Facultad de Ciencias del Mar y Ambientales Universidad de Cádiz, Campus Universitario de Puerto Real, Puerto Real, Cádiz, Spain
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Jiang Z, He J, Fang Y, Lin J, Liu S, Wu Y, Huang X. Effects of herbivore on seagrass, epiphyte and sediment carbon sequestration in tropical seagrass bed. MARINE ENVIRONMENTAL RESEARCH 2023; 190:106122. [PMID: 37549560 DOI: 10.1016/j.marenvres.2023.106122] [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: 02/01/2023] [Revised: 07/10/2023] [Accepted: 07/31/2023] [Indexed: 08/09/2023]
Abstract
Herbivores strongly affect the ecological structure and functioning in seagrass bed ecosystems, but may exhibit density-dependent effects on primary producers and carbon sequestration. This study examined the effects of herbivorous snail (Cerithidea rhizophorarum) density on snail intraspecific competition and diet, dominant seagrass (Thalassia hemprichii) and epiphyte growth metrics, and sediment organic carbon (SOC). The growth rates of the herbivorous snail under low density (421 ind m-2) and mid density (842 ind m-2) were almost two times of those at extremely high density (1684 ind m-2), indicating strong intraspecific competition at high density. Herbivorous snails markedly reduced the epiphyte biomass on seagrass leaves. Additionally, the seagrass contribution to herbivorous snail as food source under high density was about 1.5 times of that under low density, while the epiphyte contribution under low density was 3 times of that under high density. A moderate density of herbivorous snails enhanced leaf length, carbon, nitrogen, total phenol and flavonoid contents of seagrasses, as well as surface SOC content and activities of polyphenol oxidase and β-glucosidase. However, high density of herbivorous snails decreased leaf glucose, fructose, detritus carbon, and total phenols contents of seagrasses, as well as surface SOC content and activities of polyphenol oxidase and β-glucosidase. Therefore, the effects of herbivorous snail on seagrass, epiphyte and SOC were density-dependent, and moderate density of herbivorous snail could be beneficial for seagrasses to increase productivity. This provided theoretical guidance for enhancing carbon sink in seagrass bed and its better conservation.
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Affiliation(s)
- Zhijian Jiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya, 572100, China; Guangdong Provincial Key Laboratory of Marine Biology Applications, Guangzhou, 510301, China
| | - Jialu He
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Guangdong Center for Marine Development Research, Guangzhou, 510220, China
| | - Yang Fang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Jizhen Lin
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, PR China; Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya, 572100, China; Guangdong Provincial Key Laboratory of Marine Biology Applications, Guangzhou, 510301, China
| | - Yunchao Wu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, PR China; Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya, 572100, China; Guangdong Provincial Key Laboratory of Marine Biology Applications, Guangzhou, 510301, China
| | - Xiaoping Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya, 572100, China; Guangdong Provincial Key Laboratory of Marine Biology Applications, Guangzhou, 510301, China.
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de la Garza Varela A, Aguirre-Macedo ML, García-Maldonado JQ. Changes in the Rhizosphere Prokaryotic Community Structure of Halodule wrightii Monospecific Stands Associated to Submarine Groundwater Discharges in a Karstic Costal Area. Microorganisms 2023; 11:microorganisms11020494. [PMID: 36838457 PMCID: PMC9963909 DOI: 10.3390/microorganisms11020494] [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: 01/25/2023] [Revised: 02/11/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023] Open
Abstract
Belowground seagrass associated microbial communities regulate biogeochemical dynamics in the surrounding sediments and influence seagrass physiology and health. However, little is known about the impact of environmental stressors upon interactions between seagrasses and their prokaryotic community in coastal ecosystems. Submerged groundwater discharges (SGD) at Dzilam de Bravo, Yucatán, Mexico, causes lower temperatures and salinities with higher nutrient loads in seawater, resulting in Halodule wrightii monospecific stands. In this study, the rhizospheric archaeal and bacterial communities were characterized by 16S rRNA Illumina sequencing along with physicochemical determinations of water, porewater and sediment in a 400 m northwise transect from SGD occurring at 300 m away from coastline. Core bacterial community included Deltaproteobacteria, Bacteroidia and Planctomycetia, possibly involved in sulfur metabolism and organic matter degradation while highly versatile Bathyarchaeia was the most abundantly represented class within the archaeal core community. Beta diversity analyses revealed two significantly different clusters as result of the environmental conditions caused by SGD. Sites near to SGD presented sediments with higher redox potentials and sand contents as well as lower organic matter contents and porewater ammonium concentrations compared with the furthest sites. Functional profiling suggested that denitrification, aerobic chemoheterotrophy and environmental adaptation processes could be better represented in these sites, while sulfur metabolism and genetic information processing related profiles could be related to SGD uninfluenced sites. This study showed that the rhizospheric prokaryotic community structure of H. wrightii and their predicted functions are shaped by environmental stressors associated with the SGD. Moreover, insights into the archaeal community composition in seagrasses rhizosphere are presented.
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