1
|
He T, Li J, Xie L, Zheng Q. Response of chlorophyll-a to rainfall event in the basin of the South China sea: Statistical analysis. MARINE ENVIRONMENTAL RESEARCH 2024; 199:106576. [PMID: 38839454 DOI: 10.1016/j.marenvres.2024.106576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 04/27/2024] [Accepted: 05/31/2024] [Indexed: 06/07/2024]
Abstract
Chlorophyll-a (Chl-a) is an essential ecological indicator, and affected by processes such as typhoons, mesoscale eddies, and Rossby waves. However, the impact of more frequent and widespread precipitation events on Chl-a seems to be overlooked. This study utilized remote sensing data and reanalysis data to investigate the response of Chl-a to 240 precipitation events in the central South China Sea from 2005 to 2019. The results indicate that precipitation events have a significant impact on Chl-a concentration. Following a precipitation event in 2019, the Chl-a concentration in the affected area increased by approximately 0.22 mg m-³ from the 3rd to the 7th day. The reasons for the increase in Chl-a concentration were the vertical mixing induced by wind stirring and the upwelling caused by wind stress curl, which transported nutrients to the euphotic zone, lowering the sea surface temperature and triggering a proliferation of phytoplankton. Additionally, dissolved nutrients in precipitation provided a nutrient source for Chl-a growth. The contributions of nutrient supply, wind speed, and wind stress curl to the increase in Chl-a concentration during precipitation events were 18%, 37%, and 45%, respectively. Precipitation events enhanced marine primary productivity, playing a crucial role in deepening our understanding of ocean-atmosphere interactions and their impact on marine ecosystem.
Collapse
Affiliation(s)
- Tao He
- Laboratory of Coastal Ocean Variation and Disaster Prediction, College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China; Key Laboratory of Space Ocean Remote Sensing and Application, MNR, Beijing, 100081, China
| | - Junyi Li
- Laboratory of Coastal Ocean Variation and Disaster Prediction, College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China; Key Lab Continents Deep Sea Climate Sources & Environments in Continent Shelf Sea and Deep Ocean, Zhanjiang, 524088, China.
| | - Lingling Xie
- Laboratory of Coastal Ocean Variation and Disaster Prediction, College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China
| | - Quanan Zheng
- Laboratory of Coastal Ocean Variation and Disaster Prediction, College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China
| |
Collapse
|
2
|
Abstract
As evident from the nearby examples of Proxima Centauri and TRAPPIST-1, Earth-sized planets in the habitable zone of low-mass stars are common. Here, we focus on such planetary systems and argue that their (oceanic) tides could be more prominent due to stronger tidal forces. We identify the conditions under which tides may exert a significant positive influence on biotic processes including abiogenesis, biological rhythms, nutrient upwelling, and stimulating photosynthesis. We conclude our analysis with the identification of large-scale algal blooms as potential temporal biosignatures in reflectance light curves that can arise indirectly as a consequence of strong tidal forces. Key Words: Tidal effects-Abiogenesis-Biological clocks-Planetary habitability-Temporal biosignatures. Astrobiology 18, 967-982.
Collapse
Affiliation(s)
- Manasvi Lingam
- 1 Harvard-Smithsonian Center for Astrophysics , Cambridge, Massachusetts
- 2 John A. Paulson School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts
| | - Abraham Loeb
- 1 Harvard-Smithsonian Center for Astrophysics , Cambridge, Massachusetts
| |
Collapse
|
3
|
Ottesen EA. Probing the living ocean with ecogenomic sensors. Curr Opin Microbiol 2016; 31:132-139. [PMID: 27060777 DOI: 10.1016/j.mib.2016.03.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 03/21/2016] [Accepted: 03/22/2016] [Indexed: 01/30/2023]
Abstract
This review discusses the role of ecogenomic sensors in biological oceanography. Ecogenomic sensors are instruments that can autonomously collect biological samples and perform molecular analyses. This technology reduces logistical constraints on the length and duration of biological data collection. Autonomous, robotic performance of molecular assays shows particular promise in the field of public health. Recent applications include simultaneous detection of harmful algal species and fecal markers paired with same-day remote reporting of test results. Ecogenomic instruments are also showing promise for molecular ecological studies. Autonomous collection and preservation of biological samples is facilitating high-resolution ecological studies that are expanding our understanding of marine microbial ecology and dynamics. This review discusses recent applications of these instruments and makes recommendations for future developments.
Collapse
Affiliation(s)
- Elizabeth A Ottesen
- University of Georgia Department of Microbiology, Rm. 550 Biological Sciences, Athens, GA 30602, United States.
| |
Collapse
|
4
|
Karl DM, Church MJ. Microbial oceanography and the Hawaii Ocean Time-series programme. Nat Rev Microbiol 2014; 12:699-713. [PMID: 25157695 DOI: 10.1038/nrmicro3333] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Hawaii Ocean Time-series (HOT) programme has been tracking microbial and biogeochemical processes in the North Pacific Subtropical Gyre since October 1988. The near-monthly time series observations have revealed previously undocumented phenomena within a temporally dynamic ecosystem that is vulnerable to climate change. Novel microorganisms, genes and unexpected metabolic pathways have been discovered and are being integrated into our evolving ecological paradigms. Continued research, including higher-frequency observations and at-sea experimentation, will help to provide a comprehensive scientific understanding of microbial processes in the largest biome on Earth.
Collapse
Affiliation(s)
- David M Karl
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii, 1950 East-West Road, Honolulu, Hawaii 96822, USA
| | - Matthew J Church
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii, 1950 East-West Road, Honolulu, Hawaii 96822, USA
| |
Collapse
|
5
|
Karl DM. Microbially mediated transformations of phosphorus in the sea: new views of an old cycle. ANNUAL REVIEW OF MARINE SCIENCE 2014; 6:279-337. [PMID: 24405427 DOI: 10.1146/annurev-marine-010213-135046] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Phosphorus (P) is a required element for life. Its various chemical forms are found throughout the lithosphere and hydrosphere, where they are acted on by numerous abiotic and biotic processes collectively referred to as the P cycle. In the sea, microorganisms are primarily responsible for P assimilation and remineralization, including recently discovered P reduction-oxidation bioenergetic processes that add new complexity to the marine microbial P cycle. Human-induced enhancement of the global P cycle via mining of phosphate-bearing rock will likely influence the pace of P-cycle dynamics, especially in coastal marine habitats. The inextricable link between the P cycle and cycles of other bioelements predicts future impacts on, for example, nitrogen fixation and carbon dioxide sequestration. Additional laboratory and field research is required to build a comprehensive understanding of the marine microbial P cycle.
Collapse
Affiliation(s)
- David M Karl
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii, Honolulu, Hawaii 96822;
| |
Collapse
|
6
|
Oswald JN, Au WWL, Duennebier F. Minke whale (Balaenoptera acutorostrata) boings detected at the Station ALOHA Cabled Observatory. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2011; 129:3353-3360. [PMID: 21568435 DOI: 10.1121/1.3575555] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Minke whales (Balaenoptera acutorostrata) in the tropical North Pacific are elusive and difficult to detect visually. The recent association of a unique sound called the "boing" to North Pacific minke whales has made it possible to use passive acoustics to investigate the occurrence of this species in Hawaiian waters. One year of recordings (17 February 2007-18 February 2008) made at the Station ALOHA Cabled Observatory were examined to investigate the characteristics of boings and temporal patterns in their occurrence at this site, located 100 km north of Oahu. Characteristics of boings exhibited low variability. Pulse repetition rate and duration measurements matched those for "central" or "Hawaii" boing types. Boings were detected from October until May, with a peak in March. Although no boings were detected from June to September, the absence of boings does not necessarily indicate the absence of minke whales. Significant diel variation in boing rate was not observed. The absence of a diel pattern in boing production suggests that day- or night-time acoustic surveys are equally acceptable methods for studying minke whale occurrence. Future research should include efforts to determine what other sounds are produced by minke whales in this area, and which age/sex classes produce boings.
Collapse
Affiliation(s)
- Julie N Oswald
- Hawaii Institute of Marine Biology, University of Hawaii, PO Box 1106, Kailua 96374, Hawaii, USA.
| | | | | |
Collapse
|
7
|
Dave AC, Lozier MS. Local stratification control of marine productivity in the subtropical North Pacific. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jc006507] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
8
|
Litchman E, Klausmeier CA, Yoshiyama K. Contrasting size evolution in marine and freshwater diatoms. Proc Natl Acad Sci U S A 2009; 106:2665-70. [PMID: 19202058 PMCID: PMC2650323 DOI: 10.1073/pnas.0810891106] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Indexed: 11/18/2022] Open
Abstract
Diatoms are key players in the global carbon cycle and most aquatic ecosystems. Their cell sizes impact carbon sequestration and energy transfer to higher trophic levels. We report fundamental differences in size distributions of marine and freshwater diatoms, with marine diatoms significantly larger than freshwater species. An evolutionary game theoretical model with empirical allometries of growth and nutrient uptake shows that these differences can be explained by nitrogen versus phosphorus limitation, nutrient fluctuations and mixed layer depth differences. Constant and pulsed phosphorus supply select for small sizes, as does constant nitrogen supply. In contrast, intermediate frequency nitrogen pulses common in the ocean select for large sizes or the evolutionarily stable coexistence of large and small sizes. Size-dependent sinking interacts with mixed layer depth (MLD) to further modulate optimal sizes, with smaller sizes selected for by strong sinking and shallow MLD. In freshwaters, widespread phosphorus limitation, together with strong sinking and shallow MLD produce size distributions with smaller range, means and upper values, compared with the ocean. Shifting patterns of nutrient limitation and mixing may alter diatom size distributions, affecting global carbon cycle and the structure and functioning of aquatic ecosystems.
Collapse
Affiliation(s)
- E. Litchman
- Kellogg Biological Station, Michigan State University, Hickory Corners, MI 49060
- Zoology Department, Michigan State University, East Lansing, MI 48824
| | - C. A. Klausmeier
- Kellogg Biological Station, Michigan State University, Hickory Corners, MI 49060
- Plant Biology Department, Michigan State University, East Lansing, MI 48824; and
| | - K. Yoshiyama
- Kellogg Biological Station, Michigan State University, Hickory Corners, MI 49060
- Department of Chemical Oceanography, Ocean Research Institute, University of Tokyo, Tokyo 164-8639, Japan
| |
Collapse
|
9
|
Fong AA, Karl DM, Lukas R, Letelier RM, Zehr JP, Church MJ. Nitrogen fixation in an anticyclonic eddy in the oligotrophic North Pacific Ocean. ISME JOURNAL 2008; 2:663-76. [PMID: 18309359 DOI: 10.1038/ismej.2008.22] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mesoscale physical processes (for example eddies, frontal meanders and planetary waves) can play important roles in controlling ocean biogeochemistry. We examined spatial variations in upper ocean (0-100 m) nutrient inventories, N(2) fixing microorganism diversity and abundance, and rates of N(2) fixation in an anticyclonic eddy near Station ALOHA (22 degrees 45' N, 158 degrees 00' W) in the North Pacific Subtropical Gyre (NPSG). In July 2005, satellite-based sea surface altimetry and ocean color observation revealed an anticyclonic eddy with enhanced chlorophyll in the upper ocean in the vicinity of Station ALOHA. Within the eddy, near-surface ocean chlorophyll concentrations were approximately 5-fold greater than in the surrounding waters. Inventories of nitrate and phosphate in the eddy were similar to the concentrations historically observed at Station ALOHA, while silicic acid inventories were significantly depleted (one-way analysis of variance, P<0.01). Quantitative PCR determinations of nifH gene copies revealed relatively high abundances of several N(2) fixing cyanobacteria, including Trichodesmium spp., Crocosphaera watsonii and Richelia intracellularis. Reverse transcriptase PCR (RT-PCR) amplified nitrogenase (nifH) gene transcripts were cloned and sequenced to examine the diversity of active N(2) fixing microorganisms; these clone libraries were dominated by sequence-types 97%-99% identical to the filamentous cyanobacteria Trichodesmium spp. Near-surface ocean rates of N(2) fixation were 2-18 times greater (averaging 8.6+/-5.6 nmol N per l per day) than previously reported measurements at Station ALOHA. These results suggest that mesoscale physical variability can play an important role in modifying the abundances of N(2) fixing microorganisms and associated rates of N(2) fixation in open ocean ecosystems.
Collapse
Affiliation(s)
- Allison A Fong
- Department of Oceanography, University of Hawaii, Honolulu, HI 96822, USA
| | | | | | | | | | | |
Collapse
|
10
|
White AE, Spitz YH, Letelier RM. What factors are driving summer phytoplankton blooms in the North Pacific Subtropical Gyre? ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2007jc004129] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
11
|
Benitez-Nelson CR, Bidigare RR, Dickey TD, Landry MR, Leonard CL, Brown SL, Nencioli F, Rii YM, Maiti K, Becker JW, Bibby TS, Black W, Cai WJ, Carlson CA, Chen F, Kuwahara VS, Mahaffey C, McAndrew PM, Quay PD, Rappé MS, Selph KE, Simmons MP, Yang EJ. Mesoscale Eddies Drive Increased Silica Export in the Subtropical Pacific Ocean. Science 2007; 316:1017-21. [PMID: 17510362 DOI: 10.1126/science.1136221] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Mesoscale eddies may play a critical role in ocean biogeochemistry by increasing nutrient supply, primary production, and efficiency of the biological pump, that is, the ratio of carbon export to primary production in otherwise nutrient-deficient waters. We examined a diatom bloom within a cold-core cyclonic eddy off Hawaii. Eddy primary production, community biomass, and size composition were markedly enhanced but had little effect on the carbon export ratio. Instead, the system functioned as a selective silica pump. Strong trophic coupling and inefficient organic export may be general characteristics of community perturbation responses in the warm waters of the Pacific Ocean.
Collapse
Affiliation(s)
- Claudia R Benitez-Nelson
- Department of Geological Sciences and Marine Science Program, University of South Carolina, Columbia, SC 29208, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Corno G, Karl DM, Church MJ, Letelier RM, Lukas R, Bidigare RR, Abbott MR. Impact of climate forcing on ecosystem processes in the North Pacific Subtropical Gyre. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jc003730] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
13
|
Johnson KS, Needoba JA, Riser SC, Showers WJ. Chemical sensor networks for the aquatic environment. Chem Rev 2007; 107:623-40. [PMID: 17249737 DOI: 10.1021/cr050354e] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kenneth S Johnson
- Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, California 95039, USA
| | | | | | | |
Collapse
|