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Mustaffa NIH, Khairul Anuar AN, Zaini NS, Mohamed KN, Latif MT. Distribution of surface-active substances in the sea surface microlayers off the Malaysian peninsula. MARINE POLLUTION BULLETIN 2024; 206:116798. [PMID: 39116752 DOI: 10.1016/j.marpolbul.2024.116798] [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: 04/14/2024] [Revised: 07/16/2024] [Accepted: 07/30/2024] [Indexed: 08/10/2024]
Abstract
The sea surface microlayer (SML), particularly in monsoon-influenced regions, remains largely unexplored. This study aims to determine the concentrations, enrichment, and factors controlling the enrichment processes of surface-active substances (SASs), which include surfactants, dissolved monosaccharides (MCHOs), polysaccharides (PCHOs), total dissolved carbohydrates (TDCHOs), and transparent exopolymer particles (TEPs) around the coastal area of Malaysian Peninsula. The SML samples and underlying water (ULW) from a depth of 1 m were collected during the southwest (August and September 2023) and northeast (November 2023) monsoons. Surfactants, TEPs, and dissolved carbohydrates were measured spectrometrically using methylene blue, the Alcian blue assay, and 2,4,6-Tri(2-pyridyl)-s-triazine (TPTZ), respectively. The results showed that stations influenced by anthropogenic activities were generally enriched with surfactants (Enrichment factor, EF = 1.40 ± 0.91) and carbohydrate species (TDCHOs = 1.38 ± 0.28, MCHOs = 1.54 ± 0.57, PCHOs = 1.85 ± 1.43). However, TEP enrichment was not observed in our study (EF = 0.68 ± 0.24). The SASs in the SML were correlated with their underlying concentrations, implying that transport from underlying water could be a major source of substances in the SML. High carbohydrate concentrations and enrichment were found during the northeast monsoon, implying that rain and runoff water affect concentrations in the SML. Besides, the enrichment of SASs persists at moderate wind speeds and is depleted at high wind speeds.
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Affiliation(s)
- Nur Ili Hamizah Mustaffa
- Department of Environment, Faculty of Forestry and Environment, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
| | - Ayu Nabila Khairul Anuar
- Department of Environment, Faculty of Forestry and Environment, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Nor Syafikah Zaini
- Department of Environment, Faculty of Forestry and Environment, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Khairul Nizam Mohamed
- Department of Environment, Faculty of Forestry and Environment, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Mohd Talib Latif
- Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Selangor, Malaysia
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Enders AA, Clark JB, Elliott SM, Allen HC. New Insights into Cation- and Temperature-Driven Protein Adsorption to the Air-Water Interface through Infrared Reflection Studies of Bovine Serum Albumin. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:5505-5513. [PMID: 37027519 DOI: 10.1021/acs.langmuir.3c00249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The chemistry and structure of the air-ocean interface modulate biogeochemical processes between the ocean and atmosphere and therefore impact sea spray aerosol properties, cloud and ice nucleation, and climate. Protein macromolecules are enriched in the sea surface microlayer and have complex adsorption properties due to the unique molecular balance of hydrophobicity and hydrophilicity. Additionally, interfacial adsorption properties of proteins are of interest as important inputs for ocean climate modeling. Bovine serum albumin is used here as a model protein to investigate the dynamic surface behavior of proteins under several variable conditions including solution ionic strength, temperature, and the presence of a stearic acid (C17COOH) monolayer at the air-water interface. Key vibrational modes of bovine serum albumin are examined via infrared reflectance-absorbance spectroscopy, a specular reflection method that ratios out the solution phase and highlights the aqueous surface to determine, at a molecular level, the surface structural changes and factors affecting adsorption to the solution surface. Amide band reflection absorption intensities reveal the extent of protein adsorption under each set of conditions. Studies reveal the nuanced behavior of protein adsorption impacted by ocean-relevant sodium concentrations. Moreover, protein adsorption is most strongly affected by the synergistic effects of divalent cations and increased temperature.
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Affiliation(s)
- Abigail A Enders
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jessica B Clark
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Scott M Elliott
- Computational Physics and Methods (CCS-2), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Heather C Allen
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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Uning R, Suratman S, Latif MT, Mustaffa NIH. Assessment on the distributions and exchange of anionic surfactants in the coastal environment of Peninsular Malaysia: A review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:15380-15390. [PMID: 34988826 DOI: 10.1007/s11356-021-18395-1] [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: 08/06/2021] [Accepted: 12/25/2021] [Indexed: 06/14/2023]
Abstract
Terrestrial anionic surfactants (AS) enter the marine environment through coastal region. Despite that, in general limited knowledge is available on the coastal AS transfer pathway. This paper aims to assess the distributions and exchange of AS in the Peninsular Malaysia coastal environments, adjacent to the southern waters of South China Sea and Strait of Malacca. An assessment case study was conducted by a review on the available data from the workgroup that span between the year 2008 and 2019. The findings showed that AS dominated in the sea surface microlayer (SML, 57%) compared to subsurface water (SSW, 43 %). AS were also found to have dominated in fine mode (FM, 71 %) compared to coarse mode (CM, 29 %) atmospheric aerosols. SML AS correspond to the SSW AS (p < 0.01); however, highest enrichment factor (EF) of the SML AS was not consistent with highest SSW AS. Direct AS exchange between SML and FM and CM was not observed. Furthermore, the paper concludes AS mainly located in the SML and FM and could potentially be the main transfer pathway in the coastal environment.
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Affiliation(s)
- Royston Uning
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030, Kuala Nerus, Terengganu, Malaysia.
| | - Suhaimi Suratman
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030, Kuala Nerus, Terengganu, Malaysia
| | - Mohd Talib Latif
- Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Nur Ili Hamizah Mustaffa
- Department of Environment, Faculty of Forestry and Environment, Universiti Putra Malaysia (UPM), 43400, Serdang, Selangor, Malaysia
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The Role of Extracellular Carbonic Anhydrase in Biogeochemical Cycling: Recent Advances and Climate Change Responses. Int J Mol Sci 2021; 22:ijms22147413. [PMID: 34299033 PMCID: PMC8307829 DOI: 10.3390/ijms22147413] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/06/2021] [Accepted: 07/07/2021] [Indexed: 12/14/2022] Open
Abstract
Climate change has been predicted to influence the marine phytoplankton community and its carbon acquisition strategy. Extracellular carbonic anhydrase (eCA) is a zinc metalloenzyme that catalyses the relatively slow interconversion between HCO3− and CO2. Early results indicated that sub-nanomolar levels of eCA at the sea surface were sufficient to enhance the oceanic uptake rate of CO2 on a global scale by 15%, an addition of 0.37 Pg C year−1. Despite its central role in the marine carbon cycle, only in recent years have new analytical techniques allowed the first quantifications of eCA and its activity in the oceans. This opens up new research areas in the field of marine biogeochemistry and climate change. Light and suitable pH conditions, as well as growth stage, are crucial factors in eCA expression. Previous studies showed that phytoplankton eCA activity and concentrations are affected by environmental stressors such as ocean acidification and UV radiation as well as changing light conditions. For this reason, eCA is suggested as a biochemical indicator in biomonitoring programmes and could be used for future response prediction studies in changing oceans. This review aims to identify the current knowledge and gaps where new research efforts should be focused to better determine the potential feedback of phytoplankton via eCA in the marine carbon cycle in changing oceans.
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Yang M, Smyth TJ, Kitidis V, Brown IJ, Wohl C, Yelland MJ, Bell TG. Natural variability in air-sea gas transfer efficiency of CO 2. Sci Rep 2021; 11:13584. [PMID: 34193883 PMCID: PMC8245487 DOI: 10.1038/s41598-021-92947-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 06/18/2021] [Indexed: 11/29/2022] Open
Abstract
The flux of CO2 between the atmosphere and the ocean is often estimated as the air–sea gas concentration difference multiplied by the gas transfer velocity (K660). The first order driver for K660 over the ocean is wind through its influence on near surface hydrodynamics. However, field observations have shown substantial variability in the wind speed dependencies of K660. In this study we measured K660 with the eddy covariance technique during a ~ 11,000 km long Southern Ocean transect. In parallel, we made a novel measurement of the gas transfer efficiency (GTE) based on partial equilibration of CO2 using a Segmented Flow Coil Equilibrator system. GTE varied by 20% during the transect, was distinct in different water masses, and related to K660. At a moderate wind speed of 7 m s−1, K660 associated with high GTE exceeded K660 with low GTE by 30% in the mean. The sensitivity of K660 towards GTE was stronger at lower wind speeds and weaker at higher wind speeds. Naturally-occurring organics in seawater, some of which are surface active, may be the cause of the variability in GTE and in K660. Neglecting these variations could result in biases in the computed air–sea CO2 fluxes.
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Affiliation(s)
- Mingxi Yang
- Plymouth Marine Laboratory, Prospect Place, Plymouth, UK.
| | | | | | - Ian J Brown
- Plymouth Marine Laboratory, Prospect Place, Plymouth, UK
| | - Charel Wohl
- Plymouth Marine Laboratory, Prospect Place, Plymouth, UK
| | | | - Thomas G Bell
- Plymouth Marine Laboratory, Prospect Place, Plymouth, UK
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Plastic Accumulation in the Sea Surface Microlayer: An Experiment-Based Perspective for Future Studies. GEOSCIENCES 2019. [DOI: 10.3390/geosciences9020066] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Plastic particles are ubiquitous in the marine environment. Given their low density, they have the tendency to float on the sea surface, with possible impacts on the sea surface microlayer (SML). The SML is an enriched biofilm of marine organic matter, that plays a key role in biochemical and photochemical processes, as well as controlling gas exchange between the ocean and the atmosphere. Recent studies indicate that plastics can interfere with the microbial cycling of carbon. However, studies on microplastic accumulation in the SML are limited, and their effects on organic matter cycling in the surface ocean are poorly understood. To explore potential dynamics in this key ocean compartment, we ran a controlled experiment with standard microplastics in the surface and bulk water of a marine monoculture. Bacterial abundance, chromophoric dissolved organic matter (CDOM), and oxygen concentrations were measured. The results indicate an accumulation of CDOM in the SML and immediate underlying water when microplastic particles are present, as well as an enhanced oxygen consumption. If extrapolated to a typical marine environment, this indicates that alterations in the quality and reactivity of the organic components of the SML could be expected. This preliminary study shows the need for a more integrated effort to our understanding the impact of microplastics on SML functioning and marine biological processes.
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