The sea surface microlayer: Biology, chemistry and anthropogenic enrichment

Hardy, John S.

doi:10.1016/0079-6611(82)90001-5

Cited by 339 publications

(275 citation statements)

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“…Dissolved compounds such as nutrients, dissolved organic carbon (DOC), and amino acids are often enriched in the SML, especially in the visible slicks of nearshore environments (Williams et al 1986). The enrichment of these compounds in the SML has been attributed to surface-active matter collected by rising gas bubbles in the upper water column (Kuznetsova and Lee 2002) or by Langmuir circulations in the open ocean (Hardy 1982). Atmospheric deposition of matter might be important for the development of a SML as well (Wotton and Preston 2005).…”

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confidence: 99%

Dissolved organic matter and bacterial production and respiration in the sea‐surface microlayer of the open Atlantic and the western Mediterranean Sea

Reinthaler

Sintes

Herndl

2008

Limnology & Oceanography

124

156

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The sea-surface microlayer (SML) is the boundary layer between the ocean and the atmosphere. We measured bacterial production and respiration along with dissolved organic carbon (DOC), nitrogen (DON), and phosphorus, inorganic nutrients, and dissolved amino acids in the SML and the underlying water (ULW) of the subtropical Atlantic gyre (SATL) and the western Mediterranean Sea (WMED). Dissolved amino acid concentrations in the SML were one order of magnitude higher than in the ULW. DON, ammonium, and nitrate were also significantly enriched in the SML as compared with the ULW. Bacterial leucine incorporation ranged between 3 and 50 pmol L 21 h 21 in the SATL and 5 and 488 pmol L 21 h 21 in the WMED and was generally not significantly different between the SML and the ULW. In contrast, bacterial respiration was significantly higher in the SML than in the ULW, varying between 3.6 and 9.5 mmol L 21 d 21 O 2 at both sites. The resulting bacterial growth efficiencies ranged between 0.1% and 14% using different leucine incorporation to carbon conversion factors. Given the high dissolved free amino acid (DFAA) yield of DOC (,12%) and of DON (,30%) in the SML, bacterial growth efficiencies in the SML were low. This indicates that the DFAA in the SML are not readily available for bacteria. The underlying mechanisms of this immobilization of DFAA in the SML and their production remain enigmatic.

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confidence: 99%

Dissolved organic matter and bacterial production and respiration in the sea‐surface microlayer of the open Atlantic and the western Mediterranean Sea

Reinthaler

Sintes

Herndl

2008

Limnology & Oceanography

124

156

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“…The enrichment of organic matter in the SML is generally related to biological processes in the euphotic zone (Hardy, 1982). Organic materials are transported upward from bulk water to the SML through diffusion, positively buoyant particles (Azetsu-Scott and Passow, 2004), and rising air bubbles (Gershey, 1983).…”

Section: Discussionmentioning

confidence: 99%

“…All materials exchanged between the ocean and atmosphere, including gases, particulate organic matter, and sea salt, have to pass through the SML (Liss and Duce, 2005). With a total thickness between 1 µm and 1000 µm, depending on the sampling technique (Shinki et al, 2012) and region of interest (Hardy, 1982), the SML remains sufficiently stable at a global average wind speed of 6.6 m s -1 (Wurl et al, 2011b) to control the rate of air-sea exchange of gases and heat, highlighting its global relevance. It is well established that the SML has unique physical, chemical, and biological properties that differ from those of the wellmixed underlying water masses (Hardy, 1982;Cunliffe et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

“…With a total thickness between 1 µm and 1000 µm, depending on the sampling technique (Shinki et al, 2012) and region of interest (Hardy, 1982), the SML remains sufficiently stable at a global average wind speed of 6.6 m s -1 (Wurl et al, 2011b) to control the rate of air-sea exchange of gases and heat, highlighting its global relevance. It is well established that the SML has unique physical, chemical, and biological properties that differ from those of the wellmixed underlying water masses (Hardy, 1982;Cunliffe et al, 2013). Biological and physical processes in the water column, such as primary productivity, diffusion, buoyancy flux, and rising bubbles, are the main factors determining the enrichment of chemical compounds and microbes in the SML (Wurl et al, 2009;Stolle et al, 2010).…”

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confidence: 99%

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High-resolution variability of the enrichment of fluorescence dissolved organic matter in the sea surface microlayer of an upwelling region

Mustaffa¹,

Ribas-Ribas²,

Wurl³

2017

Elementa: Science of the Anthropocene

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Mustaffa, NIH, et al 2017 High-resolution variability of the enrichment of fluorescence dissolved organic matter in the sea surface microlayer of an upwelling region. Elem Sci Anth, 5: 52, DOI: https://doi.org/10.1525/elementa.242 IntroductionThe uppermost part of the ocean, covering approximately 70% of the surface is defined as the sea surface microlayer (SML) (Liss and Duce, 2005). Due to its unique position between the atmosphere and ocean, the SML plays an important role in biogeochemical processes, including the marine carbon cycle, photochemistry and air-sea exchange of climate-relevant gases. All materials exchanged between the ocean and atmosphere, including gases, particulate organic matter, and sea salt, have to pass through the SML (Liss and Duce, 2005). With a total thickness between 1 µm and 1000 µm, depending on the sampling technique (Shinki et al., 2012) and region of interest (Hardy, 1982), the SML remains sufficiently stable at a global average wind speed of 6.6 m s -1 (Wurl et al., 2011b) to control the rate of air-sea exchange of gases and heat, highlighting its global relevance. It is well established that the SML has unique physical, chemical, and biological properties that differ from those of the wellmixed underlying water masses (Hardy, 1982;Cunliffe et al., 2013). Biological and physical processes in the water column, such as primary productivity, diffusion, buoyancy flux, and rising bubbles, are the main factors determining the enrichment of chemical compounds and microbes in the SML (Wurl et al., 2009;Stolle et al., 2010). Enriched materials include surface-active dissolved organic matter (DOM) (e.g., carbohydrates, proteins and lipids) and particulate organic matter (POM), as well as autotrophic and heterotrophic cells (Williams et al., 1986;Cunliffe et al., 2009). Fluorescence dissolved organic matter (FDOM) is a fraction of chromophoric DOM (CDOM) which not only absorbs but also emits a blue fluorescence when it is irradiated with ultraviolet (UV) light (Coble, 2007). FDOM is often used as an indicator for humic-like marine DOM (Yamashita and Tanoue, 2009) and frequently enriched in the SML (Zhang and Yang, 2013) due to its hydrophobic properties.CDOM enrichment in the SML is of particular interest due to its active role in photochemistry (de Bruyn et al., 2011), as the SML is the part of the ocean with the highest exposure to radiation. For this reason, some photochemical reactions in the SML can be unique (Carlson, 1993), and the SML may act as microreactor (Blough, 2005), including changing the composition of surface active species RESEARCH ARTICLEHigh-resolution variability of the enrichment of fluorescence dissolved organic matter in the sea surface microlayer of an upwelling region Nur Ili Hamizah Mustaffa, Mariana Ribas-Ribas and Oliver Wurl Enrichment of fluorescence dissolved organic matter (FDOM) in the sea surface microlayer (SML) provides insights into biogeochemical processes occurring at the sea surface, including cycling of organic matter, photochemistry, and air-se...

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“…Contaminants accumulate at interfaces; transiently at the sea surface (Hardy 1982) and more permanently on the sea bottom. Both interfaces are also regions of high biological activity, indicating that toxic effects are more likely to occur there.…”

Section: Introductionmentioning

confidence: 99%