Abstract:

Testing the effect WAF (water accomodated fraction) on TEP and CSP. Samples were collected as a time series in the Control, WAF, and the WAF silicon tube treatment. Qualitative, but not quantitative samples were also collected from the sea surface microlayer and the sunken marine snow.

Suggested Citation:

Uta Passow. 2017. GOM coastal waters (GOMCOAST): Production of TEP (transparent exopolymers) and CSP (Coomassie stained particles) as a function of oil. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7RV0M1R

Publications:

Bretherton, L., Kamalanathan, M., Genzer, J., Hillhouse, J., Setta, S., Liang, Y., … Quigg, A. (2019). Response of natural phytoplankton communities exposed to crude oil and chemical dispersants during a mesocosm experiment. Aquatic Toxicology, 206, 43–53. doi:10.1016/j.aquatox.2018.11.004

Bera, G., Doyle, S., Passow, U., Kamalanathan, M., Wade, T. L., Sylvan, J. B., … Knap, A. H. (2019). Biological response to dissolved versus dispersed oil. Marine Pollution Bulletin, 110713. doi:10.1016/j.marpolbul.2019.110713

Purpose:

This mesocosm experiment investigated the response of coastal plankton community from the Gulf of Mexico to dispersed oil in comparison to conditions without oil. Specifically, the effect of oil addition for the production of transparent exopolymer particles (TEP) and CSP (coomassie stainable particles) was tested. TEP, that are rich in polysaccharides, are central for the formation of marine snow. The role of CSP, which are protein-rich is less clear.

Data Parameters and Units:

Date (MM/DD/YYYY) Sample time (HH:MM) Timepoint (hrs) SSW = surrounding seawater, sample does not include marine snow; Avg = average (of three replicate mesocosms); Stdev = standard deviation; TEP = Transparent Exopolymer Particles (ug GXeq/L); CSP = Coomassie Blue Particles (mg BSAeq/L); GXeq = Gum Xanthan equivalent; BSA eq = Bovine serum albumin equivalent; Control = Control treatment containing seawater and plankton community; WAF = Water accommodated fraction treatment, containing WAF made from the seawater (see methods) and plankton community;

Methods:

In order to create an environment for controlled testing of TEP and CSP formation six 112 L capacity glass tanks (40x40x72 cm3) were used as mesocosms. Three replicate tanks were considered controls and three oil treatments, produced with a water accommodated fraction of oil (WAF; WAF-treatments). The WAF was produced using 130 liter baffled recirculating tanks (BRT) and Macondo Surrogate oil. Seawater was collected close to TABS buoy R (29˚38.1000’N, 93˚38.5020’W) in the Gulf of Mexico 16 July 2016. This water was greenish and turbid. The three Control tanks were filled directly with seawater from the storage tank (90 liters each). WAF was prepared by mixing 25 ml (5 ml ~ every 30 min for 2.5 hrs.) of Macondo Surrogate oil into 130 L of seawater then mixing for 12 to 24 hrs. The WAF was then introduced into the WAF mesocosm tanks (87 L). Macronutrients were added at F/8 to all mesocosms. Plankton (≥63 µm), which was collected at the same side as the seawater, was added. This concentrated plankton sample was introduced to the tanks and stirred (2 L to each mesocosm) immediately prior to starting the experiments. Banks of lights were placed behind each of the glass tanks and a 12:12 light dark cycle used (7pm to 7 am dark). Samples were drawn through a 5 cm diameter Teflon faucet, positioned 10 cm from the bottom of each tank. Samples were collected every 24 hrs. up to 72 hrs. TEP concentrations were determined in triplicate twice daily (every 12 hours) using the colorimetric method and are expressed in Gum Xanthan equivalents (GXeq.) (Passow and Alldredge, 1995). CSP was determined once daily (every 24 hrs.) using the colorimetric method (Cisternas-Novoa et al.).

Error Analysis:

Coefficient of variation (standard deviation / average) were calculated from the triplicate TEP analysis to identify problems. Averages and standard deviations were calculated from the three replicate mesocosms of each treatment.

Provenance and Historical References:

Cisternas Novoa, C., C. Lee, A. Engel (2015). Transparent exopolymer particles (TEP) and Coomassie stainable particles (CSP): Differences between their origin and vertical distributions in the ocean. Marine Chemistry, 175: 56-71, doi.org/10.1016/j.marchem.2015.03.009. Passow, U., Alldredge, A.L., 1995. A dye-binding assay for the spectrophotometric measurement of transparent exopolymer particles (TEP). Limnology and Oceanography 40 (7), 1326-1335.

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