Abstract:

The Deepwater Horizon oil spill spilled 130 million gallons of oil into the Gulf of Mexico. This was followed by an application of 1.4 million gallons of chemical dispersants in an effort to disperse the oil into the water column and promote the biodegradation of oil. Photooxidation of oil is a natural process that causes oxygenation of an oil slick. Although the toxicity of oil on phytoplankton has been extensively studied, the effects of photo-oxidized oil, especially in combination with dispersants is virtually unknown. Phytoplankton vary in their sensitivities to oil and dispersant exposure. Here, we study the effects of photo-oxidized oil on the growth and photo-physiology of the natural phytoplankton community. We also looked at the effects of nutrient amendments as both C and N on the above-mentioned treatment. Several parameters such as EOE (estimated oil equivalent), ETRmax- maximum electron transport rate, and relative fluorescence (Fv/Fm) were measured.

Suggested Citation:

Manoj Kamalanathan, Jessica Hillhouse, Antonietta Quigg. 2019. The effect of oil and weathered oil along with nitrogen and carbon supplementation on natural phytoplankton community composition, growth and physiology. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/CXTPJ6JR

Purpose:

To test the effect of oil and weathered oil along with nitrogen and carbon supplementation on natural phytoplankton community composition, growth and physiology.

Data Parameters and Units:

The dataset consists of several excel files containing information on the parameters described below: Alpha: micromol e-.micromol-1 photons ETRmax: micromol.electrons m2.s-1 Chlorophyll: Micrograms per L Fv/Fm: relative fluorescence Sigma PSII: Å2 (quanta)-1 Tau: microsecond P: p EOE: mg per L Relative abundance: relative fluorescence ETRmax- maximum electron transport rate EOE: estimated oil equivalent

Methods:

The oil was weathered by exposing a thin layer of oil floating in a bucket of seawater to 5 days of natural sunlight. The buckets were closed during night times and when rained. Nitrogen and carbon provided to the natural phytoplankton. The weathered oil was then extracted by soaking a Teflon cloth in the floating layer of oil, followed by placing the Teflon cloth in a scintillation vial and flicking manually to extract the oil from the Teflon cloth.

Instruments:

Estimated oil equivalent (EOE) was measured using a Shimadzu spectrofluorometer (RF-5301PC; Shimadzu, Houston, TX, USA). All the photosynthetic parameters were measured using a pulse amplitude modulated fluorescence system (Phyto-PAM, Walz, Germany) and the FIRe fluorometer system (Satlantic, Halifax NS, Canada).

Individual Files: