Abstract:

This study involved a 7 day land-based mesocosm experiment within 120 gallon tanks placed in a temperature controlled water bath. The mesocosm set up is located at UTMSI, Port Aransas, Texas. Natural seawater was pumped from the shipping channel into each tank during an incoming tide to obtain natural plankton communities. Each tank had a gentle aeration system installed to provide mixing and ensure oxygenation levels remain consistent. The experiment was carried out between August 9th and 15th, 2016 during which three treatments were tested alongside a control. All treatments plus the control were tested in triplicate tanks. These treatments consisted of crude oil only at 10ppm, chemically dispersed crude oil at 10ppm (dispersant to oil ratio of 1:20) and dispersant only at the same concentration used in the 10ppm dispersed oil treatment. Samples were collected every 24hrs to analyze protozoan community alterations. Both live and preserved samples were analyzed via microscopy methods. This allowed the examination of daily survival, mortality and potential recovery rates of protozoan species within conditions which best reflect ambient environmental conditions.

Suggested Citation:

Sarah Cosgrove, Edward Buskey, Maud Moison, Sylvain Lenoir. 2017. Community analysis of planktonic protozoa following exposure to dispersant only and physically and chemically dispersed crude oil. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N70C4T4F

Purpose:

This data set represents micro-planktonic densities from over 42 genera in order to represent community changes in marine protozoa during a short term mesocosm experiment. The purpose of this data-set is to gain insight into how the protozoan community is affected following exposure to chemically dispersed crude oil, crude oil alone and dispersant alone. The data set also includes additional measured parameters including temperature, salinity and fluorometry (UV measurements of relative oil levels).

Data Parameters and Units:

Treatments: O = Oil alone (Sweet Louisiana crude oil) DO = Dispersed Oil (ratio of 1:20 Corexit 9500A to Sweet Louisiana crude oil) D = Dispersant alone (Corexit 9500A) Trial number, Concentration (ppm or ug/L), Date (MM/DD/YYYY), Tank treatment (species), Temperature (°C = Celsius), Salinity (ppt), Fluorometer (raw fluorescence unit) Diatom diversity x= presence d= dominating All counts represent the total number in a 50 ml sample.

Methods:

Each density represents the results from a 50 ml preserved sample counted via microscopy using the Utermohl method.

Instruments:

Temperature was logged using a HOBO Temperature logger Salinity was measured using a temperature/ salinity probe Oil levels were measured using a trilogy fluorometer

Individual Files: