Are MPs found in the Rio Grande/Bravo available to cause toxicity in zooplankton?

Due to the amount of plastic residues found in aquatic systems, various studies have been done to determine micro plastics (MPs) toxic effects in zooplankton organisms such as rotifers under laboratory conditions. However, not all MPs found in aquatic systems may cause toxicity, since not all can be ingested: rotifers from genus Brachionus ingest MPs of a 5-20µm size, while it is reported that Daphnia magna can ingest 300 and even 1400 µm MPs fibers. Based on this information we were interested to determine if the MPs found in the Rio Grande/Bravo could be ingested by rotifers or other zooplankton organisms. We quantified MPs, by fluorescence microscopy, from water samples collected at six sites along the Juarez, Chih. (Mexico) - El Paso, TX (USA) region, and determined MPs sizes by confocal microscopy. About 0.40 to 17 MPs/L were detected: sizes ranged from 24.83-4786.73 µm and 12.62-373.16 µm for fibers and fragments, respectively. Class interval for particle sizes was determined following Sturges’ Rule. It was found that fragments from three sites could be ingested by zooplankton organisms: Borderland (1.4 particles/L), Casa de Adobe (1.3 particles/L), and Altozano (0.3 particles/L). The information provided by this research gives us a hint of the real exposure of zooplankton to MPs.

Presentation Preference: Either

Primary Presenter: Judith Ríos Arana, Universidad Autónoma de Ciudad Juárez (jvraunicornio@gmail.com)

Authors:

Judith Ríos-Arana, Universidad Autónoma de Ciudad Juárez  (jrios@uacj.mx)

Stephanie Hernández-Carreón, Universidad Autónoma de Ciudad Juárez  (al216616@alumnos.uacj.mx)