Effect of oxytetracycline on the community structure of nematodes: results from microcosm experiments

Abstract

The release of antibiotics to the environment after use by fish farms could have potentially negative effects. Here, we assessed how the antibiotic oxytetracycline (OTC) affect the meiofaunal communities of Jeju Island in Korea. We assessed how: 1) nematodes responded to 0-2000 ppm OTC over 48 h; 2) Metoncholaimus spp. (the most abundant group) responded to 0-500 ppm OTC over 48 h; and 3) the meiofaunal community responded to 0-200 ppm OTC for 1-month. In experiment 1, all nematodes died at high antibiotic concentrations (1000 ppm, 2000 ppm), but death rates rapidly decreased at 500 ppm (42%) and below (0-9%). In experiment 2, Metoncholaimus spp. death rates were similar to those documented in experiment 1 for OTC concentrations of 500 ppm (45%) and decreased at 125 ppm and 250 ppm (to 30% and below). In experiment 3, long-term exposure to low concentrations (200 ppm or less) of OTC did not have a strong effect on meiofaunal density, with meiofaunal density in the experimental group showing no decline with OTC concentration. However, we confirmed that differences in OTC concentration affects the structure of meiofaunal communities, making it important to regulate their use by fish farms.

The Antidepressants Amitriptyline and Paroxetine Induce Changes in the Structure and Functional Traits of Marine Nematodes

“…An open experimental enclosure was used to study the locomotion reaction of nematodes and to assess their tolerance to these two antidepressants. The (eco)toxicological effects of pollutants on nematodes are generally tested within closed experimental microcosms, which are usually filled with sediment and topped with aerated water, in containers such as bottles [20][21][22][23][24][25][26][27][28][29][30], jars [31], Erlenmeyer flasks [32], tubes [33], boxes [25][26][27][28][29][30][31][32][33][34] and cores [35]. Such containers are widely used due their low price and easy maintenance costs, but debatable in mimicking reliably the natural conditions.…”