Effects of Crude Oil Exposure on Bioaccumulation of Polycyclic Aromatic Hydrocarbons and Survival of Adult and Larval Stages of Gelatinous Zooplankton Rodrigo Almeda 1 *, Zoe Wambaugh 1,2 , Chao Chai 1,3 , Zucheng Wang 1,4 , Zhanfei Liu 1 , Edward J. Buskey 1 1 Marine Science Institute, University of Texas at Austin, Port Aransas, Texas, United States of America, 2 Department of Oceanography, Humboldt State University, Arcata, California, United States of America, 3 College of Resource and Environment, Qingdao Agricultural University, Qingdao, China, 4 School of Life Sciences, East China Normal University, Shanghai, China Abstract Gelatinous zooplankton play an important role in marine food webs both as major consumers of metazooplankton and as prey of apex predators (e.g., tuna, sunfish, sea turtles). However, little is known about the effects of crude oil spills on these important components of planktonic communities. We determined the effects of Louisiana light sweet crude oil exposure on survival and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in adult stages of the scyphozoans Pelagia noctiluca and Aurelia aurita and the ctenophore Mnemiopsis leidyi, and on survival of ephyra larvae of A. aurita and cydippid larvae of M. leidyi, in the laboratory. Adult P. noctiluca showed 100% mortality at oil concentration $20 mLL 21 after 16 h. In contrast, low or non-lethal effects were observed on adult stages of A. aurita and M. leidyi exposed at oil concentration #25 mLL 21 after 6 days. Survival of ephyra and cydippid larva decreased with increasing crude oil concentration and exposition time. The median lethal concentration (LC 50 ) for ephyra larvae ranged from 14.41 to 0.15 mLL 21 after 1 and 3 days, respectively. LC 50 for cydippid larvae ranged from 14.52 to 8.94 mLL 21 after 3 and 6 days, respectively. We observed selective bioaccumulation of chrysene, phenanthrene and pyrene in A. aurita and chrysene, pyrene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]anthracene in M. leidyi. Overall, our results indicate that (1) A. aurita and M. leidyi adults had a high tolerance to crude oil exposure compared to other zooplankton, whereas P. noctiluca was highly sensitive to crude oil, (2) larval stages of gelatinous zooplankton were more sensitive to crude oil than adult stages, and (3) some of the most toxic PAHs of crude oil can be bioaccumulated in gelatinous zooplankton and potentially be transferred up the food web and contaminate apex predators. Citation: Almeda R, Wambaugh Z, Chai C, Wang Z, Liu Z, et al. (2013) Effects of Crude Oil Exposure on Bioaccumulation of Polycyclic Aromatic Hydrocarbons and Survival of Adult and Larval Stages of Gelatinous Zooplankton. PLoS ONE 8(10): e74476. doi:10.1371/journal.pone.0074476 Editor: Howard I. Browman, Institute of Marine Research, Norway Received June 24, 2013; Accepted July 31, 2013; Published October 7, 2013 Copyright: ß 2013 Almeda et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: Zoe Wambaugh was supported by the National Science Foundation (NSF) Research Experiences for Undergraduates (REU) program (grant OCE- 1062745). This research was made possible by a grant from BP/The Gulf of Mexico Research Initiative through the University of Texas Marine Science Institute (DROPPS consortium: ‘Dispersion Research on Oil: Physics and Plankton Studies’). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: This study was partly funded by a grant from BP/The Gulf of Mexico Research Initiative through the University of Texas Marine Science Institute (DROPPS consortium: ‘Dispersion Research on Oil: Physics and Plankton Studies’). There are no patents, products in development or marketed products to declare. This does not alter the authors’ adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors. * E-mail: ralmeda@utexas.edu Introduction Petroleum or crude oil is one of the most common pollutants released into the marine environment [1]. Rising global energy demand has resulted in an increase in the search for and transportation of crude oil in the sea, making marine environ- ments especially susceptible to increased risk of crude oil spills [1– 2]. Although catastrophic oil spills are not the most important source of crude oil discharge into the sea [1,3], they have strong acute and long-term impacts on marine ecosystems, including effects from physical damages (physical contamination and smothering) and toxicity of their chemical compounds [1]. The Deepwater Horizon Oil spill in the Gulf of Mexico in 2010 is a recent example of the dramatic ecological impacts caused by oil spills in marine environments [4–5]. Among the biological components of marine ecosystems, planktonic organisms are particularly susceptible to crude oil pollution [6–8]. Zooplankton cannot overcome the effects of currents , limiting their capacity to avoid crude oil patches and, potentially, forcing them into highly polluted water masses after crude oil spills. Small crude oil droplets (1–100 mm in diameter) generated by wind and waves and or by treatment with chemical dispersants are effectively suspended in the water column [9–11]. These crude oil droplets, which are frequently in the food size spectra of many zooplankters, can easily interact with planktonic organisms. For instance, ingestion of crude oil droplets has been observed on different taxonomic groups of zooplankton, from micron-sized ciliates to large gelatinous zooplankton [12–19]. Some of the components of crude oil, such as polycyclic aromatic hydrocarbons (PAHs), can be highly toxic to zooplankton and be accumulated and transferred up through food webs [6–8,20–21]. Therefore, given the key role of zooplankton in marine food web dynamics, biogeochemical cycling and fish recruitment [22–24], knowledge of the interactions between crude oil and zooplankton PLOS ONE | www.plosone.org 1 October 2013 | Volume 8 | Issue 10 | e74476