Interactions between Zooplankton and Crude Oil: Toxic Effects and Bioaccumulation of Polycyclic Aromatic Hydrocarbons

Abstract

We conducted ship-, shore- and laboratory-based crude oil exposure experiments to investigate (1) the effects of crude oil (Louisiana light sweet oil) on survival and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in mesozooplankton communities, (2) the lethal effects of dispersant (Corexit 9500A) and dispersant-treated oil on mesozooplankton, (3) the influence of UVB radiation/sunlight exposure on the toxicity of dispersed crude oil to mesozooplankton, and (4) the role of marine protozoans on the sublethal effects of crude oil and in the bioaccumulation of PAHs in the copepod Acartia tonsa. Mortality of mesozooplankton increased with increasing oil concentration following a sigmoid model with a median lethal concentration of 32.4 µl L−1 in 16 h. At the ratio of dispersant to oil commonly used in the treatment of oil spills (i.e. 1∶20), dispersant (0.25 µl L−1) and dispersant- treated oil were 2.3 and 3.4 times more toxic, respectively, than crude oil alone (5 µl L−1) to mesozooplankton. UVB radiation increased the lethal effects of dispersed crude oil in mesozooplankton communities by 35%. We observed selective bioaccumulation of five PAHs, fluoranthene, phenanthrene, pyrene, chrysene and benzo[b]fluoranthene in both mesozooplankton communities and in the copepod A. tonsa. The presence of the protozoan Oxyrrhis marina reduced sublethal effects of oil on A. tonsa and was related to lower accumulations of PAHs in tissues and fecal pellets, suggesting that protozoa may be important in mitigating the harmful effects of crude oil exposure in copepods and the transfer of PAHs to higher trophic levels. Overall, our results indicate that the negative impact of oil spills on mesozooplankton may be increased by the use of chemical dispersant and UV radiation, but attenuated by crude oil-microbial food webs interactions, and that both mesozooplankton and protozoans may play an important role in fate of PAHs in marine environments.

Ecological effects of oil spill on water and sediment from two riverine communities in Warri, Nigeria

“…The oil spill purportedly released an estimated quantity of 12.56 m 3 (12560 L) of refined petroleum products into waters of Ubeji, Jeddo, Ogunu and Ughoton communities situated in Warri Riverine area (Akpofure et al, 2000). Oil spilled on water forms a layer on the water surface and prevents oxygen from dissolving in it thus affecting aquatic organisms by interfering with the functioning of various organs of these species and subsequently death (Almeda et al, 2013). Polyaromatic hydrocarbons (PAHs) are chemically quiet stable; thus, due to their lipophilic nature, they can easily penetrate biological membrane and accumulate in organisms (Kanchanamayoon, 2008).…”

Evolutionary responses to crude oil from the Deepwater Horizon oil spill by the copepod Eurytemora affinis

“…These results suggest that adaptation to the high oil concentration might be difficult to achieve. The high mortality suffered at 100% WAF in E. affinis was comparable to responses of other calanoid copepod species in response to WAF from the Deepwater Horizon Macondo Well crude oil (Almeda et al., 2013; Cohen et al., 2014). Although, these other studies examined acute or chronic responses of adults or nauplii to WAF, rather than survival during development, and did not investigate evolutionary responses.…”

“…See Almeda et al. (2013) and Cohen et al. (2014) for the composition of PAHs contained within the WAF of Deepwater Horizon Macondo Well oil.…”

Responses of sympatric Karenia brevis, Prorocentrum minimum, and Heterosigma akashiwo to the exposure of crude oil

“…Increased levels of brevetoxins only add to the negative impact the accumulation of hydrocarbons cause to species that graze on K. brevis and, ultimately, to higher trophic levels within the impacted area (Jiang et al 2010;Almeda et al 2013). The affect can be advantageous to K. brevis, since the populations of organisms that feed on it are reduced (Cohen et al 2007;Hong et al 2012;Waggett et al 2012).…”