We investigated the modifying effects of ultraviolet (UV) light and chemical dispersant (Corexit 9500A) on crude oil toxicity in juvenile mysids (≤ 24 h) (Americamysis bahia) and larval red drum (24-72 hpf) (Sciaenops ocellatus). These results demonstrate that crude oil toxicity significantly increases with co-exposure to environmentally relevant UV levels in both species, indicating photo-induced toxicity. This toxicity was further exacerbated by the application of chemical dispersants which increased the dissolution and concentration of oil-derived polycyclic aromatic hydrocarbons (PAHs) in test solutions. To better understand the mechanisms and initiating events of this observed photo-induced toxicity, the incidence of apoptotic cell death and global transcriptomic changes were assessed in larval red drum (24-72 hpf) following co-exposure to crude oil and UV. These results showed that co-exposure to UV and low concentrations of crude oil (<1 µg/L ∑PAH50) induced apoptotic cell death in skin and eye tissue and altered transcriptomic pathways related to visual processing and dermatological disease. To link these cellular and molecular impacts of photo-induced toxicity to apical endpoints of ecological performance, sublethal impacts to growth, metabolic rate, and visually mediated behaviors were explored in larval red drum at 2 developmental stages. These results suggested that earlier life stages may be more sensitive to photo-induced toxicity and that growth and development, particularly of sensory systems, can be sensitive targets of photo-induced toxicity. Together, these studies provide novel insights into the photo-induced toxicity of crude oil in aquatic organisms and can be used to inform future ecological risk assessments.
| Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc2256780 |
| Date | 12 1900 |
| Creators | Leads, Rachel Renee |
| Contributors | Roberts, Aaron, Burggren, Warren, Lund, Amie, Mager, Edward, Morris, Jeffrey |
| Publisher | University of North Texas |
| Source Sets | University of North Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Format | Text |
| Rights | Public, Leads, Rachel Renee, Copyright, Copyright is held by the author, unless otherwise noted. All rights Reserved. |
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