<p>The intensive drilling and extraction of fossil fuels in the Gulf of Mexico (GoM) result in a considerable risk for oil spills impacting coastal ecosystems in the GoM. Two ecologically-important macroinvertebrate species on the northern GoM coast are the gulf marsh fiddler crab Uca longisignalis and the gulf sand fiddler crab Uca panacea. These decapod crustaceans are ecosystem engineers as their burrowing and feeding activities modify biogeochemical processes. They are also important as prey for a wide variety of other crustaceans, fish, birds and mammals. The present study used mesocosm and microcosm designs to investigate effects of crude oil on fiddler crab burrowing and to assess cellular and tissue damage by the oil. Fiddler crabs were exposed for periods of 5 or 10 days to oil concentrations up to 55 mg/cm2 on the surface of the sediment. Burrowing was delayed, burrows were smaller, and movement of sediment transport was less efficient in oil-contaminated sediment. The hepatopancreas had elevated levels of lipid peroxidation and showed an increase in the relative abundance of specific cells (blister cells) that play a role in secretory processes. Interspecific differences were also observed for most endpoints, suggesting higher oil-sensitivity in U. panacea than in U. longisignalis. These new insights into the effects of crude oil on fiddler crabs demonstrate that oil spills are likely to impact both the fiddler crabs themselves, as well as the many species that depend on them for their diet or for the ecological changes that result from their burrowing.
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:10286530 |
| Date | 21 December 2017 |
| Creators | Franco, Marco E. |
| Publisher | University of Louisiana at Lafayette |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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