Oceanic sediments harbor most of the world?s biodiversity, primarily comprised of minute organisms that perform key ecological functions such as nutrient cycling, critical to the biodegradation of hydrocarbons. Unfortunately, knowledge of these communities of organisms in the Gulf of Mexico (GOM) is sparse, thus precluding informed mitigation and remediation of the BP Deepwater Horizon oil spill. Knowledge-based action requires that three key questions be addressed: 1) How unique are the communities in the GOM? 2) How structured are the communities within the GOM? and 3) What has been the effect of anthropogenic disturbance on these communities? Cutting-edge, high-throughput DNA sequencing technologies will be utilized alongside traditional taxonomic methods to assay the diversity of virtually all complex organisms from sediment samples collected prior to the April 2010 spill, representing diverse habitats across the GOM.
The BP Deepwater Horizon oil spill represents one of the most dramatic anthropogenic events in human history. It will both require and inspire the interest of future biologists for decades. This funding will specifically provide new opportunities for student engagement in the long-term characterization of biodiversity, using new tools to understand the response of organisms to environmental change and the consequences, mitigation and remediation of such a severe environmental disturbance. Training will include support for undergraduate students to attend a workshop in GOM biodiversity assessment as well as graduate and postdoctoral training. In all cases participation by underrepresented groups in science will be actively encouraged. Most importantly, all data collected will be made openly accessible to the public and scientific communities to facilitate ongoing research and maximize the engagement of all stakeholders.
Our research program has focused on microscopic eukaryotes (nematodes, protists, fungi, etc.) which are ubiquitous in marine sediments and play pivotal roles in maintaining ecosystem function in diverse environments and critical components of the "foodchain". Coastal marine habitats in the Gulf of Mexico experienced visible, heavy impacts following the Deepwater Horizon oil spill in 2010, yet our scant knowledge of prior eukaryotic biodiversity has precluded a thorough assessment of this disturbance. Using a combination of metagenetic and morphological approaches, we conducted an intensive evaluation of microbial eurkaryotic communities prior to and following oiling around heavily impacted shorelines. These studies have allowed us to sample virtually every small eukaryote in the coastal sediments. Our results show significant changes in community structure, with pre-spill assemblages of diverse multicellular animals giving way to dominant fungal communities in post-spill sediments. Post-spill fungal taxa exhibit low numbers of species and are characterized by an abundance of known hydrocarbon--degrading groups, compared to prior communities that contained smaller and more diverse fungal assemblages. Comparative taxonomic data from nematodes (roundworms) further suggests drastic impacts; while pre-spill samples exhibit high numbers of species and evenness of genera, post-spill communities contain mainly predatory and scavenger taxa alongside an abundance of juveniles. Based on this community analysis, our data suggest considerable (hidden) initial impacts across Gulf beaches that may be ongoing, despite the disappearance of visible surface oil. This project has also supported significant training in bioinformatics through a workshop offered to undergraduates at Auburn University and has also supported the organization of an international meeting that brought together ecologists and computational biologists interested in tackling the enormous task to understanding the biodiversity of these hyperdiverse communities. These results will provide critical knowledge about important components of the environment and serve to shape science informed public policy.
