Hydrocarbon communities in Louanne salt the • , salt, and hydrocarbon rich fluids • Methane is the energy source for the food chain • These fluids come from buried Jurrasic salt deposits that are also rich in crude oil

Methane gas hydrate

• Crystalline water and methane • Stable at high pressure and low temperature • Can sometimes “explode” violently and leave pockmarks on the seafloor • May explain the Bermuda triangle • http://www.youtube.com/watch?v=ahmjHLyF9G M&feature=related • http://www.youtube.com/watch?v=y7dmRtlXaYQ &feature=related • http://www.youtube.com/watch?v=KzUEr7uMnX U&feature=related

Hydrocarbon seep communities in The Pool the Gulf of Mexico • Methane, salt, and hydrocarbon rich fluids • Formed by a • Methane is oxidized free-living hydrage and symbiotic bacteria in mussels and explosion, then tubeworms filled with salt saturated fluid • Pool is surrounded by mussels

1 mussels

• Have symbiotic bacteria that use methane • Brine pool is a rich source of methane, but is also extremely salty and has sulfide (poison) • Gradient of mussels around brine pool • Diverse other consumer organisms live associated with the mussels

tubeworms

• Have sulfide oxidizing symbiotic bacteria • Acquire sulfide from the sediment via permeable “roots” • Can live hundreds of years • Many of other organisms live in and around tubeworm bushes

Ecology of hydrocarbon seeps Deepwater horizon oil spill

• Patches of methane seepage and also • April 20, 2010, an explosion on the Deepwater Horizon drilling platform in the • Bacteria, mussels, and tubeworms are Gulf of Mexico primary producers using methane or • largest spill in American history sulfide • Other organisms are consumers on • 87 days an estimated 4.9 million barrels of primary producers oil were released into the Gulf. • Patches appear to be fairly long lived • 80,000 square miles of commercial and (several decades) recreational fishing grounds were closed

2 http://www.nnvl.noaa.gov/Media Detail.php?MediaID=419&Media TypeID=2

Consequences

• Damages to organisms and communities • Toxicity in seafood • Use of dispersants • Contributing to gulf hypoxia

• Deep water expedition after spill • http://oceanexplorer.noaa.gov/explorations/10lo phelia/welcome.html • http://live.psu.edu/flickrset/72157625597515684

The sea fan Paramuricea sp. with the symbiotic brittle star Asteroschema sp. from a site in the Garden Banks region of the Gulf of Mexico. This apparently healthy One of the impacted corals with attached brittle starfish. Although the orange coral was observed during the first leg of the cruise at approximately 360 meters tips on some branches of the coral is the color of living tissue, it is unlikely that depth and over 450 km away from the site of the Deepwater Horizon any living tissue remains on this animal.

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