Fiddler Crabs as Pollution Markers after Oil Spills

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In 1969, the oil barge Florida ran aground in Massachusetts, and it released approximately 200 thousand gallons of fuel into Cape Cods' Buzzards Bay. The spill killed many fish and lobsters, damaged sensitive oyster and clam beds, and devastated the local marshlands. Today, signs of the disaster remain.  In particular, fiddler crabs that normally burrow deep down, funneling oxygen to the roots of marsh grass, stop digging in Buzzard Bay when they reach oil , turn sideways, and burrow back to the surface. More than 40 years after the spill, they still act “drunk’’ from the oil they ingest, and predators can catch them more easily, research from Woods Hole Oceanographic Institute shows.  Many think that the Deepwater Horizon event will play out differently than Buzzards Bay, perhaps involving more of a shorter-term "smothering" effect due to the light crude oil rather than the longer-term penetration and persistence of the diesel fuel.  But, no one knows.  We'll have to wait and see.  And fiddler crabs will be a major "canary in the coal mine."

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Potential Method of Sealing the Deepwater Horizon Leak?

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Here's a suggestion to consider for stopping the Deepwater Horizon leak.  If necessary, use a linear shaped charge to cut the leaking pipe more uniformly.  Then, use a high pressure pipe stopper such as a hydrostatic test isolation plug, for example, the Curtis Wright Flow Control Company’s GRIPTIGHT TEST PLUG GT-24P120, to seal the pipe temporarily.  To permanently seal the pipe, explosive coating can be applied to the pipe surface that covers the isolation plug, and explosive welding can fuse the pipe to the plug  ( See http://estgroup.cwfc.com/productsServices/spokes/01a_HTplugs_01-GripTight_HiPressure.htm or http://www.mechanicalresearch.com/hp.html ).

Deepwater Horizon oil spill rate larger than initial estimates

Ian McDonald of Florida State University has calculated that the Deepwater Horizon oil spill's flow is approximately 26,500 barrels per day.  Here's a report from the SkyTruth blog (http://www.skytruth.org/):

Deepwater Horizon spill estimates derived from USCG fly-over data (28 April 2010)

Figure 1. US Coast Guard map showing size and appearance of oil slick on April 28, 2010.

These estimates of the total volume of oil released by the Deepwater Horizon spill were derived from the USCG fly-over map (Figure 1). The map was geo-referenced in Arc Map and the areas of each of the slick types (dull oil streamers, etc) were measured with a planimeter tool. Thickness estimates for each slick classification were taken from the BONN guidelines as published in the NOAA field manual (Figure 2). Conservative values were used for each slick types. Note that the predicted average layer thickness are still very small.

Figure 2. Chart of oil thickness and appearance.

A human hair is approximately 100 µm (microns). The main slick, which corresponds to the cross-hatched area was assigned a low value of 0.5 µm. We calculate a total volume of oil for this slick as 8.94 million gallons (212,000 barrels) (Figure 3). Considering that the oil in the water on April 28 has been deposited since the blowout and explosion on April 20, the flow rate should be on the order of 26,500 barrels per day. Some fraction of the total oil released will have been evaporated or emulsified and sunk in the time since the spill began, or collected by the response crews, so this should be considered a minimum estimate.

Figure 3. Volume of oil based on Coast Guard map (Figure 1) and thickness (Figure 2).

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