High Number of Sick Dolphins May Be Linked to Gulf Oil Spill

gulfspillrestoration.noaa.gov

Bottlenose dolphins in Barataria Bay, Louisiana, are showing signs of severe ill health, according to NOAA marine mammal biologists and their local, state, federal and other research partners.

Barataria Bay, located in the northern Gulf of Mexico, received heavy and prolonged exposure to oil during the Deepwater Horizon oil spill.

Based on comprehensive physicals of 32 live dolphins from Barataria Bay in the summer of 2011, preliminary results show that many of the dolphins in the study are underweight, anemic, have low blood sugar and/or some symptoms of liver and lung disease. Nearly half also have abnormally low levels of the hormones that help with stress response, metabolism and immune function.

Researchers fear that some of the study dolphins are in such poor health that they will not survive. One of these dolphins, which was last observed and studied in late 2011, was found dead in January 2012.

NOAA and its local, state and federal partners started the Barataria Bay dolphin study in 2011 as part of the Natural Resource Damage Assessment (NRDA), the process for studying the effects of the Deepwater Horizon oil spill.

View a photo gallery of dolphin assessment work.

NOAA is sharing the preliminary results from the study so that stranding responders and veterinarians can better care for live stranded dolphins and look for similar health conditions.

Investigation of Dolphin Strandings in the Northern Gulf Continues
Since February 2010, more than 675 dolphins have stranded in the northern Gulf of Mexico (Franklin County, Florida, to the Louisiana/Texas border)–a much higher rate than the usual average of 74 dolphins per year, prompting NOAA to declare an Unusual Mortality Event (UME) and investigate the cause of death for as many of the dolphins as possible. The vast majority of stranded dolphins have been found dead; however, 33 have stranded alive and seven have been taken to facilities for rehabilitation.

In the spring, it is typical to see some newborn, fetal and stillborn dolphins strand, and there has been an increase in strandings of this younger age class during this UME in 2010 and 2011. Yet all age classes continue to strand at high levels. NOAA is working with a team of marine mammal health experts to investigate the factors that may be contributing to the dolphin mortalities.

Gulf Seafood Safety
Since the 2010 oil spill, the Food and Drug Administration, NOAA and the Gulf Coast states have used an agreed-upon protocol to test seafood and ensure that it is free of harmful oil and dispersant residues. NOAA opened federal waters to fishing after extensive testing, and the Gulf states continue to use the protocol to routinely test finfish and shellfish to ensure all seafood reaching the consumer is safe. Some waters in the northern Barataria Basin, a larger area that includes Barataria Bay, remain closed to commercial fishing, as visible oil is still present along the shoreline where the closures are in place. The joint protocol directs seafood safety testing to begin only after visible oil is gone.

NOAA and its state and federal partners are researching multiple ways Gulf dolphins may have been exposed to oil, including through ingestion, inhalation or externally. Dolphins could have routinely ingested oil from sediments or water while feeding or by eating whole fish, including internal organs and fluids such as liver and bile, which can harbor chemical contaminants. These are not likely routes of exposure for most people.

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This October 2010 photo provided by Penn State University shows the arms of a brittle starfish, red in color, clinging to coral damaged by the Macondo well in the Gulf of Mexico. After months of laboratory work, scientists say they can definitively finger oil from BP’s blown-out well as the culprit for widespread damage and the slow death of a deep-sea coral community in the Gulf of Mexico. (AP Photo/NOAA and Woods Hole Oceanographic Institute)

huffingtonpost.com - March 27, 2012

NEW ORLEANS (AP) — After months of laboratory work, scientists say they can definitively finger oil from BP's blown-out well as the culprit for the slow death of a once brightly colored deep-sea coral community in the Gulf of Mexico that is now brown and dull.

In a study published Monday, scientists say meticulous chemical analysis of samples taken in late 2010 proves that oil from BP PLC's out-of-control Macondo well devastated corals living about 7 miles southwest of the well.

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Study - Impact of the Deepwater Horizon oil spill on a deep-water coral community in the Gulf of Mexico

pnas.org - March 27, 2012

Abstract

To assess the potential impact of the Deepwater Horizon oil spill on offshore ecosystems, 11 sites hosting deep-water coral communities were examined 3 to 4 mo after the well was capped. Healthy coral communities were observed at all sites >20 km from the Macondo well, including seven sites previously visited in September 2009, where the corals and communities appeared unchanged. However, at one site 11 km southwest of the Macondo well, coral colonies presented widespread signs of stress, including varying degrees of tissue loss, sclerite enlargement, excess mucous production, bleached commensal ophiuroids, and covering by brown flocculent material (floc). On the basis of these criteria the level of impact to individual colonies was ranked from 0 (least impact) to 4 (greatest impact). Of the 43 corals imaged at that site, 46% exhibited evidence of impact on more than half of the colony, whereas nearly a quarter of all of the corals showed impact to >90% of the colony. Additionally, 53% of these corals’ ophiuroid associates displayed abnormal color and/or attachment posture. Analysis of hopanoid petroleum biomarkers isolated from the floc provides strong evidence that this material contained oil from the Macondo well. The presence of recently damaged and deceased corals beneath the path of a previously documented plume emanating from the Macondo well provides compelling evidence that the oil impacted deep-water ecosystems. Our findings underscore the unprecedented nature of the spill in terms of its magnitude, release at depth, and impact to deep-water ecosystems.

http://www.pnas.org/content/early/2012/03/23/1118029109.abstract

huffingtonpost.com - Reuters - June 8, 2011

BILOXI, Mississippi (By Leigh Coleman) – Scientists confirmed on Thursday that they have discovered oil on dead dolphins found along the U.S. Gulf Coast, raising fresh concerns about the effects of last year's BP oil spill on sea life.

Fifteen of the 406 dolphins that have washed ashore in the last 14 months had oil on their bodies, National Oceanic and Atmospheric Administration scientists said during a conference call with reporters.

The oil found on eight of those dolphins has been linked to the April 2010 BP oil spill in the Gulf of Mexico, scientists said.

(READ COMPLETE ARTICLE)