Tag Archives: chemicals

The future of Galveston Bay: Implications of the oil spill

Fishing boat coming in from Galveston Bay. Photo Credit: Roy_Luck

Fishing boat coming in from Galveston Bay.
Photo Credit: Roy.Luck

Galveston Bay is a busy body of water. It carries the traffic of the Houston Ship Channel. It is a popular recreation destination for fishermen and others. It not only serves as a home to birds and large marine animals, but also as a nursery ground for many important seafood species. It is the nation’s seventh largest estuary and among them the second most important seafood producer, behind only the Chesapeake Bay.

The immediate effects of the oil spill on March 22, 2014, are visible in the oil sheens and tar balls floating in the water and the “oiled” birds and animals that crews are trying to help. But, we can’t see how this heavy marine fuel, containing toxic chemicals including polycyclic aromatic hydrocarbons (PAHs), is harming shrimp, crabs, oysters, red drum and other fish that call the waters of Galveston Bay home. This contamination can hang around for a long time. Studies from the 2010 Deepwater Horizon Oil Spill show that even in low concentrations PAHs can disrupt the development of fish and invertebrate larvae; and in high concentrations can be lethal. Recent reports of tunas susceptible to deformities from the 2010 spill attest to the potential risks long after the spill itself is gone.

The timing of this spill is bad for several key species especially important to the seafood industry and consumers. Brown shrimp have already spawned offshore, and March is the month when the young ride tides coming back inshore to settle in seagrass beds and marshes, habitats that are their nurseries – and where the water is now contaminated with oil pollution. The young are especially vulnerable from now until about May or June. Young blue crabs that settled during the winter in Galveston Bay are also in danger, as are baby fish; including Gulf menhaden, a large harvest in the region’s fishing industry and a fish that is a vital food for larger fish and other animals. Marine life in the way of the oil is dying; and those not killed are exposed to toxic chemicals that could impair their reproductive potential, and some fish that feed on worms in bottom sediments may acquire and carry toxics in their tissues. The seafood “crops” in the area could well be reduced.

Anyone who has been to Galveston Bay has seen the many dolphins are other large marine life that frequent the area and eat these other fish. As these contaminants enter Bay food chains our concern turns not only to how these animals are affected by the spill in the short term, but also to their longer-term health, and even to whether or not seafood species that live there could constitute a human health risk that must be guarded against into the future. Read More »

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“Red Herrings” in the Gulf of Mexico – Part 1: It Ain’t the Oil

This is the first post in a four part series discussing the ongoing – and “cascading” – effects in the Gulf, not from oil, but rather its toxic components and their impacts on sensitive ecosystems. Read the rest of the series.

In recent weeks, nearly every discussion about the BP Oil Disaster in the Gulf of Mexico has focused on the question: “how much of the oil from the broken well is left in the Gulf?” 

The answer is simple:  “None – it ain’t the oil, stupid!”    

For some time now,  the problem hasn’t been the oil in the Gulf,  it’s the complicated series of impacts caused by the diverse substances that made up the oil as they are degraded in stages, both biologically and chemically. Each step along the way – and even the final breakdown products – poses important threats to a different suite of living things.  The total damage done by this complex array of shifting impacts on the sensitive ecosystems  and the people of the Gulf remains largely unknown.


Sure, some elements of the complex ecology of the Gulf of Mexico may get off scot-free from the disaster.  But many others have been or will be heavily impaired, at least for some time.  Taken together, there will be a significant total effect on the ecological systems of the Gulf, including the productivity and safety  of seafood, and significant  bottom-line impacts will be felt  on human health and social and economic well-being. 

Oil or Not Oil?

From the beginning of the disaster back in April, as “Gulf Light Sweet Crude” oil spewed  into the depths of the Gulf, the components of that oil – a “toxic soup” of hundreds of different chemicals – have been subjected to intense physical, chemical and biological sorting and processing, and to transportation by currents both towards and away from shore. 

This is an underwater look at one of the oil plumes in the Gulf of Mexico in late May. Click to watch the video.

By the time the well was capped in mid-July, a significant amount  of the approximately 200,000,000 gallons of liquid flowing from the broken well made it to the surface as recognizable oil.  But from the very beginning, the various “toxic soup” ingredients have followed radically different pathways through the complex oceanographic and living systems of the Gulf, spreading and being processed in different directions at different depths, and at different rates.

It is clear that all layers of the sea in a large zone around the well have been exposed, from bottom to top, as the spreading and rising cone (or “plume”) of oil-based materials spewed from the well. In contrast to a more typical oil spill on the water’s surface, where the transport and ecological fate of oil components are well-known, there are still many unknowns related to how the various chemicals have moved and are breaking down underwater, including the biochemical pathways and timetables.  Intense scientific investigation and complicated modeling are necessary before these complex relationships can be understood fully.

The addition of dispersants, both at the bottom and the top of the water column, has further altered the chemicals’ pathways through the ecosystem,  likely lessening some kinds of impacts and exacerbating others.It may well turn out that chemicals derived from oil spread over a much larger area because of the addition of dispersants, both at the bottom and the top.  The final accounting of the ecological and human winners and losers has yet to be made.

At the end of the day, the complex set of effects on the living systems of the Gulf from the oil and its chemical components will be understood, more or less.  The impacts on the human populations will be estimated, if not fully understood.  It is grossly premature to declare victory, though, until we understand the ways in which the basic fabric of the ecosystems of the Gulf has been altered, and what might be required to restore its weave.

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