Monthly Archives: September 2010

“Red Herrings” in the Gulf of Mexico – Part 4: Persistent Effects?

By / Bio / Published: September 16, 2010

This is the last 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.

Once the more easily processed materials and their breakdown products have completed their complicated journeys through the Gulf ecosystems, that still leaves the toxins that don’t break down easily, both the polycyclic aromatic hydrocarbons (PAHs) and metals like arsenic that are associated with drilling accidents. By some estimates, as much as a quarter of the total volume of these toxins might end up back on the sea floor, and subjected to processing – and reprocessing – by sediment-eating “infaunal” invertebrates (worms and such), which are prey for bottom-feeding fishes and crustaceans. The same applies to marshes and beaches — foraging grounds for many sought-after fishes — as well as protected species, like migrating shorebirds.


These relationships provide re-entry points for toxins back into food webs that sustain seafood production.

It could be many years before those chemicals wend their way – much more slowly, and through different pathways – through both the ecological systems of the Gulf and their human counterparts.

The pathways for many of these longer-lived toxins will also be altered as human uses resume. Shrimp trawling, for instance, will stir up sediments, potentially exacerbating the impacts of both toxicants and oxygen-demanding substances.

Again and in conclusion, some elements of the complex ecology of the Gulf of Mexico may well get off scot-free from the disaster. But many others will be heavily impaired, at least for some time. Taken together, there will be a significant total effect on the ecological systems and on the productivity and safety of seafood from the Gulf, significant human population impacts are expected, and those impacts must be remediated.

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“Red Herrings” in the Gulf of Mexico – Part 3: Undersea Plumes?

By / Bio / Published: September 15, 2010

This is the third 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.

It could well be that the now-notorious subsurface plumes contained –or contain – a mixture of tiny oil droplets (both from oil spewing, hot, under pressure into cold water, and then being dispersed into even smaller droplets courtesy of Corexit) and dissolved or partly dissolved lower-molecular weight materials, like BTEX (benzene, toluene, ethyl benzene and various xylenes).

Components of these plumes broke down – and are breaking down – not in one felled swoop from oil to not-oil, but through a series of breakdown pathways, while it was transported in various directions as the currents shifted over several months of the active oil disaster. These materials would have been exposed to biological processing by bacteria. Bacterial populations were low initially, but have grown exponentially through time within the plumes as they drifted.

There is no free lunch in the sea: Did bacteria “eat” the oil?

Many people are sighing in relief that the apparent explosion of mid-water bacteria have processed much of the original oil load of the system. The cascading impacts of that phenomenon – if verified – have yet to be established. Perhaps the “oil,” per se, is largely gone, but the array of produced materials, and their ramifying ecological effects must be fully accounted.

Full and final processing of this huge load of oil would both demand oxygen and produce carbon dioxide. While there have been some observations of adequate oxygen presence, there has as yet been no modeling of total oxygen demand and its implications for ocean ecosystems, including some already under oxygen stress. Moreover, the sea is already being subjected to acidification from absorbed carbon dioxide (the final breakdown product where oxygen is adequate from biotic degradation of hydrocarbons).

While an “Andromeda strain” scenario is far-fetched, many questions remain. What are the likely impacts of such massive loads of both oxygen-consuming organic substances and produced carbon dioxide, on oxygen levels and acidity patterns in the depths? What will happen to this large, new and artificial, biomass of bacteria, as they respire and then decompose? How will this major perturbation of mid-water biota cascade through ocean ecosystems? All unanswered questions.

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Joint U.S.-Cuba-Mexico shark catch share gaining media interest

By / Published: September 15, 2010

This weekend Reuters wrote a story about two EDF staff members’ recent trip to Cuba. Last week Dan Whittle, Pamela Baker and U.S. scientists visited with Cuban officials to discuss collaboration between the U.S., Cuba and Mexico to better protect the Gulf of Mexico’s struggling shark population. EDF and Mote Marine Laboratory are promoting improved management for sharks, including exploration of catch share management systems increasingly used to meet the conservation and economic objectives in diverse parts of the world.

httpv://www.youtube.com/watch?v=AsNrwo6g5mE

Shark populations have been troubled for years, primarily due to overfishing, in part resulting from China’s high demand for shark fin soup. Sharks are “highly migratory,” meaning they travel throughout the Gulf and beyond, not just in U.S. waters.

For Gulf sharks — and the benefits they provide to local communities — to be sustained over the long-term, a cooperative effort between the three countries that fish in Gulf waters is key. Catch shares can offer advantages over conventional regulations by creating incentives for fishermen to focus on a steady and high quality catch over higher volume, often lower quality harvests. Important political and other challenges exist, but the potential benefits of cooperation make the effort worthwhile.  Management programs should be designed to achieve the conservation, economic and social objectives of the three countries.

Read the full story.

At the end of September, EDF will be participating in a tri-national workshop with U.S., Cuban and Mexican scientists to finalize a long-term marine research and conservation plan for the Gulf of Mexico at Mote Marine Laboratory in Sarasota, Florida. Sharks will be discussed as one of six working groups focused on priority resources in the Gulf of Mexico. More information will be posted on EDFish as the event approaches.

Read more about our work in Cuba or about shark populations in the Gulf.

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“Red Herrings” in the Gulf of Mexico – Part 2: Key Ocean Ecosystems at Risk

By / Bio / Published: September 14, 2010

This is the second 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.

I remain extremely concerned about what has happened to the out-of-sight, underwater ecosystems of the Gulf of Mexico, especially at middle depths and on the bottom. These little known but ecologically vital elements of the ocean have been heavily exposed to oil-based pollution, both rising from the bottom and sinking back down from the surface, and – at least in some places – bathed in persistent underwater toxic plumes.

Marine life in the mid-waters is so rich and profuse in places that sonar waves bounce back as a “deep scattering layer” and provides key food for many familiar, surface-diving animals, including whales, dolphins, billfishes and giant tunas. Deepwater coral reefs and other bottom dwellers have been at great risk all along, and not even the initial explorations have yet been done to assess the impacts of reefs less than twenty miles from the broken well bathing in oil-based pollution.

An actual track of a sperm whale diving through rich mid-water feeding zones (shown in green) from the northern Gulf of Mexico. Credit: Modified from Azzara, 2006.

The oil and oil-derived pollution that made it to the surface followed – and is following – one set of pathways through the Gulf ecosystem, exposing and injuring not just sea turtles and sea birds, but also near-surface marine animals and plants, large and small, and entering foodwebs through a complicated series of entry points, which we don’t yet fully understand.

Fine droplets of dispersed pollution are more likely to be adsorbed onto particulates, sinking back through the midwaters and into the abyss. The moreresistent elements, like tar balls, either float away or sink back into the abyss, and follow a different set of pathways.

The total “dump” of highly toxic oil components, including low-molecular weight aromatic hydrocarbons (known familiarly as “BTEX” – benzene, toluene, ethyl benzene and various xylenes), could have been up to 50,000,000 gallons. These are heavy-duty pollutants in their own right, including known carcinogens and reproductive toxicants, with a fair solubility in sea water. In a surface spill, pollution mostly evaporates, and the only real concern relates to emergency response workers that are exposed while on duty. In this underwater case, scientists simply do not know – yet – exactly how the massive load of pollution is being processed in the Gulf.

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

By / Bio / Published: September 13, 2010

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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A Lifeline for Gulf Fishermen: Catch Shares Cushion Blow for Commercial Snapper Fleet in Wake of BP Oil Disaster

By / Bio / Published: September 3, 2010

At the time of the BP oil disaster, the once-failing Gulf commercial red snapper fishery was beginning to rebound, in large part due to a catch shares program called individual fishing quotas introduced in 2007.  Before catch shares, fishermen competed against each other in a dangerous race-to-fish before the short seasons ended. Now, fishermen are assigned a percentage of an annual sustainable catch and have a year round season. Individuals decide when to fish their secure amount, and can trade their allotments with other boats, providing incentives and accountability to save fish and the marine environment.

The system works for fishermen and fish. Before, regulations forced fishermen to throw out millions of fish, wasted and dying. Fish were caught during short seasons and were sold in the market all at once, pushing down quality and fishermen’s earnings. Now, far fewer fish are wasted, fishing costs are dramatically lower, and fishing trips are timed when seafood demand is high.  In short, opportunities for a healthy Gulf and fishing industry are possible again.

While all Gulf fishing businesses have been harmed, catch shares have cushioned the blow for fishermen during the BP oil disaster in the following ways, as non-catch share fishermen – like red snapper charter fishermen – are stuck dealing with another huge blow to their industry.

  • Tangible assets to make loss recovery claims: Catch shares have a transparent market price, which may help fishermen calculate defensible claims for the loss of value of their business and assets from the oil disaster. In contrast, fishermen under old rules may find it difficult to prove the expected value of this year’s and future catches. This case is likely the first in which disaster claims can be based on catch shares.
  • Ability to trade fish now to make ends meet: Catch share fishermen in areas closed by the spill can trade their shares to others in the open Gulf waters, giving them the means to survive in the short term. In contrast, fishermen under old rules are stuck at the docks with nothing to trade.
  • Security to wait and fish later in the year: Catch share fishermen have a year round seasons and secure amount of fish, allowing them to save their fish for later in the year. For those under old rules, like charter fishermen, important fishing seasons are often concentrated during summer months, so fishermen that have been closed in by oil from Louisiana to Alabama have missed out on fishing for some prized fish and substantial fishing income.  (Regulators may re-open some fisheries to alleviate hardship caused by the oil disaster.)

Overall, catch shares help make fishermen more resilient to man- made disasters like the BP oil disaster and natural disasters like hurricanes.

Now more than ever, we need to improve fishery resiliency, reduce waste and make every fish count — for the environment and for fishermen. Catch shares are the best way to make this happen.

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