Interview: Dr. Bill Montevecchi on Oil and Dispersant Effects on Birds Wintering in the Gulf of Mexico

(This blog is part of a series of interviews with scientists who are championing marine research in the Gulf of Mexico.)

Dr. Bill Montevecchi is a professor of psychology, biology and ocean sciences at Memorial University of Newfoundland. He conducts long-term interdisciplinary ecosystem research on the behavioral ecology of marine and terrestrial birds, especially environmental influences on animal behavior and ecology. His study of migrating northern gannets, among other things, demonstrates that what happens in the Gulf of Mexico doesn’t only affect the Gulf. Gannets are monogamous for life, and though mates travel independently during the nonbreeding season and may have round-trip migrations of 10,000 kilometers (6,214 miles) or more,  they then return to their Canadian nest site where the partners reunite the following spring. A substantial proportion of the northern gannet population winters in the Gulf of Mexico, many in the vicinity of the area oiled by BP.

Ocean Conservancy:  Tell us a little bit about the northern gannet and your research.

Dr. Montevecchi:  Northern gannets are the largest seabirds that breed in the North Atlantic. In North America, there are only six colonies. All are located in eastern Canada with three found off the east coast of Newfoundland and three in the Gulf of St. Lawrence. Gannets make spectacular missile-like dives from heights of 50 feet or more to capture large fishes like mackerel and herring. Our long-term studies of gannet diets during the nesting season are used to assess changes in fish abundance, movement and conditions.

Northern gannet on Baccalieu Island, Newfoundland, Canada. [Photo: Bill Montevecchi]

OC:  You’ve written that the first image you saw in 2010 of the effects of the BP Deepwater Horizon oil disaster was a photo of an oiled gannet. What did this photo tell you?

Dr. M.:  Shock and dismay were my first impressions of the TV news image of the oiled gannet. There was no identification of the species, and certainly no realization of where it had come from. Instantly, I realized that the bird was from Newfoundland and knew that I would be fully drawn into the unfolding tragedy. The long and insidious reach of the blowout in the distant Gulf of Mexico was vividly evident.

Oiled northern gannet in the Gulf of Mexico. [Photo: Bill Montevecchi]

OC:  Your research shows that about a quarter of the North American population of northern gannets winters in the Gulf, many in the vicinity of the area oiled by BP. How critical is the environmental influence of the Gulf of Mexico on this population?

Dr. M.:  We do not understand the significance of the kill of gannets associated with the Deepwater Horizon blowout. We know that the gannet was the second- or third-most oiled bird recovered in the Gulf, and that the body counts represent minimum numbers, given the huge extent of the slicks and the impossibility of collecting all the carcasses at sea and along uninhabited coastal stretches. The other most impacted species breed locally; they include warm-water gulls, pelicans and terns. Owing to the gannet’s age-related migration chronology and the timing of the blowout in April, our assessment is that the mortality would have most greatly impacted immature gannets, which suggests that the potential impacts could be extended over years.

Four-week-old gannet chick and parent on Baccalieu Island, Newfoundland. [Photo: Bill Montevecchi]

OC:  Does the health of the Gulf’s ecosystemaffect the birds when they return to Canada?

Dr. M.:  I am sure it does. Conditioning during the nonbreeding season can have carryover effects on breeding performance. We don’t know very much about the winter diets of gannets. We know they scavenge discarded fishes from boats and that they prey on menhaden. In February 2011, about 25 miles off the coast of Ocean Springs, Miss., we found an extensive kill of tile fishes and croakers that were belly-up on the water with their mouths agape as if they had suffocated. I estimated that there were hundreds, possibly thousands, of fishes and presumed we were over a hypoxic dead zone. There were flocks of seabirds in the area, apparently feeding on the fishes. About 75 gannets and 300 to 400 gulls (mostly herring gulls, and also laughing gulls) were observed. A common loon, brown pelicans and a royal tern were also in the area. These are minimum counts and estimates of species diversity as flocks dispersed as the vessel approached. Many seabirds reaggregated further offshore.

 OC:  What do we know today about the effects of the BP disaster and crude oil spills on gannets?

Dr. M.:  From our assessment that immature gannets may have suffered the most immediate and direct mortality from oiling, we would expect any population effects that might occur to be lagged over time as young birds recruited or not to the breeding population. At the outset of the 2010 breeding season, immediately after the BP disaster, there were multiple independent observations of gannets with oiled plumage at the colony at Cape St. Mary’s, Newfoundland. What we don’t know are the potential indirect effects on the gannets. For example, the possible effects of dead fishes found in the winter of 2011 when the major segment of adult and immature gannets would have returned to the Gulf.

One other very interesting fact about gannets (and that we cannot be certain of for any other avian species) is that every gannet in the Gulf is of exclusively Canadian origin.

Northern gannet colony at Cape St. Mary’s, Newfoundland, Canada. Birds with oiled plumage were found here during the breeding season after the BP disaster. [Photo: Bill Montevecchi]

OC:  If you were to create a map for research still needed in the Gulf of Mexico to assess the impact of the BP disaster on seabirds like the gannet, what would it include?

Dr. M.:  Long-term studies of the spatial and temporal distributions of seabirds in the Gulf of Mexico are essential for understanding the impacts of any environmental perturbation. Given the very extensive oil exploitation that has been ongoing in the Gulf for many decades, it is really quite disconcerting to realize the dearth of background information about wildlife ecology. Independent wildlife observers on oil platforms could be extremely helpful in this respect. And as we were able to document with our tracking studies of gannets, there is a huge potential for research applications of tracking studies in identifying oceanographic hot spots and seasonal wildlife aggregations.

Juvenile northern gannet with a satellite tag taped to its tail feathers; antenna protrudes at end of tail. [Photo: Gene Herzberg]

OC:  The North American migration route of the gannets you’ve studied spans an area from Canada to the Gulf of Mexico. How different are the ecologies found at the northern and southern ends of this route? And what purpose do they serve in the gannet life cycle?

Dr. M.:  The cold-water, low Arctic marine ecosystem of eastern Canada is radically different from the warm-water, subtropical system in the Gulf of Mexico. Yet one essential feature that they share (though via divergent expressions) is an abundant supply of pelagic fishes. As the gannets have a maximum dive depth of about 60 feet, they depend on fishes and squids relatively close to the ocean surface. In the Newfoundland region, capelin is a key prey, though warm-water migratory species like mackerel, saury and short-finned squid that move into the area in late summer when the water is warmest are also important prey. In the Gulf of Mexico and in other areas along the eastern North American coast, I expect that menhaden is also a key dietary staple, and I am concerned about the ongoing exploitation of menhaden by industrial fisheries.

Scientific evidence indicates that the major energetic costs and risks associated with long-distance migration are offset by the benefits of moving from a region of harsh winter conditions to a warmer area with a reliable food supply – hence the highly mobile annual lifestyle.

The gannet is a powerful flyer with a 6-foot wingspan. [Photo: Bill Montevecchi]

OC:  If seabirds can provide significant indications of changes in prey availability and the state of ecosystems, do we have this research information on the Gulf of Mexico?

Dr. M.:  No, unfortunately we do not understand that much about the oceanic behavior and ecology of seabirds in the Gulf of Mexico. For gannets, we know that the region around the Mississippi River and Mobile Bay (which were heavily oiled) are hot spots – but we need to learn a lot more about the species’ distributions throughout the Gulf and the seasonal entry, exit and occupancy dates of the different age classes. It would also be extremely useful to assess seabird associations with oil platforms throughout the Gulf and especially episodic occurrences of nocturnally active and migrating species. To do this properly would necessitate a systematic program of independent observers on oil platforms. Sadly, the regulatory regimes in the U.S., as in Canada, are too weak to invoke such a precautionary practice.

It would also be extremely valuable to assess the winter diets of gannets and other seabirds in the Gulf during winter and to have reliable biomass estimates of key forage fishes like menhaden that are being overexploited.

Owing to a lack of this basic information, what occurred following the Deepwater Horizon explosion has been a chaotic exercise of crisis management. We should have had sufficient biological and ecological knowledge in order to be better prepared to understand the potential consequences of the pollution. As offshore oil production is now moving into deep water, there is much more uncertainty about accidental occurrences and hence much more reason to support and run the needed ecological research programs that will address the massive knowledge gaps that persist.

OC:  You have noted that tracking research is proving of great value in locations such as the Gulf of Mexico, where despite the presence of more than 3,300 active oil platforms, there is no program of comprehensive systematic surveys for marine animals, and environmental regulations may be inadequate or nonexistent. Tracking research holds important potential for biological information, risk assessment and monitoring. Could you explain what this means in the wake of the BP disaster?

Dr. M.:  The weakness of the regulatory regime is very disconcerting and is a key element in the lack of adequate ecological data in the Gulf. In the wake of the Deepwater Horizon explosion, President Obama attributed the engineering errors that precipitated and unnecessarily extended the duration of the blowout to a “scandalously close relationship” between regulator and oil corporations. I am certain he got this right. This whole notion that the “polluter pays” sounds grand. But in essence it is giving away environmental responsibility to vested corporate interests. What we witnessed following the Deepwater Horizon explosion is that BP exerted inordinate control over what could be assessed and how it could be assessed. BP has a massive influence on the information released to the public and the media.

So, to answer your question directly, tracking research is essential for better interrogation of the biological consequences of environmental perturbations. One of the key elements of this is public access to animal distributions where we are not allowed to comprehensively study them, i.e., at and around oil platforms. In Canada, our tracking studies have highlighted seabird associations with offshore oil platforms where we are not allowed to have independent observers.

OC:  It’s probably safe to say not many people consider how changes to the marine and coastal ecology of the Gulf of Mexico are directly affecting birds that nest thousands of miles away in Canada. But the Gulf of Mexico must be exerting a similar influence over hundreds of species coming and going through its waters. Is that right?

Dr. M.:  Yes, and we must also importantly consider the indirect effects that are ongoing and will be for some time. Marine birds are the most highly mobile animals on the planet. Consequently, they can be exposed to risk in many different locales throughout their annual life cycle. The Gulf is an important marine region for seabirds and land birds alike. A great flux of birds moves into, through and out of the Gulf throughout the year. Many species like gannets, some of the gulls, skuas, jaegers and storm petrels are there only during the nonbreeding season, and many travel from afar to winter in the Gulf. For instance, a herring gull from South Hampton Island in the Canadian Arctic traveled directly to the waters of the Mississippi Delta and the pollution area of the Deepwater Horizon. We are well aware now that an oceanic perturbation in one place can have a major influence on migratory marine animals from elsewhere. And besides birds, these would include migratory marine mammals and fishes.

OC:  You also wrote in the “Birds I View” essay you publish each month of the “long and potentially lasting reach” of the BP disaster. Can you explain?

Dr. M.:  Seabird mortality from the equatorial region to the Arctic outlines the very substantial ecological footprint of the Deepwater Horizon blowout in the Gulf of Mexico. The cumulative influences of the direct and indirect effects of the disaster, including sublethal influences on physiological conditions, will in time bracket the temporal dimensions of the disaster. It’s ongoing, as we also know it still is for some species following the decades-old Exxon Valdez oil spill, which was almost microscopic compared to the releases of crude oil and the unprecedented application of chemical dispersants with unknown biological effects in the Gulf of Mexico.

OC:  You also noted in your essay “there is general misperception that the environmental impacts of oil are only of concern when they hit the shores. What we don’t see does not bother us nearly as much as what we experience firsthand.” Could you elaborate a little more?

Dr. M.:  From a human perspective, no information is usually taken to mean no problem. Yet to make such an inference in the absence of adequate procurement of information can be fallacious. In statistical inference, we refer to this as a type II error. That is, drawing a “no effect” conclusion when indeed there may be an effect. The way to guard against such error is to increase the power of the investigation by increasing the available information. In scientific experiments this implies increasing experiment rigor, effort and sampling.

We know that many marine birds, mammals and fishes associate with offshore platforms and that many major interactions can be of episodic occurrence, often during migration periods. During overcast and foggy weather, birds are often attracted to the skyward projection of light from the rigs. To adequately assess these interactions requires a very substantial on-site observer effort. Yet the regulatory agencies in the U.S. and Canada do not permit such programs by independent observers.

Why are independent observers required on fishing vessels? Because we would not expect a fishing captain who is fishing undersized or nontarget species to provide self-incriminating reports. Yet consider the paradox of self-reporting of wildlife occurrences and mortality at oil platforms. Given the potential for environmental litigation, should we expect vested interest oil operators to provide full disclosure of incidents that could lead to legal action? I don’t think so. There are lots of examples of underreporting and misreporting. It is a striking irony that independent observers are required on fishing boats but not on oil platforms, especially when considering the ecological scale of the damage that can be done by the later compared to the former.

So when there is no information, or inadequate information, or more importantly inadequate regulatory protocols to access that information, then clearly important things can be missed, ignored or even hidden.

Northern Gannet

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