The Blog Aquatic » Matt Love http://blog.oceanconservancy.org News, opinions, photos and facts from Ocean Conservancy Sun, 17 Aug 2014 13:00:56 +0000 en-US hourly 1 http://wordpress.org/?v=3.4.2 Interview: Dr. Bill Montevecchi on Oil and Dispersant Effects on Birds Wintering in the Gulf of Mexico http://blog.oceanconservancy.org/2014/01/09/interview-dr-bill-montevecchi-on-oil-and-dispersant-effects-on-birds-wintering-in-the-gulf-of-mexico/ http://blog.oceanconservancy.org/2014/01/09/interview-dr-bill-montevecchi-on-oil-and-dispersant-effects-on-birds-wintering-in-the-gulf-of-mexico/#comments Thu, 09 Jan 2014 20:56:51 +0000 Matt Love http://blog.oceanconservancy.org/?p=7300

Dr. Montevecchi applying a tracking device to a northern gannet at its northernmost oceanic colony site, Funk Island, Newfoundland, Canada. [Photo: Stefan Garthe]

(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

More from This Blog Series:

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Interview: Dr. Blair Witherington on Oil’s Impact on Turtles in the Gulf of Mexico http://blog.oceanconservancy.org/2013/12/23/interview-dr-blair-witherington-on-oils-impact-on-turtles-in-the-gulf-of-mexico/ http://blog.oceanconservancy.org/2013/12/23/interview-dr-blair-witherington-on-oils-impact-on-turtles-in-the-gulf-of-mexico/#comments Mon, 23 Dec 2013 14:50:33 +0000 Matt Love http://blog.oceanconservancy.org/?p=7230

Dr. Witherington with an oiled Kemp’s ridley turtle 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.)

A research scientist with more than 24 years of experience in sea turtle biology and conservation, Dr. Blair Witherington has worked with the Florida Fish and Wildlife Conservation Commission’s Fish and Wildlife Research Institute since 1992. He is also an adjunct assistant professor, department of zoology, University of Florida; served as president of the 20th International Sea Turtle Symposium; and is vice chair of the Northwest Atlantic region of the Marine Turtle Specialist Group of the International Union for Conservation of Nature. He has authored or contributed to more than 40 scientific articles, monographs and book chapters. In addition, he has written five books on sea turtles and other natural history subjects.

The BP Deepwater Horizon oil disaster had an immediate and particularly harmful effect on early juvenile sea turtles in the Gulf of Mexico. The worst marine oil spill in history also served to highlight a compelling need for assessments of open-sea habitats – research critically lacking in 2010, yet essential for conservation efforts and restoration planning.


Ocean Conservancy:  Turtle researchers call the post-hatchling and juvenile life stages “the lost years.” With the exception of one species, loggerhead juveniles, the early open-sea surface lives and distribution of juvenile green turtles, hawksbills and Kemp’s ridleys have been poorly understood. Your recent research is changing that. Tell us how.

Dr. Witherington:  Many other researchers have been intrigued by the mystery of the so-called “lost years.” Work I am doing with colleagues Shigetomo Hirama and Robert Hardy builds on the accomplishments of others who have inferred from indirect evidence how the youngest sea turtles disperse from land and live on the open sea. The importance of our recent contribution may be in the opportunity we’ve had to study these turtles directly. We hypothesized where we might find these “lost” turtles, went out to locate them there, and there they were. In observing these turtles within their sea-surface habitat and capturing them to allow measurements and assessment of their diet, we’ve learned definitively how these turtles live.

OC:  How does knowing more about the distribution of juvenile sea turtles in the open waters of the Gulf help guide conservation and protection efforts?

Dr. W.:  One of the most important conclusions we’ve drawn concerns the nature of the habitat that young turtles depend on. The early life stages of at least four sea turtle species in the Gulf are closely tied to surface convergence zones. As the name suggests, these zones are places at the sea surface where water converges and things accumulate. One of the most important accumulations is of the brown alga (a seaweed) called pelagic Sargassum, a floating plant that is the basis for a diverse community of unique organisms. Young sea turtles are closely tied to Sargassum, float within it, and feed on the animals that drift within these open-sea rafts. To fully protect sea turtles it will be essential to understand how Sargassum drift habitat is distributed and what threatens it. Some threats are direct, like the harvest of Sargassum for livestock feed (a practice that has been stopped in U.S. waters). But most threats are indirect and come from the nature of the oceanography where the Sargassum floats—oceanic convergence zones. These zones collect many bad things, including plastics and petroleum. We are just beginning to understand how extensively these pollutants threaten turtles with entanglement and ingestion hazards.

A juvenile green turtle within a seaweed mat in the Gulf of Mexico.
Photo: Blair Witherington

OC:  You spent time in the Gulf rescuing turtles and studying how they were injured by the BP Deepwater Horizon well blowout, the worst oil spill in history. What did you see and learn?

Dr. W.:  The Gulf spill harmed young surface-pelagic turtles profoundly. My involvement with response efforts during the spill was with a team of scientists and field workers whose job it was to rescue turtles at sea in a quantitative way. By this I mean that we carefully recorded our search effort and where we observed turtles so that we could not only tally the numbers of animals affected by the oil, but we could also estimate turtle numbers from places we couldn’t get to. The spill was enormous, and unfortunately we could only get vessels and search teams to a thin fraction of the event’s area and time period. Storms periodically threatened crew safety and much of the area that could be searched was over a hundred miles offshore and inaccessible to the small vessels we had available. What we learned was that our fears of the vulnerability of small sea turtles to oil were well founded. The convergence zones where Sargassum habitat collects and where young turtles live were the areas of surface water where petroleum concentrated the most. In the convergence zones we searched, we collected hundreds of oiled juvenile sea turtles representing four species: green turtles, Kemp’s ridleys, hawksbills and loggerheads. Most were 1- to 2-year-old turtles, about the size of a coconut and a kilo in weight. In the worst cases, the turtles were imbedded in mats of congealed grease and covered so thickly with tenacious oil that they were barely recognizable as turtles. In addition to external oiling, turtles also had oil lining their esophagus. It was pretty bad. The live oiled turtles we rescued were taken to facilities for cleanup and rehab. Hundreds of turtles were saved. It was difficult but rewarding work.

OC:  What risks are posed by an oil spill to the widely scattered seaweed-raft habitats occupied by these young turtles?

Dr. W.:  Although there is a lot to be learned from massive events like the BP spill, many hundreds of smaller spills occur in the Gulf each year. These releases of petroleum result in floating oil and tar that is carried by surface water into pelagic turtle habitat. We see evidence of this in the years with no headline oil spills, when young turtles on the open sea float amongst tar balls and have their mouths gummed by sticky tar. Apparently, the indiscriminant feeding style of young sea turtles promotes accidental ingestion of many things that are not good for them. We know that large oil spills are disastrous, but the chronic effects from small spills, multiplied by thousands of events over time, may be a greater cumulative threat.

OC:  How does petroleum affect a transient young turtle in the open sea?

Dr. W.:  Oil is sticky. It adheres to the outsides of turtles and if it is extensive enough it can keep them from swimming and feeding, and it can suffocate them. Oil also gets very hot in the sun and can raise the temperature of a turtle into the lethal range. Turtles also ingest oil, which contains numerous toxic compounds that have the potential to affect life functions both in the short and long term.

[See Ocean Conservancy’s “Restoring the Gulf of Mexico: Establishing a Platform for Success” for a statistical snapshot of sea turtles recovered from the BP Deepwater Horizon oil impact area; also “Restoring the Gulf of Mexico: A Framework for Ecosystem Restoration in the Gulf of Mexico” for a deeper dive into Gulf ecology, sea turtle life and more.]

OC:  Have we seen a dwindling of the sea turtle population in the Gulf? Has the health of the population been established for loggerheads, green hawksbills and Kemp’s ridleys? Do we have a baseline for any of the species?

Dr. W.:  You’d think that we would know a lot about that, but we don’t. A population’s health (that is, its ability to persist) has to do with the number of its members at all life stages, their probability of survival and how many new turtles are produced. With this information, population biologists can forecast population changes for better or for worse. We do a pretty good job of counting sea turtle nests on their nesting beaches, but we know much less about survival at sea. For example, Kemp’s ridley sea turtles nest mostly on one stretch of beach in northern Mexico. We know that there were once many tens of thousands of ridleys nesting on those beaches and that the population declined dramatically. Beginning in the 1980s, workers counting nests recorded that numbers were increasing, a trend that has continued until the last few years when the upward arc of nest counts has flattened. These changes likely reflect rates of survivorship and sources of mortality where sea turtles live most of their lives—the sea. If we had measurements of these survival rates that we could depend on, we could predict interruptions to sea turtle recovery… and ideally, do something about it. Right now, we’re a little in the dark and cannot recognize the results of some threats until many years after they occur. As for baselines on any sea turtle population, we have mostly just nest counts on beaches to turn to. These represent an index of just one life stage: adult females. And as baselines go, we find ourselves unsatisfied with the time span of our information. Most nest-count time periods have yet to approach the generation time of loggerheads and green turtles, which is about 45 years. Still, through our brief window in time, we can say that the oldest members of the population have been increasing for green turtles living in the Gulf of Mexico. For ridleys, we’ve seen a similar increase until recently, which may be only a statistical blip. Loggerheads have had nest counts with considerable ups and downs, but have shown no definitive recovery. Hawksbill nest numbers are either up or down depending on which nesting beach one examines.

[See Ocean Conservancy’s “The Gulf of Mexico Ecosystem: A Coastal and Marine Atlas” for maps and information on Kemp’s ridley turtles (pages 94-97) and pelagic Sargassum (pages 36-38). These two maps are also included at the end of the blog.]   

OC:  So what is the state of current Gulf turtle research? What don’t we know but we will need to know to undertake effective Gulf restoration efforts? And what about protection and conservation planning?

Dr. W.:  Scientists concerned with sea turtles in the Gulf have begun to consider how an organized network of research locations could contribute the information that population biologists, resources managers and regulators need to assess populations and bring about their recovery. Sea turtles live in many locations, and each of these is likely to be biologically unique. A hope we have is that a network of index sites could contribute the information needed for a collective understanding of populations—information like how quickly turtles grow and their probability of survival to the next life stage. Of course, we also need to understand the factors that dictate growth and survival, like availability of food resources and intersections with threats.

OC:  Given that so much more awaits research, how would you map the research that needs to be carried out the most urgently? What would that look like and why is it needed?

Dr. W.:  This is where the population biology of the animal helps a bit. Because very few sea turtles live the decades required to mature and reproduce, these older turtles on the cusp of maturity are the most valuable members of the population. Losing them hits the population hard. So understanding how to reduce threats that take these subadult turtles is critical. The chief threat in the Gulf to this life stage, especially in loggerheads and Kemp’s ridleys, is incidental drowning in trawl and long-line fisheries. But some threats of high magnitude to younger life stages are also critical to conservation. For all life stages it will be important for regulators to understand where sea turtles intersect with threats we can manage. Technology that allows both tracking of turtles and monitoring of our own behavior (fishing, boating, release of pollutants) should be in our long-term plan.

OC:  Which species of turtles are found in significant numbers in the area of the Deepwater Horizon spill? You propose in your research that the open waters of the northern and eastern Gulf are of “unique importance” to Kemp’s ridleys. So do we know yet precisely how they have been harmed?

Dr. W.:  The Gulf is unique for its role in fostering the Sargassum drift community of organisms, which includes young sea turtles. I’ve mentioned four species (green turtle, Kemp’s ridley, hawksbill, loggerhead), but a fifth species also occurs in the Gulf. This is the leatherback turtle, which remains in the open sea for its entire life. Harm from the BP spill on all of these species is still being assessed, and as one might imagine, the task is under intense scrutiny. It’s also cloaked within a legal veil that does not permit me to say much about it. Sorry.

OC:  When you investigated the diets of turtles occupying mats of Sargassum you found they had ingested marine animals and Sargassum, etc., but you also reported an “alarming indicator of mortality,” which was that approximately 8 to 21 percent of the dry mass of ingested material was “debris,” and mostly plastic.

Dr. W.:  Yes, this was an alarming result. Sea turtles eat floating plastic. It can reduce their growth and kill them, but we don’t fully know the magnitude of this threat. Post-hatchling loggerheads and green turtles that strand dead following tropical cyclones show plastics in about 90 percent of necropsied specimens. The plastics are typically shards of plastic containers degraded in sunlight and broken up by waves. The shards stack up in the intestine, block the gut, and puncture it. Unfortunately, the sea is full of plastic and the floating bits accumulate precisely where little turtles live—in the convergence zones I described.

OC:  You also found that the mortality rate of these turtles is difficult to gauge, pointing out that there are few “strandings” of dead turtle carcasses on shorelines. Thus, understanding threats to early juveniles and post-hatchlings has been a missing element in management efforts. How is this to be remedied?

Dr. W.:  This is tricky. One way to measure mortality is to put marks on lots of turtles and make repeated observations of how many you see again. We are currently putting tiny injectable encapsulated radio tags into the juveniles we catch, but we have had so few returns we can’t say anything about survival. We simply have not tagged enough. Another method may be to give turtles broadcasting tags (satellite transmitters) that are small enough not to be a burden and affect survival. Then, turtles that go missing could be assumed to be dead (given a numerical model to account for error). We’ve put satellite tags on small pelagic juveniles, and we’ve gotten interesting movement data, but because the tags sink if they pop off the turtle, we can’t conclude much about turtles that go off the air. More advanced floating tags that archive data will need to be developed that are small enough to not cause trouble for these small turtles. I look forward to that future.

OC:  Without this research into the mortality risks posed by plastics and petroleum is it even possible to assess damage from catastrophic oil spills?

Dr. W.:  Yes. Given measurements of where turtles are, how many there are, and extent of oiling observed, and given assumptions about mortality given the intersection of turtles and oil, we can estimate mortality within intervals of statistical confidence. It’s much more helpful to our understanding of the disaster than simply claiming we don’t know.

Pelagic Sargassum map.

Kemp’s Ridley sea turtle

More from This Blog Series:

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Interview: Dr. John Incardona on Oil’s Heartbreaking Impact on Fish and What it Means for Gulf Restoration http://blog.oceanconservancy.org/2013/12/17/interview-dr-john-incardona-on-oils-heartbreaking-impact-on-fish-and-what-it-means-for-gulf-restoration/ http://blog.oceanconservancy.org/2013/12/17/interview-dr-john-incardona-on-oils-heartbreaking-impact-on-fish-and-what-it-means-for-gulf-restoration/#comments Tue, 17 Dec 2013 18:32:55 +0000 Matt Love http://blog.oceanconservancy.org/?p=7142

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

Dr. John Incardona is an ecotoxicologist and researcher at the National Oceanic and Atmospheric Administration’s (NOAA) Northwest Fisheries Science Center who spent much of his childhood in the Gulf of Mexico. Trained as a physician, he did his postdoctoral research into human birth defects, which eventually led him to study how chemicals affect fish embryos. He found that specific chemicals in crude oil are toxic to the hearts of developing zebrafish – a major finding with implications for assessing the health of wild fish before and after large-scale disasters. Ocean Conservancy talked with Dr. Incardona about his work and the new research tools that could be put to use in the Gulf and elsewhere.

Ocean Conservancy: What is ecotoxicology?

Dr. Incardona: Ecotoxicology seeks to understand how chemicals impact ecosystems, from individual molecules at the biochemical level up to the level of cells, individual animals and entire populations. We often need to know how chemical contaminants impact individuals before we can understand the effects on a population or ecosystem.

OC: Could you elaborate?

Dr. I.: Consider the Pacific herring population in Prince William Sound after the Exxon Valdez oil spill. At the time, it was the biggest commercial fishery there. The population collapsed four years after the spill. No one could explain why, or draw clear connections to the oiling of herring spawning habitat. The state of the science in 1989 wasn’t far enough along that the natural resource community understood how exposures to very low levels of crude oil could have subtle but important effects on developing herring embryos — or that these effects could subsequently reduce individual survival later in life.

OC: How broadly studied is this field today? Is it still being developed?

Dr. I.: Ecotoxicology is a relatively young field. The term was coined in the late 1960s, and integrates ecology and toxicology, disciplines with much older roots. For comparison, modern medical toxicology has its roots in the early 1800s.

Ecotoxicology is still very much under development today. The field is moving away from the older “kill ‘em and count ‘em” approach emphasizing simple mortality assays, towards much more sophisticated assessments of organismal health, or so-called sublethal effects. In parallel to human health research, ecotoxicology is benefiting from recent, major advances in molecular and computational biology.

OC: What’s the major challenge?

Dr. I.: The big challenge is taking all this new and complex information about an individual animal’s physiology and connecting to the ecology of large coastal and open ocean habitats. That’s really the cutting edge right now – putting the “eco” in ecotoxicology.

In the U.S. Pacific Northwest, an example is coho salmon populations that have been driven locally extinct in urban watersheds. A small urban stream looks very different from a rural stream, largely due to the multiple stressors put on it. That changes everything, from the insects that live in the stream, to the fish that spawn there and the health of juveniles that survive. The challenge is to find out which stressors are key to limiting population recovery.

OC: How long have you been studying fossil fuel toxicity?

Dr. I.: Since the week I started [at the Northwest Fisheries Science Center], more than 10 years now. Crude oil and its products are extremely complicated chemically. There are a lot of compounds that have biological activity, many of which we haven’t even characterized yet. And the effects can change across different life stages of fish. Early developing embryos and larvae, juveniles and adults – they all have different physiologies, and this affects how they respond to chemicals in the environment.

We focused on a general syndrome in embryos comparable to a birth defect in humans. We wanted to identify the precise cause. We’ve learned that the syndrome results from heart failure. It’s caused by malformation of the developing fish heart by a specific, small set of chemicals among the thousands in crude oil.

Photos of zebrafish embryos. The arrow points to fluid accumulation around the heart. The scale bar (black line) in the top photo is 1 mm.

OC: That seems significant.

Dr. I.: It’s proven to be quite significant. It has also generated a new line of research that is helping us develop novel tools. The goal is to improve our ability to assess the health of a wide range of fish species in habitats affected by fossil fuels throughout the country and the world.

OC: What does your research in the Pacific Northwest tell us about the Gulf of Mexico and where to begin looking for the harm caused by the Deepwater Horizon disaster? And what do we want to know before restoration can begin?

Dr. I.: The take-home message from our work in the Northwest, Alaska and California is that developing fish embryos are very sensitive to oil toxicity – more so than nearly all life forms that have been studied to date.

The key question for the Gulf of Mexico spill is whether fish were spawning in proximity to oil, and, if so, whether environmental levels were high enough to cause losses of embryos and larvae, or cause adverse effects that might be delayed in time. Answers to these questions will eventually help NOAA and others estimate impacts to fish species under their management.

OC: Can you talk about work being done with “indicator species,” or species that give us a snapshot of the relative health of an ecosystem?

Dr. I.: Like a canary in a coal mine, fish have always been very good indicators of habitat quality, as a basis for ecosystem health. In fact, NOAA has been monitoring indicator or sentinel species throughout the U.S. for decades. How we choose a sentinel species depends on a number of different factors – distribution, sensitivity to pollution, economic and ecological significance, ease of sampling, and so forth. Indicator species can reveal long-term trends, identify pollution hotspots and serve as a warning for newly emerging contaminants.

For our work on fossil fuels in particular, we are trying to develop tools that will help those involved in surveillance and restoration. In most cases, you are not likely to have healthy fish embryos in unhealthy habitats.

OC: So these are all areas of research that can contribute to establishing a baseline for restoration efforts?

Dr. I.: That’s the idea. As restoration goes forward, the progress should be evident in the health of the species that are supposed to benefit from the cleanup efforts. In the Pacific Northwest, we’ve seen this from the long-term monitoring of fish at Superfund sites, before and after restoration.

OC: How do you do your research? What’s involved?

Dr. I.: We do research the same way it’s done at major academic medical centers. Medical scientists use models for humans, such as mice, rats, cell lines and molecular assays. We use the small, tropical freshwater zebrafish as a model for wild fish. This way we can rapidly answer basic questions about the physiological effects of chemical pollutants like crude oil.

Some wild marine species are really difficult to cultivate and work with in a laboratory, but we benefit from some very good partnerships with academic and other government labs. When we transfer studies from our laboratory model zebrafish to a marine species, it’s almost always a big team effort.

The recent advances in molecular and computational biology are a big help for our studies on marine species that are tough to obtain in large numbers, such as bluefin tuna.

OC: Can you share more about the research involving fish exposed to sublethal levels of oil?

Dr. I.: Studies of pink salmon after Exxon Valdez led to the discovery of what we call “oil exposure syndrome,” which resulted in malformed embryos. Embryos exposed to lower crude oil levels looked normal on the outside. But when released as juveniles, those fish died prematurely. That was a big black box and we really had no idea what the mechanisms were.

Zebrafish embryos are transparent. You can get a lot of information by simply looking at them under the microscope, which is how we were able to tell the hearts of exposed fish were being impacted by crude oil.

We could see that hearts in oil-exposed embryos functioned so poorly that fluid backed up behind them, leading to malformation. The fluid backup is a sign of reduced cardiac output, just like fluid accumulates in a person with heart failure.

In embryos that survived lower level exposure and looked normal – no fluid accumulation – we still found that these animals had subtle heart malformations later as adults. Later in life the speed with which a fish can swim depends on its cardiac output, and adults exposed to crude oil as embryos swam slower than their siblings grown in clean water. Swimming speed obviously is important for survival, for species that are either predators or prey.

OC: Any thoughts you wish to leave with us? Perhaps on what restoration standards might look like?

Dr. I.: (Laughing.) Pay attention to the fish! They will tell you if restoration is working as intended. You just have to ask them the right questions.

View bluefin tuna maps and hazardous materials spill maps from the Gulf of Mexico by clicking the thumbnail images below.

Hazardous materials spills.

Bluefin tuna

More from This Blog Series:

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The New Gulf of Mexico Disaster Imperative: Scientific Baselines and Long-term Monitoring http://blog.oceanconservancy.org/2013/12/17/the-new-gulf-of-mexico-disaster-imperative-scientific-baselines-and-long-term-monitoring/ http://blog.oceanconservancy.org/2013/12/17/the-new-gulf-of-mexico-disaster-imperative-scientific-baselines-and-long-term-monitoring/#comments Tue, 17 Dec 2013 18:29:07 +0000 Matt Love http://blog.oceanconservancy.org/?p=7131

Today, Ocean Conservancy introduces the first in a series of interviews with leading marine scientists whose research is helping to fill many critical and long-standing gaps in our knowledge about the Gulf of Mexico.

This blog series will highlight the need for scientific research and monitoring of the Gulf’s ecosystem. When the BP Deepwater Horizon oil disaster began more than three years ago, we discovered precisely how little we understand about the potential impact of a major oil spill on the Gulf, especially on its already stressed marine life and fragile coastal ecology. The disaster’s lasting legacy is being shaped by our current response to this lack of basic knowledge.

Despite the billions of dollars worth of oil pumped out of the Gulf, and the billions more invested in the oil industry itself, there is virtually no corresponding investment in baseline science. The long-term impact of the oil industry on the Gulf ecology (which means looking beyond a five-year window) is not being monitored. Baseline science provides the status of the marine environment to which all future studies will be compared to determine trends in ecosystem integrity.

With these interviews, we aim to drive home the urgent need for more research, such as that being carried out by Dr. John Incardona. An ecotoxicologist at the National Oceanic and Atmospheric Administration’s Northwest Fisheries Science Center, Dr. Incardona has identified the chemicals in crude oil that cause deformed hearts in developing fish and hold the potential to devastate entire local populations of fish.

The blog series, which will include information on new research and insights into the lives of young Gulf sea turtles and migrating Northern gannets found in the Deepwater Horizon pollution zone, will also underscore the benefit of sustained, long-term ecosystem monitoring in the Gulf.

These interviews point to the tools and additional baseline research needed to meet the growing imperative to do more – much more – science in the Gulf.

We need to understand what we know and what we don’t know if we hope to better manage the marine environment. And we need to know this now.

The fines from BP and other responsible parties are now beginning to flow to the Gulf region. This money gives us a major opportunity to immediately invest in this missing science and to create the scientific monitoring programs that will enable local communities, state and federal regulators, and anyone who depends on the Gulf economy to join in more effectively managing and protecting this unique resource.

Establishing a scientific baseline for a healthy ecology in the Gulf is not only essential to recovery, it will also support and enhance our response to any future ecological threats and disasters.

Even in the absence of disaster, the return on our investment in a scientific baseline will be immense. We will know with greater certainty when the Gulf is merely surviving and when it is thriving.

More from This Blog Series:

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The Gulf of Mexico Ecosystem: There’s a Map for That http://blog.oceanconservancy.org/2013/06/24/the-gulf-of-mexico-ecosystem-theres-a-map-for-that/ http://blog.oceanconservancy.org/2013/06/24/the-gulf-of-mexico-ecosystem-theres-a-map-for-that/#comments Mon, 24 Jun 2013 12:53:35 +0000 Matt Love http://blog.oceanconservancy.org/?p=6148 Blue crab map from Gulf AtlasDo you know the Gulf of Mexico? Do you really know the wildlife that lives in its waters or how we use its resources—for better or worse—to support our economy?

I thought I had a grasp on this before beginning a multi-year project that mapped important things in the Gulf. Now that the project is finished, I know there’s even more to see than I knew about! Ocean Conservancy’s new tool, “The Gulf of Mexico Ecosystem: A Coastal and Marine Atlas,” can help you get a better view of the Gulf too.

The Gulf is a complex ecosystem full of an amazing diversity of wildlife and an abundance of resources. We need to know what lives in it and where it can all be found so we can protect, conserve and restore this beautiful natural treasure.

Gulf Atlas coverThe atlas is a unique collection of 54 maps and related descriptions that illustrate and describe where you will find many invertebrates, fish, birds and marine mammals in the Gulf. Among many other species, you can learn more about sperm whales, whale sharks, blue crabs (see map above) and black skimmers.

You can look at the physical characteristics, habitats and environmental stressors in the Gulf. Sea surface currents, bottom sediments, hurricane track density and all of the known locations of coral are shown in the atlas.

You will also be able to see how people use the Gulf for recreational fishing, shrimp trawling and major oil and gas development. The areas set aside for coastal and marine protection have been included as well.

Not only is this atlas a great resource for everyone to learn about the Gulf ecosystem, but it can also serve as an important decision-making tool for resource managers who are charged with balancing the ever-increasing demands on the ocean with conserving a vibrant and resilient ecosystem.

These maps and their related descriptions are also important tools to use as we plan for the unprecedented restoration programs that are beginning to develop in the wake of the BP Deepwater Horizon oil disaster. These restoration programs are an amazing opportunity to help improve the health of the Gulf.

It is important that the critical resources illustrated in the atlas are taken into account in order to develop the most effective and comprehensive Gulf-wide restoration projects.

Check out the atlas now!

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