Dead Zones Webcast Transcript

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LILY WHITEMAN: Hi, I'm Lily Whiteman from the National Science Foundation. I want to welcome you to today's webcast and teleconference on Dead zones of the Pacific Northwest. We are very fortunate to be joined today remotely by Dr. Jack Barth of Oregon State University, who is an expert on dead zones of the Pacific Northwest. We'll kick things off with Dr. Barth in a few moments. I just want to make a few brief announcements first. Today on NSF's website at NSF.gov, we will be releasing a variety of multimedia materials on dead zones, and also today on our website at NSF.gov, this webcast will be posted. I just want to give a few tips to reporters. You can submit your questions at any time during this webcast, but please remember to identify yourself and your organization whenever you ask questions. If you are joining us just by telecom, please remember to hit *1 before you submit your question, and you can also email questions to webcast@nsf.gov. If you're joining us just by teleconference, we invite you to join us by webcast as well by going to science360.gov/live. You can get on by using the username "webcast," and the password "deadzones." Dead zones has an "s" at the end and both those words are one word and lowercase. One last thing for reporters, please limit yourself to two questions at a time.

Now, we'll kick things off with Dr. Barth, who'll give us a brief overview on his research ongoing on Oregon's dead zones. Dr. Barth?

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DR. JACK BARTH: Thank you, Lily. Good day, everyone. Today I'd like to share a little bit about the discoveries we've been making from our investigation off the Oregon coast of what we're calling low-oxygen zones or hypoxic zones, also known as dead zones in the coastal ocean. Now, when oxygen gets too low in the ocean, it has a deleterious effect on organisms. So, the oxygen goes too low, they either have to flee the area or they get stressed or even die off. Those marine die-offs are what we refer to as a dead zone. Now, these low-oxygen areas are formed when there are plankton blooms which then have excess organic material that decompose and decay and through that process, it robs the ocean of the oxygen content. So, where do the plankton blooms come from? Well, often they come from excess nutrients running off from rivers into the coastal ocean. That fuels those blooms of algae. It turns out there's about 400 places worldwide now that are suffering from this hypoxia or low oxygen and ultimately some dead zone effects. Now, off the coast of Oregon, things are a little different. First of all, it's an open coastline so you might guess that the ability to flush the water on and off shore is pretty good so it would keep the oxygen levels high. Secondly, there are no identifiable river sources of nutrients so the way the story is going to unfold is that the nutrients come from natural sources and what we're seeing is changes in the oxygen content of the water and the winds that drive the ocean and cause that flushing. So, in summary, what we're seeing is lower oxygen levels in the waters that get brought up onto the coast and secondly, less flushing of those waters over time.

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The other thing I'd like to share today is our use of new technology to measure these low-oxygen areas. So, traditionally, we've been limited to ship-based observations or perhaps use satellites to look at the very surface of the ocean. Well, now we're using these underwater robots that are completely autonomous. We can send them out to sea for up to three weeks and measure a whole bunch of parameters related to ocean health. We're measuring temperature, salinity, and most importantly, dissolved oxygen, and that data can be sent back through an iridium cell phone right to my desk so I can get pretty much a real-time picture of what's going on out in the coastal ocean. And because they dive beneath the surface, we get a view beneath the sea that we've never had before. So, our investigation's been going on now for about four years with the robots flying underwater offshore of Oregon and what we've seen are various degrees of hypoxia. For example, in 2006, we saw zero oxygen, something we call anoxia. We've partnered with the Oregon Department of Fish and Wildlife and their ROV, remotely-operated vehicle, camera footage showed us just piles of Dungeness crab littering the sea floor, dead worms, anemones, other creatures that could not flee, being stressed and dying off in that area. We did not see a single fish during the surveys during that year. That was perhaps the worst year we've seen. In recent years, including 2009, we've had hypoxia, but it hasn't been as severe, and we think that's because we understand how both the source water oxygen levels and the winds are changing. Now, just to finish, I'd like to pull in how this might be influenced by climate change. The suggestions from the climate change models are that coastal winds will change. For example, off Oregon, the forecast is for stronger upwelling winds and more persistent. So, less of this flushing back and forth. And secondly, in the entire North Pacific and perhaps even in the world's ocean, the deeper waters are becoming less oxygenated. As the surface layers of the ocean warm, the deeper layers are isolated more from the atmosphere where the oxygen comes from. So, it's kind of a double whammy that we're seeing off the Oregon coast, that that upwelled water is lower in oxygen and, secondly, it's not being flushed as efficiently up on the coast, hence the appearance of these dead zones and hypoxic areas. So now, with that as a summary, I'd be happy to entertain questions.

LILY WHITEMAN: Thank you, Dr. Barth, for your concise overview. We're ready for questions now. Are there any emailed questions or questions from webcast@nsf.gov? Operator, do you have any questions for us?

Well, I'll start things off then. You described the dead zones as being pretty much devoid of life and, yet, the Oregon area is one of the U.S.'s most important fisheries. What impact do you think dead zones might have on fisheries?

0:07:44

DR. JACK BARTH: That's a very important distinction. So, the area I'm describing is right near the sea floor so as that plankton material falls down to the sea floor and gets consumed by bacteria, that's where the low-oxygen or dead zones are forming. If we go back up to the surface of the ocean, that plankton and those blooms are actually a good thing. That fuels the zooplankton, small fishes up through the large fishes. So, Oregon's coastal ocean is very much alive. It's that lower area near the bottom where we see the dead zones. Now, we're starting to work and have drawn attention to this problem. We're working with some of the fisheries groups to understand how fish might react to this dead zone area. That is, where do they go when they have to flee this area? Is it changing the ecosystem such that the fisheries might be impacted? That's very much an ongoing piece of research right now.

LILY WHITEMAN: Great. Thank you very much. We have a question from Frank Pope. "How can you be sure this is not just a non-climate change-related cycle?"

DR. JACK BARTH: One thing we did when we first saw this and it first came to our attention in 2002, is we went back in the archives of all the data off the Oregon coast and we have good oxygen data back to the 1950s and we asked exactly the same question. Is this related to an El Nino cycle or a Pacific decadal oscillation where things go back and forth every ten years or so? So, with that 60-year record, we could not see any evidence for a cyclical change. Rather, we saw the appearance of the hypoxia in the latter part of that record and, further, if you go out into deeper water, it really does look like there's a trend over about this 60, 70-year record.

LILY WHITEMAN: I want to remind our reporters on the teleconference to hit *1 if you want to submit a question. We have a phone question, I understand, from Scott Learn from The Oregonian.

0:09:58

SCOTT LEARN: Hi, Dr. Barth. I guess this is a related question. Just how, at this point, how certain are you that climate change is causing this effect off the Oregon coast at this point?

DR. JACK BARTH: Thanks, Scott. Let's go back to those two parts of the puzzle. So, there's that deeper water that's upwelled onto our coast and I mentioned that that was going down – had oxygen levels going down in that deeper water. That now appears to be corroborated by many studies in the North Pacific, and even worldwide. Taking it a step further, it's consistent with that warming in the upper layers and the isolation from the atmosphere. So we think that part of it's holding together pretty well. The other part of it, the changes in the winds and the flushing of the coastal ocean, that's less certain. I don't think we have the record to say, a-ah, you know, that's the climate change changing the local winds. It's more of a consistency argument based on the physics of the problem.

LILY WHITEMAN: We have another email question from Christina Reed. Here's the question. "Are there any nutrient loading issues for the Oregon dead zones or is it all wind and upwelling driven?"

0:11:18

DR. JACK BARTH: From what we can tell, there aren't any identifiable surface sources of nutrients. The Columbia River, which is the closest large river to our study area, actually gets stripped of most of its nutrients within the estuary, so the water that comes out is not particularly high in nutrients. We also don't see the Columbia River water down off central Oregon that much. So, it definitely is – the nutrients are definitely coming from a natural source, the deeper offshore water that's upwelled up onto our coast.

LILY WHITEMAN: We have another email question. "Why is the Oregon coast special, or is it? Have you studied further down the Pacific coast, perhaps as far as San Diego? What types of dead zones exist along the East Coast, or do they?"

DR. JACK BARTH: Let me take the second part of that first, and that relates to this over 400 hypoxic or dead zone areas that I was referring to. If you look at a map across North America, or even the world, many of those dead zones are near populated areas with river runoff. On the East Coast of the U.S., there are many areas that are subject to hypoxia and this dead zone phenomena. Many of the bays up and down the East Coast. As far as North America, the other famous one is near the outfall of the Mississippi River. OK. Going back to whether Oregon is unique. We've been now working with our NOAA colleagues to put oxygen sensors on the vessels that are traveling up and down the coast from at least Northern California up to the Canada/U.S. border and our preliminary results show us that the hypoxia is not very severe yet south of the Oregon border or so, and that's partly because the Continental Shelf is so narrow off California. It's very well flushed. The shelf widens as we get into Oregon and Washington waters. We have seen evidence for hypoxia off the Washington shelves and our job now is to actually draw a map from Oregon up into Washington waters. Our preliminary estimates are that the hypoxic area near the bottom does extend in Oregon waters up into Washington waters, and if you sum the area of that, it's about the size of the Mississippi dead zone and for comparison, that's about the size of the state of New Jersey.

LILY WHITEMAN: I want to remind the reporters to hit *1 if you're on the teleconference and you can email questions to webcast@nsf.gov. Do we have any phone call questions coming in right now?

Let me ask you, Dr. Barth. How rare is it that of these 400 worldwide dead zones that any of them are suspected of being caused by climate change besides off the Pacific Northwest? Is this a unique situation?

0:14:42

DR. JACK BARTH: The Oregon coast, especially the oceanography and the way the winds drive the ocean, is very similar to actually three other areas around the world. The best comparison is, perhaps, with the Chile and Peru systems. That's known as the Humboldt Current. Another comparison is off South Africa, Namibia and Angola. That's called the Benguela Current region, and lastly, off northwest Africa, the Canary Current. We've been working with our international colleagues to compare all these systems. It turns out that both Peru and Chile and the Benguela system have more hypoxia than we have, and that's related to the large-scale circulation of the oceans. So, they've also, in particular off Namibia, have looked at climate change as perhaps changing that coastal ecosystem. So, what we think is that Oregon and Washington are part of that continuum where Peru, Chile and the Benguela systems are other analogies that we might look towards.

LILY WHITEMAN: Another thing I'm curious about, Dr. Barth, is if these dead zones are so huge, sometimes covering hundreds or thousands of miles of the ocean, how can you possibly get your monitoring equipment across such huge areas? What are some of the new and some of the traditional ways to study these dead zones?

0:16:12

DR. JACK BARTH: Yeah, not only are these low-oxygen areas large, but they change with time so the ocean is not a static place. As you look out from the shore, it's not just a pool of water that sits there. It's very dynamic. So, even if you place a sensor in a single spot, you're going to get just one picture of what the oxygen content looks like. So, what we're trying to do is couple single sites with these new robotic technologies and with the robots, we can patrol quite large areas. We can go all the way across the Continental Shelf in a couple of days off Oregon, turn around and come back and sample that area again. So we're not only getting the spatial coverage, but we're getting many samples in time. So, it's really this beautiful blend of space and time coverage of the dead zones.

LILY WHITEMAN: I want to remind reporters that they can ask questions at webcast@nsf.gov and if you're on the phone line, please hit *1 to submit questions. Are there any phone questions on the line?

I understand that some of the dead zones seasons on the Pacific Northwest have been worse than others. What determines, from year to year, how bad it is?

0:17:42

DR. JACK BARTH: We've been sampling quite extensively now for about eight or nine years, and that's absolutely right. From year to year, the severity of the hypoxia changes. Now, in 2006 when we had the worst hypoxia and even anoxia, it was pretty clear to us that the upwelling process was kind of in overdrive. Lots of upwelling, lots of plankton, kind of a supercharged system related to the wind strength that year. So, as we go from year to year, we can look towards the wind records and the flushing that happens. We can also track that water offshore and its oxygen levels. It is trending down slowly and so each year the upwell water is slightly less in oxygen. So, now we have to look towards the winds from year to year about how that influences how severe the hypoxia is.

LILY WHITEMAN: Again, reminding people how to ask questions. Hit *1 if you're on the phone or email webcast@nsf.gov, and please remember to give your name and your affiliation. We have an email question from Rebecca Lindsey of Sigma Space. "Are you using satellite data to observe either the cold SST anomalies or chlorophyll plankton anomalies associated with this phenomenon? If so, what part do they play in your research?"

0:19:14

DR. JACK BARTH: Yes, we do use the satellite data and we can definitely see the cold sea surface temperatures near the coast as a result of upwelling. That deep water I've been referring to that comes up is low in temperature. It's also low in oxygen. So, it's kind of a proxy for where the upwelling water comes. As far as the plankton blooms, we also can see that from space by actually the color of the water. We see the green of the plankton so we can measure the amount of chlorophyll in the water and we use those satellite images to look at certain areas that might have more plankton compared with others. And, off Oregon, right off something called Heceta Bank, right over Heceta Bank, that's an area of large plankton blooms that we can see from space and that's actually an area where the hypoxia is the worst, as that plankton material falls towards the bottom and decays and robs the oxygen from the water.

LILY WHITEMAN: We have another email question from Christina Reed, who's a freelancer. "Are you working with Argo floats or liquid robotics? How deep do your robots go?"

0:20:31

DR. JACK BARTH: The robots we're sending around are actually called underwater gliders. They're very much related to Argo floats. Argo floats go up and down from the sea surface to about 1,000 meters, perhaps 2,000, but they are at the whim of the currents to push them around through the ocean. When we put wings on those same kinds of floats, we can glide sideways and cover horizontal space. So, we're using the gliders which I guess you would call – it's a cousin of an Argo float, up on the Continental Shelf. We're using two versions of those. One can go to 200 meters and the second to a thousand meters. So, we use the deeper one offshore and the shallow one right up near the coast.

LILY WHITEMAN: We have another email question from Randy Shostack of EOS. "What has been your interaction with policymakers and what has been their response to your work? What would you want their response to be?

DR. JACK BARTH: We've actually had a fair bit of attention, both at the state level and the federal level about these new emerging hypoxic and dead zones off the Oregon coast. In particular, state legislators and ocean users in Oregon are very keen to learn about the extent of the dead zone areas and how severe the hypoxia is, and right now we're going through a process in Oregon to place some marine reserves, areas where there would be no take and as more and more uses of the ocean come into play, you better have a pretty good idea of where the dead zones are, where particularly good fertile areas are, and our research is playing a role into getting those spatial maps better defined so it can go into decision making for use of the ocean. At the federal level, a couple years ago we had a field hearing in Newport, Oregon, where we drew attention to this question of these emerging hypoxic zones. So, I think at this point, we're seeing the need for the information and the way I see it is we're very close to starting to influence some of the policy decisions.

LILY WHITEMAN: Again, I want to remind reporters that we're taking questions at webcast@nsf.gov and over the phone, push *1, please.

I've always been curious, can a dead zone reverse itself? Once a dead zone occupies a space, can it ever be un-dead zoned?

0:23:17

DR. JACK BARTH: Sure, and let's go back to those two different types. The one that's dominated by river runoff with excess nutrients, certainly if you change land use or work on ways to cut down the nutrients, there are good examples of areas that were formerly hypoxic actually recovering from that problem. Now, if we go to the Oregon coast, the hypoxia is most severe in late summer after we've had this growth season of plankton and it being held up on the shelf, but at the end of the season, say about now, in October, the winter storms flush that low-oxygen water offshore and re-oxygenate the waters. So, what we're really keen to understand is during the summer how often that flushing or reversal of the low-oxygen happens. That, I think, is something that, as we get more persistent winds and less back-and-forth flushing, we've got to keep our eye on that.

LILY WHITEMAN: We have another email question from Sunny Lewis of the Environmental News Service. "There is much attention being paid in current climate change negotiations on limiting the level of atmospheric concentration of carbon dioxide to 450 parts per million or less to avert the worst consequences of climate change. Do you have a target level of CO2 in the atmosphere that you believe would allow areas of hypoxia to grow smaller?"

0:24:51

DR. JACK BARTH: I think if you connect the dots back towards the global warming scenarios where you're warming the surface layers and isolating the lower layers from the oxygen source at the surface, I think that all holds together. We do not have quantitative models that would allow us to pick a target level of CO2 that would, in turn, change that – you know, lessen the warming of the surface layers. So, no, I do not have a target based on the influence on the oxygen levels.

LILY WHITEMAN: Do we have any questions on the phone?

Let me ask you one final question. Do you think that the dead zones of the Pacific Northwest are here to stay? Are they regular summer fixtures?

0:25:46

DR. JACK BARTH: We've been looking hard at this problem for eight years now and each year, we've seen hypoxia and it really comes down to how big of an area, how severe and how long-lasting, but from what I've seen, we reached hypoxia each year and I really think we're in a new pattern, a new rhythm offshore here and that I would expect hypoxia to show up, to some degree, every year now.

LILY WHITEMAN: OK. That wraps up, I think, all the questions we have. Dr. Barth, is there any additional information that you think is important that you'd like the reporters to know?

DR. JACK BARTH: Well, I think just going back to the new technologies that we've been using. As we now have this new view beneath the sea surface, I think the time's really right to deploy more of the robotic explorers, both off our coast and along the entire West Coast. There was the question about how far do these extend along the shore, and the gliders are a perfect tool for doing that. They're an existing technology, they can be run by graduate students and bring the data back to shore. So, I'm very hopeful that we're going to have even better views beneath the sea of these low-oxygen zones.

LILY WHITEMAN: OK. I want to close up now by thanking Dr. Barth for all his fascinating information. I want to remind reporters that on our Web site, NSF.gov, this webcast will be posted later today. And also, on our Web site we have a host of multimedia materials on dead zones including a slide show, photos, videos, explanatory text and illustrations. Thanks very much for everybody for joining us. I'm Lily Whiteman for the National Science Foundation.

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