Solingen 93

Domestic Violence and Abuse

National Liaison Committee Meeting: Harmful Algal Blooms (HABs)


Alright folks I figure we might as well get going. There’ll probably some stragglers as there usually is for these sorts of affairs. So for those of you that don’t know me I tried to get around and introduce myself. I’m Gary Rowe with the USGS. I’m the program coordinator for the National Water-Quality Program. I sit in Denver, Colorado. But these days I seem to get up to DC and Reston at least a fair bit. We’re happy to have you today for our National Liaison Committee Meeting for the National Water-Quality Program. Just to kind of remind folks in 2016 the USGS realigned the funding lines for what used to be water quality work in the Water Mission Area. So as you all know this used to be the NAWQA Program that Pat helped start back in the day. So the NAWQA piece, they basically combined NAWQA with our National Atmospheric Deposition Program are National Park Service Co-Operative Water-Quality Program. And the water quality pieces of our Co-Operative Water Program and our National Research Program. So all those pieces now fall under one banner in a single appropriation that’s made for water quality work within the USGS Water Mission Area. So NAWQA was traditionally funded around 50, high 50s low 60s and now the overall funding with those other pieces added in is about 90 million dollars. With respect to FY 18 funding the omnibus contained a slight bump for us. We went from 90.5 to 90.8 million. We were just happy to get an increase. We’re still waiting to allocate that money. There’s the rescission talk and some spending plan reviews that the department’s doing. But we’ve been continuing to do our data collection, and out modeling, and our work. So what you’re going to hear about today because we’ve kind of moved to the National Water-Quality Program emphasis, we’re gonna start in this meeting, in future meetings, bringing in other elements of NWQP. And today for example we’re gonna be talking about harmful algal blooms. Now NAWQA is doing some work, and you’re gonna hear about that today. On HABs, but most of the other current work is actually being done in our water science centers through co-operative studies. And you’re gonna hear from Jennifer Graham who works in are Kansas water center. The work that her office is doing in cooperation with Tom Stiles. So we brought in an outside person, Tom to give sort of the external stakeholder and co-operator perspective on what they’re doing in partnership with USGS. What he likes and doesn’t like. And areas for future collaboration. And so the purpose of this meeting really is again, as it always is for you folks that know us, know our work, to hear about what we’re up to and provide feedback on things you like, things you don’t like, future directions we could be going. Things we should be aware of that we may not be aware of that we can potentially partner or collaborate on. Well great. Well thanks everybody for coming today. So I guess I’ll start off. Let’s jump right into it. What we’re gonna do is we’re gonna have three presentations from Tom, Jennifer, and Paul. And after each presentation we’ll have some time for discussion and questions. And hopefully we’ll have a productive next hour and 45 minutes or so. So our first speaker is Tom Stiles. He’s with the Kansas Department of Health and Environment. He’s been working with Kansas on water issues for I think 36 years. He participates in AQUA and other organizations related water. One of our leaders here, and again he brings a perspective of working hand-in-hand with the Kansas USGS, Kansas Water Science Center, and Jennifer in particular. And they have a long history of working on HABs issues in Kansas. And so we’re gonna have Tom tell us about that and provide some perspective, some outside perspectives on that work. So Tom. As Gary’s setting up I want to thank USGS for having me come out. I’m not only going to give a state’s perspective, I’m gonna give a Midwest perspective which may be somewhat different than what people along the coast experience when it comes to harmful algal blooms. Certainly we are purely a freshwater situation. We don’t anything relative to marine or estuaries et cetera. So our perspective and the other aspect is for a state like Kansas we’re semi-arid. And we really don’t have lakes. We have reservoirs and they were constructed ostensibly for flood control. But they’ve also feature water supply functions as well as recreation. And for a state where 99% of the lands are privately held the availability of public recreation at our lakes is paramount. And so as harmful algal blooms is impinging upon that, the public has raised their collective awareness on water quality. So just start off with the basics, what is an algal bloom? It’s in the eyes of the beholder. We know that there are high cell count densities, they tend to be monocultures dominated by one species or maybe a couple. And the most, from the lay perspective, the most important thing is they’re visible. Not only they’re visible, but they’re noticeable. They give off odors. And as you come into contact with them you may or may not have a reaction. Not all these balloons are necessarily toxic and not all toxins necessarily come from these blooms. But for them, what this really is, and for those of us that have been in the the science field and dealing with water quality for years and decades, what this has become is the final, the manifestation of the impact of what is eutrophication. The excessive application of nutrients and presence in our waters there. For decades we’ve said our waters probably have too many nutrients contained within ’em. This is the bulk of the iceberg from those early tips that we saw. The most important thing is furrowing our world again. The public generally doesn’t get water quality. They don’t understand what we do, but they understand when things go off the rails. Harmful algal blooms is for a lot of the public is something’s gone terribly wrong. I can no longer use my lake and that makes it a little more personal to ’em. And so while we’re dealing with the crisis we also need to seize the opportunity to make some inroads on how important water quality management is. And in expressing it for us scientists, I mean we feel the cyanobacteria for managers is essentially, it is harmful algal blooms. For the lay public, it’s blue-green algae. So it comes in many shapes and forms, but it all basically represents the culmination of excessive nutrients and an ecosystem that has gone horribly out of tilt. For Kansas sitting in the middle of the country, semi-arid, it’s climatically diverse. We have 10 inches of rainfall out on the west borders and it runs 36 to 40 inches on the east. But as you can see from the map and when we started in earnest looking at reports on harmful algal blooms since 2010, essentially no quadrant of our state has been immune to suffering. Seeing their lakes suffer from this phenomenon. And it’s comfortable peak with our main problem child, for many it’s Lake Erie or down in Florida, St. Lucia. Or Utah Lake, for us it’s Milford Lake. It’s our largest lake. And I’m usually calling things lake, there are in fact reservoirs. But I slip in and out of that vernacular pretty quickly. It has a strong regional water supply function, it supplies water to the Kansas River that heads out from its outlet and heads eastward to Kansas City. Of course it’s got flow control function from the Republican River which represents its watershed. But it’s also our primary, of one of our primary regional recreation centers. Prize blue ribbon walleye fishing, many Bassmaster tournaments. It represents for the lay public the ultimate in terms of a recreation type of situation. Both from the fishing perspective as well as jet skis and so forth. It’s our water body. 2011 the lake blew up on us and this was in part because of the way the Corps had to manage it because of the Missouri River floods. And had to hold water back for months at a time over the summer time period. And that water just, with chock-full of nutrients it basically had a chance to get warm and it took off with our largest mega bloom that we’d seen up to that point in time. Ever since then, then we followed that with two years of drought. And we saw subsequently the blue numbers dropping off because the influx of nutrients coming in from that spring or those spring inflows had diminished considerably because of drought conditions. And the blooms correspondingly were quite moderate. And then it was followed by back-to-back-to-back years of extensive blooms that were highly intense in terms of their magnitude, in terms of the cell counts, or toxin concentrations. Predominantly microcystin, and just duration with the blooms essentially happening around 4th of July plus or minus a week. And then continuing on past Veteran’s Day. So there was a strong persistence to the blooms there in Milford. 2017 represented a little bit more moderate condition. But part of that again was partly due to water manipulation by the point of the Corps to consistently draw water off the reservoir. And ostensibly, essentially not let the bloom accumulate in one area. It’s a complex lake in terms of its shape in how again, because it is essentially an inundated valley, and in looking at it as you’re sampling, does one sample represent the lake as a whole? Many of our lakes that is the case. If we sample one place we know what’s going on throughout the lake. But in Milford we wound up zoning it because conditions were quite different as we moved from its headwaters down toward the outlet of the dam. And with the headwater area essentially representing ground zero for our problems with harmful algal blooms. And consistently the area that was hammered time and time again by the impairment issues associated with the HAB itself. Conversely Zone A down at the bottom was relatively left untouched. It suffered occasional blooms there in some of the coves and where the state parks are, and the marinas, and in the beaches. And toxin levels would occasionally be there but they were much, much more moderate. And so during the duration of any given summer while the upper part of the lake was just chock-full, with the cell counts and associated toxins the lower part tend to ebb and flow a little bit with essentially a prevailing wind condition. And more often than not was still able to maintain its recreational function. These are annual averages of the microcystin toxin levels there. And we follow the WHO guidelines of that 20 part per billion. Once we see toxin levels up and over that we issued warnings there. We use two criteria. We use toxins and we use cell counts. And I’d say 90% plus of our public alerts are driven by cell counts. The cell counts are always escalate much faster and the toxins come along after the fact a little bit later. But as you can see generally from the 2011 period there where we initially saw the elevated situation of the bloom along with the toxins were there throughout the lake. Both in the upper zone and as well as down by the dam followed by the drought condition. And then again our three stressful years of ’14 through ’16 peaking out at over a 1,000 per billion for toxin as an average over the summer time period that we collected it. And then the diminishment last year again partly because we were able to essentially stretch the bloom out over the lake and not let it accumulate with such critical conditions. This is where we utilize USGS’ health because we were often accused of cherry-picking. Of going out and finding conditions such that we could basically make a worst-case situation, essentially drawing it from a scene from Jaws. Saying there’s no real problem here according to the locals. This is the way it’s always been. And you guys are just looking for the trouble area, sampling it, then using that to backup your pronouncements in terms of alerting the public. Which is killing our business by the way. We appoint USGS to help us out on this. And in 2015 we went out and collected all three agencies, ourselves, USGS, the Corps of Engineers, who routinely sampled their lake. We all collected in the manner that we did simultaneously. Now KDHE samples along the shoreline. Basically where the highest probability of public exposure is going to be with people wading, swimming et cetera there. And those were always the data that were used to base our pronouncements in terms of the relative level of concern that the public should be aware of. USGS basically ran down through the lake and just did random draws out of the out of the water column. And the Corps of Engineers basically ran transects in various spots along the lake. Back and forth across the lake. USGS analyzed those data and basically came back and said it doesn’t matter who samples, where they sample, when they sample, the general conclusion of the relative risk to the public is always the same. And that basically emboldened us to basically say we’re not cherry-picking that we are basically basing on the facts that what we are sampling there does in fact represent the immediate threat to the public relative to that. So this was very, very helpful for us to basically do that. And it does back up the fact that as you see with the red dots, up and in the Zone C, that’s problematic. Those were very high levels there. The transition zone, Zone B began to moderate that out and then again that Zone A. Where most of the recreation did in fact occur oftentimes. It was still pretty harmless. The impact is that when we made public pronouncements Zone C would be isolated as saying that’s the problem area. But you can still enjoy the lake down in Zones B and A. More than hard science, sometimes all you got to do is get some information to make some observations. And these blooms are incredibly dynamic. These are from fixed cameras that USGS established on the upper end. And they basically showed how quickly conditions change. The top one was early in July of ’16 where the blue was there along the shore, and one hour later it’s been swept back out into the lake. It’s gone, I mean stripped clean off the shore. Followed toward the latter part of July within a 15 minute period there we see moderate conditions at that location followed then 15 minutes later, the bloom is sitting right on top of it as well. So using these photographs we basically said with our sampling yes, we basically are looking at more in terms of patters than of an incidence. And that these conditions are so dynamic that it may be bad now and then when you go out a half hour later it might be clear, but believe me the bloom’s coming back. It comes back and forth. And so just the only way we can stay on top of it is to basically sample throughout the perimeter of the lake and then basically say the pattern that has been holding over time is basically representing of the input of what we make relative due to management. This isn’t hard science, but it’s one of the most important features of science is just making observations of what’s going on there. And it’s visible, and it’s optic. And that is what the public responds to. But you can’t be out there all the time. So we employ USGS to put in real-time sensors to begin to say, ’cause there is some type of signal we can see relative to when blooms are starting to pick up. And USGS pioneered the use of these real-time sensors to look at water quality on a continuum, a continuous basis. A lot of data being generated there. And as is the case with most water quality data, it’s pretty noisy. But what we found is that as the sensor is looking and things are relatively stable and calm, there’s no bloom out there. All of a sudden we start getting noisy data and it basically is the harbinger of a bloom is developing. And then the sustaining of that throughout the remainder of July of 2016 showed that bloom was there to stay for a while there. And the sensor of the phycocyanin which has been very key to the cyanobacteria, has been really helpful. More so probably than chlorophyll and being able to sort out when we’ve got these harmful algal blooms taking hold relative that. And the beauty is we don’t have to be there necessarily. We can begin to trust the instrumentation to tell us what those situations are. So much so that then along with ambient data that we collect we can start developing relationships between what the sensors are picking up and how it relates to actual ambient data coming from the water column there. And looking at that and using sensor data to basically say what’s the probability of conditions there? And this basically follows along the same line of 2016 where it basically starts out as low condition, clear condition. We start slipping into maybe okay, you need to be somewhat, the public needs to be aware. Keep your head on a swivel. Bloom’s are developing. And then, also when we’re in a warning stage. And this is all driven by what the sensors are telling us there, that tends to back up what our then we ground truth week in and week out with our own sampling there that says the blooms are there. Again, for the public. We’re only there once a week but the sensors back it up saying while you were gone, here’s what’s happened there. Very, very important for us to convey this sense of dynamics across time as we work through the recreative week there after we’ve been there. So you can set up with regressions and this is the beauty has always been, the beauty of real-time sensors is that you get sensor data such as the pigments associated with the cyanobacteria. And you match it up with the toxins that result that are produced by the cyanobacteria. And this is an incredibly tight relationship that we picked up with our sensor in the northern end of a Milford Lake. That allowed us then to make projections on terms of, because in the end the cell counts don’t really matter that much. They basically represent the potential problem. The toxins are the real problem. Well while using the sensor data and then letting USGS run out on boat and doing transects across there with a sensor, they’re able to essentially map out the lake of the relative concentrations of toxins that are present there. And again, the upper part is just hammered with toxin. And then we slip into some transition and we’re relatively clear on the lower end there. Again, the message is the upper end, for the general public, is typically should be avoided. But you can still enjoy the lake down at the southern end of it. It’s not just a lake issue. 2011 introduced the notion of well again, these are reservoirs and the reservoirs support the downstream river reaches. Well once the Corps let loose of the water after the floods on the Missouri subsided and Milford had been up 10, 10, 15, 20 feet up, they started letting it loose. And it had a noticeable impact of setting a signal of microcystin toxin on the Kansas River. The Kansas River represents the majority of our surface water suppliers that probably supply up to 2/3 of the population of the state. This freaked ’em. And when then they embarked USGS to begin a long-term study to examine how toxins are being transmitted downstream along the river reaches by the reservoirs. Predominantly again Milford being primary the source of that. The upshot from here we can definitely see that from those conditions in 2011 there was definitely a slug of toxin delivered to the river. And that it basically, no other tributary, no other reservoir was contributing. And so there was almost a dilution effect and so we saw a sliding out of those concentrations as the river worked its way toward the Kansas City metro area and the Missouri River. The subsequent follow-up studies by the public water suppliers and USGS basically said you know this is kind of a perfect storm. It doesn’t happen all that much. Which was gratifying saying we can focus our attention back up on the lake itself where the primary conditions were. And that while the public water supplies can maintain some level of vigil in anticipation of these occasional inserts of toxin into the river system, they generally are not something to worry about. Frankly taste and odor issues were much more prevalent from the river then the presence of microcystin. Again, very gratifying information to basically say not only, it’s just not that common an occurrence. But also when it does occur the public water suppliers can be ready to apply activated carbon and treat it out. We have never had a breakthrough in finished water of any type of our toxins, either microcystin or cylindrospermoxum. So our public water supplies had maintained a clean record in delivering toxin free water. Well, we’ve got a science shift because we’re now understanding the dynamics of the bloom and the bloom are of the public, publicly aware effect of all this. What the shift has to go to okay, let’s get to the cause. Why is this happening? And why is it happening so prevalently and so vigorously on a lake like Milford Lake? We had USGS go out and begin to track biologically available phosphorus, ortho-p found the river inlet, and then throughout Zone C. And we saw ortho-p concentrations up between averaging around half a milligram per liter. That’s unheard of for Kansas surface water, let alone a lake. We typically are seeing non detects with ortho-p and here it was just chock-full of ortho-p. Okay, that’s a question. Why is that ortho-p so high? And why is it so uniquely high in this lake? That’s the new question. The Corp of Engineers will have samples monthly throughout the recreation season. From April through October. They’ve typically done that for years. And they’ve noticed the same phenomena and they noticed a couple things. Over time the level of phosphorous and ortho-p has risen over time, with year by year. Within a given year through the season the level of phosphorous and ortho-p rises up toward the late summer early fall period there. Which coincides with the period when the Republican River really isn’t flowing all that much. So it’s not necessarily coming in from the river. And again, these are ungodly amounts of ortho-phosphorus and biologically available phosphorus that is up in the upper river, upper lake that we just never see anywhere else. So what’s happening there? So our tension shifts from what the watershed’s contributing to what do we have in terms of internal cycling of the phosphorus that’s already embedded within both the biota and the sediments of that upper proportion of Milford Lake. Well it does take watershed, when you have a reservoir, which is essentially an impoundment, its water quality clearly reflects everything. It’s basically the cumulative effect of everything that’s come down from its watershed. And it causes me to remember back when we took limnology classes the concept of the sources and sources. Those that are coming from outside the lake and those that are being generated within this lake. And that’s certainly depicted by this display there of all the potential sources of nutrients that can go in. And so we potentially have during the springtime inputs coming in from the watershed. I mean it is a rural state and it is highly agricultural. And we started during runoff period, we see nutrients moving from the landscape back on down to the reservoir. What happens to them there is the question. Do they basically go down, it gets into the sink and never to be seen again? Or in these upper areas there that tend to be somewhat shallow, do we start seeing some level of recycling, and resuspension, and renewed bioavailability that fuels the activity of the bloom? And we’ve just been looking at phosphorus. We have not hardly touched on the nitrogen. But the blooms are definitely and the lakes are definitely nitrogen limited there. So what is the rule of nitrogen to basically trigger and then sustain the bloom as well? Recognizing that nitrogen is the more volatile of the two nutrients and that there are many pathways for it to go including up into the atmosphere. So my closing takes there from the state’s perspective. And teeing it up for Jennifer and Paul is here’s what the states need. We need three things. We need research to begin to understand the things that we don’t know. We need science to basically back up, and verify, and apply what we believe is the case. It certainly that’s the case with things like nutrient cycling. And we need more than anything, we need data and observations to verify that our belief system and our working hypothesis is holding so that we can begin to address and translate science into management. To begin to abate these types of blooms. The dynamics of the blooms and the biology of the blooms still is something open for research. And there have been many takes on what drives the blooms, including why do some blooms go bad and produce toxins while others remain benign? Nutrients and nutrient cycling is basically application of the science that we know but both of those have to be backed up by the acquisition of data. And again, USGS employees perfectly to explore innovative ways to collect data to help shed some of the light on these areas that we don’t know or to test our working hypothesis. The beauty also is that USGS is neutral. They have no dog in the fight. And so from the state’s perspective my closing remarks is and for the youngsters here, they probably won’t get it. But we just need USGS to be Joe Friday, just need the facts. Appreciate the time and the privilege talking to you today. Thank you very much. (applause) Gary one last thing, one other thing, AQUA over fall and winter put out a survey for the states looking at how we’re managing nutrients and looking at them pull through the point source perspective. And not points perspective as well as what we’re finding in trends. The findings relative to trends were most telling in that the most dominant answer that came back in terms of how are you seeing trends in either nutrients or the manifestations when it’s dissolved oxygen, or pH or chlorophyll et cetera? The most prevalent answer was I don’t know. It’s unclear, that’s an area ripe for exercising research science and data acquisition to help us sweep away some of that unclear and allow us to begin to see whether efforts we’ve made to move the needle are effective or not. Thank you Tom. We’ve got time for a few questions or comments for Tom. Tom I was impressed with the role USGS is playing with the neutral party, but does the public view it that way? Do all parties view it that way, or what does it mean exactly? Well when we’re out in public and making a presentation like this USGS is up there frankly emotionless because all they’re doing is presenting the facts. Here’s what it isn’t, here’s what it should be, or here’s what it could have been. It’s here’s what it is. The agencies are responsible for regulating water quality or the Corps is regular that is responsible for managing the uses of the reservoirs? And so as you impart management decisions in there we’re making policy decisions. USGS isn’t imparting policy. The state agencies, or the Corps, the managing agencies are imparting policy. The public can recognize facts and then they can start addressing or attacking us relative to the chosen policy we’ve taken to take those facts and put forth and produce that policy. So I would say yes the USGS has not been stained by any connotation of bias whatsoever. Because of the way they not only collected the data, but also in the way they present the data. Which is cool, calm, and collected. So Jennifer Graham works with our USGS Kansas Water Science Center out of Lawrence. She is our de facto HABs expert in the Water Mission Area. And she’s been with the USGS either in volunteer or an official employee about 15 years, 13 in Kansas. And she represents the USGS on the HABHRCAA The Harmful Algal Bloom and Hypoxia Research Control Amendment Act, that’s a mouthful. Inter agency working group with EPA. You know and a bunch of other folks. And so she’s gonna kind of, she actually picked up a copy of this early bar at the table she was a lead author on this. And this really was put any other kind of document USGS science capabilities with respect to haves. And outlying areas of future research kind of the niche we occupy right now and where we might go in the future. So we asked Jennifer to come in and even overview talk on some examples of support. Sorry, Tom talked about the Kansas experience and I think that is an experience that a lot of our states will echo. Harmful algal blooms are a national problem and they’re a global problem. A lot of our effort has been focused on our inland freshwater lakes, and reservoirs, and also in our coastal, and marine areas. But we’re learning that harmful algal blooms are affecting all of our nation’s waterways. From our smallest streams, into our coastal estuaries and marine systems. And so this is a big problem in all of our water bodies. And so I’m gonna give you an overview of some of the work that we’re doing to really start to explore some of those other places that we’re seeing harmful algal blooms develop. Tom talked about what a bloom is. I want to touch on what makes some blooms harmful. Because again, this really depends on your perspective and where you’re sitting. A lot of the emphasis on the harmful algal bloom is on how they affect human health. We know that they produce some potent toxins that can result in human illnesses and in rare cases human deaths. There are multiple exposure routes. So that’s really been a lot of the focus of what we do. But these types of blooms also have major impacts on ecological health. On the upper part of this slide is an example from Florida where there was a major fish kill. And this kind of event really affects and alters ecosystem processes. We don’t know a lot about what those impacts are and that’s really an open area of research. Another issue then is the economic and aesthetic concerns. Tom mentioned the loss of recreational revenues from vendors. And again, this is another open area of science really is how do we value economic impacts of blooms like this or something that affects all of Lake Erie? And the 2014 drinking water then in Toledo has had some preliminary economic work done and that work estimates that individual event resulted in 65 million dollars of lost benefits. 43 million of those benefits were associated with the recreation and tourism industry. About 14 million are associated with property values, property losses. And then four million was associated with the drinking water treatment for that event. So events like this, we don’t have a lot of those kinds of numbers but they can have very high price notes. We talk about how common are toxic cyanobacteria blooms. I think this is really something that’s occurring across the nation. This map illustrates to two different points and again, this is something that we have updated continually as we get more information. I want to emphasize that right now we don’t have a great common reporting database for when and where toxin blooms are occurring. We have made a lot of progress. Leslie Dangladden keeps a great record and sends out monthly reports which is a long going. I mean it’s further than we were before. CDC has one health harmful algal bloom reporting system where events can be input, but it’s really tough to go out and quantify at any given time across the nation how many toxic blooms we’re experiencing. And what those human health impacts are. What the effects are on our companion pets, wildlife, things like that. So in this map all the states that are colored in green are states where there have been some kind of anecdotal report of either human, or animal illness, or death associated with the toxic cyanobacteria bloom. And as you can see most of our states are affected. And I will say since we put this map together there have been a couple, South Carolina has also started reporting some incidents in fresh waters. And so it’s widespread and common. But again, this is anecdotal and those were really gleaned from newspaper reports, and things like that, or word of mouth. And so I think that if we look, just because states aren’t affected or aren’t shaded here it doesn’t mean they aren’t having problems here. It means their reports aren’t in a location where they’re easy to find. And then just to illustrate how widespread this issue can be particularly during summer months. In our fresh waters the states that have hashes through them, are states that had some kind of health or recreational advisory for cyanobacteria in fresh water during August 2016. And there were 19 states that were affected at that time. So again this is widespread and common. This is an issue that we’re dealing with. So one of the things that USGS has done in partnership with other agencies like EPA, we have gone and really tried to quantify how often are we seeing toxins in the environment? And where are they? Where are we seeing them? So we partnered with EPA in the 2007 National Lakes Assessment to look at occurrence of several different types of cyanobacteria toxins. The microcystins are the most commonly occurring in the U.S. and they’re the most commonly occurring worldwide. So that’s really where we focus right now. But during the National Lake Assessment these lakes were sampled once sometime during the summer. Maybe September in 2007 and they were sampled in open water areas. So this is really just an ambient snapshot of what was out there at that point in time. And 32% of the lakes across the nation had detectable microcystin at that point. Those are indicated here in blue. That’s fairly widespread. When we start to look at those concentrations that are of concern for public health protection, again, using that 20 micrograms per liter by the World Health Organization, those are the red triangles. And those were relatively rare during this particular study. And so there have been some other regional studies that show the same kind of pattern that while the microcystins are widespread and common throughout the nation, those high concentrations that really start to cause concern are relatively rare. This study was a single snapshot at one point in time. It wasn’t focused on blooms. And we know that there are other toxins out there. So we did a study in the Midwest. We went out to lakes that we knew were experiencing blooms at that time. And we sampled, we cherry-picked. This is an example of what happens when you do cherry-pick. And there are a lot of things going on here. There were a couple of questions we are trying to answer but we really wanted to look at mixtures. Because that’s again, in this field that’s not something that we’ve really focused on when we’re talking about recreational public health protection. Or we’re talking about drinking water treatment. The cyanobacteria can produce a whole bunch of different compounds that are concerning as the toxins. There’s taste and other compounds that don’t have human health impacts, but it can greatly effect aesthetics of drinking water quality. And so really we wanted to know what was going on with mixtures? And so there are a couple of things that came out of this study. One was that every single bloom that we cherry-picked had detectable levels of microcystin. And we saw really high microcystin concentrations in this. All of these had levels that were around or above that 20 microgram per liter threshold. The highest that we saw here was 17,000 micrograms per liter. Which is a lot, as an aside and some of the work that we’ve done on Milford Lake in Kansas, the highest we’ve detected there’s about 350,000 micrograms per liter. So we’re talking there are cases where there’s a lot of toxin out there. But really the more interesting thing here was that almost every bloom that we sampled had a mixture and about 30% of the blooms had multiple toxins. And that creates challenges for treatment because not all toxins are removed the same way. And it causes problems when talking about public health protection because the different toxins have different toxicities and different mechanisms of action. And then again the fact that I think over 90% of these blooms also had taste and other compounds. And again when we’re talking about drinking water treatment concerns it’s complex. And it’s complicated. So mixtures are out there and that’s something that we’re gonna really need to start to look at and start to tackle. As I mentioned a lot of our work had really focused on lakes and reservoirs with the cyanobacteria in particular because we can see them there. We can see the blooms accumulating but we had the opportunity to go out and look at small stream sites as well. And so we took that opportunity in a regional assessment in the southeastern United States and we just collected some samples for cyanotoxin analysis and in this particular study 38% of the small stream sites that were sampled had detectable levels of microcystin. This was surprising. When we started this study I think that the thought was well, we’re gonna do this, and we’re not gonna find anything. And we can kind of cross that off the list. But we didn’t, and really this study was enlightening. And it really opens a lot of doors and raises a lot of questions where maybe our small streams aren’t necessarily huge exposure routes for people. But they might be for pets, or for livestock. And there might be huge ecosystem effects here as well. And so again, this opens up a whole new area of questions that we can ask and things that we should be looking towards. So this is small streams in 2015 there was the event on the Ohio River that affected hundreds of miles. Multiple states, multiple drinking water supplies. And this event, it captured a lot of attention. But we asked the question you know, we know that sometimes there’s a perfect storm where we will see events in rivers. Tom talked about what we saw in the Kansas River. We know in the San Francisco Bay there’re systems that occasionally export microcystin into the bay and cause sea otter issues and other marine life issues. And we see reports like this and what we saw down in Florida in 2016, but there aren’t a lot of data out there documenting how common the cyanobacteria the cyanotoxins are in large rivers. And so the NAWQA projects started to have pilot last summer to really look at occurrence in large rivers. And so our objectives were to describe cyanotoxin occurrence in the large river systems that we selected. And then also look for the potential for harmful algal bloom occurrence using a combination of traditional approaches like microscopy looking for cyanobacteria and chlorophyll. But also look using some of the emerging approaches like genetics and some of the sensor technology that Tom mentioned. So we selected 11 sites across the nation that represent a range of water quality conditions. We also looked for sites that already had instrumentation in place, water quality sensors in place. And about half of our sites had that available. And then all of these have some kind of drinking water significance. There’s not necessarily proximate to intakes but there are drinking water uses on these rivers. And so I’m really excited to be able to talk about the results from that. For the first time we’re really getting into data analysis and interpretation. I think the good news story from this is that we only detected microcystin in two of our study sites. And they are in the Midwest, they are indicated here by the stars. And the Mississippi River and in the Kansas River in Kansas. However, we also went and we looked for the genetic potential for toxin production. So we were looking if the communities that were there were able to produce toxin. And this slide just shows a broad summary that over the summer in 2017 all of our sites except for one, had genetic potential at some point in time for toxin production. And there were multiple toxins there. This wasn’t just a microcystin story. And so this is exciting. Now we’re asking the question, what exactly does this mean? And how do we use this information? And so to answer that we’re going to do this again this summer and continue to look at our data, and build this data set. And hopefully expand what we’re doing. This is the first time that this has been looked at in large rivers in this way across the nation. And it’s the first time that the genetic data have been used in this way. And so this is really exciting and something that we’re really excited about. Tom talked a lot about the water quality sensors that we use and gave some great case studies of the fact that the water quality sensors really show promise as early warning tools for blooms. We have our nationwide water quality sensor network. Right now about 65 of our sites are equipped with chlorophyll. Which it is a good indicator, not necessarily good as some of the other pigment sensors that we have out there, but we’re looking at a range of different site types and exploring how we can use these data. And again Tom gave some great examples of how these data are being used. We can use these data, really this is just reiterating what Tom said, we can use these data just by looking at the patterns that we see there. And he focused specifically on the cyanobacteria pigment sensor and the seismograph that we see in Milford Lake. There are other patterns there that we can see in other variables. Oftentimes when we have an algal bloom, dissolved oxygen, and pH concentrations will vary substantially, we can look at that and see if we’re looking at something like we see on the upper graph here that might be an indicator that there’s something going on. And you might want to pay attention or go out and collect a sample, or investigate it further. The other thing that we can do with the continuous water quality data, is really start to look at long term patterns and trends over time. So the lower graph is showing chlorophyll concentration in another reservoir in Kansas. And we actually have continuous, nearly 20 years of water quality data from that reservoir. And it’s continuous. So we can start to tease out the patterns and trends that we’re seeing over time and look for anomalies and start to link the conditions associated with those anomalies. And really get some of that understanding behind the causes. Another thing that we can do with a continuous water quality data that Tom talked about, is develop these surrogate relations to act as indicators and early warning systems. An indicator, an early warning, I think it’s really important in management because it starts to allow movement away from reactive approaches to these events to proactive. So if you’re paying attention to your sensor data you can say oh, maybe I need to increase sampling frequency. Maybe I need to start looking at ways I can adjust, or prepare for an event in my drinking water treatment facility. Tom gave an example of how we use linear associations to actually map microcystin concentrations. Another thing that we’ve been able to do at several sites across the nation is use a logistic approach where we’re actually measuring the probability of an event occurrence. And so in the graph here that is on the left it’s just the probability, really it’s the probability that microcystin is going to be detected in a system. So the black line is a probability and then the red dots were actual measured microcystin concentrations. We’re working on a couple different ways to deliver this kind of information to our collaborators and partners. One is through are National Real Time Water Quality Website which is on the upper right. And that is just basically, it’s giving the probability. And so whoever is using that information can look and say, oh the probability of occurrence is 20% and make a decision for themselves on whether 20% is when they want to take action or they’re gonna wait until the probability is higher. The other is through our now casting system. And there are several sites on Lake Erie that are using this. And we’re starting to integrate some of the cyanotoxin information there as well. And these sites instead have basically a color coding approach rather than probability. It’s doing some categorization. So and these are tools that we’re working on and we’re developing. And we’re really excited about them, but we’re still learning best practices on optimal use and how these data can be used. And what are best practices. This is just an example of looking at one of the sensor data. This is the cyanobacteria pigment. And we’re looking at compared to microcystin concentrations. And we know that this doesn’t hold up, like we can’t just make one national relationship and say this is what it is. These are very site-specific relations. But this is information from one site in Lake Erie. And depending on how you parse the data you see different patterns. And so again, that’s something that we’re really working on, is what are the best practices and the best way to use these to maximize the information that we’re getting? So I’m going to talk about this is something that we’re working on that I’m really excited about. The cyanobacteria have different hyperspectral signatures. We talked a little bit after Tom’s talks about drones technology. There’s a lot that we can do with drones. But the cyanobacteria have unique hyperspectral signatures. And so you can put them under a microscope and actually generate a library of like hyperspectral fingerprints for different types of algae. And so on the upper left are two different types of cyanobacteria. One’s aphanizomenon and one is microcystis. And then in the middle is just what the hyperspectral fingerprint is. And then on the lower right is a micrograph showing that you can indeed differentiate between the microcystis and aphanizomenon based on the hyperspectral fingerprint. So that’s really cool but I think the real potential application that we’re looking at here is that you can then mount a hyperspectral camera onto some kind of aerial based platform and fly over an area. Whether it’s an individual lake, or whether it’s a region. And you can start to get a better idea and a better understanding of how much cyanobacteria are out there and what the composition is. And if you have cyanobacteria out there that aren’t known to produce toxins maybe you don’t need to pay as much attention there. Maybe you need to focus in the regions and the areas where you have potential toxin producers. So again, this is something that we are working on. And I wish I had examples to show you this. But this is something that right now we’re working on developing some of those hyperspectral libraries and looking for opportunities to test out that particular approach. The other thing that is really neat about this is that it ties together. I talked to you about genetics. And I talked about cells. And now we’re taking information and we’re moving in scale to aerial aircraft. And the last thing that I’m going to talk about today is satellites. So again, we’re using a lot of different tools to study this particular issue. USGS is collaborating with EPA, NASA, and NOAA on the CyanoBacteria Assessment Network Project. And the ultimate goal of that project is to take satellite derived information and turn it into something that’s very usable and accessible to everyone through something like a mobile application. To get information about a site of interest. And I think right now that the vision is to have some kind of mobile app that again has a kind of a stoplight system where red would indicate there’s a potential problem. The green would indicate that, there’s probably not an issue. This project is I believe in the third year of a five year study. And there’s a lot of great information products and potential applications coming out of this study. These are two different examples. On the left, it’s just a satellite scene, one from Lake Erie and then one from in Florida. And a cyanobacteria index has been used so areas where there are cooler colors, cyanobacteria abundance is low. Areas with red color cyanobacteria abundance is high. And on the left that’s just one snapshot, so at one point in time. But this kind of information could be used if we focus in on the state of Florida, it could be used to, say if you have limited monitoring resources, you could focus in on those sites where you have red instead of the cooler colors. Or you can just say well it looks like there’s lakes here that are experience some issues and maybe we need to pay more attention. The other thing once these approaches are developed, the other thing that we can do is do retrospective analysis of satellite imageries and actually start to look at the history of blooms and lakes. And a lot of places we don’t have good records of bloom events. And so on the right here, this is focusing on Florida. Again, the cooler colors are lower frequency of occurrence and the warmer colors are a higher frequency. But this is looking at across all of the satellite imagery that were available on this scale. If you’re on the warmer end or at the upper end, there is always cyanobacteria in those lakes. And so again, this is another tool that we can use to really start to ask some different questions and go back in time and look at what was happening in places where we might not have data on the ground. And so our science is really focused across three different areas. We’re continually developing field and lab methods to identify and quantify cyanobacteria and other algae that cause harmful algal bloom events. We are doing science to understand causal factors, look at occurrence, and environmental fate, and transport ecological processes and effects of environmental exposure. And we’re also working on developing early warning systems and tools for potentially harmful blooms, again so we can move from reactive management approaches to proactive management approaches. And I think one of the really exciting things about where the state of the science is right now for harmful algal bloom research is that our studies are integrated and we’re using everything from information at the cellular level to the satellite level to inform our science and inform the direction we’re going. (applause) So while I’m switching it up Paul you can come on up. We’re gonna change gears a little bit here and Paul Capel is with the USGS. He works with the National Water-Quality Program. He’s also an adjunct professor up at the University of Minnesota in their civil environmental and geoengineering. Geoengineering, we just added geo. I know I saw that, so that’s impressive. He’s been working with NAWQA Program for what? Over 20 years or so. He led in cycle two our agricultural chemical transport topical study which really focused on the hydrology of different Ag settings across the country and how that impacted transport of Ag chemicals, and nutrients, pesticides, et cetera. And we asked him in the cycle three, this current decade to head up our integrated watershed study team. And they’re really focusing on kind of three areas of advancing what we’ve done in the past. Which include looking at nutrient interaction from a surface water groundwater interaction perspective. Looking at how we can apply some of this continuous sensor data. Particularly nitrate type sensors, high-frequency data to apply to our modeling efforts. And then integrating all this information into a couple models, dynamic models of surface and ground water that can be used to develop forecast. A future water quality condition. So no easy task there that he’s taking on. But they’ve been working in a couple locations around the country. Chesapeake Bay and in in the glacial systems in the upper Midwest. And he’ll talk today mostly on the Chesapeake Bay work which we thought was relevant to this part of the world. Since most you live in Chesapeake Bay right? Exactly. Where actually watershed existed. Yep. Well thanks. As Gary said I’m gonna change the focus here. We’ll talk about the nutrient part of the elbow blooms and it’s something that’s widespread across the country including Chesapeake Bay. Both in the watershed, in the freshwater in the U.S. area. A picture a photograph of somebody from VIMS. In one of the areas in the bay. So Tom showed the same cartoon about the processes that are important to algal blooms. And there’s a chemical processes, and environmental process in hydrologic things. So the residence time of the water body, it’s interaction with the sediment. Whether the temperature, sunlight, wind, but there’s also a lot of watershed processes and these particularly are things that would move nutrients from the watershed to the water body. So that I highlighted the ones here in pink that are specific to the nutrients. It’s been suggested that the nutrients are the only real control we have over algal blooms. These hydrologic things like residence time and weather, were kind of out of our control. So if we are going to actively try to manage the blooms it’s the nutrient piece that becomes really important. At the bottom here just to again highlight the importance of the nutrients I took the kind of typical biomass for and algal itself, and you’ll see that both nitrogen and phosphorus are interval components of the algae itself, right? And so they become an integral parts of how the bloom forms and works. So I’m gonna talk mostly or all about Chesapeake Bay. One reason is that you guys, the activity here and in Chesapeake Bay has this wonderful data set. And so from a national perspective we’re taking Chesapeake Bay and kind of looking it as an example to develop models and tools based on the data that exists here that we can then take to other parts of the country. So the guinea pig for NAWQA. Part that rich dataset is due to the TMDL that was established in 2010. And essentially to put the Bay on a nutrient type, which these guys are all very well of that in the reductions are in the orders of 25% for nitrogen and phosphorus over this time period from 2009 to 2025. It’s really hard to estimate, to get numbers on what that means economically. The Chesapeake Bay Foundation suggests that if they actually fulfilled these TMDLs it would be benefited something like what was it? $22 billion annually. So it’s important both from environment perspective, but also from a economic perspective. So I like to do is kind of give some big picture of the nutrients nitrogen phosphorus in the watershed. And contributing to the bay. And then focus on a couple stories about the importance of storage in the system and how that ultimately affects our ability to control nutrients. So this is a model, this is a results from the recent Sparrow model for the Chesapeake Bay. And the y-axis here is total load delivered to the local watershed. So this is numbers without loss in the streams. And there’s two sets of graph here. One compares 1992 to 2012. So this 20 year period what’s happened to matron in the bay in terms of its sources. And then we’ll talk about the graph that’s closest to me in a second. And so the way this model works is that attributes the nitrogen to cropland pasture, developed areas. Atmospheric deposition and point sources. So if we look at these two 1992 and 2000 this 20 year period, we see that indeed there has been this reduction of nitrogen exported from the watershed to the bay. So from that perspective it’s a strong success story. But if we look a little bit closer most of that reduction has happened in point sources. Of our control of the wastewater treatment plants in certain areas, the other sources have reduced a little but not necessarily, not substantially. So kind of the big picture of nitrogen, the other way we can look at nitrogen is by how it gets to the stream. And so here I divided into three areas nitrogen contributed from groundwater pathways to the stream. Water contributed to stormwater or run off quick flow resulting from storm events or point sources. And so about 30% of the water across nitrogen from across the bay comes through this groundwater pathway. And about 15% comes through the point source pathway, and the rest comes through this stormwater. And I’ll try to draw a couple implications for that at the end. So if we put this spatially how does spatially, the numbers on the the farm that side over there. Kind of map out where the nutrients are coming from their sources. The darker color is the blue are the higher sources of nitrogen, so it’s not an even distribution across the watershed in terms of the source of nutrients. The Delmarva Peninsula and then up into the Harmony area in Pennsylvania here contribute significant amounts of the total load. One thing we’re able to do with this models look at where this reduction has taken place. And stuff in here. The red colors are increases over that 20 year period. The green colors are decreases over that 20 year period. So again we have seen this kind of uneven distribution of how the nitrogen loads have changed. And we’ll find out that a lot of these red areas here are where groundwater becomes a very important part of the picture from nitrogen and so there is this source that has been stored in the nitrogen system. We can do the same sort of thing for phosphorus. Again here the sources are agricultural sources, developed mineral sources. So natural phosphate minerals that are in system. And point sources. There is no atmospheric piece to the phosphorus. Again, we’ve seen this overall reduction to the bay over this 20 year time period. And again most of that reduction has taken place in the point sources, the upgrades of the wastewater treatment plant across the landscape. And we have a similar map where we can look at what the difference between the 20 year period is. And so again we see this uneven distribution. Greater contributions in certain parts of the watershed and improved contributions in other parts of the watershed. So I’d like to stick with phosphorus for a minute and talk a little bit about it in more detail and how we think it’s moving to the bay. And talk about one specific thing. So here’s the bay watershed and all these dots here are in the various river sampling sites that we have this historic record where we can look at what the trends are in this case from 2007 to 2016. So kind of at the beginning of the TMDL period. And then a decade in. If we look at this bar chart over here this is essentially the river sites in the Susquehanna. So I just put that out just to make a little bit to see. You can see that there are sites that are decreasing over this time period probably from a combination of implementation of best management practices and removal of agriculture, from removal plan from active agriculture. Particularly in the upper parts of New York. But it’s uneven, it varies from stream to stream through the watershed. And it’s interesting to see this part down in the lower Susquehanna here that actually has many sites that are increasing over this time period. And these first three here of this quartet are small rivers in south eastern Pennsylvania. And so these are kind of difficult areas under control. They’re actually this part is struggling to have these decreases. Well what I want to talk about here is this last one here. Which is the sampling site at the exit of Conowingo Dam. So this is a topic that has got a lot of talk I think in recent times in this area and its effect on the nutrient cycling debate. So I thought it would be worth just kind of telling the story and talking about it. And this idea of storage in the system and how that kind of impacts our ability to control the nutrients exports of the day. So the longer part of the Susquehanna starting in the Marietta, there are series of three reservoirs that were put in the 1900s. And they had lots of purposes. Hydropower or flood control, drinking water supply for Baltimore. One of the probably non-plan purposes is the sediment trapping and protection of the bay from sediment and phosphorus. And so it has then accumulated over this century period. But we’ve reached kind of a tipping point within the last few years. And so these two lines over here represent sampling at the upstream of the reservoirs in Marietta. And then downstream at the release of the series of reservoirs Conowingo. And so you can see the blue line, the concentrations are, or this is actually loads, angle loads are higher coming into the system in these early years here than lower. And so what has happened is that the sediment has lost in the water and accumulated in the bed sediment. And so this has been essentially a protection removal of a couple million tons of phosphorous each year over that time period but in recent years we’ve entered a system where there is no longer active storage of sediment and phosphorous in the reservoir systems. They’ve essentially filled up. And so we’ve reached this point where the reservoirs are either acting neutrally or actually contributing phosphorus to the system. And so we do this kind of in a cartoon fashion. In the early part of the 1990s and well before when sediment was when the water was deeper and there was less sediment. Something like about 50% of the sediment of the phosphorous was trapped in the reservoir. As we moved to the early 2000s that reduced to about 40%. And in about 2010 2012 we kind of had this crossover point where the reservoir are no longer trapping the phosphors but that’s kind of entering and releasing more or less at the same rate. So from a nutrient perspective what we’ve done is lost our really big control. And which is kind of against what the TMDL is trying to say. And so this is a controversy or not controversy, but a challenge I think, to the water quality managers. And this is not just unique for the Conowingo in Pennsylvania. There’s reservoirs all over the country that have been trapping phosphorus for decades. And so it’s going to be a new part of the piece of dealing with these nutrients in the reservoirs across the country. So let’s switch stories to nitrogen. So the same sort of map I added here the sampling sites on the eastern shore. I want to talk a little bit about them. And so you can see again there’s this kind of mixed bag in various streams of nitrogen improving or not improving. But in general nitrogen has been a more of a success story in this part of Susquehanna where there’s a lot more decreases over this time period. But we see these clustered sites on the eastern shore where we have seen increases in nitrogen. And so we want to look at this a little bit more. And here the thought is that this is due to storage of nitrogen that has been used over the last few decades in the ground load. The nitrate is much more mobile when compared to phosphorus. It moves through the subsurface, through the soil into the subsurface and can be trapped in the groundwater. And so over this time period as we’ve been putting nitrogen on the landscape, some small fraction of it has moved to the subsurface. Has now refilled up this reservoir of nitrogen in the subsurface and then as it releases the streams it provides essentially a steady underlying amount nitrogen, that moves through the system. And so we’ve done some modeling based on observations in streams, the base flow across the watershed by looking at aqua types and land uses. And have been able to develop a model to estimate what the spatial concentrations across the bay would be for the groundwater. So again, so there’s areas that have relatively high concentrations, particularly under some of the agriculture areas on the coastal plains. In the sands and in the carbonate aquifers where the water moves fairly readily. We can take these results and combine them with the Sparrow models that we looked at earlier and start estimating what percent of the annual stream load for any given area would come through the groundwater. So the good idea in terms of thinking about control and management. So the yellow colors here are about 50% of the annual load coming through groundwater. The green areas are less, the red areas are more. And so there are significant areas that have that’s high concentration and discharge flows to the streams or groundwater is an important player of the overall. So we take this kind of one more step we can start apportioning the sources of where we see nitrogen in the streams coming from. So the far one over there is a total stream load of nitrogen map. Spatially here this would be the groundwater component coming up. This is the the point source loads that we know from data collected for the EPA permitting process for wastewater treatment discharges. And so then the difference then here would be the stormwater. The quick flow, the water that runs off the landscape into the street. And so you can see again that there’s areas where ground waters are important to the overall picture and particularly on the eastern shore. So that’s why we think that we haven’t seen this decline over the last decade like we’ve seen in other parts of the bay area. So we have this ability to kind of a portion the nitrogen in the stream by both source, whether it be from an agricultural source, or an urban source, or point source. And by float path coming through overland flow through stormwater, or through groundwater, or through point sources, we can start kind of teasing out and thinking about what the implications are that for water quality management. So for this example a catchment that I show here there is about 2/3 or so of the nitrogen coming through overland storm water type processes, about 10% from point sources and about 25% or so from groundwater. And so since there’s an agricultural catchment. A lot of the nitrogen is coming ultimately from an agricultural source. So it’s interesting to think about this from a water quality management perspective is that point sources we can make big investments and have immediate effects of where the improvement in the nitrogen load. Storm water is what we’ve been really focusing on I think in the last decade or so best management practices for agricultural areas. Best management practices for urban areas and stuff. And so this is where we’ve put a lot of focus of trying to control the export of nitrogen from the watershed to the stream. The groundwater piece poses a challenge because once it’s in the groundwater we don’t really have any effective way of controlling and source to the stream. And so there we need to readjust I think our mindset about what’s able to happen under our control and then think about you know the age of the groundwater as it comes out. So this nitrogen groundwater may come out in some areas in the next few years, in other areas like on the Delmarva, it may be over the next few decades. It’s an adjustment and as we think about controlling nutrients to the bay for algal blooms there’s this limitation that the groundwater imposes on us. So one of the things we’re trying to do is think ahead. So with the time scale can we start thinking about what would be the loads of nitrogen going to the bay given different types of future scenarios? And these future scenarios might be things like changes in land use and climate as to their deposition. Which are kind of regional changes out of the control of local water quality managers. And then things like agricultural management, and urban management, and control of point sources. So there’s been a lot of work on climate and land use in terms of what the future projections are. This is from a USGS colleague future land use projections around Washington. The gray areas are the existing development and the red is what would be new by 2050 given a certain growth projection. And so we can start taking this sort of information and thinking about the future. And ultimately what we want to do is a map like this to be able to say given this future what would be the change in loads from say 2010 to 2050? To help people plan for water quality needs for the bay, for the future. So this is an area that we’re actively working on right now. One of the things that we got into in the process of doing this is to ask the question given land use changes, given changes that are likely to take place that is changes in land use or our decisions to implement best management practices compared to the way how important are they going to be to this overall change? That is an implementation of a BMP on agricultural land equivalent to a land use change also in the bay. So this is why we’re kind of doing this. Here the graph on the side here is change in nitrogen yield to the stream. So they monitored nitrogen yield. This is a zero bar, below that would be decreases in nitrogen above the bar. The horizontal bar would be increases. And so we played out, I think there’s 16 different kind of changes that are probably expected in different places across the Bay watershed or across the country. Things like agricultural land being converted to CRP or undeveloped land, agricultural land being converted to urban landscape. Which is a big process that’s going on here. And so those are actually very positive changes in terms of decreasing the load, of doing urbanization as a best management practice for nitrogen control. We lose agricultural land to urban, it’s actually a good thing, likely a good thing in terms of the nitrogen contribution. On the other hand the big things that are off the graph here are conversion of undeveloped land to developed land. Either urban or agricultural. So these are the things that have the potential to work against us most in terms of controlling nutrients in the system. And interesting, a lot of the things kind of in the middle that are pretty neutral are things that we’ve been focusing a lot on. Particularly the implementation of best management practices in urban and agriculture areas. They’re important. They decrease it, but relative to the importance of things like land use change. They may not be that effective. So that kind of bringing back to the algal blooms and then thinking about nitrogen is really the knob that we have to control nitrogen. And that the nutrients are intimately linked to the algal blooms. And we can go back to the discussion for the morning with the algal blooms. Thanks. Thanks Paul. (applause)

Cesar Sullivan

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