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HomeMy WebLinkAbout11.17.23 SAC Meeting Minutes1 NC Nutrient Criteria Development Plan – Scien�fic Advisory Council (SAC) November 17, 2023 Attendees SAC members in atendance: Hans Paerl (SAC co-chair) Jud Kenworthy (SAC co-chair) Michael O’Driscoll Jim Bowen Marcelo Ardon Wilson Laney Fritz Rohde Lauren Peter Guests in atendance: Anne Coan Nathan Hall Paul Cough Andy McDaniel Cli�on Bell Doug Durbin Courney DiVitorio Astrid Schnetzer Joel Hansel Jamal Cooper NCDEQ staff in atendance: Karen Higgins Paul Wojoski Cam McNut Elizabeth Liebig Elizabeth Koun�s Anne Deaton Charlie Deaton Tim Ellis Daniel Wiltsie Mark Vander Borgh Elizabeth Fensin Pam Behm Forest Sheperd SAC mee�ng facilitator: Paul Wojoski Meeting notes ***All ques�ons, comments and answers are paraphrased*** 1. Convene Introduc�ons by each atendee Each atendee provided an introduc�on, and eight of the 10 appointed SAC members were present. Approve minutes from 7/14/23 and 9/29/23 Elizabeth Liebig: In the July mee�ng minutes on page 7, there was a reference that Jesse Jarvis made about the Hensel paper, and we needed clarifica�on that Hensel was the right author. On the same topic, there was a paper that we believe was authored by Lechet? Jud Kenworthy: I can't recall the Hensel paper. Can we s�ll approve the minutes and then get the clarifica�on later? Wilson Laney: I would just move that we approve them both subject to that qualifier. 2 Tim Ellis: That Hensel paper, at least the recent one, was the ar�cle about replacing eel grass in Chesapeake Bay? Jud Kenworthy: Yes. Do you want me to dig that up right now? Elizabeth Liebig: No, if that is the right reference, then we can just note it in the minutes. Wilson Laney: Several of us have it. Do we need to send it out to everybody? Paul Wojoski: Yes. If there are no other objec�ons or concerns with the minutes as they are writen, they can be approved, subject to confirming those noted paper authors. We'll have the mee�ng minutes from the July and September mee�ngs approved subject to the paper references being double checked and corrected if need be. A quick note to remind the SAC where we are in the process: we've produced a clarity standard and we're now reviewing the assessment methodology for that standard. A�er that is concluded, the SAC focus is to be on harmful algal blooms and cyanotoxins, a topic for focus over the next two mee�ngs through January and March of 2024. 2. Clarity assessment parameters and Water Quality Standards (WQS) approach, discussion, consensus vote (for approach, see presenta�on provided by Cam McNut en�tled “Clarity Monitoring, Assessment and Restora�on”) Discussion: Jud Kenworthy: It's not the meter that's taking the measurements, it's the sensor. The meter is just the device that stores the data, so the language should reference an approved sensor. Hans Paerl: Or what about an approved method? Because if we're using say, a Secchi disk. I agree with Jud that it should be changed away from a meter because meters report whatever is being sensed. Cam McNut: We are incorpora�ng these into an SOP, so we'll have more language in here. These are the points to cover, and I don't know much about these collec�on devices, so someone else would write the specifica�ons that are needed to collect the data for Tier 3 purposes. Also, I was considering Secchi data to be Tier 2 data but that's another discussion for us and might be associated with using the collec�on instruments and Secchi data together or looking at the rela�onship between those two over the course of the next year or so. Hans Paerl: Instead of using “collected,” maybe we could use “determined” and that will get us around any method that's approved. Do we need to have the word “collected” in there? Cam McNut: Not necessarily. Hans Paerl: So, if we said, “ex�nc�on coefficients shall be determined using an approved method or measurement.” Jud Kenworthy: At what point are we going to determine or come to agreement on the method? That would be important at this point, but this is the first �me I've been involved in this type of process. Cam McNut: The collec�on methods for right now are so that we can get people in the field star�ng to collect data that we can use to assess clarity at least for dra� purposes, but we won't need to finalize this un�l a�er the standard is finalized. Consider this as a working collec�on method because right now a lot of the clarity data are being collected in mid-channel and with various types of different instruments. So, 3 we want to standardize it as much as possible so that we can buy the gear that we would need to do this and then start ge�ng some sampling loca�ons lined up. Nathan Hall: At some point, there probably should be, and this could be in the more detailed document, specifica�on of the wavelengths that are being measured by the sensor so that we make sure that we're covering PAR and not wavelengths that aren't as relevant, and also a descrip�on of exactly how the profiles of power are going to be done so that we're collec�ng either having two instruments so that you can have one measuring the incident light and then you lower one down to account for the changes in cloud cover or something that might happen during the measurement, or a minimum number of depths that are measured, and a threshold for the strength of the regression. It’s a quality control thing, but it's going to be important because PAR profiles can get screwed up when you're measuring with clouds coming over. So, at some point those kinds of nity grity details probably need to be worked out. Hans Paerl: So how would you change the wording for #1 (on slide #4)? Nathan Hall: Maybe the word “method.” And maybe “ex�nc�on coefficients we measured by making PAR profile measurements using an approved sensor.” Hans Paerl: What about Secchi readings? Nathan Hall: When I read this ex�nc�on coefficient, that eliminated me thinking about Secchi disk altogether because you don't measure ex�nc�on coefficients with Secchi disks. Hans Paerl: People have historically made ex�nc�on coefficient measurements using a Secchi reading, right? Using different Secchi readings at different depths. Nathan Hall: If you measure a bunch of ex�nc�on coefficients and measure a bunch of Secchi disks, you can develop empirical models that are related and they work with varying degrees of success, depending on where you're at, but you don't get an ex�nc�on coefficient out of a Secchi depth measurement. Cam Mcnut: Secchi data would be considered Tier 2 data that we could use for effec�veness monitoring and to priori�ze sites to use the sensors on, but for regulatory purposes, we're probably going to need to measure ex�nc�on coefficients so that we can compare that to the standard, so using a sensor that's for that. Marcelo Ardon: What exactly are we doing right now because it sounds like this isn't the actual methods; Cam said these were the main points, and it sounds like there's a lot of detail that needs to go into the actual methods, but that's not covered in the slides. Cam McNut: These were the points that going through notes and talking to other people that we needed to discuss, but mostly where to monitor and how much to make an assessment. In a QAPP or SOP, there would be more detail and specifica�ons on the sensors and what depth to measure, but we were mostly trying to figure out through this process of where to measure in rela�on to the SAV that is there or has been mapped in the past and then how many data collec�ons do we need to make the assessment. I'm assuming that there's going be a manual that goes with the sensor and that you will follow how the manual says that you will measure PAR. Marcelo Ardon: Does that mean what you want feedback on is #3 because that's the one you have a ques�on mark for (on slide #4)? Does it make sense trying to talk about the wording of #1 if it’s clear that it’s going to need more detail? 4 Cam McNut: The biggest thing that we were trying to determine is spa�ally where to monitor because right now we have a lot of ex�nc�on coefficient data that's in mid-channel and it's not that close to the SAV areas. For regulatory decision making, tradi�onally we've required that the monitoring data be inside of the waters of interest, and in this case that would be inside or very close to the SAV areas. I threw 5 meters out there because I was imagining how close a boat could get to this, and then how deep the water is and there'd be a lot of metadata that would be collected with each sample, just like there is with when you're s�cking a botle in the water. Paul Wojoski: We're looking for scien�fic support for our approach with �er three data in the regulatory process. This will have to go through in the standard development process. We'll have to go through the Environmental Management Commission’s review and approval. The purpose here is to try to gain scien�fic consensus on what makes sense. How close to the edge of the SAV is close enough? How many months? These are the red factors that Cam has highlighted in the slide here. If you want to expand on that, maybe you can help clarify a bit more too. Cam McNut: The �er three data are the data that we need to incorporate into our quality assurance plan and SOP so that our staff or others can do the monitoring and follow those instruc�ons. The details of the depth profile we can put into that methodology as well, top or botom, five different depths, etc. The instrumenta�on that we're using I'm assuming is going to have some instruc�ons with it that we can adopt by reference or put in a specifica�on for the type of instrument that needs to be used in the wavelength it’s collected, etc., all stuff I'm not familiar with. So again, this is not something that's going to be finalized. Hopefully we'll be able to use this to sharpen up an SOP document as we're collec�ng data. If we get out there and we determine that 5 meters is either not close enough or it's too close, then we'll s�ll have plenty of opportuni�es to change that. The EMC will not actually approve the QAPP for �er three data collec�on. That will be done by DEQ staff. The EMC will approve the assessment methods that we use to take the data and compare it to the water quality standard. Hans Paerl: For #1 (on slide #4) then, maybe we should just keep it very general because there is going to be more specific descrip�on of it. So, something like “ex�nc�on coefficient shall be determined using an approved method?” Cam McNut: Right. If we can put that approved method in and specifica�ons for the instrument that's used, then we can do that as well. And we might just be able to use what Nathan already has as an SOP for collec�ng the data right now. Jud Kenworthy: Regarding #2 (on slide #4): It's not necessary to state the deep edge because in many cases the mapped or historical distribu�ons did not have depth associated with them. We just don't have that informa�on. The important thing is it's within a certain distance from SAV, as indicated here, either as mapped as SAV or historical extent. Cam McNut: It's easy to es�mate that distance if you have SAV in your line of sight, but in the historical areas it would be an es�mate. For the mapping that we have right now, I don't know what the accuracy was on that, but my understanding is a lot of it was the SAV areas or the historic SAV areas delineated from imagery. So, specifying a deep edge and historic areas is probably not really a possibility. Jud Kenworthy: Right. We have good maps for the high salinity SAV, but we don't have good maps for the low salinity SAV. The maps’ spa�al ar�cula�on is in that historical extent layer that DMF has produced. 5 Cam Mcnut: That's what I'm using right now to do these es�mates from and look at sampling loca�ons. Anne Deaton: Wouldn't this be done by using the historic SAV layer in the office and come up with your points in advance? You're not going out trying to get to a certain point, so you have your points that you're going to go to perhaps within 5 meters. Cam McNut: That's what I was going to do is use the map and get sampling points that are X meters off the mapped water bound edge, maybe not deep edge, and then so if you’re in a boat you could at least get close to that site. Anne Deaton: That makes it a lot easier, and I agree that the deep edge wording may not be necessary because you don’t know where shoals were at a certain �me, but we do know the grass was there. Conserva�ve. Cam McNut: How about “data collected within 5 meters of the mapped SAV both exis�ng and historical map that we already have.” We could put that map up on a public facing site also. Jud Kenworthy: The high salinity SAV is already posted on a public site that Tim Ellis is responsible for. Cam McNut: So “5 meters from the mapped SAV?” “Within 5 meters of the mapped SAV?” And then we'll capture that actual distance or the actual distance when there's SAV present. Anne Deaton: Unless it was in there to get to the point of you don't want to go way in and you don't want to take your measurement from near the shore or the middle. You want it to be as close to the outside edges as possible. Cam McNut: That was the thinking. Anne Deaton: I’ve got it: “outer edge.” Cam Mcnut: The “outer edge as mapped.” Anne Deaton: Maybe. Lauren Peter: Those were some helpful clarifica�ons because I was curious about where the SAV is not currently present but within the map area. So that's good to know that it's a pre-sampling exercise to look at that map, figure about where that would be and then you have the addi�onal metadata to discuss what happened. And avoiding the shore and avoiding running into the seagrass, damaging it while sampling. So, the ques�on I had le� is regarding 5 meters: does that sound like a reasonable distance? As far as it is concerned, I don't know if that's just the scale of the resolu�on. Are there any other scien�fic considera�ons for distance to make sure you're sampling where that clarity needs to be tested? Jud Kenworthy: It gets a litle dicey as we know that SAV has a direct effect on the water and that includes having an effect on the resuspension of sediments, and the trapping of sediments; the plants can affect the water clarity, so taking into considera�on this historical extent layer when there may not be SAV there now. We know they’re not in a lot of places as of our last rapid assessment survey. So, everyone will have to realize if we're not taking the measurements within the SAV meadow, it's outside of the direct influence of the plant canopy and the physical aspects of the meadow that affect the water 6 quality so that's what we're standardizing here. If we take it outside of the meadow and within or no greater than 5 meters away from it, that needs to be understood. Lauren Peter: And which place is more important if you're trying to ensure that level is met. Does it need to be what is over it but confounded maybe by some of the processing or is it beter to have it outside so it's the adjacent water that could be impac�ng it? Jud Kenworthy: What is your perspec�ve on applying the standard, is this water source affec�ng the meadows or is it the meadows affec�ng the water overlying it? So as long as we standardize it to that posi�on without the actual influence of the SAV in all the sampling sta�ons, that's the mechanis�c defini�on of what we're applying the standard to. Cam McNut: So maybe we should specify “not within, but at, approximately 5 meters?” Jud Kenworthy: Or “no further than 5 meters” because if we use the historical extent layer as a reference to cite the sta�ons, we know that a lot of that historical extent is gone. So, if we specify in #2 (on slide #4) that it must be within 5 meters of the deep edge of SAV area, some of the places there's going to be SAV and some there isn't, especially if we use that historical extent layer. Cam McNut: If we do that as mapped, then that would not have to be done when you're on the water. You would go to that point that has been predetermined based on the historic mapping. Jud Kenworthy: It should be noted whether SAV is there or not. Cam McNut: That's part of the metadata I would say is to visually confirm presence/absence or some other data collec�on method. Jud Kenworthy: And the other thing is that we know, for example in Albemarle Sound, there's been a significant decline in SAV, and where do we want to apply the standard to get that improvement, so we can get it back? Is it �ed to water where there is SAV right now? It's sort of like the chicken or the egg; which came first? But if we're trying to restore SAV, we don't want to necessarily take measurements in a SAV meadow where the SAV is influencing the water column. We want to apply that standard to a water column that we'd like to see SAV restored to. Lauren Peter: So based on that, you have the map on the computer before you go sampling, and so at the edge of the map, wherever that is on different places, there would be a 5-meter buffer from that edge on the map that sampling could occur. Jud Kenworthy: Right. And it should be noted whether SAV is there because it's quite possible that SAV is recovering in some areas so that must be accounted for. Lauren Peter: So, does everyone feel good about the 5 meters outside that map edge with documen�ng whether it ended up being present in that zone or not? Laney Wilson: I like Jud's use of the term “source water” to dis�nguish the water column area outside of the SAV meadow because that's the target as he noted. You want water clarity high enough for the SAV to either be sustainable if it's there already or to reestablish if it's not there. So, using that term “source water” makes it clearer and avoids the issues that would be associated with measuring water clarity within the meadow because then when you do that, you introduce other variables, possibly by disturbing the bed trying to get into the middle of it or disturbing it with instrumenta�on. So, should it 7 be 3 meters or 5 meters because whether the water adjacent to the bed is “source water” depends on all sorts of things, which way the wind is blowing, how fast the currents are moving, etc. If you try to collect the metadata associated with those sorts of variables, then you greatly increase the complica�on of it, and you'll spend more �me logis�cally in the field trying to measure all those things that could be affec�ng the measurement that you're taking. Maybe we leave it at five or do we want “three to five” or “five to ten?” Five is a good compromise probably. Lauren Peter: Cam - is there a numeric limita�on on the mapping that you have of what the resolu�on can even be? Cam McNut: The SAV mapping, since it was digi�zed over the old imagery, the historical mapping, I don't know what the accuracy of that might be, but as far as if we use GIS, then we can pick a point that's within 5 meters, plus or minus a meter, we can put a buffer on that and then the boat ge�ng to that point and being able to take the sample within that point is another introduc�on, so we don't need to specify exactly 5 meters, but have an es�mate of where that is; we don't want them to be 45 meters out and yet we don't want them to be in the bed so 5 meters seems like something a boat could handle. Lauren Peter: Regarding marking if SAV present at the same point as a clarity measurement: does that invalidate it or is that just observa�onal informa�on because maybe it is expanding? I was curious if that was going to discount the result because the SAV was present. Cam McNut: We're depending on what we come up with for #5 (on slide #4). There's going to be variability, you might have some that where the ex�nc�on coefficient is higher than the standard and some�mes when it's not and that may be due to many things; that's why in our regular assessment methods we allow 10% of the samples to exceed the numeric standard before we start trying to decide on that. And since this is a median that we'll be using, the median is going to allow for excursions, and it's going to allow for some to be lower that may the next day be higher. But making a decision off one sample in one place, it can be done. We've done that before. Lauren Peter: I was asking if that was a concern, I wasn't going so far as to make it an assessment call on the one site, but if we're going with this five plus or minus one distance to ballpark where the sampling should be done, but then Jud men�oned that no�ng on the form that SAV was present but part of why we did that five plus or minus one was to get away from the bed. I just was curious since it could be a posi�ve thing that it was appearing further out. Cam McNut: They could capture that in the metadata that SAV was present within 3 meters of the specified loca�on, so we moved out to five because there's SAV there. You just can't do that when there's no SAV there. You'll just have that one point. Lauren Peter: That all makes sense. Charlie Deaton: About excluding SAV, like not being able to sample within an SAV bed: We've been coun�ng on being able to reuse many DMF current sampling sta�ons and Cam I sent you those maps. If we are not able to sample within those, within SAV that's been mapped, then that'll cut the sampling sta�ons we can use from about 100 down to maybe 5-6 sta�ons across the state. We need to do the right thing in terms of what's going to be most accurate for sampling within versus right next to the beds, but I wanted to register that if we can't sample within the beds, that'll reduce the role DMF will be able to help with this effort. 8 Cam McNut: That's something that we need to know when we're going through the next step in the analyses is we can monitor X number of sta�ons based on this specifica�on using exis�ng monitoring resources and then we'll have to explore. It depends on how much monitoring we want to get done or need to get done. So, it may cost more to stand up a program to do thorough, widespread monitoring of a clarity standard associated with SAV and that's something that we need to know. We've been trying to do it with the exis�ng resources like when we introduce a new water quality standard, i.e., dissolved metals, we didn't have to stand up any new sta�ons, they were already there, and they were already driving there. They just had to get different botles, so this is different than adding a parameter to an exis�ng monitoring sta�on. Jud Kenworthy: Regarding #3 (on slide #4), that's a good common-sense decision to keep the sensor. Again, I wouldn't call it a meter, I'd call it a sensor because the meter is just the device that stores the informa�on that is sent to it by the actual sensor. Keeping the instrument off the botom is important. The issue that needs to be considered again goes to the detail of the method. Depending on how we decide that the ex�nc�on coefficient is going to be collected, for example, if it's collected with a profiling method, you need so many points in a profile to be able to calculate the ex�nc�on coefficient. So, water depth becomes important because if you specify it must be half a meter off the botom, then you must think about how much water column you have to profile. And that's going to depend on how that method is prosecuted so we have that half a meter off the botom, that's a good idea, but it'll only work if we know what our profiling method is and how many points we're going to take and if that's what we're going to do, or that's what we're going to recommend. Cam McNut: So, #3 (on slide #4) will depend on how we do #1 (on slide #4) basically. Jud Kenworthy: Yes, the method that's selected for #1 (on slide #4). Cam McNut: If you’re in shallow water, then 0.5 meters off the botom might be most of the water column. Jud Kenworthy: It could be. That's another issue you get in the high salinity SAV areas where you must deal with �de. There could be 1 1/2 to 2 meters of water on high �de and 1/2 meter on low �de. So that raises a logis�cal problem there. For the low salinity areas that are not so much �dally driven, the water column path is fixed except for the wind �des that change it. Cam McNut: So, it sounds like there can be a lot of variability and many that impact the clarity measurements, ex�nc�on coefficient measurements, so for #5 (on slide #4), is 3 months out of the growing season sufficient to get a median that we can compare to the standard? Jud Kenworthy: If we're talking about a growing season, that's six months long and you have this three- month constraint. You could be at one end of the growing season or the other. Cam McNut: I was looking at a minimum of three of the months during the growing season and they could be back-to-back, or we could specify that you need to have one at the beginning, one in the middle, one at the end, or you need to have one in all the eight months of the growing season. Jud Kenworthy: When we were thinking about these measurements in the growing season from the scien�fic perspec�ve, we were thinking that measurements would be acquired throughout the growing season as opposed to packaging them into a subset. 9 Hans Paerl: I agree with Jud. What would we do if we had a major storm or hurricane, for example, during that three-month period or outside of that three-month period? Cam McNut: They wouldn't have to be consecu�ve months. I'm talking about having three ex�nc�on coefficients to calculate a median. They could be March 1st and October 31st. Hans Paerl: I understand that, but you could s�ll hit one of those hurricanes within three months. Cam McNut: I would say we would avoid those. Hans Paerl: May have to put a qualifier in there. Cam McNut: If you monitor every month, you’re going to be monitoring some point either shortly before or a�er a tropical event. That's probably a given. Hans Paerl: If this is �ed in with the ambient monitoring programs that we have, those are monthly anyway, right? Cam McNut: They are monthly. Hans Paerl: So, what we're talking about six months. It would be an effort difference between three and six months, but I would favor doing it in concert with the ambient monitoring program. Cam McNut: So monthly during the growing season. Hans Paerl: Yes. Wilson Laney: Back to the half a meter off the botom issue: Hans and Jud - regarding the comments about where that half meter point might occur rela�ve to �des and in those areas which are subject to strong lunar �des, but also in areas for the low salinity, the depth is going to vary, and you do need mul�ple points to generate that profile. So, would it be beter here to specify a percentage of the depth as opposed to an actual measurement for half a meter? If you're in 1/2 a meter of water, then you could say that the instrument should be at least 20% of the depth off the botom? Would that be a beter way to do it because that would fit any depth. Cam McNut: Or we could just specify to not disturb the botom with the instrument. Hans Paerl: There are other issues, and one is there's a lot happening within 0.5 meters of the botom, par�cularly if you get into a place like Pamlico Sound, where you got this nepheloid layer that's si�ng above the botom. I thought that was one of the reasons why that 0.5 meter was put in there. Nathan Hall: You do see that talked about in the seagrass literature quite a bit. If you see people talking about that increase in atenua�on, that happens right near the botom. Hans Paerl: Yes. So, above the botom at some defined depth, maybe it could be 0.5 meters, then in the case of shallow water come up with something like Wilson sugges�ons. Jud Kenworthy: This goes back to the method for #1 (on slide #4). If we were to setle on a method to profile, what sensors we'd use and how many points would be collected, and a profile and what the distance between those points should or would be to a certain extent. That would govern the depth of the water that the profiles would be obtained. Number one and three (on slide #4) are coupled, but you 10 can't make a decision un�l you decide what your actual method is going to be. So, Nathan, what do you think the minimum number of points in a profile should be to get an ex�nc�on coefficient? Nathan Hall: 5. That's a gut feeling but you start ge�ng sta�s�cal confidence in a slope when you have five data points. Jud Kenworthy: So, the next ques�on would be is how you know mechanically what's the minimum distance between those points that you could be confident that you're hi�ng, like 20 cen�meters or 40 cen�meters. Those things come into play. Nathan Hall: It's hard in a bouncing boat to feel confident. That's why I said if you're going to use the profile method, then you also must have a measure of how good that regression is. And you’ve got to toss data if you can't fit a linear regression to your data that you're confident in, and you can't calculate the ex�nc�on coefficient, so it's hard. In Lake Matamuskeet I'm doing 5-cen�meter depth profiles. Jud Kenworthy: That's good if you can do 5 and feel good about it. Nathan Hall: In some areas I do. Where it's not moving, it's easy. But there you've only got water that deep; you’ve got a foot and a half of water, and you can't do half meter depth intervals. Jud Kenworthy: So, we went backwards and got on #5 (in slide #4) for a minute but we didn't come to a resolu�on on #5. Cam McNut: I heard monthly during the growing season. Jud Kenworthy and Hans Paerl: Yes. Wilson Laney: So, the depth varies. Nathan - You said you need at least five points, so do you space those equidistantly from top to botom? Do they have to be spread out a certain amount, or do you just need five points from any loca�on within a given depth? Nathan Hall: You're working on a linear regression. Say you want to get as much of the depth as you can because that spreads out your X axis. Your goal is to span the water column from as close to the surface as you can keep the sensor in the water down to a depth that's not as deep as the instrument botoms out; the instruments always botom out at some low number, so you must know where that's at too, so you're not collec�ng a bunch of useless data. Jud Kenworthy: So, what would you think would be the ideal separa�on and the profile for each point? Nathan Hall: If two sensors could be purchased and you could mount them so they're measuring simultaneously, that would probably be the easiest way and not do the depth profile method. Space to half a meter apart and run it for a minute, take an average of the two different depths and… Jud Kenworthy: That's a method that's used frequently. The nice aspect about that is both sensors are being exposed to the varia�on in the cloud cover. Even though there's litle quirks that go on, with diffuse light and incident light due to cloud cover with two sensors fixed on a pole a distance apart, both are experiencing that fluctua�on at the same �me whereas if you're profiling, like Nathan said earlier, to make those correc�ons, you have to have a deck sensor, because if you're profiling and it takes you 5 minutes to do a profile and a cloud comes over halfway through there, you need to make that correc�on 11 with the deck cell. So, you don't have that problem with the sensors unlike on a fixed pole arrangement like Nathan just said. Marcelo Ardon: Aren't there standard methods on how to measure these things, or alterna�vely places like Chesapeake Bay: Haven’t they developed methods to assess these things that we could inves�gate? Jud Kenworthy: The two methods we just talked about, the profile and the fixed posi�on of two sensors, are the most common methods that are used working with PAR sensors. Marcelo Ardon: So, it would make sense to use whatever the standard methods are or whatever's been used in other places for these kinds of assessments. Jud Kenworthy: The next ques�on is what's most prac�cal for the field team to use, and as Nathan just pointed out, it's almost more prac�cal to use the sensors fixed distance apart on a pole. Hans Paerl: Nathan, wouldn't that be a problem poten�ally if you had like a chlorophyll maximum or some layer that either would or would not catch with that arrangement? Nathan Hall: There's no more problem than it is with the depth profile, because if you have differences in the atenua�on over depth, it's going to screw up the rela�onship between depth and the PAR atenua�on in the profile, too. Hans Paerl: I agree with Jud. If we use the same approach as what's being used in Chesapeake Bay, I'm sure they've done much thinking about that and they have very shallow areas, too. Consensus (for items #1 - #5 on slide #4): • The sense of depth should follow the approved method in #1, whether that be a profile method or a fixed posi�on method. • For #1: The SAC modifica�on is that the ex�nc�on coefficient shall be determined using approved sensors and methods. • For #2: Data will be collected within the historical SAV and no further than 5 meters of the outer edge of the present SAV. SAV presence or absence and distance of sample loca�ons from the present SAV will be noted during data collec�on. • For #3: o The sensor depth should follow the approved method in #1 whether that's a profile method or a fixed posi�on method. o Where possible the instrument should be no closer than ½ meter from the botom. (Jud Kenworthy suggested this language, and Hans Paerl noted the shallowness of the involved waters as the poten�al need for a qualifier.) • For #5: o Data shall be collected monthly throughout the growing season. (Cam McNut said that this is what would be used to do the �er three data assessment for 303(d) purposes, data collected in this way, but noted if we say data should be collected monthly, but what if it's not? Does that discount using that season’s median for...? Hans Paerl 12 responded by saying you could put in a qualifier like weather dependent or depending on any issues with the ambient monitoring program.) o A minimum of three different months during the growing season, one with one sample being in the first two months, one in the middle two months, and one in the last two months if monthly data can't be collected. (Jud Kenworthy said that's a condi�onal statement and Hans Paerl agreed. Jud Kenworthy added that if that's a condi�onal statement, he'd be ok with it but felt whatever it takes to encourage the monthly collec�on and not minimize the “must be” would be appropriate. He also didn’t know how delicate this language had to be when the standard is writen and Cam McNut stated that this won't be in the standard, so can be changed whenever we want it to change, which Jud Kenworthy and Hans Paerl were okay with. Lastly, Lauren Peter stated that the standard s�ll had the annual growing season median, so it would need to be clear that whatever data is there would be calculated, and Hans Paerl agreed.) Paul Wojoski: To help guide this next discussion on algal issues, ques�ons for SAC resolu�on are at the botom of the agenda, and these are ques�ons to try to get the SAC thinking about the informa�on that we need feedback on to help address this issue. 3. U�lizing satellite imaging technology to visualize algal blooms (see presenta�on provided by Mark Vander Borgh en�tled “U�lizing Satellite Imaging Technologies to Visualize Algal Blooms”) Discussion: Courtney DiVitorio: Satellite imaging is really underu�lized. I just came from a conference, but it's been put into prac�ce opera�onally within the ocean science community since the 70s. And we're just now ge�ng the satellites to really improve the technology over inland water bodies so it's just a mater of �me before it becomes more opera�onal in lakes and it's not meant to replace any ins�tute data, but augment it, it shows paterns in space and in �me. There's a ton of poten�al opportuni�es to look at what you men�oned like hot spots. It might not give you exact concentra�ons with high confidence, but it can be used to help target monitoring and manage things in a more adap�ve way than simply just collec�ng data for regula�on. There’s just a lot of poten�al beyond regula�on that this can be useful for. Mark Vander Borgh: They're talking about transparency and clarity, and this is another tool that can augment what they're trying to do with the PAR meters and possibly help on some of those areas, too. Hans Paerl: I agree with what both of you are saying for use in a monitoring context. One thing to remember is that the satellites basically only see what's at the surface, and we know that there are blooms that are not surface blooms. For example… Nathan Hall: Dinoflagellate blooms. Hans Paerl: Yes. And some of the cyanos that are not buoyant. Nathan Hall: Like cylindrospermopsin? 13 Hans Paerl: Yes. We know cylindro blooms can bloom extensively in places like Currituck and other areas in the South, so we need to be aware of that. And equa�ng toxicity with biomass is tricky and no one has resolved this well. We have some data sets from places like Lake Erie and the lake I've worked on in China, Taihu, that shows a rela�onship, but the scater is very large, and it depends on seasonality and other factors, the amount of nitrogen that is available and who knows what else. So those are just two things I wanted to s�ck out there just in case we thought all our problems were solved here. Biomass wise, you’re spot on and those guys are doing a really good job there, but we s�ll have this lingering issue with toxicity. Unfortunately, that will just require a lot of monitoring to see what the scater is going to be for places like Albemarle Sound and the Chowan. Mark Vander Borgh: And that's why this imagery is so important is to show, to try to get the funding to when you're pu�ng in the proposals that you all work on. We’re just looking at microcys�n. All the other toxins they’re coming up with, trying to get assessments. If we try to get beter toxic tes�ng capabili�es at DWR, we're going to need to show that there's a need and that's a whole basis, is just being able to visualize and document and that's why I really appreciate the help of the EPA doing that because it makes our job easier and beter. Hans Paerl: Yes. The one good thing is that microcys�n is on EPA's hit list, so that is a plus. Some of those others are not and may be problema�c, like cylindrospermopsin and anatoxins. But let's go with at least what the agencies and we are concerned about at this point and microcys�n is the obvious target to begin with. Mark Vander Borgh: Looking at what other states are crea�ng, microcys�n standards and water quality standards for algal toxins, that could be something that the NCDP works on as you approach this. Hans Paerl: Yes. Wilson Laney: I would like to have a copy of the report. Mark Vander Borgh: I'll get them to Libby. Wilson Laney: Mark noted that there is a rela�onship between the clarity and the algal blooms, but from our previous conversa�on that isn't a subs�tute as far as being able to assess clarity with respect to SAV sustainability, and as Hans pointed out, what the satellites are looking at is the surface and you got to have that profile in order to assess the clarity for the SAV. But it certainly, as you noted, seems like it's a very important addi�onal source of informa�on and if we have enough data collected from the field on the ground in associa�on with the satellite data, it can go a long way toward clarifying our understanding of what is going on in these complicated systems. Hans Paerl: And it will allow a lot more targe�ng. Mike O'Driscoll: Along the lines of what Wilson was saying, I’ve seen work where they've used a mineral sediment related turbidity looking at sediment plumes and was curious if there's the possibility with the water clarity work to tease out the more organic related changes in water clarity versus mineral sediment using some of the satellite approach. Mark Vander Borgh: I don't know. Hans Paerl: The colored organic mater, too. 14 Courtney Di Vitorio: You can also map CDOM and suspended solids with satellite. I saw some work. There's a post doc that just started working with Blake Shaeffer, David, and he's working on using the satellite-based informa�on to also inform process-based models and there's some model they have for SAV. So, he was doing some mapping there. And there's other work being done in that space, but there's also opportunity to combine it with process-based models to help drive them and then simulate what happens. Suspended solids, color dissolved organic mater, and chlorophyll are the three things that are op�cally ac�ve that you can decompose and then use CDOM as a proxy for other things if you wanted, like DO. There are people who have used it for that. Paul Wojoski: We want the SAC to consider the next speaker’s informa�on regarding EPA’s 2019 Cyanotoxin Recommended Criteria Guidance regarding the ques�ons that we placed at the end of the agenda; what are the appropriate considera�ons for criteria in North Carolina? And again, our effort here with the NCDP is to protect the designated uses of these water bodies, one being recrea�on, so swimming in these water bodies, we want to make sure that we have protec�ons in place that allow those uses to be protected and restored going forward. 4. EPA’s 2019 Cyanotoxin Recommended Criteria Guidance (see presenta�on given by Joel Hansel en�tled “EPA’s 2019 Cyanotoxin Recommended Criteria Guidance) 5. Guided discussion of algal blooms and cyanotoxins (Jud Kenworthy and Hans Paerl) Hans Paerl: Joel men�oned that this is really the �p of the iceberg. And I remember one of my graduate students working on cyanotoxins and saying there’s probably 1000 for every one that we know about. So, you have to do them one at a �me. Microcys�n is certainly the top one from a regulatory perspec�ve, it makes sense to give that one a high priority and we know a lot about its effects on organisms so it's a problem. If folks are interested, Libby, I’ll send you a couple of papers that show the variability in the rela�onship between biomass as chlorophyll and toxicity in western Lake Erie and in Lake Tiger, and the nice thing about that data is biomass was prety much dominated by cyanobacteria so you can use chlorophyll a as the biomass indicator. Astrid Schnetzer: From the work that we've done in the Chowan we do see that chlorophyll does not necessarily match with cyanotoxins. We've seen hundreds of micrograms of chlorophyll and no toxin and then some�mes a very high amount of microcys�n, over 1000 micrograms per liter, in one instance. One of my students is now publishing this stuff and I would love to send everybody some of these papers, too, which are specifically for the Albemarle. We do monitor microcys�n in up to 15 different species of fish south of Edenton. We find it in liver, guts, and muscle �ssue, and not o�en in the fillet, but in high concentra�ons in the other parts of the fish that goes and some�mes exceeds the total daily intake rate. We have a community grant where we look at juvenile fish and work with local fishermen to look at cyanotoxin concentra�ons throughout the Albemarle. We'll keep you informed and might come by to give a quick update on what those levels are. I agree with Hans that microcys�n needs to be on the forefront of everybody's mind. Wilson Laney: What species of fish have you looked at thus far? 15 Astrid Schnetzer: Several river herring species, blue ca�ish, channel ca�ish, white ca�ish, blue crab, rangia, freshwater clams, gizzard shad, white perch, yellow perch. Wilson Laney: Do those filter feeding species tend to have higher concentra�ons than the non-filter feeding species? Astrid Schnetzer: That's what we're looking at right now sta�s�cally. Stay tuned. Also, we're working with Blake Shaeffer on some of his data to try and match that with some of the blooms that we were able to report. We’re really excited about what they can do with Mark, and all this stuff that Mark had summarized before. Wilson Laney: So, are you looking at the levels of toxin that cause direct mortality to fishes? And are you also trying to assess what the physiological impacts are of the bioaccumula�on in their �ssues? Astrid Schnetzer: I do not. There are a lot of studies out there and there's not a lot known about the direct impact on fish species, their depura�on rates, etc... I do work with Dr Tal Ben-Horin at CMAST, a shellfish pathologist, and we're looking at some of the pathology in correla�on with microcys�n and domoic acid, which is both in the oysters and some of the marine sounds within the area. So, he's the person you would want to ask. Hans Paerl: There are good case studies on even non-fish transmitance of microcys�n; Monterey Bay in California, where there are several lakes that drain into Monterey Bay that are very high microcys�n lakes. Pinto Lake is the one I'm thinking of and the microcys�n ends up in shellfish. The shellfish are not adversely affected, but the sea oters that eat the shellfish are, so it gets complicated. Laney Wilson: Maybe the same thing could be happening with rangia in our estuaries, although I can't think of anything that eats rangia. Another interes�ng one to inves�gate, Astrid and Hans, would be to see if Corbicula is accumula�ng these toxins because blue ca�ish do feed heavily on Asian clams. So that's a possible food chain somebody could look at and see if these things are affec�ng those. Both those species are introduced invasives so from a health perspec�ve, it wouldn't be necessarily a bad thing if the toxins were knocking off some of the blue ca�ish, but they are the subject of a fishery and we do have the human inges�on angle. Hans Paerl: Nathan, Astrid, I, and others were involved in an eco-hab proposal with crabs that got no funding and that's another poten�al route because crabs eat everything off the botom. So, Astrid, have you done a lot of stuff on crab’s content? Astrid Schnetzer: We found microcys�n and cylindrospermopsin in blue crab south of Edenton and in the Tar Pamlico; there were only a few samples that we analyzed that were loaded. Pam Behm: For the standards people in North Carolina: Has there been any thought to adopt these new criteria or use it more as an advisory approach? For Joel: Have any states who have adopted this been able to get it to TMDL or nutrient management strategy and been able to connect toxin informa�on to nutrient concentra�ons and develop a strategy for reduc�ons off that? Paul Wojoski: What we're looking for from a standard program development is how you teed it up. We're looking for SAC feedback as to whether it's appropriate to take a specific numeric nutrient criteria approach to reduce cyanotoxin blooms. Or as Joel aligned, several states have adopted this and done this from an advisory approach. There are several ques�ons that feed off that that we teed up in the 16 mee�ng agenda about at what level is appropriate. Is it appropriate to issue swimming advisories and how can we take that approach? That's really what we're going to be working through over the next two mee�ngs with the SAC. Joel Hansel: Nobody's done that work. You might recall when we had modeling with mercury, not the problems but the transla�ons that you must go through between discharge of mercury conversion in the environment to methyl mercury uptake via fish species in the local area. It wasn't complex modeling, but you had to work through all the pieces and parts. And as Hans said, there's a lot of unknown as to why toxin produc�on occurs, and so if you've got a lot of unknown, you could in theory target chlorophyll a and then you're probably dealing in the simple nitrogen phosphorus world and maybe some sort of other micronutrient that might be of concern to you with specifically cyanobacteria blooms. But the direct �e between nutrient and other inputs leading to toxin produc�on in a linear or geometric fashion, so that you can accurately target things in a TMDL to reduce, to prevent, no, and again part of the problem is there's a big black box in the biochemistry on this one. There are a lot of compe�ng ideas as to why toxin produc�on occurs, like if you have mul�ple genera around that certain genera will start to turn on genes to toxify other blue greens out and become the dominant monoculture. There are others that deal with micronutrient availability and other stressors. Pam Behm: This group is focused on nutrient criteria development, even if we decide that toxins are not the route to get us there, it is certainly something that the standards side of the house needs to keep on the radar, even if it doesn't go through this process, it needs to go through some other, a separate process. But then I'm terrified when it ends up on the 303(d) list and people ask what are we going to do about it? Joel Hansel: Yes, I understand. Hans Paerl: From the studies I've been involved in, toxin produc�on tends to be early in the bloom phase when lots of nutrients are around. So that's temp�ng to think of that there as a link. The real problem is that we call them toxins, but they may not be toxins at all to a bacterium, and that's one of the things that really hinders us from understanding it. I have my own hypothesis on some of this stuff but when the bloom is really ac�ve early in the year, it's ge�ng all the nutrients it needs, par�cularly nitrogen, because there's a lot of nitrogen in the structure of the toxins, they’re also really cranking up in terms of photosynthesis, and o�en in those blooms, the oxygen levels produced by the bloom can be super satura�ng to the extent where they're actually inhibitory to the organisms producing it. One of the hypotheses is that these are not toxins at all. They're compounds that deal with ge�ng rid of or inac�va�ng reac�ve oxygen species produced during the bloom. So, this would �e in well if they’re early in the season when they're ac�ve. So maybe this toxin produc�on goes all the way back evolu�onarily to when the cyanobacteria first were around and had to deal with oxygen, but there are other hypotheses, too, to deal with sequestering iron, you men�oned some of them, Joel, there’s the school of allelopathy and lots of interes�ng but not consistent hypotheses. One last thing about the Lake Taihu in China is there are 5 different species of microcys�s in the lake, the ones that are producing the toxins at the highest rates are the early species during the early bloom and then later in the late summer and fall, there are microcys�s species that don't even have the genes for producing the toxin. So, it can vary even among species as well as within species and is very complicated. You'll see when I show those data, the regressions from Erie and Taihu, you'll see the variability there. There is a link, when you get high chlorophyll in the bloom, you're likely to get elevated toxins. But as Astrid has pointed out, some�mes 17 you don't get any toxins, so you've got these species that may not even have the genes for producing the toxins. Wilson Laney: I'm looking at the list of ques�ons and #4 is are there different cyanotoxins of concern for freshwater versus saltwater? Astrid Schnetzer: The only other thing that we found in Bogue Sound, outer reaches of Core Sound and down in Masonboro Sound was domoic acid, but it's like Chesapeake Bay where you have poten�ally toxic species present, but you do not see these bad blooms with high toxicity. So, for now, I would say we're good. We keep on monitoring it, but it's by far not as much of an issue from my personal perspec�ve as microcys�s is. Wilson Laney: But let me go back to 1985 and that harmful algal bloom that spun up from the Gulf of Mexico and knocked out our bay scallops. Hans Paerl: That was Karenia brevis. That was the Florida red �de. So that was a dinoflagellate. Astrid Schnetzer: That was a freakish event where they had an outer swirl of the Gulf Stream push into the estuary and with it a popula�on of Karenia but there’s several people who monitor up and down, and we have a �me series now for 10 years in Bogue Sound and we've not seen Karenia show up. That doesn't mean that this can't happen again, and especially with temperature changes and the climate, there might be some shi�s. I'm not sure that is a very immediate issue. Hans Paerl: It's unrelated in some ways to what we're talking about, with tying it with the nutrients because Astrid you're right. What happened was it was a very calm fall. The Gulf Stream was well organized and there was a back eddie that ended up ge�ng trapped in Onslow Bay and then ended up going into Pamlico Sound and the whole episode was probably not very �ghtly related to nutrients because it was driven by physics, very different than what we’re talking about with the cyanobacteria. And if anyone's interested in it, Pat Tester at the NOAA Lab wrote a couple of nice papers on that whole episode. We want to get into the realm of nutrients next or the �e-in with nutrients. And there is a lot to talk about regarding changes we've seen with nutrient loading in some of these systems that are impacted by cyanobacterial blooms and toxicity. We could talk about that at our next mee�ng and star�ng to make the �e-in a litle bit with nutrient loads and linkages to what we've been looking at with issues such as chlorophyll and problems that are caused by op�cs as well as nega�ve impacts on food webs and toxicity. I would like to stress that nitrogen is certainly one that should get very high priority. If you look at bioassays that have been done. If we look at historic changes in nutrient loading and the fact that phosphorus is an element that has accumulated in our sounds and rivers for quite a long �me, simply because there were marine deposits at some point. In fact, it's mined in Pamlico. We need to have a high priority on what's going on with nitrogen and the changes in nitrogen. That's not to say that we shouldn't deal with phosphorus, but if you look at the reports that have come out, par�cularly the nice report that was done on the Chowan by folks at DEQ and DWR, it's really the nitrogen that has shown a very dynamic set of changes. And Nathan's done a great job in linking some of the nitrogen loads to increased chlorophyll produc�on in Albemarle Sound. So, there's plenty of stuff there we can start ge�ng into in terms of the linkages. Wilson Laney: Do we need to give Paul our best shot at an answer to the 8 ques�ons on the back page there? 18 Paul Wojoski: That's the Division’s perspec�ve, and so we request that the members of the SAC and the par�cipants in these mee�ngs review and consider those ques�ons in prepara�on for and to provide feedback on at our next mee�ng. Elizabeth Liebig: We will meet next on January 26th, 2024, from 1:00 to 4:00 to con�nue discussing cyanotoxins and their impact in the Sound region. At that mee�ng, we'll use the same ques�ons found on the agenda this week. Look for the agenda to be distributed about three to four weeks prior to that mee�ng, including the mee�ng minutes from today. Before the next mee�ng, if you could pull any literature or other resources necessary to come back and answer those ques�ons and to make some decisions, that would be great. Jud Kenworthy: I don’t have anything specific to say other than it s�ll seems unusual that we don't figure out the method first. I struggled to get through that list of items on the clarity standard without first having an actual protocol and I don't know if we're going to revisit that again or you're going to seek out advice from any of us on SAC for that, but I felt it's the cart before the horse kind of issue. Elizabeth Liebig: As far as the clarity assessment, that is on my to do list, to capture what was discussed today and put it in a memo format to distribute to the SAC members for review and poten�al discussion. Jud Kenworthy: And I will get those two references for you. 6) Adjourn Jud Kenworthy: Mo�on to adjourn. Hans Paerl (and Jim Bowen): Second.