C-CAN 2019 09 Ocean Acidification and Harmful Algal Blooms

Ready? Welcome thank you for tuning in at least to have you join us for the September 2019 California Current acidification Network ocean acidification roundtable discussion. The title of today’s presentation is ocean acidification works hand-in-hand oh well – two. How ocean acidification works hand-in-hand with warming and other global change stressors to promote toxic pseudo-nitzschia harmful algae blooms along the west coast. This series is so hosted by C-CAN in short the series is intended to create a dialogue and facilitate understanding and collaboration among industry members not to resource managers and scientists within the California Current ecosystem On blue steel number seacam webinar committee I’ll be moderate. Terry King from Washington Sea Grant and seek an chair will run the logistics of today’s session. During the presentation attendees will be in listen-only mode You are welcome to type questions for the presenter into the questions box at the bottom of the control panel on the right of your screen we will be monitoring incoming questions and will respond to them after the presentation We will also we are also recording the session and will share their recording on the C-CAN website. We are very excited to have Dr. Dave Hutchins speaking with us today Dave Hutchins is professor of marine and environmental biology at University Southern California L.A. Most of his current research examines how global change processes affect marine biology ocean biology and biogeochemistry. Particular areas of interest include how future ocean acidification sea surface warming and changing ocean biology chemistry and physics will impact harmful algae blooms, carbon and nutrient cycling, iron and trace metal cycling I nitrogen fixation and phytoplankton community structure marine ecosystems. Dr. Hutchins received his PhD at UC Santa Cruz followed a postdoc at Stony Brook then worked ten years on the facility of the University of Delaware before moving the USC twelve years ago. I’ll hand it over to Dave for his presentation. Thank you Bruce and thank you for the opportunity to to give this talk today for the C-CAN community. Let me see if I can get this so yeah you’ve already given my title here this is a work that’s being a lot of it is being supported by USC Sea Grant we definitely need to acknowledge them. So let’s go on and talk about some of the kinds of changes that are going on in the ocean today. So we all because you’re tuning in to C-CAN I assume that you’re quite familiar with ocean acidification it’s a big big problem that a lot of us are working on this little graphic here shows the situation today and the situation sometime in the future say for year 2100 and we all know there’s more CO2 coming into the ocean and that’s going to cause the pH to decrease in the future but we also know there’s a lot of other things going on with global change at the same time and this shows some of them the most obvious one is the world’s getting warmer the oceans getting warmer so the we expect increases in average sea surface temperatures of anywhere from four to six degrees depending on where you are and then there’s other things too that are happening at the same time for instance the ocean and losing oxygen hypoxic areas are expanding another side effect of warming is that the mix layer depth is predicted to shallow and the the density gradient between surface water and deep water will get more more pronounced and so what’s going to happen is organisms that live up in the surface ocean are going to be held closer to the surface by this shallower mix layer they’re gonna see more solar radiation but they’re gonna see less nutrients because of this increasing barrier to mixing across the the the picnic line there. And we also know that there are

harmful algal blooms that are spreading all over the world. Harmful algal blooms seem to be getting worse in extent in severity and in frequency all over the world scenes like this are becoming all too common. This is a right whale calf that was killed by the same toxin we have problems with here that I’ll be talking about domoic acid produced by Sudanese yeah but this is in Argentina so if we’re not the only ones in the West Coast that have problems with domoic acid in Sudanese yeah obviously most of you are aware that both paralytic shellfish poisoning is a problem in areas like Puget Sound and Alaska and other parts of the west coast but domoic acid also has caused major closures of shell fisheries going on for years and it’s impacting not only our ocean environment but also our ocean economy the people many of you that depend on harvesting resources from the ocean are paying a big price for this this is the kind of thing that we’ve seen the unprecedented incidences of harmful algal blooms so this is a huge mortality of red valuable red abalone that happened in 2011 in Northern California and this was caused by an organism called Gonyaulax which never had caused problems in California before it just kind of suddenly appeared and started making yessotoxins and caused a major shellfish die-off. Other parts of the world here’s China they’re having in Qingdao they’re having huge blooms of macro algae so this is OVA and they had these poor policemen out there trying to clear it off with their bare hands it doesn’t look like a very fun job to me In a issue of science just a few weeks ago it talks about Sargassum blooms so this floating seaweed in the tropical Atlantic has been building up into huge harmful algal blooms that are burying beaches in the Caribbean and Central America and has suddenly become a problem so all over the world we’re having issues and a lot of people have linked these increasing harmful algal bloom issues to things like climate change issues go temperature increases and of course acidification as well as things like hypoxia and shoaling of the mix layer. We think that climate change has something to do with this expansion of harmful algal blooms globally and also the ones that were concerned with in the North Pacific. Of course human nutrient inputs are not decreasing in most of the ocean too- so that’s another anthropogenic impact that can interact with these other variables. Here’s some evidence from the San Francisco Bay Area from Jim Cloern a few years ago he shows when you have active upwelling a nice cold nutrient-rich water you get healthy diatom blooms dominated by things like Chaetoceros but when it warms up and upwelling ceases then you get dinoflagellate blooms that move in instead. Here’s another example of changes in harmful algal blooms globally this is Northern Europe these are for harmful algal bloom dinoflagellates and these red areas so where they’re moving into new places farther north where they’ve never been seen before and this is been attributed to increases in temperature in these areas. And finally here’s the coast of Asia here’s Korea, Japan, China. Cochlodinium is another one that is showing higher growth rates and a longer bloom season as the ocean gets warmer so it’s the evidence is really mounting that climate change as a whole including ocean acidification but also all those other factors I mentioned are involved in this This is one of my favorite graphs from Moore et al. 2008. She looked at the bloom window for toxic Alexandrium in Puget Sound which is about two months now but this graph does a nice job of showing as the ocean warms up two degrees you

almost double the balloon season at four degrees you triple it and it’s six degrees it lasts for most of the year almost nine months of the year so this is again a warming issue not an ocean acidification issue. So let’s get down and start talking about pseudo-nitzschia most of you that are listening probably familiar with it. I’ll give a little introduction but I think probably the reason you’re listening is because you’re already well aware of the pennate diatom genus Pseudo-nitzschia, and the kind of huge balloons that can make this is the Juan de Fuca Eddy which is one of the big hot spots for pseudo-nitzschia blooms up in the northwest and this is the toxin that it makes, domoic acid is a very potent neurotoxin that is the cause of amnesiac shellfish poisoning We know that the if toxic pseudo-nitzschia are present they will accumulate domoic acid mostly in their cells most of its not released to the water and then that gets into the food chain and it’s accumulated at every trophic transfer and it ends up in things like sea lions at the top of the food chain and causes major problems a deaths of seabirds and marine mammals. Here’s a big bull sea lion that is likely been poisoned by domoic acid who’s climbing out of the ocean onto Highway one in California. This is my ex-graduate student– I’ll show you some of his data today Avery Tatters and he was on his way going surfing he pulled over to talk to this cop who’s keeping an eye on the sea lion and he’s telling him about neurotoxins and trophic transfer. I’m not sure exactly what the cop thinks of this I do notice he looks a little skeptical and is keeping his hand on his gun here this guy with the dreadlocks has got him a little worried but you all know these issues probably as well as I do. So let’s talk about some of the experimental work we did. We are concerned about how ocean acidification is going to affect pseudo-nitzschia blooms both in the western part of North America and around the world. The first experiment we did was this one back in 2011 we got a culture from Eastern Canada not a local one, but then we grew it at three CO2 concentrations 190 ppm like a pre-industrial, a 380 ppm which was which was the present day when we did the experiment it’s higher now and 750 which is a future CO2 concentration and we knew from previous work that phosphorus limitation would intensify domoic acid production so we did all three of these CO2 concentrations both p-replete and p-limited. We grew cultures and we measured domoic acid and we also took RNA samples which I didn’t write down here for gene expression let me show you some of the results we got from that early work so here are the growth rates of our cultures and just to orient you this is growth rate on this axis down here these three bars represent the phosphorous limited treatments these three bars are the phosphorous repeat treatments and in each of those phosphorus conditions this is low medium and high co2 low medium and high and you can see right away that they grow faster when you give them phosphorous they when they’re phosphorous limited no surprise there but you can see that whether there are phosphorous limited or phosphorous replete they always increase the amount of domoic acid they make as CO2 goes up so the proximate cause of the proximate cause of excuse me the growth rates increase with CO2 not the domoic acid that’s the next slide this is so you can see growth rates go up with CO2 regardless of whether they’re phosphorous limited or phosphorous replete same story for carbon fixation Well let’s look at the toxins now. How do how do they look in this experiment. So it’s a little bit unexpected if you don’t know anything about pseudo-nitzschia but the phosphorous replete ones hardly making the domoic acid and we’ve known that for a while the phosphorous limited ones are the ones that produce domoic acid but once they’re making domoic acid when you put

them at high CO2 they make a tremendous amount more of domoic acid than they do just from phosphorus limitation alone and you can see that in a cellular DA is almost five times as high at future CO2 then at present a CO2 in the phosphorus limited treatments a lot more this is dissolved DA it’s a it’s an order of magnitude lower than because they release most of it but it has the same trends on the the CO2 actually exacerbates the domoic acid production that’s caused in the first place by phosphorus limitation. So luckily we did put away gene expression samples RNA and froze those away because these samples were used in a paper that came out last year and the reason that they were so valuable is because this shows we can turn DA off and on like a spigot basically just by controlling the amount of nutrients it’s getting and the amount of CO2. So we can manipulate our cultures to produce very little domoic acid or a lot by just by changing their phosphorous availability and CO2 and that was really valuable because it allowed people to cut them up for the first time excuse me with the synthesis pathway for for domoic acid which this these samples were used to figure out in a science paper last year of Brunson et al. science paper no one knew how domoic acid is made that science paper elucidated the whole gene complement that is involved in da synthesis which is going to move us way forward in this field because now we can do things like go out in the field and look for expression of these genes in natural domoic acid producing blooms of pseudo-nitzchia and it could be act as a biomarker for instance. Here is another experiment that of that Avery that i showed use picture earlier did we used a pseudo-nitzschia fraudulenta that we isolated in southern california here again a similar design of an experiment. We grew it across three CO2 concentrations but this time we grew up silicate and without silicate or silicate limited not without low levels so this is a different nutrient limiting it now but this is also known to increase domoic acid production and as you’ll see the CO2 again intensifies or magnifies the effects of nutrient limitation here this is out of order sorry this is the bio synthesis paper that I was talking about of the domoic acid synthesis that our samples were used for. So this is the the silica- limited results so the open symbols are the replete cultures and they don’t make much domoic acid at all the silica limited ones do make it as we knew from before but again look as CO2 goes up from here to here to here you get more and more domoic acid being produced in these silicate limited cultures. So what’s happening is that the silicate limitation or phosphorus limitation is triggering domoic acid production but ocean acidification is intensifying that There is some supporting field data for this this is from MacIntyre et al. 2011 They did a survey across an estuary ingredient so they as they saw CO2 concentrations go up as they went down the estuary to the open ocean silicate concentrations went down so here’s the condition of the high CO2 low silicate and sure enough pseudo-nitzschia abundance went up it’s not shown here but domoic acid levels actually went up with it so it’s a similar response to the ones we saw in our cultures. So the domoic acid and CO2 I didn’t show you the Karlodinium data so ignore that but the cell specific toxicity of pseudo-nitzschia is greatly increased by this synergistic interaction between nutrient limitation and elevated pCO2. So some of the points to consider

is that we know there’s a lot of economic impacts of ocean acidification on larval development of bivalves and calcification but it also seems that doesn’t that acidification is going to increase the toxicity of has in particular pseudo-nitzschia that we’re talking about today and it’s something that we need to think about ocean acidification but not in isolation in combination with these other variables like nutrient limitations like changes in warming and in temperature of the ocean so let’s talk about that for a minute this is one of my favorite warming slides it was a it’s given out by Edie Hawkins at Reading University it’s free to use if you know somebody who’s skeptical still about the earth warming up show them this this is very convincing I think these are all the countries of the world group by continent and what they’re looking at is the 10 that average temperature relative to the whole time period from 1900 to 2018 each row of pixels here is a country so the US would be there in alphabetical order would be down here somewhere but it it shows you that no matter where you are in the world the world is getting hotter there’s no doubt about it and we need to consider that when we’re talking about harmful algal blooms and domoic acid as well as ocean acidification and as a lot of you uh know we have our own major warming issues here we had a massive heat wave event that happened in the North Pacific went from late 2014 to early 2016 The Blob Bloom they called it in which temperature were much warmer than they normally are and it just sat there for over a year and as you also know this woman ain’t really nice when the cabe paper shows that there was tremendous soot and ichiya bloom the biggest one that’s ever been seen and the most toxic one the highest levels of toxins and they go through here and show you all the different shellfish closures crab closures impacts on marine mammals and Wildlife anchovy closures it was a disaster for the West Coast and a lot of you are well aware of that because you were caught up in this huge toxic blue so we isolated a culture of a toxic suited engineer the beginning of the blob event and we used that to look at the thing that was costing West Coast Dungeness crab fishery as much has been estimated as much as a hundred million dollars so we thought it was pretty urgent to look at temperature effects on domoic acid production and we just fortuitously had an isolate that we got right at the beginning of the BLA bloom of a toxic suit Anita of course crab the crab fishery was basically destroyed by this balloon and a lot of a lot of families had trouble paying their bills up and down the coast because of this the crabs were far too toxic to sell and this is all been put into a video by Rachel Becker if you haven’t seen this at the verge here’s the URL you can go and watch this video so she goes through and talks about the blob bloom and the toxic pseudo-nitzschia that resulted and the impacts on the crab industry along our coastline and then she also goes into a something that I know a lot of you are all aware of is that the Pacific Coast Federation of fishermen’s associations is suing the oil companies for climate change damages and it’s a bit of a David versus Goliath battle there to take on the biggest companies in the world but we need to wish them well with this lawsuit because they really do need some some help so let’s look at the results of those experiments that we did with that the toxic suit in each culture versus temperature so this is a pretty

simple experiment we took this culture we grew it across a range of temperatures from 12 degrees C up to 30 degrees C it’s what we call a thermal response curve and as it as is normal for phytoplankton growth increases with temperature up to an optimum point in this case 23 degrees for this isolate and then decreases very quickly after that as it gets into stressful high temperatures until it basically dies by about 30 degrees but the interesting thing was when we analyzed the domoic acid produced in this experiment this isolate didn’t even produce domoic acid at all until we hit its optimum temperature and then as growth rates declined due to stressful high heat the domoic acid levels went up and up and up and this suggests to us that a blue can grow in the early stages when there’s upwelling and nutrients and the water is a bit cooler that it will grow and produce a lot of cells but they will be a not very toxic but as the temperature goes up if a heatwave event moves in they will switch over to being quite stressed and they’ll begin cranking out the domoic acid that’s our interpretation of this is that stressful high temperatures produce high levels of domoic acid at least in this isolate this is the same data and I want to show you a different way so this is the amount of domoic acid per cell versus the growth rates in the culture and you can see below 23 degrees that optimum temperature there’s a DES I said there’s basically no domoic acid at all in the culture there’s no relationship between growth rates and domoic acid because there is no de Maupassant but if you look at those declining growth rates above 23 where it’s under thermal stress there’s a very strong linear relationship inverse relationship that the lower the growth rate drops the higher the domoic acid content of the cells so we also did some natural community experiments as part of this study so this is Sudan in a delicate Issam in a natural community with a lot of other phytoplankton mixed in so delicate issome is not a toxic pseudo-nitzschia it’s one of the non-toxic ones and uh it just happened to be the one that was there when we did the experiment so we need to do this again with some toxic communities but what you can see is as we increase the incubation temperature of this community the Sudanese dominant became more and more dominant so it was almost 50 percent of the cells in this one experiment nothing much happened until 28 and then it took off and began to increase its dominance so warming not only made our toxic pseudo-nitzschia more toxic but it made this suit in each iya become more dominant in the community just just because a picture is worth a thousand words here’s some photos through the microscope from those experiments so the arrows show you pseudo-nitzschia cells at 15 degrees C where we isolated it there was only a few and lots of other things present here but when we got it up to 28 degrees it turned into also pure culture of soot in each year so it was emanating the community there’s still a few other cells left but you can see how many more Sudan issue there are at a warm temperature so our conclusion from this and we need to look at more isolates in more communities but our preliminary conclusion is that both toxicity and abundance of song pseudo-nitzschia species can be greatly increased by warming which is exactly what we saw during the blob bloom and this is a very interesting paper that came out in PNAS by McKibben that all and they they went back and looked at historical data sets and they find whenever you have the warm fade climate phase of the Pacific decadal oscillation of course you get warmer sea surface temperatures they correlate very closely but they also correlate pretty well with the amount of Mac maximum domoic acid that’s been reported so warmer water that is caused by these decadal scale climate oscillations is appears to be

increasing the amount of domoic acid and that I think that gives some strong support to our hypothesis from our experiment by the way here’s the blob blue here and you can see how it correlates with domoic acid and also the PDO is index so about the future it’s kind of scary this is the prediction from a paper by keV all at all for the eastern Pacific Ocean and by the 2050 to 2100 minus the past this is how much that we expect temperatures to increase by the last 50 years of this century by up to two to four degrees throughout the North Pacific and so basically they’re talking about having a blob boom that is permanent out there if this comes to pass and as a lot of you know here is blaah bloom in 2015 a picture of that in August of 2015 but what’s really scary is here is the North Pacific last week this is September 12th a week ago and it looks very much like another heatwave event is building up in the North Pacific it’s not as intense as the blob yet the water the hot water is not as deep it hasn’t quite come onshore in some areas it’s not as intense and there’s a lot of hope from NOAA and elsewhere that this bloom is that this warm water heat wave is going to dissipate but it’s very possible that it’s not going to and we’re going to go straight into another blob event this year so we’ll have to wait and see what happens but I think what the lesson from this is we urgently need to look at interactions of other global change variables with ocean acidification not just ocean acidification alone because warming and ocean acidification together could give you much different results than you get from just looking at a single variable and they’re both happening together so here is an experiment that we are doing right now supported by our Sea Grant funding so my student Kyla Kelly has taken a culture of a toxic suited Nikia and she’s looking at an interactive effect so this new project that we’re just starting is going to look at interactions between acidification warming nutrient source and also solar radiation and we really want to get a handle on the interactions between these variables because we think those are going to be as important or more so then just the changes in individual global change processes like warming or ocean acidification we need to look at all of these in the same experiments this is the first experiment just preliminary data that she she came up with with his toxic isolate of a straw list that we have and what she looked at was she looked at photosynthetically active radiation that’s normal sunlight that cells used to photosynthesize but she also looked at the sunlight plus UV radiation why do we do that well the reason that we also are interested in UV is because of that one aspect of climate change that I mentioned which is the shallowing of the oceans mix layer is going to hold phytoplankton including pseudo-nitzschia much closer to the surface they’re going to get a bigger dose of not only the kind of solar radiation that helps photosynthesis but also the damaging UVB rays that come from the Sun and because of the energy of UVB it is quickly absorbed by the water so it’s only a problem in the top few meters of the water the problem is climate change has the potential to push Sudan ichiya closer to the surface where they are more they are more exposed to UVB and so she looked at UVB and she looked at a nitrogen source and temperature so these

the reason we looked at nitrate vs urea is there have been papers out that suggest that more domoic acid is produced from the organic nitrogen source urea then from nitrate also nitrate comes from natural upwelling urea is the kind of thing you get from sewage treatment plants or agricultural runoff it could be an a model for for anthropogenic nitrogen and then she looked at two temperatures 20 and 25 degrees so this is her experimental matrix is the interactions between UV stress nitrogen source and temperature and so let’s go through her results these are just the growth rates we’re still analyzing the domoic acid samples right now but the first thing you can notice is that the cells grown under just photosynthetically active sunlight grow much faster than the ones that are exposed to UVB and what I have to tell you is this is a really low dose of UVB we’ve done experiments with other algae this phytoplankton this this pseudo-nitzschia is really sensitive to UVB and so it really reduces its growth rate so the first thing is it grows much faster with just sunlight then when you add UV radiation in trying to mimic what may happen in a future shallower mix layer you can also notice that the highest growth rates are at the warm temperature with nitrate again in the photosynthetically active radiation treatment another thing you can notice is although growth rates are really low in all the treatments when we include a really modest dose of UVB they are highest in the warm urea treatment so it seems our preliminary hypothesis from this is that the growth on organic nitrogen at warmer temperatures may confer some resistance to UV damage so I’m going to start winding it up here I want to talk to some of the students perhaps that are out there listening. Some of you may be interested in doing some of these multiple variable experiments for global change with various types of marine organisms such as soon and pseudo-nitzschia and i just want to talk to you guys for a minute and give you maybe a resource that you can go to that might help you to put together your experiments because Kyle is doing these experiments I showed you her first one there right now she’s starting one now she’s looking at interactions between warming and acidification and light so we’re using three variables and coincidentally this is a the variables that were showing in this graph that we put into a paper we published a couple years ago this is not pseudo-nitzschia it’s another phytoplankton but it’s just to illustrate a point so these are a bunch of experiments that were done with the same species and they vary acidification CO2 they varied temperature and they varied light but they all use different levels of these variables and so you get this kind of experimental if you think of it as a meta space here and I’m trying to tried to portray it in three dimensions you get this experimental meta space that’s all over the place so maybe it’s not surprising that the results of these experiments vary a lot because they’re really not looking at the same interactions between these variables the other issue with doing multiple variable global change experiments is they get big really fast so you start off with triplicate replicates of two and with one variable you have six bottles the high and low treatment six bottles if you had another variable you have twelve bottles if you had a third variable you’ll have 24 bottles if you put in a fourth variable and start to get more realistic towards what’s really happening to these cells in the ocean you have 48 bottles the handle so it get out of control very quickly and there are ways you can deal with that problem of having

the experiment spiral out of control so I just wanted to point the students who are interested in working on this to the metal website I’m a member of the score 149 working group the scientific committee for ocean research and we are trying to work out some of the difficulties with these complex multiple variable global change experiments and help people to design experiments so you can go to this website this metal website and you can it’s a guide to run a best practice guide for running multiple variable experiments in ocean research like the ones that I would argue we need to do to understand the pseudo-nitzschia to Molech acid problem in a complex changing ocean so if you look down here you’ll see there’s learning material that’s background for experimental design there’s a decision support tool that will help you to pick ways to design your experiment there’s a video gallery with a lot of us from the Committee talking about aspects of experimental design for multiple variable experiments and there’s a PDF handbook, best practices handbook you can download but to me the funnest part is there’s a simulator that you can click on and that will let you design and run an online simulated global change experiment of your own you can pick how many variables you can pick what treatments you use and you can do a simulated variable and it will give you simulated results that you can then practice analyzing and the one of the things this website will do is it will let you build your own topography or landscapes of responses to global change variables so if you can envision this so here is a graph of a response let’s say domoic acid production could be a response here is one driver maybe that’s ocean acidification here’s another driver that’s CO2 so the response of domoic acid to the interaction between these two stressors is going to have some shape in three dimensions that you can envision and this is the kind of thing then you can choose where to put your experimental treatments that are going to give you the most information so here’s another topography of a theoretical or a hypothetical interaction between two drivers and here’s where the student chose to put their treatments now it’s probably not a very good place to put it because they would have missed the most important part of this feat which is this large feature where the response goes way up in the middle here because of where they chose to put their their treatments in their experimental matrix so this is the kind of problems it can help you to solve hopefully you can have fun playing with it and maybe it’ll help you design a better experiment and you can help us tackle this really complex problem of how do you deal with a multiple variable experiments when that is what’s really going to give you the best answer to what’s going to happen the pseudo-nitzschia and all other marine organisms in an ocean where many things are changing at the same time. So that’s all I have for today this is a where you go if you want to get a PDF of this webinar actually this is an older version of my talk which the newer one got deleted I will probably put the newer one up for you instead of this one and you can contact Diane Pleschner-Steele if you have any questions about C-CAN. Alright well thank you very much for your presentation we’ll open the floor to begin our discussion please type the questions or comments you have for Dr. Hutchins into the question box in the control panel. If you have questions about the content of today’s presentation feel free to contact Dr. Hutchins. His email address can be found in the questions control panel. Thanks again to Dr. Hutchins for his taking time to offer his expertise and perspectives on how ocean

acidification works hand-in-hand with warming and other global change stressors to promote pseudo-nitzschia. A video recording and PDF of this session will be shortly available on the C-CAN website you can also join C-CAN lizard on the C-CAN website where you can also learn about C-CAN activities and future webinars. You should also check out the ocean acidification information exchange and join the C-CAN section Great well there’s a couple questions coming in, and Bruce we can see you I have a so there’s a question from Jason he’s obviously from the East Coast he has an oyster hatchery on the East Coast and he’s identified four other smaller hatcheries that had experienced total mortalities around six days post spawn. We’re all we are all separated by 30 miles at most none of us thought to test for domoic acid Are there any fast tools to detect domoic acid better than others or is there another test that might be faster That’s a good question I mean analyzing for domoic acid there are several ways to do it Probably the best way the way that we try to use is by HPLC high performance liquid chromatography. A lot of environmental agencies have access to HPLC. You need you need to get some protocols going to do that and you need to have the instrument if you don’t have that available there’s actually some ELISA kits that you can buy so ELISA is an immunological method that is not as quantitative as HPLC but it is cheaper and quicker to get measurements of domoic acid so you just order the commercial kit and it’s it’s basically like a colorimetric assay that’s pretty simple to test for domoic acid. Great and and if I can this is Terry King from Washington Sea Grant Jason if you in your high health protocol you should have a process by which you hold sample and you can freeze it for toxin analysis at a different time but even looking for phytoplankton species in your source water that might have one of these organisms in it that causes domoic acid would be good to know also and if you need a link to any of your you know biotoxin monitoring programs let me know and we’ll see if we can connect you to somebody. Okay any other questions? I don’t see any right now. I did put up Dave’s contact information in the chat box so we can see that and he’s sitting in his office for us one of the questions that I had for you Dave was you know this newest bloom that we’ve got and the data that you had that showed when the temperature got to a certain point it seemed to turn on the toxins. Is there something your team is going to be doing now to explore that or exploit that a little bit more? Yeah I mean this is a part of our project that we just are ramping up right now with our sea grant supported project. We are really interested in looking at the relationship just between temperature and domoic acid production there’s been some controversy over whether the really high domoic acid levels see in the blob bloom work the result of the temperature per se or perhaps nutrient limitation when when upwelling it was kind of compromised later in the warm water event so some people think it was from silicate limitation. We think that that is quite possibly one of the reasons they started making domoic acid is if silicate or phosphorous ran out but that it’s quite likely that those warm temperatures again likes like acidification does nutrient limitation and increase the amount of domoic acid they are already making and so that’s part of what we’re looking at we’re interested in the interactions between temperature nutrient availability but also as ocean acidification and solar radiation for instance so we’re trying to do those multiple variable things but we will be looking at temperature alone too and that that experiment I showed you was just a single isolate I do think we need to look at more different isolates and the responses of their toxin production in their growth to temperature alone. So we also need to do to get a broader view of that Thank you for that any questions for

Dave I’m monitoring the chat box. Dave I will tell you Stephanie Moore and that the paper that Stephanie was you know lead on with the temperature change you know the two degree change was very eye-opening and we actually shared that at our Pacific shellfish sanitation conference for health officials and it was very eye-opening when she presented that to us and people started thinking about long-term effects and change in temperature overall. That’s a great paper and that graphic in particular really gives you an idea of how a warming ocean is going to expand the window the bloom window for these harmful algal bloom species it’s not just going to get a little longer but as the ocean gets warmer and warmer they’re gonna be able to bloom almost year-round in places that like Puget Sound that are too cold for them for most of the year and yeah her paper and then that that graphic really do a good job of getting that across. I’m afraid i’m worried that if the ocean is really switching over to a warm mode as predicted and as we may be seeing happening again with a new heat wave event building up out there I’m really worried we’re gonna go into a mode where the North Pacific is permanently vulnerable to these massive really toxic pseudo-nitzschia blooms where this happens every year or almost every year. I really think that’s something we need to worry about So many things to deal with. So I don’t see any further questions Bruce? Are you back online? So maybe I’ll take one question before I close this up what do you think Dave about of fish populations are moving around a lot also that that it seems to me that the the habitats that a lot of fish have been traditionally found in are starting to change and I was just wondering does does you know different portions of the ocean and the pseudo-nitzschia bloom are they stronger along the coast or offshore or no kind of how do the population change movements play into where we expect to see the HABs well is there a chance that the fish are going to move into highly toxic waters then that where we where they traditionally are say anchovies is you know a lot of the populations kind of offshore population but if it moves onshore does that going to affect their kind of risk of encountering a strong HAB bloom. Certainly could Bruce, the pseudo-nitzschia blooms don’t generally happen out in the middle of the north pacific gyre they do happen in sort of the shelf waters or the shelf waters of the coast so if a fish species is changing its distribution it’s certainly possible they could be moving into or out of the real hot spots for domoic acid production and yeah just I mean I showed data about harmful algal bloom species there are changing their ranges too so they’re moving as the temperature of the water changes they’re moving into new area where they’ve never been seen before of course the fish are even more mobile than the microorganisms so they’re moving around too and as you’re probably aware during the blob bloom a lot of the normal fish stocks that we have along the west coast like anchovies and sardines were really hard yet but we also saw a lot of tropical species moving up into that warm water so things like albacore and various tuna and so forth are likely to come become a lot more common off of California and you know if there’s a big domoic acid bloom going on it may not do the fishermen any good to have new fish stocks to fish for because they may be toxic too they’re gonna accumulate if there’s a domoic acid bloom going on even fish that are coming in from warmer water and are more comfortable in a warmer ocean are also going to be contaminated by domoic acid if their coming into where the blooms are so you’re right it’s a complicated scenario where the fish are moving

around but you know anywhere that they intersect there’s gonna be problems Well thanks again Dave great presentation oh well everything having to do with this subject scary but I want to thank everybody for attending or C-CAN as to ocean acidification roundtable today we welcome any feedback further questions or suggestions on topics for future webinar series you can submit it at the address listed on the slide and thanks again for taking the time to join us. This is the end of the session Thank you and thanks for listening