Thesis Defenses – Jackson Hoeke presents: Seasonal dynamics of the introduced sponge Hymeniacidon perlevis in the Elkhorn Slough, California, USA
Thumbs up please uh can you ring the Bell okay welcome everyone thank you so much for coming happy Friday happy end of semester um I’m very excited today to uh introduce you to Jackson hecky right before he gives his thesis defense uh presentation so uh Jackson is uh I think probably one of the uh truest inverto
Files in the invertebrate ecology lab um I would find him oftentimes uh crouched down in the mud identifying or grabbing things here he is with his study organism of choice and one of the things you’ll notice here is that many of my pictures have Jackson in a mask so
Jackson was part of our 2020 covid cohort um so he toughed it out in the field in the lab out of the lab at first because we weren’t allowed in with a mask um before he came here he was a student at the University of Oregon where he got a Bachelor’s in Marine
Biology and he did an honors thesis with Dr Craig young where he studied the native and introduced hydroids from the marine and estaran Waters of cusb Oregon so he had some great um field lab experience and field experience before that um and uh I think the introduced
Species were a key element that uh informed his pces project here also while there he had great opportunities to travel and do field work elsewhere so he went on a cruise on the RV Atlantis with Dr Young um and it was an HOV Alvin Cruise so I think you didn’t go in the
Submersible but definitely were there and yeah um and then also he went to lwh Hine Ireland with uh Dr Cynthia trobridge for some ecological surveys so had a lot of really great field experience before coming here where then he had to stay indoors for a long
Stretch but um at mlml uh he was here during covid with a mask on but still taking as many field courses I think as possible uh he could often be found holding on to invertebrates or sifting through Kelps to find invertebrates um so he was a key participant in the
Advanced invertebrate zoology course um and uh also we had a lot of good field excursions there here he is on a boat uh recovering um some settlement plates so we had put out in Moro Coos slooh he took uh the molecular techniques class where they were puzzling through alal
Frequencies um and also he spent a lot of time out on the slooh so this uh that here’s Jackson during one of our lab socials out on the water of the slooh so you could find him there but um also he went out on larger boats as well so he
Came out on a deep ocean inspiration group Cruise uh led by Dr kakani Kaa where we went out and he um got to sit in the science seat and um you know work the cameras with the ROV and was part of the science team there uh he also learned a lot of skills
Out at Sea so here uh he uh participated in the Gumby suit challenge this is sped up uh but he did meet the challenge of getting a Gumby suit on in less than a minute while also describing His science um while on the ship so uh lots lots of
Skills that were developed here um in addition to those field skills he was an instrumental part in analysis of the decadal review of The middepth Deep subtitle MPA uh program um as a research assistant he also um got his aty experience and go forward oh we’re stuck on that slide it
Wants us to keep going there we go and he also presented his research at conferences so he was great uh with Outreach so he went to the wsn meeting along with a good cohort from invertebrate ecology lab presented his research there as well as in Maryland at the international Congress of Marine Bio
Invasions which has led to uh submitting H the research that he’s going to talk about in the conference proceedings uh for that uh meeting meeting um in addition Jackson is an accomplished science illustrator and so his Outreach is not just in presentations he was the overall coordinator of open house for last
Year’s mlml open house in 2022 and he sold his art then and he in addition to um completing his Masters has built up a side hustle of um of basic of selling his art which is fantastic it’s really beautiful and you can see a lot of his inverto file
Knowledge going into that art so uh truly a Renaissance set of skills and so with that uh I’m happy to welcome and I ask you all to join me in welcoming Jackson to the stage to present his master’s thesis research [Applause] Jackson all right uh thank you all for
Coming uh I’m super excited to talk talk about my thesis uh the temporal and spatial changes in the abundance of the introduced sponge haston privus in the elorn slooh try saying that 10 times fast uh this is just a little bit of road map of what I’ll be talking about
So I’m going to start with an introduction and go over some of the concepts that I’ll be bringing up throughout my talk and then I’ll go through my three research questions each of these will have a methods and result section to it uh and then I will bring
All of that together into a discussion where I talk about some of the wider implications of this and lastly I will wrap up with a conclusion and if I time this right we’ll have some chances for questions so first I want to talk about what an introduced species is simply put
It’s any species that’s taken from its native range and moved somewhere else and this isn’t a good or bad thing in and of itself um some introduced species very rarely are good but usually they’re a cause for concern when they are uh invasive which means that they have uh
Some kind of negative impact that we can quantify um some of these are they can displace native species so this is a picture of a murder Hornet um as they’re sometimes called you may have heard about these guys being introduced to Washington State a few years back um and
They were able to keep them from being established but um there was a lot of concern because they can decimate local pollinator species like bees uh they’re also known for destroying habitat this is a photo of an invasive uh European green crab and when they’re looking for food they often tear
Up the eelgrass beds that they like to call home so they will destroy that habitat in the process another example of this is the Chilean ice plant uh and if you drove here today along Highway One you probably saw in the dunes uh and not only does this push out local Dune
Species but unlike those species it doesn’t stabilize the dunes very much so they tend to shift and collapse a lot more uh when this ice plant takes over they can also damage infrastructure and none of these examples here are particularly good um at damaging infrastructure but this one is this is
The quag muscle dry census it was introduced into the Great Lakes a number of years ago and since then it has not just colonized the bottom of the lakes in these great numbers like you can see here but also any pipes Pines any sort of um hard structure that humans put in
There they completely cover it causing huge um damage and costs not only that but these are filter feeders so they eat a small algae called phytoplankton and there used to be a annual phytoplankton bloom in the Great Lakes before these guys moved in and completely disrupted
That by consuming so much of it and they consumed it so much that they actually destroyed the local fish populations there um because they didn’t have enough to eat so all of those fish populations shrunk considerably and this is what we would call like a worst case scenario Invader where it’s completely disrupted
The ecosystem it’s been introduced to uh but speaking of filter feeders um we’re not going to talk too much about muscles to say we’re going to talk about sponges and sponges are also filtrine invertebrates but they very very rarely eat anything like algae they usually eat dissolved organic material viruses and
Bacteria so much smaller organisms that um a lot of invertebrates don’t really feed on and so they’re a little bit unique in that regard where they’re able to take this very dispersed microbial biomass and concentrate it down um into a macroscopic level that’s available to other organisms and this process is
Called benic pelagic coupling uh a really great example of sponges and benic pelagic coupling are the glass sponge Reeves off the straight of Georgia um in British Columbia and these are glass sponges that have been around for a long time just filtering water and consuming bacteria and they’ve created these huge complex structures
That that enable things like that fish right there to be able to call them home so benic coupling can do a lot of really incredible things but we’re not here to talk about the straight of Georgia or the Great Lakes as cool as they are we’re here to talk about Alon slooh our
Own backyard so this is a photo I took of one of my study sites as a veto pond on a typical overcast day um and you can see some of the local habitats here like um the salt marsh and just to give a little bit of an intro on elorn SL
Uh it’s the second largest Estuary in California the only one that’s larger is San Francisco Bay and we’re used to thinking about seasons in Four Seasons so like you know spring summer fall winter but on the California Central Coast there’s really only three dry wet and foggy foggy is from about April to
September the dry seasons in October and November and the wet season is December to marchish so we’re currently in the wet season right now um there’s also a pretty significant environmental gradient in elorn slooh those lower slooh off to the left of that line um pretty much tends to mimic
Whatever the conditions of the Monteray Bay are um so it’s very um salty most of the time um almost completely a marine ecosystem and the upper slew off to the right is influenced considerably by Monterey Bay but um the water branching off into those all those little like um
Extensions tends to be retained a lot longer so uh you get a lot more variation uh when there’s a lot of rain uh the salinity is lower um when there’s a drought the salinity tends to be higher the water gets warmer um and it also has a long history of human
Impacts the a lot of the wetlands were converted into Farmland so sometimes when it rains you get a lot of runoff uh nitrates phosphat Fates things of this nature um we also see that um right now it’s directly connected to Monteray Bay but it used to not be the harbor didn’t
Exist um before the 40s and the selenous river emptied into the slooh so it was primarily a freshwater system before the 1940s and now it’s shifted into a marine system uh it still hosts a huge array of habitats including those salt marshes uh eelgrass beds and mud flats this is an
Example of a tidle mud flat uh the name is the description it’s uh flat it’s muddy and when the tide comes in it tends to flood spaces like this and then it Retreats and exposes them at low tide and this is what a pretty typical part of elorn slooh looks like unless you
Were to say introduced some sort of sponge species from halfway around the world and it might look something like this so that entire orange uh band is the study species that we’re focusing on today h many ason privus uh this is a little zoomed in photo right here where
You can see the structures a bit better and this species is native to Northern Europe probably but it’s been globally distributed for a long long time uh found all over the world it’s been here since at least 1998 that was the first recorded sighting of it here but it was
Probably brought here as fowling on non-native oysters so we don’t know exactly where it came from um the oysters were broughten from a variety of locations and it just hitchhiked on the shells at some point but um it could have been anywhere during this period so the 30s all the
Way up through the 80s it also grows to pretty massive size you can see here it gets to be the size of my head that’s just an individual this map is from semi at Al and it records uh scientific discoveries of haston prous the green dots are where
It’s been recorded and DNA sequenc so we know we being the scientific Community um it’s known that it’s absolutely for sure there uh and the blue dots are where there’s um it’s been seen and reported but it hasn’t been sequenced so it’s only probably there but even if you
Just count the green dots it’s on five different continents so it gets around quite a bit um and since for such a widespread species we obviously have a lot of data on it um whoops uh so it’s tolerant to sediment this is pretty unique among sponges uh most of them because they’re
Filter feeders if you introduce sediment or silt into the water it’ll clog them and they die but uh not have any acid on uh it’s also tolerant to air exposure so it’ll be in the intertial zone where it’s exposed for hours at a time where the tide goes out and once again we
Don’t see it have much of a negative impact on the species we know from uh laboratory experiments from the literature that it is um a it tends to grow faster in warmer water so that seems to be something that benefits it and there’s been a seasonal growth pattern reported
In other parts of the world so we see that abundance kind of go up and down over the course of a year a couple other facts is that it’s semi infal so in the elorn slw we’ve actually seen it be partially buried in mud um and once again that’s very
Unusual for a sponge but it doesn’t seem to bother it in the slightest but it doesn’t um just live in the mud it needs some kind of small um hard substrate like a rock or a cobble or something to like attach to at least initially so I mentioned that there was
A seasonal uh pattern of life history the uh the general trend is that in the spring or the summer uh it’s that bright orange or yellow color and it grows and then in other parts of the year in the fall or the winter for example it will decline it’ll turn the
Brown color it’s not dead per se but um a lot of the tissue kind of shrink back uh but it comes back uh the next year with that bright orange color again but this does bring you into question how much that biomass might be changing
Because if you look at this photo if you imagine that maybe they you know shrinks down and it turns brown like that other photo uh there’s quite a difference between the biomass there and the biomass in this photo and that is going to bring me into my three research questions so the first
One is that this species has been here since 98 it’s been here for 25 years and have we seen any sort of growth or spread of this species in that time has it simply stayed in one place or has it started to expand throughout the sleo
The second one is do we see that seasonal change in abundance reported in other parts of the world does it and doesn’t mimic those in any way and lastly the estimated scale of ecosystem function and what I mean by that is is this going to be like those quag muscles
In the Great Lakes where it’s going to completely devastate um the orn s ecosystem that’s been introduced to or is this more of a nuisance species where it’s not really a problem but maybe it’s not great and this is going to take me to my first question I’m investigating the
Patterns in recruitment so these are fowling plates uh fowling just means that when you put them in the water uh organisms settle and foul them uh this is part of a program that uh my adviser kin uh leads where they are looking for Native oyster recruitment uh Austria
Lura uh and these have been deployed every year since 2007 uh typically five of them are deployed to a site in May or June and uh one year later they’re collected everything on them is identified uh and they are replaced so this is what these plates
Look like uh when H many ason grows completely over them after about a year and even though these PL which were initially deployed to look for oysters uh everything is recorded on them so I was able to make use of them these are the sites they were
Deployed to um the Stars just mean that some of those sites I had uh I used for a secondary purpose that I’ll talk about later uh but for this part of the talk uh they’re the same as the dots for all intents and purposes so as you can see
There’s a pretty good spread of um deployments across the elkor SLO and the data from that look a little bit like this so this is a lot of information so just to break it down the gray background means that there was no sampling of any kind the blue indicates that uh there
Was sampling and no haston was reported as recruiting that year the open green boxes indicat that we saw H many asdon but uh there was no cover data and the white to dark green boxes indicate that there was percent cover between 0 and 40% the left column there is the initial
Discovery so there was no plates and therefore no percent cover but we did see that when it was initially discovered it was at two different sites when the fing plates began being deployed we see that it had actually already moved to a new site and that
Only increases we see it mooved to about six different sites um from 2007 to 2023 and it recruits more frequently there’s occasional episodes where there’s no recruitment but on the whole it’s generally increasing uh although you might notice that 2023 there’s a pretty clear drop off in Recruitment and we’re going to
Talk about that a bit later another Trend you might notice is that those four rows at the bottom have very few years of data and the FES they are there there’s no recruitment so this is when the sampling was briefly expanded into the lower slew um but as
You can see uh no sponges were found and there were also no oysters found so the the sampling sites there were sort of uh sheld and um sampl was then brought back to just the upper slew but since we never saw any him many acid on there during that time and we’ve never
Had any reports of it even haphazardly in the lower SLO it seems that it’s currently restricted to recruitment in just the upper slew at the moment so to recap all of that have there been increases or spread yes there have it’s gone to more sites more frequently but with some periods where
There’s no recruitment that we see currently as far as we can tell it’s restricted to the upper slew and there is that strange drop off in recruitment in 20123 that I’ll bring up later so the next question is about seasonality does the abundance change seasonally in elorn
SLO so in order to assess this I use quadrats the quadrats are one meter squared uh which is a nice reference point and the sponges you can see here I it allows me to you know figure out what’s sponge what’s Rock because I would photograph all of them I did set
Three different sites um as AO Pond uh that is a channel between the main channel of elorn slooh and a tidal pond so when the tide goes in or out a lot of water rushes over the site and it’s mostly Rock and Cobble which is a lot of
Hard substrate for those sponges to attach to and you can see from the photo that they’re pretty dense in the site Kirby Park is a tidal mud flat by contrast so it’s a large wide sight mostly mud occasional cobbles and boulders spread throughout so we see a
Lot of sponges here but they’re much less dense at this site and lastly we have uh the South Marsh Bridge or rbr which stands for the reserve Bridge we um this site is this sort of strip of mud and Cobble between uh a wooden berm the bridge in question and the water at
Low tide and we see an intermediate density of H aceton here so the way this worked was I had these three sites they were broadly rectangle shaped um and I would generate some random numbers beforehand in order to figure out where I would be putting my quadrats down I
Photographed all of them and I ran them through a program called image J uh where I was able to trace out and calculate all of that sponge area as you can see in purple there and I did this 3500 times over two years uh started in
August of 2021 and I only ended July of this year so there’s quite a bit of data and it looks like this uh the aavo pawn sponges are in purple the Kirby Park ones are in pink and the South Marsh ones are in Blue uh the lower axis on the bottom is
The month that I sampled and the axis to the left is the percent cover so right off the bat we see a pretty clear uh what looks like a seasonal pattern because we see Peaks and valleys but I’m just going to go through it in a bit more detail so I
Started in the foggy season of elorn slooh uh there was some Sponge increase then we saw sponge cover peak in October and November of that same year during the dry season during the wet season when uh there was a little bit of rain the sponges declined over time at all
Three sites and they bottomed out at around April um but once the foggy season started they started growing again and they actually grew much more this year uh during that dry season uh all three sites um the cover was high that year so there was a considerable
Change but we see what looks like a pretty seasonal pattern at this point uh which is kept up by the wet season when they declined although it was much faster this time which was interesting and then during the next foggy season there something weird happened where
They bottom out at about two sites I couldn’t find any sponges at the aavo or Kirby sites um which wouldn’t be so weird in say March or April but then I couldn’t find any all the way through July the South Marsh Bridge site didn’t quite follow this pattern there were
Some that always stuck around but they were at pretty reduced cover during this time so visually it does look like a seasonal pattern but uh just to run some statistics I used an aova bootstrap uh and that P value you see there it just means that the lower the P value the uh
Greater evidence there is of a seasonal pattern and as we see from here the P Valu is very low for asabo pond it’s kind of low for South Marsh bridge that site doesn’t have as distinct a rise and fall so that’s probably part of the reason but there’s still mild evidence
Of a seasonal pattern uh but we do see a strong seasonal pattern at Kirby Park but this brings up another question which is what’s driving these changes so obviously seasonal changes because they’re changing with the foggy to dry to uh wet season but what parameters are responsible for this is it temperature
Is it salinity uh and how is it working uh and these sites are spread out enough you can see them on the stars on the map so I had enough of a difference in conditions where I was able to do some investigating this graph here just looks
At temperature as a veto Pond and sponge cover temperature is the dark line the sponge cover is in white um and the interesting thing you can see here is that the sponge cover almost seems like it reacts negatively to increased temperature which is not what we would expect based on previous results from
The literature so that got me thinking that maybe it just take some time for the sponges to demonstrate this this change in cover and response to temperature and what I did was I lagged the temperature and all that means is that the U Top graph is the same as the
Last Slide the bottom graph where temperature is in blue is lagged by one month so as opposed to before where I’m looking at temperature from August 2021 at the same time as sponge cover from August 2021 um this bottom graph looks at sponge cover August 2021 but temperature from
July and it actually lines up a little bit better so I just kept on doing that um and you can see as it goes from zero months to one to two to three It lines up better and better until about three months you see that uh they’re increasing and decreasing in tandem the
Sponge cover in temperature uh and that pattern breaks down once we move on to four five and six months so once again I need a bit more statistical analysis to back up what the graphs are informing me of uh and I used uh Spearman ranked analyses and you see a new statistic uh
Row uh and all that means is that um zero on a row value indicates no evidence of correlation um positive one indicates a um extreme evidence of a positive correlation and negative one ex evidence of a negative correlation so um here we see it’s almost uh one for that
Three Monon lag period it’s 0.92 uh which just indicates that we have a lot of evidence that that thre Monon uh lag period is a true pattern and then I did a whole lot more of that I know this a lot of numbers and colors I’m going to explain it don’t
Worry um so these are colorcoded by the site so purple is as a veto pink Kirby sou Marsh’s blue as before um and each one I did what I did for aavo and temperature where I figured out the highest row value and lowest P value um
For a lag period and put all of those there and the ones that are colored are just the ones where I have enough evidence to say that yes we are pretty confident that that this is a representative of true pattern uh and you notice that it might
Be a little bit patchy and they’re not all three months some of them are are two or four a few of them are even like zero but uh typically the delay we see is between two and four months we also see that the only uh factors that uh
Matter across all three sites are temperature and dissolved oxygen and therein lies the rub because I was looking for a single factor that would explain some of this stuff and that wasn’t really possible because a fun fact about temperature and dissolved oxygen are that as you increase water temperature dissolved oxygen decreases
Is so they’re actually what we call co-variates and all of these factors are coar to some extent so what that means is that this table indicates that yes sponge cover is broadly delayed from environmental conditions by about two to four months um and we also see that while temperature and dissolved oxygen
Are good predictors uh we can’t necessarily say that they are what’s driving these changes so to wrap all of that up up do we see abundance change seasonally we certainly do it does change it grows during the foggy season Peaks during the dry season declines during the wet
Season uh we also see that sponge cover changes um about two to four months after the conditions in the slew change so that’s interesting because it means that the dry season is not responsible for the sponge Peak cover that’s the conditions during the foggy season probably around June or
July and we also saw that temperature and dissolved oxygen are pretty good predictors but we couldn’t quite be clear if that’s what’s driving these changes um and on to our third and final question what is the estimated scale of ecosystem function so as a sponge H many
Ason is a bit limited what it can do it can basically only sit in one spot in filter feed and take up space um to look at how much water is being pumped through this species I need to know a few things I need to know the
Average osculum size and osculum is just one of these like excurrent pores so when you see one of the tubes with a hole at the end that’s an osculum and that’s where the water exits the sponge uh and I need to know how many of these
There were for a given area of sponge and also how fast the water is being able to move through that sponge so in order to figure out the average osculum size I would just take a lot of photos of sponges top down and with a reference ruler I would be able
To measure the average osculum sizes in image J uh and I could use those same photos to put down a random Square centimeter and from that square centimeter just calculate how many uh oscula I could count and lastly I got to use the uh d a
DI method in order to figure out the speed at which the water was leaving the sponges and this was the fun bit so uh using a plastic tube uh d goes in one side uh it’s capped with my thumb I put it in front of an sponge osculum and
What that looks like is I uncap my thumb from it and the sponge osculum pushes that die front through the tube and you can measure on video how fast it takes from the D to get from one end of the tube to the other and figure out how
Fast the water is moving through the sponges so taking all of these data together uh I was able to use to scale up my covered data to calculate if all oscula are pping at the same time how much water is moving through these sponges at one of my SES I also needed
To look at how much space they were taking up and the metric I used for this was biomass so all of the you know organic tissue in these sponges and I couldn’t just use my cover data for this because that’s two-dimensional and these are 3D animals
So I needed to know firstly how to convert from 2D to 3D area to volume I also need to know uh the wet weight the dry weight and the ashree dry weight and this just me and the wet weight is just if you take it out of the water and put
It on a scale dry weight is if you remove the water from it and weigh it and ashree is when you remove all of the organic tissue from that weight as well so area to volume is pretty simple I would scrape sponges off of the Rocks photograph them calculate the area in
Image J and I would put those specimens into a container where I could see how much uh water displacement they would cause for the weights um I took a few tissue samples from sponges in the field and uh rinsed them in fresh water and weighed
Them uh then I would uh put them in an oven at 55 degrees C for 12 hours and that dehydrated them and I could weigh them again and then to get rid of all of the um you know extra organic weight I set them on fire
Scientifically um I put them in a muffle furnace at 450° C for 4 hours and this removed all of the organic tissue which is what I was looking to weigh uh and so through a little bit of math uh I was able to take the difference between the dry and the
Ashree dry samples and figure out how much organic Mass was in there so this is the result of all that scaled up from that cover data I showed you before uh on the left axis is the volume of water filtered in milliliters per hour per square cm and on the right is The yes the right uh is um milligrams of biomass per square centimeter and these are small units because um it it makes the units uh easier to digest but uh it’s also great for comparing the individual sites and we can see that between these three it comes down to
Density and interestingly uh how much hard substrate was available so as AO pond with the most hard substrate had the most uh biomass and water filtered per square centimeter followed by South Marsh followed by Kirby but if we scale up to include the entirety of all the
Sites we get much larger units uh we’re talking uh at the peak so in like October and November of 2022 the sponges at Kirby Park and aabo pun were filtering over a liter of water a second it’s worth noting that that’s assuming all oscular pupping so it’s a high-end
Estimate but even so it’s very high uh and we were talking about kilograms of biomass crucially we Al also see that uh this is changing by about an order of magnitude uh every year so from the Peaks to the valleys and that indicates that all of these
Functional effects are not going to be present at all times of the year so another recap um assuming this high-end estimate uh we see over a liter of water a second filtered at some of these sites during their Peak cover uh we also saw that uh the hard substrate
Uh seems to affect how many sponges will settle and the sponge density is what’s driving these effects so uh the function of haston strongest as AO Pond uh we also saw that these change by about an order of magnitude over the course of a year so sometimes we’ll feel
The effects in the alorn Sue from the species other times that function will be completely absent or close to it and now we’re going to bring all this data together so just to recap seasonality grows during the wet season Peaks during the dry season and declines
During the wet season or sorry I think I said wet season the first grows during the foggy season uh we saw that the conditions change and we see the sponge cover visually change about two to four months later um so those foggy season conditions are driving the sponge cover
When they peek in the dry season whoops uh and we also see that um that that seasonal pattern kind of broke down at the very end and I maybe spoiled you a bit but that is probably due to the storms from December 2022 to April 2023 so when these storms happened
Um the sponges declined as we saw the year before but they didn’t come back at two out of three of the sites and couldn’t even find them so what that indicates is that the precipitation and the really heavy storms seems to uh just decimate most of these populations but
They still manage to hold on at the South Marsh Bridge site so it’s such a resilient species that even when um weather patterns that seem to really be rough on them occur it doesn’t destroy the population elorn slw uh it just kind of maybe sets it back a
Bit uh you can see this uh laid out Across My Graph here where um the start of the storms uh coincides with the decline like the year before but it’s much sharper and stronger and they don’t come back afterwards at least at two of the three sites this is also a good time
To bring up um that I did do a little bit of research into their reproduction cycle so I was dissecting for embryos in the second year of this study um however um the storms interrupted that so when I started in September um I found embryos and I kept finding them every month
Through November December I couldn’t find any in the few specimens that were still around and after December there was just not enough sponge left to be able to even get a no um I don’t know if the sponges have been if they had started growing again in um the summer
Of this year if I would have seen embryos or not but we do know at least from this that they are brooding during their Peak biomass so here’s that in graphical form where you can see the decline in red minimum in Periwinkle growth in green and Peak and orange and those yellow circles
Indicate when I found brooded embryos in their tissues uh and this is a comparative study from uh the UK by Stone um and we see a pretty SE similar seasonal pattern in what is this presumed native range um there’s a longer decline period um but there’s pretty considerable overlap with
The uh brooding phase and it also overlaps with Peak biomass uh moving over into the Yellow Sea we see that uh sponges there have a longer growth phase uh and they have a pretty short decline but then they’re at this like very low biomass for a much
Longer time so difference is there but once again the peak um and the uh embryo bring overlaps pretty considerably and then we move into the ionian C uh this is from gyo at Al and they did not measure cover at all uh they only looked at reproductive elements but uh it
Occurred much earlier starting in April and then all the way through August and then in September the sponges just disappeared and never came back so that’s a very strange um variation on the life history especially compared to the last three and it just demonstrates that this species is pretty variable
When it comes to life history and where it’s introduced to so why does this timing change well it could be anything it could be temperature salinity dissolved oxygen but we know all of these are coari so it’s very difficult to figure it out um however if you were to hold all of these
Stable and then mess around with some other factors that might help so we do have such a case study this was from a paper by Mercurio at all that came out uh very early this year where they looked at H previs in an um outflow from
A fish farm so the conditions in the fish farm are kept stable and the outflow is in the dark so there’s so they’re just in the dark in the water in these conditions that are that are the same year round and what they saw is that well there’s no Seasons
But crucially What mattered was how close they were to the fish and therefore how close they were to all the extra pellets all the fish poop and all the bacteria that was coming out of that tank so so the group closest to it group three that’s that dashed black line on top um
They grew steadily over two years while the spong’s further Downstream didn’t really grow much at all and the reasoning for this was that well the sponges uh closest to the tank had first dibs on all the food and were able to make use of that throughout the entire
Year because there were no conditions that um made them decline whereas those other populations had a much tougher time uh feeding and therefore stayed a relatively consistent biomass during the year so that indicates that all of things being equal food becomes a determining Factor um so perhaps those
Conditions in the foggy season maybe there’s more food available that uh enables uh the sponges to grow and reach their Peak biomass in the dry season of elorn slooh um and this study also looked at reproduction and it saw when you remove uh Seasons from an ecosystem that this
Sponge is in the reproduction kind of takes place sporadically across the year so all seasonality kind of grinds to a halt so while we can’t really say what’s the driving Factor we do see once again that seasons do Drive what this sponge does it’s the point where you can almost
Arrest the the seasonal cycle entirely uh and speaking of seasonal cycle when we have um that Peak biomass during the dry season I ran some numbers and combining all sponges and all of my sites my high-end estimate was that during November of this not this year last year um haston was filtering
250,000 lers of water a day that would fill an Olympic swimming pool in about 11 days and that’s just the sponges at my sight not including the many many many sponges in elorn slooh and I’ve mentioned that they are uh bacteria vores uh a lot of previous literature from the from Laboratories
Has seen that when you feed them bacteria like ecoli for example uh they feed very fast very vigorously um and elorn SL this is of particular interest because there’s a lot of nutrient runoff from the nearby farmland and this uh gives a lot of nutrients input into the
Water allowing bacteria to flourish so just as an example of how this can be really bad in the 80s they actually had to stop the oyster culturing because the fecal coliform levels were kind of high and they were concerned that the oysters wouldn’t be good
Product uh and H privus is able to make use of all this is able to take um all of that biomass fling around of the water at the bacterial level that most animals can’t really get at and condense it down into this form where other animals can can interact with it and
There’s that benic blagic coupling again so just like those glass buong reefs when you get all that bacterial biomass concentrate down brings up the question is this habitat can animals make use of this um introduced species as a seasonal habitat well I did find um ampop pods in
Them when I dissected them for embryos the um they’re just like little tiny guys but still it proves that something is able to use haston as habitat now I don’t know if these were Native or introduced amp aods um identifying ampop pods is a little bit tricky
But it does bring up other questions such as seasonal availability in other organisms so if an organism is also seasonal and um at inverse times of have any asdon it’s if it’s a bundance Peaks and say April how many Aon is useless to it as habitat as opposed to an animal
That’s around the entire year where it might be able to make use of it at certain times so it does mean that there is some sort of potentially even beneficial functions here although that would require a little bit more research but just the fact that some animals are
Able to make use of it is very cool and just to bring all of this home in our main conclusions first of all we know that this species is fully naturalized in elorn slooh uh there’s times when it doesn’t when it doesn’t have successful recruitment there’s times when population declined but in 25
Years it’s been unable to be extrap and it’s been here the entire time so it’s probably not going anywhere we also see that it has seasonal patterns of abundance much like other parts of the world but um the conditions that predicted uh predicted about two to four months in
Advance and those um conditions that do are temperature dissolved oxygen and they’re pretty good proxies for figuring out even if we don’t know if that’s exactly what’s driving these increases and decreases and lastly we saw that this species does have significant ecosystem function and it’s almost non-existent
It’s barely pumpy and provides almost no biomass in April and March but in the dry season boy howy it provides a lot of biomass and it is filtering an ungodly amount of bacteria um and that is going to be that so I’d like to thank all of my funding
Sources um Coast uh sjsu um mosan uh through the night baching and wave Awards uh and also the Myers trust um that all provided funding for this project I also want to um thank esner and uh cdfw for um working with me and giving me the permits that allowed me to
Go out and do all of this sampling but um even Beyond funding uh so many people made this project possible um it takes a village to get a master’s thesis done and I certainly had that first and foremost I there’s my committee um my chair uh my first chair
Of my committee is Amanda Khan who is the best adviser a grad student could ask for um there’s been a lot of tough times where I thought I was going to give up or um leave the program and maybe not come back and Amanda always kept me grounded and kept me coming back
And is the reason I was able to finish this project um I’d also like to thank Sarah Smith um who has just been an incredible source of advice and edits and critiques and just being able to really like Focus this thesis into the best that it can be and my last
Committee chair is uh kistin who was initially not on my committee but was still involved with the project from the very beginning uh always telling me like oh this is the best spot to look at high many acid on uh here’s this fing plate data I have I’ve seen this before I
Think this would be of interest to you she’s been amazing and bringing her on with a real turning point in this project um I’d also like to thank all the volunteers that helped me um that came out into the mud with me um sometimes at ungodly hours in the
Morning um Sydney Alex Rachel Taylor Travis Grace and basil uh you guys are the best um but even the people who didn’t um uh come out with me into the mud um just the rest of the con laab if Amanda is the best adviser gradu could ask for
Uh the con lab is the best lab that someone could ask for uh Seline Jacob Anna Sam Isaac Randy um Christian and Sarah I know you’re here as well I um you guys are all the best um I appreciate all the all the support and editing and suggestions that made this
Project what it is uh my family who’s here uh Grandy Mumsy um Mom Dad had uh my siblings who uh have also been very supportive um they’re all great even even my in-laws some some in-laws wouldn’t care about um this thesis especially as something like sponge but
Um Gabe Nikki Finley Kaden um have always been incredibly supportive and I have some special thanks I’d also like to talk about for one thing uh Katie Duncan who was not just another volunteer but volunteered more than anyone else was always down to come out
With me into the slooh and get muddy um and just this was not possible to do with just one person so um having I needed a partner and Katie was always there when uh it was tough to find people I’d also like to thank Keenan
Gillis who um not only showed me how to use that die front method but um supplemented a lot of my uh data with his own that he took from uh pumping measurements of how many asdon which is just awesome and a huge shout out to him
And last but certainly not least uh my incredible fiance Sarah jeder who has just been so sweet and so supportive and just absolutely incredible listening to me Yammer on about sponges for over three years I love you and I think that’s it so uh if anyone has any questions they’d like to
Ask me um I am more than happy to answer them thank you if anyone has any questions in the room we’ve got the microphone here to let everyone on Zoom be able to hear as Wella will indicate we’ve got questions excellent excellent work Jackson and really really cool analysis
Um my question is I thought this season ality was really interesting and um and you talked lot a lot about the growth and and cover that you observed um how do you think that seasonality or maybe that lag affects um the the distribution of the sponge and I’m not really sure
How what the mechanism they use to spread out but you mentioned reproduction so I wonder you know or have an idea about how that seasonality and that lag affects their spread around the sleo right so um they brew the embryos and their tissues but they released them as
Planula larvae so they do have some swimming capability um I don’t exactly know how far they can swim um presumably they would be releasing them during and right after the brooding period that I observed so probably during the dry season and the um and maybe the first
Bit of the wet season so my guess is that uh that dry season might be a sort of like trigger for them to settle as for how far they can travel and how it affects them I’m not really too sure um plenty L don’t tend to be um in the
Water for a very long time um they they don’t really they don’t really have a lot of feeding capability or movement but um so I would assume that any um my best guess would be that any sort of of um larvel uh movement would be pretty approximate in close
Range excellent job Jackson um I have a question about the winter 2023 storms and also the mouth of the slooh yeah I imagine that the storms increased flushing quite a bit at your sites and I’m wondering if you have any thoughts on whether or not maybe it’s that
Increased FL ing down at the mouth of the slooh that might be preventing settlement or something like that and maybe is could that be a potential reason why you don’t see any sponges down towards the harbor mouth uh that could definitely be a reason uh if the
Larae were vulnerable to a lot of like low soleni that would definitely do a number on them uh and if it was washing them out into the lower sleo where we don’t see any recruitment so if the lower sleo is unfavorable for them and the flushing is pulling them all into
That unfavorable area that could be a reason that we didn’t see a lot of recruitment this yearing talking Wonder right thank you I was wondering whether you saw any evidence of this um um of the sponges actually capturing sediments whether they’re acting as a sort of a sediment trap like you
Know um so actually that benefit could be in the fact that they’re adding three dimensionality to the to the habitat and therefore you know AC Creek sediments yeah uh I mean I don’t know how much sediment they’re holding on to but they’re usually covered in um mud and it
Would and even when I to them like the mud was like sometimes pretty deep into the tissues um so they might be capturing a little bit of that of that sediment outflowing but um I don’t I don’t know if it’s that much because they would also they also
Keep having to grow up through it um so I I think my answer to that is maybe but uh I don’t know if I saw enough to really say one way or the other I have a question iana’s question made me think of this um that’s an interesting thing to think about for
Perhaps the role of them in preventing like erosion or something but with that in mind do you have a an opinion at this point are they is this a bad invasion is this a is it going to get worse is it one that we need to be concerned about
Kind of wondering if you have a a sense of that after all of your surveys and data um yeah I mean while I can’t say anything conclusively I would definitely say that from what I’ve seen right now um it appears to be maybe a nuisance species and possibly beneficial it
Doesn’t look like this is going to disrup disrupt elorn slooh in any particularly bad way uh I mean there’s other species that do like a burrowing isopods for example are really destructive but um this species I haven’t seen be destructive in that way all right we have four questions in
The zoom chat so I’m gonna add those here and we’re getting close on time so maybe we’ll we’ll go quickly through them first is from Joey who asks what factors might account for the differences in abundance between the sites measured um differ I think the biggest one is probably that hard substrate
Because just uh the more rocks and stuff that they have to attach to um the more that they the more that the juveniles can sort of settle on and grow um and that seemed to be the broad pattern that I saw so more rocks more sponges um
Another one might be that as a veto Pond the water flushes really quickly over and through them and as filter feeders that gives them a lot more access to food um it means that they might have to do you know less of the pumping and growing up through the sediment um
Because the water is Flushing a lot of that away and providing them with a lot of food all right next one comes from Leo Z who says great job Jackson my question is do you think there is any application to using the sponge as a way to help filter
Bacteria in Wastewater or drinking water as an alternate method than chemical treatment yes there’s actually been a lot of literature um investigating that uh and the answer seems to be that uh it would be pretty good for that kind of thing um it’s very efficient at uh
Taking out things like theoc coliform uh or ecoi at least in laboratory conditions the um the only concern that I would have about that is that because it’s a fowling organism it could completely clog up a system like that but if you could keep it contained uh I
Think that yeah there could be a lot of applications for it in that use right two more um Morgan James asks is there any evidence that this species is out competing any native sponge species um potentially uh I I did see it next to some other other species of sponges like
Um helona but there’s typically not that many uh Native sponges in the slooh like they’re there but they’re they’re nowhere near the abundance even when there is available substrate so um yeah it could probably outcompete them but I’m not so sure that that would be very significant okay and last question is
From Greg Cay who asked asks uh when their abundance and biomass goes down is it mortality or is it them shrinking like are some dying off um I think typically it is uh that they’re shrinking and that they kind of like resuscitate again every year um I’m
Not so sure about the sponges at aavo and Kirby during the rain I don’t know if they just went into a longer period of like almost like dorcy or if that actually killed them off um it probably is a little bit of both but typically uh
We see them sort of just like shrink back it’s not true death all right thank you so much a lot of great questions um so everyone please uh let’s thank Jackson one more time and and with that we will wrap up the public seminar we have Refreshments here
Um the Jackson’s committee is going to take him away for a few minutes and have a a meeting um but uh he will come back out and would probably love to see you and rejoin then so thanks again congratulations