Welcome to Sea of Whales, the whale geek podcast, where whale watching and whale research meet. I'm your host, Shauna Prince, scientist and whale watch operator, bringing you conversations with whale researchers and ocean experts from around the globe. Let's dive in. Today we're joined by Gale Davoren, Professor of Biological Sciences at the University of Manitoba. Gale has been doing work here in Newfoundland looking at predator-prey relationships in marine systems for over 20 years. Welcome, Gale. Hi. I'm glad to be here. Thanks so much for being here. How did you get into marine science? So what led you to doing this? Yeah. Oh, it's kind of a, a... I'll, I'll make the long story short, but I grew up in, uh, BC, in Victoria, um, on the West Coast, and everybody was into marine biology. And I was like, "I'm not going to be in marine biology because everybody else is doing it." And then I, of course, I grew up on the ocean and fell in love with it. So started doing seabird work, um, for my master's and PhD, but I was examining foraging behavior, and I realized that I needed to understand, to understand the foraging behavior of seabirds I needed to understand the fish behavior- Mm-hmm that they were feeding on. And so- Of course that just kinda blossomed from there, and I came out to, um, Memorial to do my PhD, and then have just kept coming back to do research. Excellent. Um, can you tell us about your work in Newfoundland, what you're working on, um, most recently? Yeah. So, um, I mean, sort of historically I was, I, I was working on seabird-fish interactions mostly. Um, that sort of blossomed more into capelin-focused research, just because everything comes in in the summer. All predators come in in the summer just to feed on capelin, as we know. Mm-hmm. Um, so yeah. So started doing a lot more capelin, uh, research and capelin and then other predators. So looking at, I mean, most recently we've looked at, um, jellyfish as a predator on capelin larvae. That's one of the things that, that we've started doing. Um, also started expanding our research to other forage fish like herring, which is again really recent, um, and sand lance, which is another sort of more recent, um, focus. So yeah. That's- mostly what I, what I'm doing. It sounds like lots of different projects. I know you have, um, graduate students working on various different things, and we'll talk about that a little bit later. Um- It used to be, and you alluded to this a little bit, I think people would have said cod was king here in Newfoundland. But I think probably more accurately, and maybe you'd agree, capelin are king- Yeah in Newfoundland. Um, and I often talk about on our tours how, like, the geology shaped the biology here. And so because we have beaches that capelin can spawn on, the cod came in, and ultimately that's why people came here and stayed here. And then various other, uh, industries sort of came up around the fishery, but initially people came here for that codfish, and the cod were close to shore- Right because of the capelin being here. Um, so can you tell me about the general health of the capelin stocks in Newfoundland and sort of what kinds of trends you're seeing with them? Yeah. So, um, we know- so I kinda came on the scene in 1997, so that's when I started, um, my PhD. So, um, at that point the capelin had collapsed in the early '90s along r- a- alongside the cod, which everybody knows about. Mm-hmm. Um, so the population has basically, um, a capelin population has basically just kind of bumped along at that really low, um, value, uh, f- since the early '90s. And there's been years where they've done, you know, they look like they're coming back and they're doing really well, and then they're followed by a bunch of years, um, of, of fairly low abundance, and y- you've, you've probably seen that over the years- Sure have, yeah as well. Mm-hmm. So, um, so no big rebound, and there's lots of research going on, um, with people at, at the university as well, or multiple universities as well as, um, the Department of Fisheries and Oceans to try and understand wha- what's going on with the population and whether it's going to rebound to those, like, 1980 levels- Mm-hmm and, and prior, yeah. I remember being told at one point that if you took all the capelin out of the water, they would weigh more than all the terrestrial animals on Earth. My expectation is that that's not the case anymore. Um, you know, and we do definitely see, you know, um, major differences year over year, uh, in capelin in feeding patterns, um, in, you know, spawning beaches that we remember even in recent times, you know, were much busier I would say, um, than they are now. And it is certainly concerning when that's sort of what everything is here to feed on, um, when you see dips in numbers like that. Uh, what are some of the biggest contributing factors, um, sort of what are the hypotheses about what might be happening with the stock? Yeah. So it's, I mean, forage fish, which capelin are a part of and herring, they, they typically go through these boom and bust population cycles, so they're really high in- over a couple years or even in one year, and then really low the next year. And this is all driven by recruitment, so the number of individuals that make it from, um, you know, basically post-hatch, like right out of the egg, um, to when they're spawning. So for capelin that's usually about two years, or at minimum two years. Mm-hmm. So there's something happening in that kind of recruitment window, um, that is causing these boom and bust, um, populations, um, dynamics. And so a lot of, there's a lot of research on, you know, there's, uh, on the, on the basically the body si- or body condition, pardon me, of, of the moms. Mm-hmm. Um, and so maybe not producing as many eggs as they would've in the past based on the fact that there's low abundance of really high-quality food for capelin when they're developing their gonads. Um, there's lots on predation or just, uh, not ideal or favorable conditions when those larvae are really small. So, um, d- Dr. Hannah Murphy has ha- and, and other researchers have shown that, you know, recruitment, so how many individuals make it to that spawning population, um, really is determined in the first, you know, several weeks of life- Mm-hmm um, post-hatch. So there's a lot going on. I mean, this is where this, you know, the idea of, of this jellyfish project that we have on the go, um, came in because we see these huge numbers of jellyfish sometimes in the summer. Yeah. They're associated with these capelin spawning sites. Mm-hmm. And we think that, you know, they, they're a generalist, or we think they're a generalist predator, and they could be, you know, basically eating a whole bunch of these, of these larvae, which could cause those, some of those population dynamics. So that's why we're trying to get a better handle on that. Hannah Murphy has looked at herring- Mm-hmm and whether adult herring are eating, um, capelin larvae, whether, you know, the temperature or the conditions are just not good for, for growth in those first kinda month of life. And- Mm-hmm. Yeah, so there's, uh, there's a whole host of different- There's so many factors. Yeah. Yeah, yeah. That, and it, it's hard to tie it down to one or two factors. Like people ask, well, is climate change, you know, is global warming causing this? And yeah, there's a, there's lots of questions about... Yeah. It's probably, yeah. Most likely. And it's not just one thing is my guess. Yeah. It's multiple things that have just compounded. You know, it's a snowball effect kind of thing. Absolutely, yeah. Um, I have heard a couple of things. You tell me if it's true or false. Um- Female capelin release 30 to 50,000 eggs when they are laying their eggs. Is that accurate? Yeah, uh, I think we... Yeah, yep Okay. So- Yeah, depending on the size we can still use that stat? Yes, depending on the size of the individual, um- Yes, of course obviously, yeah. Yeah Yeah. So as, as the females get larger- Mm-hmm um, yeah, they're pr- they have more eggs. And I think more recently there was around 20 to 30,000 that... Yeah, but it's hu- it's a huge number. Mm-hmm. Um, but what we're, again, we're seeing smaller and smaller fish, which means- The survival rates, yeah yeah, lower- It's a strategy to produce, overproduce because you know, you know, the, the success rate is so low that- Absolutely then at least you'll have some that make it, right? Yeah, yeah. Um, and so many species use that, but it also takes an awful lot of energy- Yeah to make that many eggs. Yeah. Um, and we know that a lot of the males will die on the beaches fertilizing the eggs because they're up there for longer, and they're, you know, in the wave action and, and spending some time fertilizing those eggs after they're laid. But with the females, you know, once they've spawned, are there any that make it to subsequent years? Or, you know, how, how does that work? Yeah, that, that's a huge question that we have some information, some studies on. Um- W- yeah, and we're thinking about, uh, collaborating to start-- A bunch of us are thinking about collaborating to get that started because that is a critical part. If- Mm-hmm if some of those females survive spawning, then, then, you know, we're possibly, um... Yeah, it just changes the way we would, we would estimate population size and- Absolutely and how we would model, you know, population size into the future for- And how to support those populations if it's not just- Absolutely they all die when they go on the beach, and then that's it, you know? So that's- Yeah a very different- Yeah a very different model. I know, I mean, we still do have a small commercial, uh, capelin fishery here in Newfoundland, which is, um, at times can be controversial. Yeah. Um, and so I, I have done some reading about how Norway changed how they fish these, these animals. Um, so they were, um, trying to get them post-spawning if possible, so the idea being that the females are able to lay their eggs on the beaches when they come off because then there's very few males and mostly females. Trying to kinda scoop them up then. Then they're getting higher percentage of females, which is what they all want anyway because usually, um, for people who are listening who aren't aware, capelin are fished, um, or were fished, um, where they only wanted females for the roe. Yeah. Um, and I'm told that, you know, studies had shown that they only, um, are able to really lay about one-third of the eggs that they have, um, and then the rest are still in the female even after she's spawned out. Is that, is that accurate, would you think? No, it's not. Um, no. I think, I think mostly they're, they're considered, um, batch spawners, which basically- Okay just means the females come in and, and, and release all of their eggs at once. Mm-hmm. That's, that's the more prevailing thought. Um- Gotcha. Okay. Yeah. So when we- So then the post-spawning maybe isn't the best way to fish them if you're looking for, if you're looking to sell the roe, right? Um- Yeah, if you're trying to get the eggs, then yeah. Yeah. Not so much. Yeah. I know when I first came here, my first summer would've been 1999, and I remember going to harbors that were completely silver on the bottom with capelin because, um, the buyers would come and look and say, "Too high a percentage of males. Dump it," and they'd just dump it on the bottom. They were absolutely worthless. And, you know, looking back- Um, I know that it was, you know, not long after the moratorium. I know that things were struggling, and fishermen were looking for other species to make money. Um, and now it's done in a very different way, of course- Yeah uh, in terms of what's done with, you know, if with the males for example once they are separated out from the females. Um, but yeah, you have to wonder sometimes about practices like that when, when they didn't know better. Um- Absolutely. Yeah and were just trying to make a go of it after, you know, their main, their main species had been removed from the equation. Yeah. Um, but I'll, I'll never forget seeing that and wondering like, what are we doing, you know? Um- Yeah. Oh, absolutely. Yeah. It was very, very wasteful. And I think the aquafeed industry, so, um, is maybe using those males. I don't know what the percentage is. Yeah. Yeah, I'm not 100% up to date on that, but- Yeah, for fish meal. Yeah but I would think that, yeah, for aquaculture, for feeding, yeah, for fooding. It's no longer garbage anymore- Yeah which is good. You know? Yeah. I would, I would hope. I mean, there, there's a huge market for aquafeed, so- Yes I would think that, yeah- Absolutely they would be using those. But I don't know what the percentage is in, in Newfoundland that gets used for that. Um, yeah. And, and year to year it may differ. I, I really hadn't, um, put much stock into thinking about who eats the larval capelin except that it's always been said here that the squid are coming to eat the larval capelin- Oh and it seems like it's around the same time, um, that they would be hatching. So, um- In Bonavista Bay in particular, we don't see as many squid here. I know, uh, historically there was a lot of squid jigging in Dunfield Bight, which is a bight off of Trinity Bight. Um, but we don't see as many squid in this area as we do in Bonavista Bay now, and I'm not sure why that is. In some years they come, of course, and some years they just don't. Um, but, uh, yeah, we were always sort of told that. But we have definitely seen squid coming right up onto the beaches after capelin, which is interesting. Oh, that is interesting. Yeah. Um, in some seasons, yeah. I don't know if there's been a study on that. If, if there has been, I'm unfamiliar with it. So that- Yeah that would be a neat thing to look at, actually, online. I'll just call you next time I see something weird. I know we had family visiting from Nova Scotia and my uncle said, you know, I think we had been pa- berry picking with the kids in the morning. They were going out for the commercial or for the recreational cod fishery. And while they're waiting, there's capelin rolling on the beach and squid chasing the capelin up onto the beach. And people were just picking stuff up in buckets. And he said, "It would be really hard to starve here." You know, so as much as things are changing, there still is an abundance of, of food here at the same time. It's just- Yeah not on the same scale- Yeah that we were seeing before. Um, which is concerning for sure when we look at, when we look at changes, um, you know, over time. Yeah. So yeah, I mean, very concerning about, um, changes to the capelin because we know that they're the basis of the food chain here. All of the seabirds right now are nesting and sitting on eggs. Yeah. Uh, sort of banking on the hatch being at the same time that the capelin are here to lay their eggs. Yeah. You had mentioned something about, um, conditions for when the eggs are incubating and hatching. So can you tell me a little bit about what would be considered sort of prime conditions for that to happen? Yeah. So, um, we've done, we've done a bunch of studies on that and, and I mean historically, so if you go back to sort of the Capelin Bible- Mm-hmm which was Templeman n- uh- Yeah 1948. Okay. Um, you know, they sort of suggested that the preferred, um, or the, the optimal temperature- Mm-hmm um, for egg incubation for capelin was between 2 and, and 12 degrees. And- Yeah and we've found that, um- You know, in our long term study area there on the northeast coast that, that that's basically it. If the temperatures are below, um, two degrees, they're not, and the capelin are around, they're not spawning. Mm-hmm. They're waiting for it to get to that, you know, that higher temperature. But again, if it's over 12 degrees, then, then they're not spawning there too. And, and so I guess one of the more surprising things, or not surprising, because Templeman actually did, did describe this, but this movement from, um, capelin spawning on beaches, 'cause you mentioned that, right? Mm-hmm. Everybody sees capelin spawning on beaches and, and if they're not spawning on beaches, they're not spawning. But they actually do move off and spawn, um, subtidally, so in, in slightly deeper water- Mm-hmm which I'm sure you're aware of as well. Yes. And, um- Yeah, so that, that was one of the more surprising things. And on the northeast coast we have a lot of what we call subtidal or, or demersal spawning- Mm-hmm um, that happens, um, th- that's not on the beach, so a lot of people, like, we've got gorgeous beaches up there, s- same as you guys- Mm. Right? Yes. And, and yeah, and there, we go out and check the beaches every second day, and we, we don't find any spawning, so. So that temperature is really, is really critical, and we've done a lot of interviews with fishers, um, around the province who basically would totally agree with that and just say, "Yeah, it's all, it j- just has everything to do with the temperature." Mm-hmm. Um, and then when they come off, that's what we know, when they, when they hatch I should say, um, that's where we know a lot less about what's optimal. Mm-hmm. Yeah. And, you know, there's, there's been a lot of work early on by, um, by researchers, uh, that, like Frank, um, Ken Frank and- Mm-hmm um, Bill Leggett that did a lot of research on, um, you know, the, having the right temperature, having low predators, low predator densities, and, and lots of food available. So having those kind of optimal conditions, which they described fairly well, but that pattern seems to have broken down a little bit, um, a little bit more post, um, the, the capelin collapse, and that's what- Mm Dr., uh, Hannah Murphy has shown is, you know, just we're not 100% sure about what those conditions, those optimal conditions for the larvae are. Yes. Yeah. And again, probably a whole slew of things impact, you know? Yeah. Predation, you know, temperature, salinity, you know, um, turbidity. Like, all kinds of different things when they're that tiny can really- Yeah impact it. Yeah. Um, it's interesting when you talk to the old-timers, we'll say. So m- my husband's grandfather would tell you that they had two stocks of capelin in Bonavista Bay, and I'm sure you've heard this. Yes, yeah. The ones that would spawn earlier than they do now, we're, we're sort of into July before we see any capelin rolling on beaches now. They would have capelin rolling before school was out, so say early to mid-June, which is- Yeah definitely not the case anymore. Yeah. Uh, and then they'd have a stock that would spawn a little bit later on, and they were different in terms of body size. I can't, I, I would totally get it wrong if I told you, but one was bigger than the other. I can't tell you which one it was. It was the earlier- And- ones were bigger. Was it? Yeah. Yeah, yeah. So now we don't really have that, I wouldn't say, or we're not seeing that. So again, he, he would say, "Some will, some will spawn on the beach and some will spawn in the deep," as he would say, you know? Yeah, yeah. And so that's what he would, would tell us about sort of what he remembers happening. Um, but it's interesting too, you know, patterns. One year it got really warm really fast. It was a really cool spring, and then it got hot. And it was a really hot and really dry summer, and we had capelin rolling on Labor Day weekend. Um- Yeah so when you look at what's normal, that's not normal. Um, and when you look at then long-term survival of those larvae- Yeah you know, and I'm not... I'm, you know, I'm out there observing, but I'm not taking any measurements. And, you know, looking at return rates then two or three years after when they are sexually mature, was that year one of those years where we saw a massive dip in this area? I don't know. Because again, how do you even measure capelin biomass if you're just on a whale-watching boat like Yeah. Whale watching like, "Well, there seems like a lot on the beach this year, and there weren't any, you know, last year" kind of thing, right? So I mean, that's not my area of expertise, but I can certainly, you know, see that there are changes happening. But that year was very worrying when they were laying off and laying off and laying off. And because they're laying off the beach and not doing what they're here to do, then they're vulnerable to being eaten by- Yeah what we're watching. And- Absolutely you know, how, how does that affect it over- overall? And so when we have these weird years, um, you know, do you see then, you know, after the fact that you can really see a big dip as a result of some of those changes? Yeah. There's been a lot of trying to, trying to correlate that, those, those observations, um, in during spawning and post, like post-hatching. Mm-hmm. There's been a lot of attempt, especially in Trinity Bay by the Department of Fisheries and Oceans,. So they have the spawning observations on the beach. They have biomass estimates. They have, um, i- you know, spawning, uh, biomass estimates from- Mm-hmm their subtidal or deep water spawning sites or demersal sites- Mm-hmm whatever you wanna call them. Mm-hmm. And then they have larval surveys, um, about a month later, so later into August and September, and trying to correlate, you know, the, the number of eggs that were on the beach versus the number that they're seeing- Mm-hmm sort of right after hatching and then way later. Um, and then of course, they have their, their offshore, um, survey in the spring before the capelin come in. So you know, trying to correlate all those things, and you think that it would be like, "Oh, yeah, well, we should see a dip the next year 'cause we didn't see that many larvae." It's like, oh- Mm-hmm it's not quite that simple. And yeah, just trying to come up with those mechanisms. There's, there's a whole bunch of links that, that we still need to figure out, and some of those, like going back to what we were talking about before, might be related to, um- Yeah, just, just post spawning survival, so maybe those, some of those, we're not accounting for some of those females that actually survive spawning. Mm-hmm. And yeah, there's just a bunch of links that we still need to kinda work out, um, because you would think that that would be directly related, and when we, we're talking to the fishers who are my most favorite collaborators- Mm-hmm um, you know, they're telling us all these amazing things, and I'm actually out there seeing that too. And yeah, and then it just doesn't relate to the population size- No. Right in a, in a couple years- Yeah and you're just like, "Wow, this is just..." Um, yeah. We just, we, there's just more and more questions that keep coming up that we need to keep trying to answer. So. That's what science is though, right? It is. The more you learn- Yeah the more questions you have. Yep Right? So. Best part of it. Yep. Yeah. Um, so you, when we talked about the two stocks that Chris's grandfather would say there were- Yeah is that still the case? And are some of these ones ones that sort of spawn in the deep so we're not actually seeing them? Or are we just down to one now? Has something happened to one of those? Yeah. It's a, that's a great question, and a lot of my work, um, research early on was trying to figure out whether, you know, the deep, deep water spawners versus the beach spawners, whether those were different populations genetically, um, or whether it was a choice based on- Mm-hmm temperature. And so we actually ended up tagging a bunch of capelin, and, um, with acoustic tags, and figured out that they are, they're actually making a choice. So- The, but as far as the timing, the individuals that come in earlier, um, we also looked into that and were able to show, um, and, and other researchers had shown this in the past as well, before the collapse, that the, you know, the larger, older individuals tend to come in first. Mm-hmm. And then the, the smaller, um, younger individuals would come in later. And so with the population being primarily composed of those younger sort of two-year-old and smaller fish- Mm-hmm that might be sort of one of the reasons that could explain why we're only seeing those later fish come in now. Right. Um, so m- more due to sort of demographics and demographic patterns than, than specifically the kinda two population- Sure thing. Yeah, 'cause, uh, I mean, early on we'd see several waves of, of capelin coming in, so they're- Mm-hmm and they were separated by a decent, you know, week to two weeks. Yes, yes. And we were thinking, "Okay, these have gotta be genetically different or, or something," but it turns out- Different that they're probably, yeah, they're probably the same population. It's just in years where there's larger individuals, we might see them coming in a little bit earlier. Mm-hmm. And yeah. And w- so the larger ones weren't necessarily older than the smaller ones, just bigger? Well, no, they were usually larger and older- Mm those ones that came in, so the larger, the larger and older individuals would come in first and, and the idea with that is that they would be, potentially one way to explain that would be they, you know, the larger individuals can swim faster- Mm-hmm and therefore make it in, so their gonads would develop. Most likely the larger and smaller individuals, their gonads would develop at the same rate offshore potentially, but the- Mm but the larger individuals could swim faster, so they're the ones that would show up first. But maybe with the sort of smaller population sizes and only primarily the smaller individuals now, we don't see those separate waves, um, coming in- Right and spawning at those different times. Yeah. And so I think you had mentioned before that, you know, is that about the quality of food that's available to them? Yeah. And the abundance of food that's available to them. Yeah. Mm. Absolutely. And yeah, these really lipid-rich euphausiids or- Mm-hmm krill, you know- Mm-hmm a lot of people call them krill. Um, yeah, they- they've, um, basically dropped out of the, of the diet, um- Mm-hmm for the most part. Um, more recently I guess they've started to show up a little bit. Um, and this is work by Department of Fisheries and Oceans that have looked through hundreds of stomach samples of capelin and it's just an- Mm-hmm amazing data set. It's a lot of work. And, and a huge amount of work, but it's really valuable to show that, you know, why their body condition, why they might not, um, yeah, why they might not be producing as many eggs, these sorts of things. Mm-hmm. Yeah. Mm-hmm. Yeah. And then couple that with maybe n- not producing as many eggs, and then not having the same success rate with the larvae, um, you know- Yeah you've got a perfect storm here. Yeah. Right? Exactly. Um, so- Well, and it's not, yeah, sorry. But it's not just, um- The number of eggs too, it's also the quality of eggs. And I, I know there's people, um, that, not me specifically, but other researchers that are looking at that as well. So maybe those eggs are smaller. There's less, um, energy reserves in there for that larvae to, um- They're less likely to survive- Yeah even if they do hatch. Yeah. Yeah, absolutely. Or if they hatch at all. Yeah. I guess. Yeah. Exactly. That's another issue, yeah, yeah. So we're well aware of who the predators of capelin are when they are pre-spawning, or when they're of spawning age I guess I should say. Yeah. So we've got, you know, various different nesting sea birds. We have codfish. We have, um, seals and whales. So who are we concerned about when they are in the larval stage? Yeah, so this could be so many different possibilities. Yeah, 'cause they're so tiny. I mean... Yeah. Mm-hmm. So Dr. Hannah Murphy, I mentioned she did, um, her and her, her student, her really awesome master's student, had done, um, a study looking at, you know, whether adult herring had, had capelin larvae in their stomachs. So, um, difficult to do. They, they digest really, those little larvae digest really quickly, so, um, it's really hard to see, um- So yeah, yeah, it's, it's a tricky, it's a tricky study to do. Um, but jellyfish are, are another one. That was one of the big ones even in the '80s that, that, uh, yeah, they just... We would expect. We're, we're trying to figure out where those jellies kinda fit into the, to the food web. That's one of my, uh, master student's, uh, work right now is trying to look at that and just to see whether they could be, you know, feeding on... Like, we know that they're around, but, um, you know, are they actually feeding on capelin? So the lots of, um, you know, flat fish, uh, would be feeding on the eggs potentially. Um, there's been some work on that, um, going back quite a bit. But yeah, there's lots of, lots... Anything you can imagine. Any little invert- Yeah invertebrate that's out there could be- Yeah could be eating them- They'll take them in as well. And like you said, it's hard because they're tiny and they would digest really quickly 'cause they're, you know, a fairly simple animal. It's not like- Yeah there's a lot of, you know, large bony parts that are left behind or any of those kinds of things, so. Exactly, yeah. How critical are the sea conditions at the time that the eggs are laid? I know I have read a little bit about sort of the wave action helping them to sort of sift down through those sedimentary layers and, um, or layers of sediment and then having them hatch and then they kinda swim off the beach or they're washed out to shallower water where they, um, will then hatch. So you know, is it, when we have capelin weather, for us it's typically southern wind, the rain, drizzle, fog, and southern wind as a whale watch operator brings really big ground swell and people get sick, so we kind of tend to hightail it over to the Bonavista Bay side where it's a little bit calmer. Um, are those wave conditions also important to the success of that larva- larva at that time? Yeah. So there's... Oh, and I'm just trying to think of what the prevailing wind direction is, but yeah. If you imagine, like, uh, for a beach specifically- Mm-hmm um, so the larvae hatch and they're thought to spend, well, we know that they spend time in the sediment before they emerge. Like, so- Mm-hmm pre-emergent larvae and then they emerge into the water column. And there's a specific wind direction that basically creates these conditions that would cause them to emerge. So it's a temperature cue, a warmer temperature, and that's upwelling- So bringing in this wa- warmer water- Mm-hmm that acts as a temperature cue for those larvae to, um, leave the sediment and go into the water column. And the idea is that that warm water temperature, um, kinda comes with, uh, low predator densities and, and high prey densities, so- Mm-hmm creating these favorable conditions. And this is this work by, um, Dr. Frank, uh, or- Mm-hmm Ken Frank that I talked about before, which is kind of broken down a little bit, but that was, um, that was the idea that those were the ideal conditions for those, for those larvae. Okay. Um, so that wind that, that really critical wind direction that would cause that, that, um, that warm water temperature cue was thought to be really key. Mm-hmm. And if we didn't have that, that wind direction- Yes then we wouldn't, we wouldn't have, um, you know, those optimal conditions for the larvae. And, you know, Dr. Hannah Murphy has figured out that that, that, that, those optimal temperatures with the wind has kinda broken- Mm-hmm down a little bit. But, um, but yeah, there's probably, a- again, optimal conditions for those little, little guys coming off- Yes um, the beach to, to cue them to emerge, so. Mm-hmm. Yeah. And I think, you know, with other species it might be possible to simulate these kinds of things in a, in a controlled environment, but it's- Right just not really possible with capelin. There's so- Yeah many factors that you, you can't do this on a small scale in an aquarium and then measure all these things. It's just- Yeah it's just not possible. It's too big of a system with too many factors to simulate that, you know, in a lab. Yeah. Um, and so, um, so much respect for what you do because it, it's not as simple as, you know, A plus B equals C. Oh, I wish. Well, no- You know it'd be boring then, right? Yeah. Yeah, yeah. Exactly. Just out of curiosity, on average, because I know it would depend on many different factors, from the time the eggs are laid until the larvae emerge, how long are we looking at? Yeah. That, that totally depends on temperature. Um- Mm-hmm so it could be anywhere from, you know, 10 days to, like, over a month, um- Okay in some cases. Wow. So if you imagine, like, a, a warmish beach, so, like, 11 degrees, and the- Mm-hmm it's about that in the sediments, it would be about 10 to, 10 to, 10 days to two weeks. Okay. And then a- at some of our subtitle sites where it's, you know, five, six degrees, then it could be, um, you know, 20 days or, or maybe even a little longer. Mm-hmm. Yeah. Yeah. Okay. That makes sense. And when you talked about them choosing to spawn in different areas- Yeah so let's just recap. Salmon return to the rivers that they hatched from. Capelin are not doing that, then? Yeah, I mean, this is, this is an awesome question. No, it's... Yeah That is, that is- Yeah like, the natal homing kind of- Because you can't tag a larvae. Yeah. And then see if it returns back to the beach. So what's sort of the generally accepted idea for what's happening there? Yeah. We're, I mean, we're 100% not sure is the- is the awesome way to put it, 'cause, you know. Yeah, yeah. Um, we've d- we've done a whole bunch of work on... Yeah, like you said, you can't tag those little guys. Like, they're three to six millimeters long when they hatch. Mm-hmm. Yeah. Um, but what we've tried to do is, um, you know, for instance, for the, for the beach, like do fish that spawn at the beach, and do those eggs that are raised on the beach, do they come back and spawn at the beach? Mm-hmm. And same with the deep water sites, you know, if the, if an egg is raised at a deep water site, do they come back? later in a couple years and spawn there. Mm-hmm. Um, we've tried to get at this with, with otolith chemistry. So- Mm-hmm if you, people, people would know about cod otolith, so their- Yes ear stones. You can buy earrings here made of them. So in the head. Exactly, right. So- Yeah capelin aren't any different. They're, they're tiny in, in a larval, um, capelin. They're about 10, or sorry, 12, or ugh, I'm getting this wrong, 20 microns. Oh, wow. So micrometers, so they're tiny. But you can actually determine the chemical, um, so the trace element composition, so the concentration of- Mm-hmm of like, um, strontium, barium, different chemicals. And you can use that as a natural tag. Mm-hmm. Um, and then look at- Figure where they came from. Yeah. Yeah. To try and, uh, that's been a, a 15-year quest in our lab- Wow to see if we can use that as a natural tag. Mm-hmm. Not necessarily for natal homing, but to see whether, again, it's about whether these, these are different populations, um- And then also looking at relative productivity across bays. Um, so, you know, is Trinity Bay more productive than Conception Bay or something like that? Mm-hmm. Yes. So we've been trying to use this otolith chemistry to, to get at that. Um- Mm-hmm and that's a, that's a whole can of worms that I won't get into here. Yes. Wow. But, um, but yeah, it, yeah, this has been on our, our minds, and the natal homing is, is really cool to try and, try and figure out as well. Yeah. Yeah. Interesting. I know even in our area, um, close to Bonaventure Head, we have a couple of really significant spawning beaches. Um, there's sort of three in a row. Uh, the middle one, there was a landslide a couple of years ago- Uh-huh and so there's a lot of very large rocks on part of the beach, which has sort of changed the makeup of the beach because it's changed the way, um, that sediment is being sort of transported across that beach with this massive sort of like boundary- Yeah almost like a dam sort of thing happening. Um, so we don't see as much spawning on that beach as we did before. And also in, on some of these beaches, just because of the way the cliffs are and the way that the shadows are on the beach, sometimes we see more spawning happening sort of in the shadowy places, where maybe it's a little bit cooler than in, you know, in m- more bright spots where historically there would've been a, a lot more spawning. And then, um, around the corner there's this neat little inlet that we always take people into because we have some really interesting conglomerate rocks there that, um, look all kind of lumpy and bumpy 'cause they're eroding at different, um, rates. But there's a very small capelin spawning beach in, inside that, and some years it's very well used, and some years it's not. So is that, um... And actually when we were in there on Tuesday for our geology tour, there was still snow in there. So- Oh the way that the sun is hitting that is significantly different than every other beach where there's literally no snow anywhere else right now, and hasn't been for weeks. So, you know, they, do they know, uh, are they aware or self-aware enough to be like, "We, we need to be somewhere where it's much cooler, it's too warm right now"? And are they able to make a decision like, "We will spawn in here this year," or on this side of the beach as opposed to that side because of light and temperature and those kinds of things? And I'm sure that that's a question you would like to know the answer to as well. Yeah, it would, yeah. Yeah. Well, I mean- But it's interesting to see yeah, and the, and the sediment, like bringing up the sediment, that's really critical. Like, so the spawning substrate. Mm-hmm. Um, I think, I think they would be making a choice, um, based on that. Um, th- knowing about where an area's gonna be cooler after they've laid, like they've basically spawned, it's hard to tell- Or maybe it just feels cooler right now and that's why. Exactly. You know? Yeah. Yeah We've, we've monitored, um, spawning sites for, for, you know, well, 20 years. Mm-hmm. And so there's sometimes, you know, we know that the optimal temperature range, or we expect that the optimal temp- temperature range is around two to 12 degrees. Mm-hmm. But once they come in and, you know, it's 10 degrees, they're, drop their eggs and everything's great, but then a week later, you know, it's like 22 degrees- Yeah or something like that. And then they just be gone. And- Yeah Yeah. And everybody's like, "Well, why would they have spawned there?" Well, well, they, they don't know. They came in, it was great when they spawned and they left and- Yeah and they're like- Honestly, if I knew what the t- what the weather was gonna be like- next week, you know, I would be- Yeah making millions right now, right? Yeah. So, I mean, they don't know. Um- Yeah and even, you know, with the nesting seabirds that we have right now, they are nesting and, you know, hopefully when the chick hatches it will be at the same time that the capelin are rolling, but maybe it won't be and they'll have to be going out further. And I know we've seen cases in some nesting colonies where the capelin have just been out so far that the survivals of- Yeah the chick, the survival rate of the chicks is much lower because they just can't feed the chicks as much as they need- Yeah when the prey is that far away, right? Yeah, that, that mismatch is, is really critical for- Mm-hmm for all species. But, uh, uh, but same, same with capelin, the mismatch with, with a good, with good temperature and yeah. I mean, the, the substrate's really important as well- Mm-hmm because like you said, you know, they'll mix, you know, that'll mix in the sediment and create, you know, opportunities for more oxygen. And- Mm-hmm so I mean, if, you know, if there's those big boulders on the beach, they're, you know, and if- Just doesn't work the, from that landslide it might, yeah, they might not use that area anymore based on that. Yeah. But- But there's so many beaches, you know, not very far from there that if a stock is coming in, there's options. But then it's not a situation where, you know, if it, if they were a salmon and the river got dammed off, for example, which is happening where you're from- Yeah you know, if they can't get there, then what happens, right? Yeah. So, um, it's, it's good to know that they're probably able to make, you know, game time decisions where it's like- this isn't gonna work. I like the game time decision. Yeah, exactly. Yeah, right? So they can move on down the shore and find something that does. And maybe it's that in Trinity Bight in particular we have just the way that the rocks weather creates those types of grain sizes- Yeah because it seems like we have a, a really, um, large amount of beaches that have capelin spawning on them. So, um, you know, I'm sure that that's not a coincidence either. Yeah. Again, how the geology informs the bi- you know, how it, how it affects the biology that's in the area, so- Yeah it's, it's always interesting. Um, what are some of the most surprising things that you've found throughout your career? I know maybe some of the things you found that were surprising at the time are no longer surprising anymore, but yeah. Well, yeah, I guess one of the biggest, um Like, again, going back to this deepwater spawning of capelin, like, you know, Templeman talked about it in 1948 in, in, um, his report. And so we knew that this was, this was happening. Um, but I guess what we were doing early on in Notre Dame Bay is, you know, we were doing these larger kind of eight- 800-kilometer kind of meso-scale sort of larger, um, surveys. And we were mostly Like, we had a hydroacoustic system that was like an echosounder essentially and looking below the boat while we were counting birds and whales. And we used to find, and we still do, find these incredible areas where we needed three people counting birds. Awesome. There was just incredible amounts of birds and humpback whales in particular that we just You know, we just couldn't capture it in our counts- Mm-hmm accurately. Like, there was just so many. And we were trying to figure out what was going on and why. And it was like year after year it was in the exact same spot, and we were trying to figure out what was going on. And, you know, we, we got access to a remotely operated vehicle, and we dropped it down and there was capelin spawning, and it was, like, everywhere in this, in this, you know, 30 to 40 meter, um, water depth. And- Mm-hmm we had gone back and told our cape- you know, capelin biologists that this was happening, happening, and they were like, "Oh, well, that's just this one year. It's not important, right?" And it was like, wait, wait, wait. We're showing this year after year. And also this year and this year and this year. Yeah. Yeah. Yeah. And our humpback whales that we've ID'd, you know, there's individuals that are coming back to this exact same 10-kilometer square area- Wow every single year, which I'm sure you guys see as well. We definitely do. And- And my guess is if you put an ROV down here, you would see something like that- Yeah happening, yeah. Yep. Yeah. So I mean, and that just sort of started a, you know, a career-long quest to look for, you know, this, these subtidal sites in, in other areas. Yeah. So we've done work in Placentia Bay. We've done, and we've found them, you know, spawning in there, um, on macroalgae, which again was super weird, 'cause we thought they were- Mm only sediment spawners. Yes. Um, we're doing work in Fortune Bay- W- you know, and, and this is, this is where the, the fishers are just amazing collaborators. You know? Yes. You just go out and say, "Hey, where do you think there's Where are they spawning in deep water?" Mm-hmm. And they're like, "Right there, right there." Yeah. They can point to places on a map- Yeah and you go there, and they're exactly right. Yeah. And they just know that this is happening and that this is important. And yeah, and just- It's important to the survival of everything that they're commercial fishing. Yeah. You know? So, yeah. Well, a- and super critical to, like, if the beaches are getting too warm, right? This is the prediction. Mm-hmm. Yes. That they have this option- Yes of potentially moving off. And so that has, that was by far early on- Mm one of the most I mean, again, we knew it was happening, but understanding the importance at which it was happening everywhere and trying to get, you know, people That are managing the stock on board to, to really, um, think about that a bit more and understand it and, and just the outcry from the fishers- Yes um, that, that I was just, "Yeah, let's, let's do this 'cause this is really important, and you guys have been saying this for years." Yes. And let's, let's have this incorporated into, you know, stock assessment estimates and, and, you know- Awesome considerations anyway. So, so that's been... Yeah. That was, that changed- That's a big deal. Yeah, and it changed- Yeah the course of my career, um, working with these fishers and finding these sites and- Yeah just, yeah, having that collaboration. We have eyes on the water, we call them, every day, who are letting- Yes us know when they see things, and it, it really helps us out too. Um- Oh, wow. Yeah, absolutely And so, I mean, when there are people who work on the water every day, they have a different sense about what's happening out there. And I know, um, when we have research teams come to visit, they, you know, utilize our knowledge in the same way. So things that they see when they're here for a week, you know, when we've been watching these animals for, some of them for decades, um, and day after day and hours a day with these same animals, you know, the, the kinds of things we see and the, the data set that we have up here- Absolutely um, is very different than what a snapshot can do when you have a, a very narrow field season just because of, you know, the nature of the beast. This is how it works. You can't- Yeah you know, you can't be out there all the time. But they are out there all the time. And we, we are out there all the time. Now, I'm not doing any fisheries research, but, um, you know, even the work that we do with the humpback whales and the sperm whales and the orcas and, and the fin whales and, um, you know. So the things that we observe on the daily basis and the changes that we're seeing. And I, I really sometimes wish that in the earlier years I had kept better notes. I'm getting better at it now. But, you know, anecdotal evidence only goes so far. You need to have actual, you know, data and proof that these kinds of things are happening. So, um, you know, it's, it's always, always grateful to have the, you know, the informed, um, not even just, like, opinions of what's happening and what people are seeing- Yeah um, both from the people who work out there every day and then the people who are studying this at the same time. And I think if everyone works together, we do ultimately get a much, um, more complete- Oh, yeah picture. Absolutely. And there was a time when I think scientists didn't- I don't know if it's necessarily scientists, but i- the, the old, like, ivory tower science sort of model- Yeah where it's like I sit here and I know better than everybody else and I don't need to listen to anybody. But if you are looking at the knowledge of the people who have worked with these stocks for a year or, like, years and years and decades and decades, and even, you know, the marks for fishing and things like that, that, you know, why are those areas so, um, rich? And then when you start to look at those, maybe those were always areas where capelin were spawning on the bottom and that's why the codfish are there or whatever the case may be. Absolutely. There are reasons for what they saw. Yeah. Um, and so yeah, super, super important I think. Yeah. Well, and honestly, yeah, the ivory tower thing is, is funny and- So out. And I, I don't think, yeah, I don't think... Well, there's, I'm, I'm guessing there probably still are people that- Mm-hmm think they know more than, than people who are out on the water all the time, but I'm definitely not one of those- No. people. I just want, like- You know, if I'm trying to find a deepwater spawning site, the ocean, the ocean's a big place, right? Mm-hmm. Yep. And it's- And she hides her secrets well. Totally, right? Yes. So I mean, what am I gonna do? Go out and start surveying? I'm gonna- Mm-hmm be in the wrong area. I'm gonna- Yeah you know, it just, it just doesn't make sense to not- No work with, with people. And, you know, we, we hire, um, like local fishers to, to do our research- Yes every year. Mm-hmm. And that c- that collaboration- Makes a lot of difference has absolute- yeah. Has- Yeah you know, even just like, what have you been seeing before we got there, you know? Mm-hmm. 'Cause we're there for two months and oh, it's just... Yeah. Yeah. They're amazing people. Yeah. And every year is a little different. I remember one year you had, um, a graduate student, Kelsey, working on humpbacks- Yeah and she was getting very close to the end of her time in Newfoundland and you hadn't had any whales yet. So I remember you being like- Oh, yes "Can I send her to you? Are you seeing whales?" Um, because typically with them it goes south to north, and you're further north than us, so where are they? And then we had sort of figured out something, and the next day you messaged me, you were like, "They're here." They're here. It's fine. Never mind. Yeah, so. Yes. You know? That was, that was the year that they didn't spawn up in Notre Dame Bay until like- Mm-hmm like early August. Late. Yeah. Yeah. And we were in a full panic, yeah. Yeah, of course. Like how are we gonna do- Yeah research on whales when they're not present? There's no whales. Yeah, right? Yep. Valid. Yep. Every year. It was a problem. It was a problem- Yeah I wasn't expecting. Definitely a big problem, right? Especially when you're, you know, you can only be there for so many weeks. Yeah. Presumably you have to teach again in September. They have classes they have to go to. Yeah. And so if everything happens later, well then, like you just missed it that year, right? Yeah. So. Yeah. You know, and you don't ever wanna be in that position to have a big gap in your data set either. And what if that's the year that, you know, solves all the, or answers all the questions or solves all the problems or whatever? Yeah. If so. Yeah. You know? Yeah. Tough, right? Um, so I know you have some very specific things you, you all are looking to gather data on when you're here this year. So do you wanna talk a little bit about that? Sure. Yeah. Um, one thing that's kind of, well both things are going on right now- Mm-hmm but I guess the more kind of thing that's happening right now is herring spawning. Mm-hmm. Um, I'll give you a little bit of background on that. So I had a student, so I was talking about that olith chemistry. Yes. We were trying to figure out whether we could do this with, with herring. Um, so long story short, last year we, she, she started, so Carolyn Curry, um, started her master's, or two years ago I guess now. And but last year we were going out, we wanted to get herring eggs 'cause we wanted to do some experiments on, on the herring eggs. So we asked people where the herring spawn, so people who were assessing the stock, and they were like, "Everywhere? I don't know." Like, like they couldn't give us specific sites. Yes. And so we were like, "Oh no, how are we gonna find..." Again, big ocean. Mm-hmm. How are we gonna find these eggs? And so we put out this call to, um, you know, everybody basically. Mm-hmm. Report your herring spawning, and the uptake was so incredible. Um, we got a whole bunch of reports, up to I think close to 40 reports- Mm-hmm um, from all around. And we were able to go and like actually collect eggs and do, do what we needed to do. And we got timing and all this stuff and, and Department of Fisheries and Oceans was really interested in, in these data. So- Mm Carolyn's now finishing up, but we figured we'd just keep this project running. So yeah, we're looking for date, location of spawning, if, um, a photo, if people could send, um, photos to... And we have a poster. I don't know if we can, we can put the poster in, in shareable. Sure. I can link it- Yeah with this when I post the, uh, podcast- Oh, okay on our social media. Awesome. So I'll be sure to do that for you. Yeah. Yeah. So and then we just can create a map, and the timing is really important because a lot of, um, a lot of information, uh, for stock assessment is ba- It would, it's, it's relevant to, to that information. Mm-hmm. Um, so yeah. So we're putting out a call. Date- Awesome location- All right for herring spawning. That's one. Excellent. Um- We saw some last year and reported it, so hopefully- Yes we'll see it again. Yes. We just got from that area today, and it was around the same time last year that we saw it, so- Awesome we'll keep you posted. Yeah. Yeah. We're, we're starting to get, we, I think we have 10 reports already. Excellent. So yeah, and they've all come in in the last couple of days, so I think it's- Mm-hmm you know, early June, um- Yeah late May, it's, it's happening. So- Mm-hmm yeah. Yeah. Excellent. Excellent. If you see that. Yeah. Great. And then you have another project happening. Yeah. So again, we're asking, um, the public to report, um, jelly- jellyfish sightings. So we're interested in three, um, like moon jellyfish, lion's manes, um, and, uh, comb jellies. There's a whole bunch of different species within that, but, um, just trying to get... So we're doing surveys, um, on beaches, so walking beaches up in Notre Dame Bay again. Um, we're doing boat-based surveys to get, um, jellyfish densities. But that's just that small area. What we really wanna be able to do is cover province-wide because, again, we know very little about the abundances and how they've changed over time and whether they're more abundant in different areas of the coast. And so we just wanna get that, that bigger picture. Um- Okay so anybody walking a beach that's doing that, you know- Mm-hmm we're asking for, again, date- Mm-hmm um, location, general area is fine. Or if you take a picture on your phone, it has location right there, so if you send us the, the picture, then we'll have, um, that specific location where that, where that picture was taken. And yeah, the loc- the picture actually helps us with, um, identifying the jellyfish as well. Um, but if you don't have that capability, just even sending us a text or, or an email, um, and just saying it was, it was one of these three kinds that you have on your poster, and- Sure approximate estimate of abundance. So, you know, whether you saw 10, one, hundreds, which can happen. It does. Yeah. Yeah. Yeah. Yeah. So that, that's really useful information. And again, we're gonna put it all together at the end of the season and get a idea of timing and, and abundances in different areas. Okay. That's great. Yeah. Um, I will put a link to both of those posters, the informational posters, uh, in the comments- Awesome um, when I post the link for the podcast. So, um, our listeners can certainly, uh, start to send you some data. Excellent. Yeah. Thank you. And it's been so great talking to you today. I've really learned a lot. Um, I know who my, my go-to person will be when I have questions about things I'm seeing out there with, um, with the prey species. Um, but yeah, I've really learned a lot, and I hope, um, our listeners really have enjoyed, um, learning from you as well. So thank you so much for joining me today. I really appreciate it. Yeah. I had a really great time. Thank you for asking. Maybe we'll talk again when your field season's over and see what- Yeah you find this year. Sounds great. Yeah, that would be fun. Awesome. Excellent. I look forward to it.