GoToMeeting Auto Voice >> This conference will now be recorded.

Heather Tabisola >> Good morning, everybody.

It's nice to say hi to everyone this morning.

Chat a little bit.

And see all your friendly faces.

Definitely not this awhile, and I sort of missed everyone getting together.

If Jesse, I don't know if that's you, can you mute?

I'll give you a thumbs up when to start just in case that's you that's doing the reverb back as well.

Yeah, so, good morning.

And welcome to our 2020 Fall EcoFOCI seminar series.

I'm Heather.

I co-lead the seminar with Jens Nielsen, who you will see as well in the chat.

He'll monitor that throughout the talk today.

This seminar is part of NOAA's EcoFOCI bi-annual seminar series.

It is focused on the ecosystems of the North Pacific Ocean, the Bering Sea, and the US Arctic.

And it's the ideas to improve our understanding of ecosystem dynamics and the applications of that understanding to the management of living marine resources.

Since October 21st, 1986, the seminar has provided an opportunity for research scientists and practitioners to meet, present, develop their ideas, and provoke conversations on subjects pertaining to fisheries oceanography, or regional issues in Alaska's marine ecosystems, including the US Arctic.

You can visit the EcoFOCI webpage for more information at www.ecofoci.noaa.gov.

We do sincerely thank you for joining us today as we continue our all virtual series.

Our speaker lineup can be found online via the One NOAA Science Seminar series and the NOAA PMEL calendar of events.

We are here every Wednesday at 10, except for a few occasions like today, through December 16th.

Please double check that your microphones are muted, that you were not using video.

And during the talk, please feel free to type your questions into the chat.

Like I said, Jens and I will both be monitoring that.

And we will address all questions at the end with Jesse.

So, today, we have Jesse Lamb he's a fisheries biologist at NOAA's Alaska Fishery Science Center with us in EcoFOCI.

Since 1999, Jesse has primarily dedicated his career as a zooplankton taxonomist.

He has expressed that his main interest is how climate change affects zooplankton ecology, and therefore the upper trophic levels supported by the zooplankton community.

He joined EcoFOCI in November of 2015 after many years working on the zooplankton community off the Oregon and Washington coasts.

At EcoFOCI, he uses his taxonomic expertise to identify both the zooplankton community and the stomach contents of larval fish of the Gulf of Alaska, Bering Sea, and US Arctic.

And with that, I'm going to turn this over to Jesse who will be sharing his work on the contribution of diet to the dramatic reduction of the 2013 year-class of age-0 Pollock in the western Gulf of Alaska.

Jesse Lamb >> Ok, um.

Am I feeding back at all, Heather?

Heather Tabisola >> You are not, you're good to go.

Sounds great.

Jesse Lamb >> Excellent. OK, thank you very much.

So, thanks for everyone for coming, especially on a Monday.

Um, today, oh hold on.

I'm going to be talking about diet data.

Um, it's part in the dramatic reduction number, or at least what could've been its contribution to the reduction of the 2013 year-class of walleye pollock and I'd like to acknowledge my co-author Dave Kimmel.

So just as a brief brief background of the fisheries part of EcoFOCI in the western Gulf of Alaska, there's been decades of work on the early life history of multiple fin fish species, primarily walleye pollock.

And there have been we've done studies in abundance, distribution, recruitment, phenology, habitat, feeding.

So on and so forth, both within the lab and field study.

And from all this data, from all this knowledge, we annually contribute to various reports to inform a fisheries managers.

So, specifically in the Western Gulf, Alaska.

We've had annual surveys since the mid-nineties.

These became biennials surveys as of 2001.

Whereas, every other year, we either sample the Bering or the Western Gulf.

And in the Western Gulf, in the spring, we have ichthyoplankton or larval surveys, and then the fall we have age-0 surveys.

These surveys also include sampling of both zooplankton and hydrography.

So specifically in 2013, larval survey showed a very high abundance of larva in what is the Shelikof sea valley, which is right here and mostly south of Kodiak.

And then that was in May, in the Fall and August-September survey, the age-0s that we found subsequently were found primarily southwest of the Shumagin Islands.

Very, very high concentration.

So, if you compare that 2013 age-0 juvenile survey, in terms of abundance, since 2000, in this plot on the right, you'll notice that 2013, it was incredibly high in terms of age-0 abundance.

This was followed by the recruitment that was very, very poor, as you can see.

And that table is from Dorn, 2019.

So the question becomes, what happened to the 2013 year-class in terms of recruitment.

So this is what I'm going to be focused on today, so I'm going to explore the possible mechanisms of those poor returns, focusing on diets.

And I'm going to be working from two operating hypotheses.

One was that pollock size and condition was related to their prey choices.

That is, their we would predict that age-0 pollock in good condition would select particular prey of higher energetic content.

Spatial differences in age-0 pollock abundances were related to prey distribution.

That is, areas with higher pollock abundance will show depletion of higher selected prey subsequently affecting age-0 body condition.

So, the next couple of slides are just going to go over some methods.

We used an anchovy trawl for age-0 surveys.

They were sorted and enumerated after catching.

Age-0 fish are delineated by a standard length of less than 140 mm.

And up to 100 age-0 fish were measured for body length.

And then, separately, a length stratified sample of 25 individuals of differing sizes were flash frozen for later diet analysis.

Zooplankton ampling, we use oblique tows of a 60 and 20 centimeter for frame bongo.

These nets are all equipped with a flowmeter to capture volume filtered.

And all of our samples after the cruise have been enumerated at the Polish Pplankton Sorting Center, then verified by me at AFSC.

So, once we get into the lab, our diet fish are processed by being measured, weighed, and then, we dissect the stomachs.

For this study, we use 791 total fish.

All gut contents are identified to the highest taxonomic level, organized, if I can identify life history stage we do that, and given a level of digestion.

Each prey taxa group was enumerated, dried, and weighed separately to the nearest 0.01 mg.

So, in terms of the stats of which I'm going to present today, I'm going to show summary statistics by domain, which I'll go through next.

Then, we modeled fish condition by using length/weight residual values after Brodeur et al. 2004.

In terms of diet analysis, I'm going to be showing prey specific index of a relative importance, and then spatial abundance of key prey taxa.

So.

PSIRI stands for the prey-specific abundance of relative importance, sorry, prey-specific index of relative importance.

So whenever we classify diets and diet, traditionally, everything is in terms of proportion.

So we use a percent number, percent weight, and then a percent frequency of occurrence.

Then from that, PSIRI is calculated.

So, in the next slide, I'm going to go through a schematic just to go into a little more detail exactly how this is done.

So, suppose you have sampled and you have four fish.

Those are being represented by j.

Those fish eat certain prey categories, which are represented by i.

From this, we calculate what is a diet matrix.

And this is done for most diet data that you ever see present, where, for example, fish j i e ate 100% of these green circles, therefore, that value is one in the deck, so on, so forth, terms of number.

Now, typically you'll have two matrices, one for numbers and one for weights.

For the, just for the brevity of this example, I'm just going to show you a numbers example, but just remember that both numbers and weights are done in exactly the same manner.

So at the end of this, we calculate the percent number then have a percent frequency of occurrence of that prey item.

Now, then you can calculate PSIRI.

So what makes PSIRI different than traditional calculation values which was previous to PSIRI there was just a calculated value known as the Index of Relative Importance.

Is that PSIRI uses what's known as prey-specific abundance

which is the percent abundance of weight of prey category i averaged only from the stomach samples from which it occurs.

Whereas, previous values, the IRI values, would average all of these over all the stomachs.

Therefore, instead of 100%, this would be 25.

And the reason for that is because, when you average over all of the stomachs, frequency of occurrence has a much higher weighted value because discrete absences are included in the calculations.

And the other thing to remember about PSIRI is that it's additive in terms of respect to taxonomic levels.

This means that the sum of PSIRI values for different species, summed together by say their genus, will equal the sum of their corresponding family.

The sum for that family will equal to a corresponding value for their order, so on and so forth.

Now, I'm going to present some results from our 2013 survey, so this is, um, graphs of both abundance and size.

So, this graph on the left, I showed previously, you have a very high abundance of fish, southwest Shumagin Islands, and then the graph on the right shows the mean weight of fish sampled per stations.

With stations, with an X, indicate abundance of zero.

So you have a very high abundances of age-0 pollock found primarily southwest.

And then, the smallest fish in terms of weight were found southwest of the Shumagins with fewer larger fish surrounding Kodiak.

So, for this study, sorry, previous studies done within my group, have broken down the western Gulf of Alaska, into multiple regions for comparison.

And this is what I'm going to do for the rest of the talk today.

So, for this talk, domain A is going to be in blue, and it's, remember, it's always southwest of the Shumagins.

Domain B will be in gray, and domain C is going to be in orange.

So, if we just look at histograms of the fish length data from our survey, 

you'll note that domain A fish were maybe slightly smaller than B, with C, being larger than both.

And then, if we plot similar diet data, excuse me, that is my cats, if you can hear it meow.

It will distract.

Um, this data are box plots of this length data here and then we have weight data in this plot.

And then abundance data in this plot.

So, similar than what I showed before, we have smaller fish, a higher abundance of very small fish found in the southwest of the Shumagin Islands.

And there's one problem with doing that, in that you have to incorporate the effect of sample day from all of that data when looking at differences between the domains.

So, this is a plot of the survey track of DYI 13-08, from where all the data came from.

Where the cruise track starts from dark blue, and ends over here light.

This whole survey was 31 days in total.

And, what you'll notice is that this represents domain A, this is domain B, and this is domain C.

This line right here, there was actually a crew change, so after this station was done, they went back into Kodiak, switched crews, then went around, and started back up here again.

So that's like a lag of maybe 3 to 4 days, just remember that.

So if you plot the exact same length, fish weight, and now I've included the length weight residual data and try to get a measure of the condition of the fish, you'll notice that, as we moved along in our survey days, the fish got larger, both in length and weights.

And that condition doesn't seem to be really different at all.

So, this plot is just a box plot of fish condition broken down by the domains, and you'll notice that there's, oh I'm sorry.
 
There weren't any statistical differences in fish conditions suggested by it.

The problem is, is that the relationship between sample data and domain are is that they are co-linear, because we sampled them when we did, and when I broke them down, the way I did, it's hard to tease apart, fish growth versus actual differences in the fish domains, in terms of fish size between the domains.

So my co-author and I have been working on this issue.

It is Dave's thought that we need to, some sort of apply some sort of universal growth rate to the fish, in order to try to tease apart any domain differences.

So right now, this data is incomplete.

So now I'm going to move on to some diet analysis results.

So what you see here are three plots of diet composition of age-0 pollock by domain by 10 mm length fence.

So, these are domain A fish.

These are B and these are C.

And I know, I apologize, it's probably fairly hard to see these prey categories that you see at the bottom.

I'll point out some specific ones later.

So, what we found from these data, for that domain A pollock on top consumed a higher percentage of pteropods and larvaceans.

Noted here, the pteropods are in orange and larvaceans are in lavender.

There was a greater percentage of them than B and C, that domain A pollock consumed a lower percentage of large Calonoid copepods mostly is made up of the Calanus marshallae, which is in purple.

Noted here, and that pollock in B and C consumed a higher proportion of euphausiids in the upper size bins than in A.

So, green is euphausiids.

Purple is Calonoid copepods.

And we should just note that for future slides.

So, in terms of the PSIRI results.

So this graph represents pooled sum values of PSIRI results for different taxa groups.

And with the domains A, B, and C, oh by domain, I should say.

And the things to notice here is that, if you notice, in terms of domains B and C, the highest PSIRI values are always euphausiids and large Calonoid copepods, with some showings of others here, but for the most part, there's a big, uh,

you could draw a big line over these, and you would notice that primarily, this is what they were choosing to feed upon, whereas domain A had a much larger suite of differing taxa groups.

So ooh, the weight of the choice of either euphausiids or Calonoid copepods was much lower in domain A than in the other two.

So, if we look at the corresponding zooplankton data taken from the bongos which is what I have presented here, these are the abundances of these specific same specific taxa or groups I had on the previous slide, um, so we can see their what their abundances were when we sampled them per domain.

And the things to notice is that domain A had a very high abundance of pteropods which was almost exponentially different than the other two domains.

That the abundances of larvaceans were higher in both domains A and C.

And that the abundances of, uh, small, small and large Calonoid copepods were actually lower in domain A than they were.

So, in terms of my results summary for abundances, the 2013 year-class was identified by a high overall age-0 abundance, followed by poor recruitments.

Uh, this highest overall abundance was greater, it was 1.6 times larger than the 2005 age-0 abundance, four times in 2007, and exponentially greater than all the rest of our surveys since 2000.

Then, the other thing to know is that the spatial concentration for this survey was unique where most of the time the average abundances were highest in domain B and for this study it was the highest in domain A that it's been not only during this surveys, but in previous surveys where there aren't that many years in FOCI's past where the spatial scale was as large as these more modern surveys.

But, the next closest domain A percentage being that high was in the late 70s, actually.

Size and condition.. besides differences between the domains found in the 2013 survey were found to be co-linear.

So, they corresponded to age growth over the month of sampling, which is currently unresolved.

And we did not find any spatial differences in fish condition, as of yet.

Diets... domain A had showed a greater preference for a broader variety of taxa.

Then domain B and C had a preference for primarily two groups of euphausiids and large Calonoid copepods.

And lower abundances of small and large copepods in domain A could suggest that they were preyed down upon by age-0 pollock.

So. The question still remains, what happened to 2013 year-class recruitments?

Why were the returns so low?

So over the next couple of slides, I'm going to go through some other possible causes for low recruitment in that 2013 year-class.

One of these could be density dependence.

Or diet affecting overwinter survival.

Cannibalism.

And advection.

So one at a time.

Density dependence.

So one could say that high abundances of age-0 pollock found in domain A could increase the likelihood of overwinter mortality due to density-dependence.

Problem with this is that we've had very little evidence of food limitation.

You'll note that, you know, even though domain A fish ate many pteropods and larvaceans, they still ate a fair amount of euphausiids.

That higher abundances of pteropods and larvaceans in domain A does not indicate competition.

Lower abundances of Calanus marshallae could suggest density dependent competition.

This is impossible to test within our datasets.

So, this is actually fairly small evidence of any sort of density dependence, even if there was, we don't have any real way to prove it.

So, in terms of poor diets, so pollock overwinter survival and recruitment success increases when fish attain a larger body size and condition.

And there have been many, many studies that have shown that marine zooplankton accumulate storage lipids which have a very high energy content.

So, two of these taxa with very high lipid content, are both Calanus marshallae which is a large calanoid copepod, and all species of euphausiid.

So.

Euphausiids and calanoid copepods have a very high energy so everything that I'm showing you here is represented in kilojoules of dry weight per gram.

So euphausiids, it's about 21 and 25.

Yet for pteropods and larvaceans, it's around 12 and 15 kilojoules per gram.

And the other thing to consider is not only are these high energy prey taxa don't have higher energy, but you have to consider the relative size of these taxa as well.

So in terms of comparing just sizes of these animals, euphausiids are very large, you know, it would only take you, you know, a couple, 2 to 3, 4 adult euphausiids could easily equal one gram.

Copepods, that Calanus marshallae, it's probably, you know, closer to, you know, 15 to 20, but then the amount of larvaceans and pteropods that you would need to equal one gram of dry weight is so many more.

So, that's something to really consider as well.

So when you're preying on euphausiid, you're getting much more bang for your buck just eating one euphausiid ever would just one larvacean or one pteropod.

So, this would suggest that a lower than that an increasing proportion of lower quality prey consumed by pollock possibly face an increase overall mortality.

So, the next possible cause cannibalism.

So, here's a backstory. So I've been writing this in a manuscript now, pretty much in the spring and over the summer.

And I sent this, you know, I sent out the manuscript to be reviewed by in house within our group and at the very end of my discussion of one of my manuscript reviews, Lauren Rogers put in like this one little sentence comment at the very end.

She's like, I like all of these reasons, but, you know, in the end, they probably just got all ate upon by the 2012 year-class.

It wasn't offhanded, but it was definitely like, Oh, like something that nobody actually ever brought up with me before.

You look at this.

Remember this original graph, from Doren et al.

You'll notice that this abundance of age-1 2012, if these are the 2012 age-1 recruitment, you have very, very, very many set.

And if you, if you take this, and then, if you look into a study by Sogard and Olla from 1994, which studied inter cohort cannibalism in a laboratory setting, it showed a combined 47% mortality of smaller pollock when attacked by larger ones.

With 11% of them swallowed whole and just mortality from being attacked at 36%.

So, this probably had an influence on returns of those.

So, the last possible cause I'd like to go through is actually from the incredibly recent paper by Matt Wilson and Laman from 2020.

And this suggests that advection has a influence on age-0 recruitment in the Western [inaudible].

So they examine age-0 pollock distributions for evidence of high abundance, southwest of Shumagin, that high abundance of a pollock southwest of Shumagin, does not translate into higher abundance at older ages possibly due to advection.

The surface winds can recently explained variation in age-0 distribution.

And then, they examine relationships between surface winds, age-0 distribution, and recruitment.

So, here are just a very brief overview of some of the results and discussion points.

So, they found that the highest population density of age-0s occurred in the southwest region in domain A.

Just, just to note, this graph right here is the exact same graph that I showed in my previous slide.

So you, it's from the exact same year, shows the exact same things.

That lower age-0 abundance is found, they found they found lower age-0 abundances off of Kodiak and Shelikof regions.

But then, in terms of predicting recruitment, 96% of variation in pollock recruitment was explained by the age-0 population density.

So, what that means is that the higher age-0 population density that you found within these regions, was informative of predicting when the recruitment of subsequent years, which you'll notice in both, this is age-0s on this ends.

This is age-2s on this end, and you'll see it for both here and here.

In 2015 and 2017, you had a higher age-2 returns.

Whereas, in 2013, it wasn't anywhere near as high.

And that, when they tried to test it from Semidi in the southwest, they found no significant relationships at all.

So, this is the same 2013 plot that I showed previously just blown up from this slide.

So, the other thing that they showed was that, what they call wind hypothetical displacement, cumulatively summed wind vectors in kilometers, was the strongest in 2013 of all of their five study years, where during 2013, they had some form of southward displacement.

This means that they had the strongest southward, south-eastward or south-westard winds from these four NDBC stations, found here, here and here and that's, that's strong winds they suggest displace the age-0 abundances to this region.

That strong southwest advection most likely also influenced the pollock.

So, in summary--

The recruitment of this year-class probably got diminished from a combination of larger portions of the 2013 fish feeding on 
lower energy taxa.

It suggested that cannibalism from the large 2012 year-class, which it's not been proven, but it's highly suggestive that large portions of the 2013 age-0 pollock advected to the southwest.

So, they were advected in the southwest, in that southwest advection.

You know, those fish being there does not inform recruitment into the next years.

So my future work is to publish all this data.

And with that, this is my acknowledgment slide, and I will take your questions.

Thanks.

Heather Tabisola >> Thank you so much, Jesse.

OK, if you want to put on your video, I will do the same.

Jesse Lamb >> Ok.

Heather Tabisola >> And, OK, all right.

Jesse Lamb >> [inaudible]

Heather Tabisola >> And your audio, do you need to swap that again?

Jesse Lamb >> Yeah, can you hear me?

Heather Tabisola >> Yep.

Jesse Lamb >> Ok. I think I'm good now.

Heather Tabisola >> Do--put it back in presenter mode and just put it back on the title slide.

Jesse Lamb >> Ok.

Heather Tabisola >> Libby says you did, had a great talk, and Colleen says clap, clap clap, which I usually do for everybody. So there you go. Clapping for everyone.

Thank you.

Heather Tabisola >> Jesse.

And obviously if you guys have questions, please go ahead and put them in the chat.

And we'll monitor through those.

And while we're waiting, Jesse, here's a question, is there any way to validate or confirm that cannibalism idea?

Jesse Lamb >> Um.

So, the best way to do that, I think would be, for me to contact folks downstairs in Groundfish who do diet work from that year

and actually, you know, confirm with them, and then, yes, I think that it is possible.

But I have not done that as of yet to ask to see if they saw a higher proportion of age-0s within their adult pollocks' stomachs from that year.

Heather Tabisola >> But that is, I mean that's data we collect every, I mean not necessarily "we".

Jesse Lamb >> But I believe so, yes.

Heather Tabisola >> Cool.

Peggy says, "Yes, thank you. Interesting and informative talk." Hi Peggy!

Any questions from folks?

Just waiting.

So it sounds like you've already written this up.

Jesse Lamb >> I, Yes. I've, uh. Yeah.

It's it's already actually gone through internal review.

Heather Tabisola >> Nice.

Jesse Lamb >> So yeah.

It's just, I'm waiting to fix that one pesky problem with the fact that the fish grew while we were sampling them.

But once that's...

Once that's tweaked through that, then we're going to be sending it off.

Heather Tabisola >> Congratulations.

And if you guys didn't know this, this is Jesse's first FOCI seminar talk.

So it was a big deal in our group when somebody gets to do their first seminar with in there with us, so, five years, it only took five years.

Jesse Lamb >> Five years.

Jens Nielsen >> I have a question, Jesse.

Heather Tabisola >> Oh. Hey, Jens!

Jens Nielsen >> This is Jens.

So you talked about the condition of the euphausiids and calanoids being much higher than larvaceans and pteropods, right?

Jesse Lamb >> Mmm hmm.

Jens Nielsen >> Did you think about whether condition, for example, Calanus, also varies and if that might have something to do with it?

I'm thinking if they don't live in sort of lipids, I said they normally do, maybe, because of food shortage for the calanoids or along those lines.

Does that makes sense?

Jesse Lamb >> It's an excellent question because this is something that we're going to be working on actually, in the future.

Actually, you know, measuring both lipid content and just relative size of the Calanus from year to year and how much an effect that would have on feeding in general, but to go back to for that year, for the 2013 fish, what we have to think about also is the climate conditions overall in the western Gulf.

So, 2014, 2015, and 2016, were the warm, quote, unquote bad years.

Yet 2012 is actually the last really cold year.

So, it seems as if 2013, is kinda like intermediate.

So, one would think that in terms of, you know, Callanus being at a higher lipid level, you know, in comparative years, you would think that, you know, colder years are usually better, in terms of them getting as fat as possible, shall we say?

So, I don't think 2013 was the worst year for them.

It was kind of like a transition year, almost.

So, I don't think that that would have as much of an effect. If this had happened in 2014, 2015, and 2016, that's an absolutely excellent question that would need to be looked into further.

But not for this year, I wouldn't say.

Jens Nielsen >> All right.

Thanks.

Heather Tabisola >> Martin Dorn had a question as well, Jesse.

He said, "Any speculation about the role of the 2013 year-class and seeding eastern Bering pollock?"

Jesse Lamb >> Um, I...That's... All right.

So, I actually, when I initially did this, and this has been discussed in other papers as well, whether or not that high population that was found in the southwest was advected through Unimak Pass, and then, would have done that very thing, and I find it interesting, I tried to figure out whether or not you could get, you know, what sort of measures we would have to get a slug of that population through Unimak Pass and just around into the Bering.

And I think it's an interesting study, but I remember, an interesting thought

but I, I remember in just our little, you know, reviews within our groups that it seemed to be downplayed by other members of my group, and I'm not like, you know, the best person of information on that, although, I would love to look into that more.

Heather Tabisola >> Martin, I hope that answers your question.

You're more than welcome to unmute and follow up if you'd like.

He says, "Yes, great answer."

Jens, do you see any other questions here in the chat?

Jens Nielsen >> I do not.

And I didn't get any written to me personally either.

Heather Tabisola >> Ok.

Jens Nielsen >> I can ask one more if that's OK.

Keep Jesse on the spot. So.

If I remember correctly, and I may or may not, Martin Dorn can probably correct me.

I seem to recall that the 2018 year-class was really high but has sort of disappeared.

Do you think I'm I'm correct on that?

Do you think similar mechanisms to 2013 occurred, or do you think it's much more in 18 or do you think it's much more related to these really warm 2019 temperatures?

Or do you think some of the work that you've done here may also explain somewhat what's happened lately?

That's maybe not a fair question, actually.

Jesse Lamb >> Yeah, Well, OK, so, I haven't looked at their diet yet, which I will.

But, my guess would be, it would be much more.

Not only do you have like, you know, like maybe the food was in poor condition because of warmer conditions as well.

And just plankton being just lower in that year.

But then, um, the other part of that is that you always have to remember that with increased temperatures, in the whole thing, that these fish will be growing faster.

And metabolism will be jacked up maybe a little more.

And I think those, what I think that, like, stepping back from, you know, like these questions, is that, I mean, it shouldn't be a surprise.

But I don't think it's ever one thing.

I think it's always a suite of things.

And, know, and the proportions of what, you know, each one on the other is, like, you know, from my talk, and from what I've done, you know, if I had to guess I'm guessing that cannibalism and [inaudible] were the two biggest factors in the poor returns of the 2013 fish.

But then in the more recent years, I would probably just go to climate and, and just poor feeding conditions.

That would be my, you know, suggested answer to that.

Jens Nielsen >> Great. Thank you.

Martin Dorn >> Should I jump in, Heather, this is Martin Dorn.

Heather Tabisola >> Go ahead.

Martin Dorn >> I don't know how easy it is to have a discussion, but we can give it a try.

Um, it's a little different for the 2018 year-class, I'm just wrapping up to assessment towards, right on the top of my mind.

And, but what happened there is that it was very abundant as age-1 in the Shelikof Strait Acoustic Survey and then sort of, um, vanished, after that.

So, it was sort of the transition from age-1 stage 2 that is sort of the puzzling situation right now and I don't know if anyone has a good explanation for that.

Yeah, we've been sort of thinking about it.

It's, it's very striking in terms of starting off very large and then getting small, but it is different, I think, than the sort of things that we've thought about for this study.
 
Jesse Lamb >> Ok.

Heather Tabisola >> Thank You, Martin.

Anybody else want to jump in that might have information as well?
 
Martin Dorn >> It's always kinda awkward doing these kinds of studies.

Because you guys are, like, every other year, sort of in the Gulf.

And it's just like we can we can't have a definitive study about the 2012 year-class

because we weren't out there and it was, you know, and then we're kind of sort of constantly sort of dealing with this.

We can only get information about what's going on in early life history, every other year.

It's just it just doesn't work very well.

Any way.

Jesse Lamb >> Yeah.

I wholeheartedly agree with that.

The one thing from doing this study is that what I realized, you know, this is like a couple of years ago that, like, oh, we weren't out there in 2012.

I'm like, oh, man, like, that's ugh!

So, yeah.

That's on point.

Heather Tabisola >> And does that change your strategy?

I mean, like, in your outcome of not of missing every other year?

Jesse Lamb >> You just gotta work with what you have, really.

I mean, it's tough.

Even if we were to be able to do, like, you know, some sort of smaller something just to have anything, you know, year to year would be great, but, yes, it's a big...

It's brought up more often than not.

Heather Tabisola >> I see Bob was on the phone. You can talk to him about that.

[Laughter]

I'm saying that with a smile, Bob. [Laughs]

Let's see.

Ok, I don't see any other question, and I will give folks a minute to do that.

And I'll just say thank you, everybody, again, for joining us.

Thank you, Jesse, for signing up to do the seminar and giving a talk.

And just to remind folks, we'll jump back to Wednesdays next week and Jennifer Provencher will be talking.

She's a conservation biologist at the Environment of Climate Change Canada in Ottawa, and she'll be discussing fisheries and seabird bycatch in the Canadian Arctic.

So we'll move up a few regions next week.

And if you miss a seminar, we do have them recorded.

It takes a couple of weeks to put them up.

But they are on the Pacific Marine Environmental Laboratory, so PMEL's, Youtube page, and you can search EcoFOCI seminar and they'll be listed there.

So, Jesse's will be there in a couple of weeks, once we are able to verify

all the verbiage.

It doesn't work perfect, so.

Yep, so Ashley, as I just mentioned, the recordings will be posted.

So just touch base with the PMEL Youtube page in a couple of weeks, and you should see it up there.

And Bob Foy says, great talk, as does Mary Beth.

And Michelle and everybody, so you can read those as well, Jesse.

But again, thank you everybody, for joining us.

Thank you, Jesse.

Jesse Lamb >> Thank you.

Heather Tabisola >> And we'll see everybody next week, OK?

See ya!

Jesse Lamb >> Bye.