Okay, Thank You Katherine, that was awesome. Next, up we have Casey. Wilson, another. 2019. Canal fellow working, as an, allure electronic. Technologies, coordinator, in the NOAA fisheries office of science and technology Casey, recently, completed her doctorate degree at Scripps Institution of Oceanography where, she studied applied ocean, science and used, passive, acoustics to study the ecology of grouper. In the Cayman Islands, prior. To this she received, her BS from the University, of Portland and an, MS from Clemson University, both an electrical, engineering and worked as a communications. Engineer for von ville power administration for. Three years in addition. To her diverse background, in bioacoustics, intelligence. Systems and network, security, she, comes from a commercial fishing fishing, family, and has worked as a deckhand, fishing, for chinook salmon and, albacore, tuna on, the fishing. Vessel Joelle, today. She will be presenting one of her chapters from her doctoral work applications. Of passive, acoustics and, fisheries observe. Observations. Of grouper spawning aggregations. And source level measurements. And Little Cayman Cayman, Island, all right Thank You. Catherine. And thank you for joining. Us today for our talks. For. The last five years have, been listening to grouper, sounds, and. Grouper. Sounds of four species, and. In. Addition to these four species there's over 800, other. Species, of fish that actually produce sound and fish. Produce sound and, two broad. Context. First. Courtship, associated, sound so. Related, to spawning or, trying, to attract mates and. Also. In, agonistic. Encounters, so, aggression, or climb disturbance, and. We. Can then use these sounds, as a, way to actually monitor. These species. So. How. We would actually go about doing this as the news passive, acoustic monitoring and. We. Would deploy hydrophone. Recorders, you. Can see here on your right. Out. To collect, these sounds, and by. Doing this then we can know when animals are present, and we. Can study the temporal and spatial, trends. Of these fishes, and then. We can also use passive, acoustic, localization. To, track the position of these films, so, to understand. Movements, of fishes habitat, use, and. Work. Towards. Abundance. Estimates by. Making, measurements of source levels, which, is essentially. How. Loud a sound is, how much energy is contained, in that sound and. Work. Towards, understanding, the call rates for these species and other information that's needed to develop, these abundance. Estimate, methods, for possible two sticks, now. Passive. Acoustics has, advantage, it was over other. Methods. For fishery. Data and. This. Includes over. Trawl. Surveys, visual. Surveys. And it was ku stick telemetry. Because. It's not invasive it's you. Can. Continuous. Long-term, data for, months to years and you're. Not limited by weather light, and other conditions that some of these other methods are. So. I've been using passive acoustics to, study, four. Species of grouper. Nassau. Grouper red hind black, grouper and yellow finger food and these, fishes, range through, the Caribbean western, Atlantic, in Gulf, of Mexico, they, contribute. Significantly. To the, commercial. And artistic landings, in many, of the countries in this region and. Due. To this due. To high fishing pressure there. Are a lot of these species are now. News. Got into endangered, Nassau grouper is an endangered species, and these, other three species. Either. At least in some areas, or throughout their range or near-threatened, and this. High fishing, pressure is, usually, on spawning. Aggregations. And, this. Is where. Many. Many fish hundreds, to thousands, of fish gather. Predictable. Times and locations. So once the spawning aggregation. Is found it becomes vulnerable to, this fishing pressure. So. I'm able to use passive acoustics to, study these four grouper, they. Produce, down then their sounds are known so, I've actually looked at nine different call types, and. What I'm gonna be talking about today though. Is a smaller. Subset if the courtship associated. Sounds so, done' orient. You to what you're looking at here this. Is. A Nassau, grouper courtship, associated. Sound and, we're. Gonna see through this presentation.
Today A couple things, labeling. And two I'm, using a letter to. Signify. What species I'm talking about and in the case for, fish. That produce more than one call type you'll, also see a number and, you. Can notice on the bottom this. Is blue. So, I have color coding, for, the different call types as well what you'll see and what, we're looking at here is two ways actually visualized, sounds. We, have on the bottom, our. Pressure amplitude. And on. The top is a spectrogram. And, it's just showing energy. Over. Time on. Our x-axis and, over, frequency, on our y-axis so. When, the energy is high we're. Seeing the red versus. Low. Energy, ambient. Background noise, in the blue. So. Come. Back before I'm gonna play a couple of these sounds for you. And. Then for a hind and. Yellow. Fan calls, which are actually going to be combined, and because. This was the lowest occurrence, of calls that we have refer, yellow thing so we, presenting. The results these two calls that were combined together and, black. Grouper. Now. All of these sounds, are low frequency. Which. Is for. Example if you're not familiar with frequency, men have lower generally. Have lower frequency. Voices, women. Higher so, that's what I'm referring, to when I say frequency, it's, really the picture the sound and, these. Are all low frequency, in, the same fallen, to the same band is ship and boat noise, males. Are, the ones that are known to produce sound in these species and, as you can see looking at these spectra bands and. The pressure amplitudes, of these calls each. Of these species has, stereotypical. Calls that are unique, to that species. So. Using. These sounds my objectives. Are, to look. At spawning. Aggregation, dynamics, where. Is calling our windows calling occur where, does it occur and, then, look. At how this actually relates, to what we know about the spawning. Behavior. Of these fish and, additionally. To measure our source levels, to. Understand how far our hydrophones, could actually detect, these sounds, and eventually. Work towards, understanding the, communication, ranges of these fish and developing. Abundance, estimates and, my. Hope. Is that going, through this presentation you'll. Start to understand, why passive acoustics is a valuable, tool for fisheries. So. We've. Been collecting. Data and a Nassau grouper spawning aggregation. In. Little Cayman the smallest of the Cayman Islands, and this. Nassau. Grouper spawning aggregation. Usually. Occurs in January, or February following, the full moon and it. Occurs at the west end of Little, Cayman, it's the largest known. Remaining. Spawning aggregation, of Nassau grouper and. In. Addition to Nassau grouper, all. Three other species are, also have, either been if they're spawning or displaying spawning behaviors, in this area as well and share, a similar spawning, season over. Those winter months so, to. Collect their data we've deployed, passive. Acoustic. Recorders. In. This area we. Actually had, took. Video, footage. Of the, habitat, and that's what you're looking at here on our right you, can see the darker green is the coral release the, lighter green is our sandy. Spots. In between and from. That we reconstructed. Of a. Cemetry map and you. Can see here that all these. Six hydrophones. That we put, out range. From, 25. To 35, meter depths. And I. Manually. Went through all of this data its extensive, we're talking about thousands, of calls, upwards. Of thousands, of calls and I, loved all the calls and that, were recorded, on recorder. Five the most northern reporter. Here. And. From. Those calls then to work on doing localization. I have to have at least three, usable, call arrivals, so, to give you an example I'm showing. You here, a red, hand call and they're rivals on all of these receivers, here or hydrophones. And on. The. Top I'm showing you hydrophone, five because this is where I'll actually logged, calls so, I used the arrival, on hydrophobe, five, as a match filter to. Then help. Me determine if there's usable, or call, arrivals, on our other channels. Looking. At this example I think it's fairly clear, that not all of these calls arrive. At. A higher level than, our background, was and so. What, I've used is, a number, of different thresholds. Including, that match filter output to.
Automatically. Determine, if I have enough. Usable, arrivals. To do localization. So. If I do which, is said for two-dimensional, localization. This actually has to be three. Or more, arrivals. Hall, arrivals, so, if I have that I can then move ahead and to. Do hyperbolic. Localization. We, take pairs. Of arrivals, we cross correlate, them so, that's essentially, taking, one of those arrivals, and then just moving the other call over it where, they veste line is where, you're going to get a peak in the output of your cross correlation, and then, at that peak it gives. You what the time difference, of arrival, is between, those two calls, from. There you. Can. Solve. An equation that, will restrain. The position. To. Somewhere the position of the fish producing, this call somewhere, along this hyperbola, and. Why. We need three is because, then we can put multiple. Of these hyperbola, together, restrain. Our resolve. Our ambiguities. And, ultimately. When working with more than three we. Can use it as a leased air solution, to, find an estimate of this position. For. Weather where the call was produced, and this. Estimate, is you, can see in this example they, don't all align so there's gonna be in a residual, error associated, with, that. Now. To get our source level measurements. We. There's, couple net ways to do this what I'm going to show you today are absolutely peak to peak source, levels and we. Just measure this from our pressure amplitude. We. Get our receive level the peak to peak receive level at our. Hydrophone. And. We. Now we've, solved for our position so we know the distance that is from the hydrophone, we, can then determine what our transmission, loss is and work, backwards, to get the source level at one meter from the source. For. My. Work I've used two hundred, of, my localized calls for. Each of these call diets it was the calls with the lowest residual, error and I. Assumed, fear of post transmission, loss and just. For, people who aren't familiar with. Underwater, sound, usually. Report, this in DBS, or decibels, and this is reference to one microphone. At 1 meter m and. The. Example, to give you a feel for you, know howl of these source levels might be when we get there is we. Have sonar, ranging. Above. 200, dB ships. From, about 170. 190. DB and. Our. Baleen. Whales. All. The way up to almost 190. DB as well. So. To move into the results, what. We're looking at here then is, the.
Call Number. Of. Calls per hour. Over. Our full, deployment. Duration, and. I'm. Showing you all the call types that worklessness, includes, those agonistic calls but, what I really want to focus in on is our. Nassau. Grouper calls this end to where, we have a lot in our red hind calls so, on these plots. Where. We have no data is in gray slider. Gray is indicating, night time and, we. Have here a lighter. Blue which. Are actually this night that Nassau grouper spawned and. We. Can see that generally. Both. Nassau. Groupers, courtship. Associated. Sound and red, hind, sound have, increased. Those. Calls increase. Following. The full moon for, Nassau grouper peaking five, days after the full moon and, for ahead red high and then peaking, right, at that first quarter, moon. Additionally. If we. Look at. Nassau. Grouper spawning nights we can really see that peak. Calling occurs. Right after sunset and if we look at the two days a. Peak. Calling with red hind we're seeing that, calls. Are peaking right at sunset. So. If we move into localizations. I'm, going to pull out and, show you all. The localizations, I was able to do for two, days of peak calling for both Nassau grouper and then red hind. So. This. Video we're playing a second gonna, see some similar things to what we just saw on those temporal, plots it's, gonna be the background is going to be changing colors and dark. Gray being nighttime, light. Gray being those twilight hour sunset. Sunrise and, then I'll be white when we're in the daytime. Additionally. At any. Instant, what you're actually going to be looking at is an, hour of localization, so, an hour of calls all, the calls that I was able to localize. The. Calls that are happening at, the time indicated, up here are. Gonna, be our darkest, and. That. As they as the. Hour moves, on, they'll. Begin to fade away and, I'm. Gonna be scrolling through one at a time it's sped up and I'm gonna try to talk, through some of what we're seeing here in these vocalizations.
So. We can see sorry. That. We, have, Nassau. Grouper and. Calling. Activity. Shifting. Around, in, the array so, different, locations, we're seeing pulling, when, we get to right around this time where it's Sun. Sunset. We, see calling, pretty. Much stop in the area and then it increases. Substantially, afterwards. So, run, that through again and, what. We're seeing at that sunset hour is. Actually. Nassau. Grouper, moving. Out of our array they, go off, the shelf edge to, spawn and then. They. Come back after. Spawning. And settle, back down on, the Shelf in the array and that's where we see this, huge abundance of pause so we're gonna start to see it right, in this time calling, stop all, of, the fish returning. So. We. Have. Then. Just. A summary has to. Show you similar, to these localizations. Now I'm just changing, our. Color bar here we're seeing a whole hour of our, calls we. See from, around. About 1730. When. Sunset. Actually, occurs calling. Stops and it doesn't really start. Again until around, 1830. And we, see a highest. Number of calls at the, 2800, hour. So. And, we're gonna look at the same thing for red hind. We're. On a different day though, same. Types of plots or, videos and. What's. Interesting, with. These ones if you, begin to see um. Sometimes, we're calling salts, in their way one time, is that sunrise, and we. Can start to see and more, apparent, in the later hours. Some. Specific. Areas where there's going to be high, activities. Of calls now, Brent Hinds finding behavior is, very different, than that's what your birthday for males form territories, and then, they patrol, these territories. They're. Not known to actually leave. Their territories. During their spawning aggregations. And. So. Looking. At that what. I'm. Able to, conclude. About these localizations. Is that Colleen, actually. Probably read Hynde likely. Stops, calling, at, sunrise. You. Can see this here in these plots falling, um after. About, 6 a.m. it stops and we, don't see calling pick up again until. Closer. To nine o'clock and. Because. The way they're not known to leave their territories, this would mean that they actually stopped calling, unlike Nassau grouper who left, the area and that's why we're probably seeing no calls during that spawning time um, we. Also then can see that, that. Red, Hinds calling, really peaks at the same 10. Set when Nassau grouper, were not normally. Present in the area and. This. Is an example of really trying to highlight those three areas that when I look at the, abundance of calls over this whole area really. Stood out as having higher, activity, and might be red hind territories. Some. Final. Results is than our grouper, source levels, and. Showing. You here histograms. Of, the. Number of calls on, our, y-axis and, then what those source level measurements.
Peak-to-peak Measurements. Work for these calls. On. A couple, of these call types because. If, you remember, back to the spectrograms. The. There, was different sound components, that these, calls are composed, of, for. A couple of I broke, them out and actually measured those distinct. Sound from Bug's, components. But. Overall what we're seeing is that their, source levels range on the low end for. Yellowfin, by to. 144. DB to the high end of 155. DB. For. Nassau. Grouper, and. What. This really, means is that then the detection, range so. How far we could detect these sounds with a hydrophone, recorder, for, your, typical shallow, water. Ambient, noise conditions would. Be 0.32. One kilometer. And. Remember. Back our. Baleen, whales were up 290 DB, one thing to know about DPS, is every. 3, DB difference is actually a. 50%. Reduction in, power, so. If it's 3 DB lower it's 50%, less power so. Compare, it to 155. DB, 290. DB fish. Are much quieter than, whales, than, ships than, all many. Other things out there. So. To. Summarize, I'm. Looking at spawning aggregation, dynamics, we're seeing that during, spawning for Nassau grouper, we're getting peak calling right. After, sunset and, we're. Seeing peak calling for red hind actually. At sunset. And. What. We're seeing in our localizations. Then we're actually able to see a change, in the calling, in. Our, array due to the. Spawning. Of Nassau grouper, and the movement of the aggregation, and we. Are possibly. Seeing red hind territories. As well in those localizations. And additionally. With those locations we, might be able to pull out individuals. Or, you can see that a lot, of the activity. When watching those movies in, a specific area, might. Be a single individual, and then you can work towards. Making, estimates of, some other things other factors. We need to develop. Abundance. Estimate methods, with. Our source levels we saw the detection ranges, 0.301. Kilometer, now. We can move towards, measuring, hearing sensitivities. Of these fishes and would actually be able to then. Determine. What the communication ranges. Are for these animals and as. I said the. Source levels is one step in moving towards those. Developing. Robust abundance, estimates using, passive acoustics. So. My. Work was, done as, a collaborative, effort, with, many.
People And, so I'd like to first, thank my advisor on a service, and then. My. Collaborators. On this work. Brice. Simmons Jaffe. Grouper. Moon project that's been studying, this population, of Nassau grouper since, the early 2000s. And involves. Many people, including Steve, getting's here and and. The, Cayman Island Department of Environment it's been involved with all of that work as well and. Take. Any questions. Yes. Yes. So. They've had. That. Production, since I believe 2002. Regulations. And um. They've. Been seeing. What. What appears to be a recovery in the population. Of Nassau grouper since that time man it's just a no no catch during. All. The way through March of, any. Nassau groupers, closed during yeah. Yeah I think from December, to March, and. Then there's limits on the catch outside, of the spawning season and as well as found the gear used. For fishing so you can. Yes. Just, outside of that spawning season and. Then limited, gear. For. How do you catch them and would limit a number of batches well. Yes. Okay, great, talk I was. Just wondering if you had any knowledge interference, and if so how. So. Yes, I also. Have, issues, with other noise strumming, and their. Flow noise from on the hydrophones, and how I don't what that is actually to just, remove that data, I didn't. Look at it and then to get my hourly, holes, rates. And. Normal. Lines based, on the amount of time of data. There was that didn't have noise and. Adjusted, it that way. You. Know you've been able to isolate the end. Of spawning, because we've all. The time in what we do we never, want to go in later certain one wants to see this morning so we never see, the end of them. I. Know when the fish finish yes yes. That's good in another big thing that I didn't mention through the talk was to, really look at what might be happening at, night if there was, more. Activity but. The calling really drops off after it looks like the Nassau, grouper returned to the shelf and. Likely. There isn't than any more, spawning activity. Not. Sorry. The. Question was, whether. Or not anyone's, looked at any. Relationships. Between size. Of, fish and the. Source. Levels, of their calls and for. These species no, actually, these were the first source level measurements. For eppela. Net flow day the family of one fo day and for. Some and their families, and species I believe people have done that but, not in the wild, and. Generally. There. Is a correlation. When. Looking at these, other species or other, animals. Of correlation, between. And. Source. Levels, but. When I look, at the, various, source levels of these grouper. I'm. Red, hind is much smaller and. Their. Source levels, seem. To be in the same range as the other so, between. Species that, same, relationship doesn't, appear to hold but, within. Species in me. Yes. The. Question was why. Might. The courtship. Associate sounds increase. Um when. Nassau. Grouper returned from spawning and. I. Asked. My thoughts on that are. Two things whether, there's, hormones. Driving, it to the hormones might still be high after spawning um. But. As well as we're talking, about. Thousands. Of fish that gather, in this area so, they're, coming back and. Settling. Down and, may just be you, know they, do have their, agonistic.
More Aggressive call type so that they might still be producing, this courtship, associated. Sound in a another, context. Um as, they, all try to settle in for the night. So. We do an online question. Someone. Who's working with the Black Sea vets, asked. They. Said we're very interested in a means of assessing abundance. In untraveled. Areas any. Advice or using, pest passive, acoustics. Yes. So. Looking. At marine mammal, what it sure is really. Where you have a, lot of guidance on how to do. Abundance. Estimates using. Passive acoustics so. First. Step, would, be, determining. What the source levels are um, as. I've done here and then. You also need to know they're things such as is. It, only males producing, sound or do both males and females and have. Some idea then about what those population, ratios, may be and. You. Can, work towards. With. Using localization. Like I've been here possibly. Trying to understand. Cue. Rates so how often is, a, single. Fish calling, and with. All of that information, including. The probability. Of detection on your hydrophones, that's, how then you can work towards. Developing, those, abundance, estimates so. To, understand, how many fish, might. Actually be, in the area, that, you're able, to. Detect calls. Over with your hydrophone, I hope. I hope that helps in answering. This. Person, to know how, did this source, level compared, to the loudest call report infrared time. So. Well. Let me roll. Back actually so oh. Because. I, have listed. The the, full range of, the. Source levels. So. Um. I. Can't see it on sorry. Thank. You. Iris. Right behind Pole. 163. DB our, lattice. Or, highest, source level, Nassau. Grouper quo is a hundred and sixty-eight dB, so um. That's. Slower. But, in. The same range and. Thank. You. Thank. You very much for hosting this in Hollis. For putting, it all together for us today.
2019-04-21