What Makes Salmon Bite? The Science Behind Tides, Moon Phases, Scent & More

0:00 Welcome back to the Fishing for a Reason podcast where we talk about the why behind your catch and the magic behind your memories. I am Jamie Props. I'm your host coming from Anacortis, Washington and the San Juan Islands. And you guys know by now that I am a little bit of a nerd, specifically a datadriven decision-making nerd. I like to understand the why behind the things that we do as fishermen to be more effective on the water. And that's exactly what we're going to talk about on today's podcast. Frankly, I love the fact that nature never stops teaching us. It never stops surprising us with layers and layers of learning and insights. And this last area 7 king opener did just that. If you did get a

0:45 chance to go out fishing, we would love to know. Either drop it below in the comments here if you're tuning in on YouTube or in our free Facebook group. Let us know how you did on the king opener. We would love to see your awesome fish picks and hear your stories about how everything went for you. So, we actually had a class that we teach called Salmon School. So, every year Scott and I have an in-person class and we dig deep into the beginning basics of targeting salmon. So, we help people that are brand new beginners, never ever fished, want to catch their first salmon out here in the San Juan Islands area or guys that have been fishing for over 50 years. I'll be honest, we had a huge range of experience in the room this year, which made it a lot of fun because

1:31 you can always learn something from the guy you might be sitting next to. So, that was one of the benefits of that. But after the class, I did have a student reach out to me directly and ask the age-old question that I would say every single fisher has asked. And today we're going to actually make this podcast centered around that entire topic. Can you guess what the question is? It's why do salmon bite? more specifically coo and shinook salmon in the saltwater during the ocean staging when these guys are coming in towards their home waters ready to head up river and they are feeding voraciously because oftent times salmon as they're heading

2:16 up those rivers to spawn they are not feeding so they want to gorge themselves right before they go up river and spawn that's a huge journey it's going to take a lot of energy and they want to maximize the amount amount of food that they consume right before they head up those rivers, which means a lot to us as fishermen out here targeting these fish as they come close to those river estuaries. So, that's what we're going to focus on today. We're going to answer questions like, do tides and currents really matter? Can the moon phase affect bite activity? What role does barometric pressure play? And does scent make a difference? Does the way we present our bait or lure really trigger the bite? So, I did a

3:03 little bit of research on this and I'm going to be going over my findings. So, let's start talking about specific factors that influence Pacific salmon biting behavior both with shinook and coo in the saltwater. So, Pacific salmon like kings and coo are active predators in the ocean, especially during the staging period right before they migrate up river to spawn. At sea, Shinook and Coho are aggressively chasing bait fish, feeding heavily. One expert even calls oceangoing shinook on one track minded killing machines when they pursue prey. Coo salmon have been observed to gain from up to a pound per week in the summer due to gorging on food. So anglers will literally see these guys jumping and striking anything that resembles food. If you've ever fished on

3:49 the west side of Vancouver Island, it's a blast. But oftentimes when the coho are in, you'll have your flasher and lure out. Like if you bring your gear up and you switch something out or you're just staging yourself to start fishing, you'll start clipping it in the clip on the downrigger to send it down to start fishing. And fish will hammer that thing before you even have a chance to send it down. That's one thing that's super fun about coo. Those things are just aggressive. I've had a king salmon do that once to me out in the San Juan Islands. We were on the east side of Cypress Island and I actually was bringing up my bait rig to go. We were moving to a different spot. So, I was bringing up my gear and I left it in the clip as I was pulling in the downrigger and just reeling in line and

4:34 once it got to the top, I took a minute to, I don't know, turn around and grab something and all of a sudden my rod goes off. It was literally sitting on the surface and a it was about a 20 pound wild king that just hammered that thing. Really fun fish to fight and play. Couldn't keep it at the time, but it was still really cool. So, it will happen on occasion, but they are aggressive and they are feeding and that's something that we want to take into consideration when we are targeting these guys. So, let's talk about tides and current. Do they matter? I would say this is something most anglers are aware of regardless of your experience unless you have no experience at all. But yes, tides and currents have a massive impact on salmon feeding and biting activity.

5:20 So many veteran Northwest salmon anglers will actually plan their trips around the tide change. As an example, if it's super rippy in the morning, sleep in, go later. You don't necessarily have to be there at first light. You can plan your entire day around what that tide and current is doing to have more effective fishing on the water. Mind you, if you only have three days a year to go fishing, maybe you just get out there at first light because, you know, you want to maximize your time. So, it just depends on your situation. If you have time, you can plan leisure fishing days around the tides and the current depending on when it is. So, let's talk about what this looks like. preve movement. Tidal current affects bait fish behavior and salmon are chasing the

6:08 bait fish. So, it really comes down to what it's doing to them. During really strong currents, bait fish are going to hunker down near the bottom or behind structure. When the current eases and slacks, that bait fish comes out to feed in the water column, which is essentially ringing the dinner bell for shinook. So, as that tide and slows down in slack, the shinook are just doing exactly what the bait fish are doing, coming out and eating. So, anglers will report that slack water coincides with salmon moving to gorge on bait fish. So, if you time it right, you can get a fast bite until the currents strengthen again and the bait starts to disperse or goes down deep. So, fishing logs from tidewater areas confirm this pattern. For example, at Buouie tempam fishery in

6:53 Columbia River mouth guides observed that the best bite occurred during low tide slack. So shinook were biting aggressively when the tide was turning. The bite would slow during mid tide and then pick up again around high slack later in the day. So strong currents also dictate where salmon will hold and feed. Shinook often position themselves near structure or in back edies to conserve energy while waiting for prey to be carried by current. So experienced anglers are going to ride the tide essentially trolling with the current to target ed and targeting different eddies in current seams where the salmon will ambush the bait. So slack or gentle currents can scatter bait fish and that makes salmon hunt over a broader area,

7:41 which is why a soaker tide is maybe not as effective when you're targeting salmon. Whereas a running tide will concentrate bait and salmon in really predictable zones. So like down current side of a reef or a point until that slack tide triggers that bait's upward movement and therefore the salmon will follow. So the bottom line is tides matter a lot. Pacific salmon feed in brief but intense spurts during tidal current changes. So plan to fish an hour or two around tide change. And we always say you need to look at the current. So check out yes, you need to know when tide changes. If you're looking at Navionics, there's two different like representations that you can there's an arrow and there's like a little rectangle and the little rectangle on Navionics is going to show you what the water exchange is going to be for that

8:27 day. The little arrow is going to show you how fast the current is moving. So, we like to look at anything from 1.5 knots through the slack up to 1.5 knots on the other side. That's usually going to be when your max opportunity to catch fish is taking place. So, that's when you want to be fishing and not running. So, this is a quick little phone demo. And one other reason I really like Navionics is it's got a great interface for your cell phone. So, if you're out on the water and you want to actually see what's going on, um it's a really good app. It is a paid app, but I highly recommend it's worth the investment to get it. Um fish swim into the current. I do want to point that out because it's it's not something that is intuitive for us necessarily, but just know fish swim

9:14 into the current, which is why we want to go opposite of that and troll with the current so that our presentation is going to present like a real bait fish on their path of trajectory. So, here is the app from my phone. It's a quick little demo and I'm gonna show you the difference. I'm going to scroll on my phone. Use your little cursor. These are the tide stations. So, that's going to say what is the water level and what is it doing over time. And you can just scroll through and see how that is changing. To view what the current is doing, you want to choose the little arrow guys. And you can see the two different arrows even in that small window. How the current will be different in different locations. So, now we're looking at the current. Okay, we're

10:00 going to get to a slack here at around I don't know whatever time that was. I did this in February. Um, but understanding where to identify what the current is doing and then choosing your spots based on the most effective current for fishing. So, if you have limited amount of time or a short ideal current window, you want to be strategic about where you fish so that in case you show up in a spot and you're just not marking anything, you're maybe close to another fishable spot that you don't have to spend a bunch of time running to. So, understanding all of this before you ever leave the dock is essential before you choose where you're going to be fishing. Now, let's talk about moon phases. This is actually a pretty controversial topic that I

10:46 would say some people are super heavy on one side of an opinion on this, others are on the opposite. So, I did not necessarily have an opinion on this because I didn't know. So, in my research, I do think there are natural cycles in nature that you cannot ignore definitely affect things. And the moon is a massive one. It affects all of our tides. But whether or not different moon phases actually affect fishing, I just honestly haven't tracked that. So I was curious if anybody else had and what was what was out there and what were people saying and what has been actually scientifically documented and this debated topic as I've done my research. Many fishermen subscribed to John Alden Knight's salooner theory which claims

11:31 that fish and game have peak activity periods based on moon position and moon phase. According to this theory, full and new moons are going to create stronger tidal currents and thus better fishing, whereas quarter moons or half moons are slower. In fact, some bite calendars assert that for a few days on either side of a full moon or a new moon, fish will be feeding at peak levels and feeding will be lowest on a quarter moon. You can find this information on islandfisherman magagazine.com where they talk about this in detail. The idea behind it is that bigger tides around the new and full moon will stir up more nutrients and bait fish. And also the moonlight can extend feeding time. So shinook tend to feed during daylight hours. They do

12:17 not feed when they cannot see at night. So if there's a really bright full moon, ideally it would be extending that feeding time into more of the night hours because they can see the prey in the moonlight. So, how much of this is just what people are saying versus real data? So, scientific evidence for the moon phase effect on bite rates is actually pretty weak. Fisheries biologists note that very few actual studies have been done with a significant amount of data that would quantify catch rates relative to the lunar phase. And therefore, this has not been proven. One of the best studies that's been done was a Florida study where largemouth bass catches were found fairly evenly distributed across the lunar month. So

13:04 21% were caught during the new moon, 28% during the full moon and the rest during the other quarters. In other words, there wasn't a huge spike. So roughly half the fish were caught in half of the month containing the new and full moon. So also some analysis of 84 years of striped marlin catch records from New Zealand showed decent amount of catches in all the moon phases. So a couple different species were looked at with this, but the best period was just before the full moon. The worst period was just after the full moon. The only overall differences were pretty modest and therefore again the moon phase did not seem to be correlating with fishing productivity. Although we don't have any data for Pacific salmon as well. So Pacific salmon in the ocean studies are pretty scarce. Their behavior pattern

13:49 suggests that moon phase is a secondary factor. Juvenile salmon on the other hand migrating to sea have actually been observed to move mostly during darker nights. So newer moons um and that's according to research done in Alaska at the geohysical institute. And some Atlantic salmon runs also show timing influenced by moon tides. However, once they're in the feeding mode in the oceans, factors like tide, daylight, and weather seem to be more important than the moon phase. So, I don't necessarily think this would be something you need to factor into your fishing strategy, but it's not a major driver for the salmon bite in saltwater compared to other factors. So, now let's talk about barometric pressure changes. And this is funny. I

14:36 had a fishing mentor when I just started fishing and I remember him saying offhand, "Oh yeah, it's a falling barometer." When he was talking about his plan for fishing and I honestly didn't get it. Like I know I know that that means something, but I had no idea how to use that information to better target fish. And I I was at the stage in my fishing career where I didn't quite feel comfortable enough to ask the question. I was like, "Oh, yeah, okay. Yeah, that makes sense." you just agreeing with what he said because I was happy to be talking to him. But yeah, so doing a little bit of digging into this, the barometric pressure is actually pretty significant when it comes to fishing. And it's cool knowing that my mentor, he was dialed into this just

15:23 through experience. He would keep track of all of his fishing data, which is something I would highly encourage anybody listening to this podcast to do. When you catch a fish, mark it on your sounder so you know the exact spot, but it's also going to give you a time stamp of the exact day that you caught the fish, the exact time, and you can use that data to figure out what was the tide doing, which direction was I trolling, was it a falling barometer or was it a rising barometer? And either way, like learning about that data and understanding what made that catch successful. Over time, if you collect that data, you're going to figure out what works and what doesn't to make you a more effective fisherman every single time you go out. So, weather changes, especially with barometric pressure swings, that does affect fish behavior. The reason for that is Pacific salmon

16:10 have a swim bladder, which gives us the ability to see them on our sonar, but this is an internal airfilled organ that can detect pressure changes in the water column. So rapid changes in atmospheric pressure which push down on the water's surface can influence the fish comfort and feeding activity. So let's break down what that actually looks like. A falling pressure, which is a falling barometer before a storm. When the barometer is dropping, it indicates an approaching low pressure system or storm, which makes sense. It would cause salmon and other fish to become more active and aggressive. They can sense the pressure change well in advance by feeling the lighter weight of the air

16:55 via their swim bladder, which you can find more information about at max lure.com. But anglers frequently observed a hot bite before a storm. Almost like the fish knew something was coming. So, they're feeding when they know that it's going to be easy for them to eat. And they'll just have non-stop action followed by a day of no bites right before a storm arrives. So low pressure during a storm. Once the low pressure system fully sets in, the storm is overhead. There's steady rain. Fish tend to become lethargic, go off the bite, and salmon will often move deeper into the water to equalize the discomfort in their swim bladders. In shallow waters especially, they feel the change more. And because of that, they will just shut down their feeding. So people will describe this as the bite will just turn

17:42 off. Now a rising pressure right after a storm. So those poststorm highs, right after a storm passes, the pressure begins to climb and the bite actually will gradually pick back up. Many anglers do note that the bite doesn't immediately turn back on until the weather really stabilizes. So a quickly rising barometer under clear skies can still keep the fish from biting necessarily as intensely as they would with a stabilized barometer. Knowing all this information in the Pacific Northwest, this suggests that the bite might actually be a little bit better on a rising barometer than a falling one. Again, though, observations do vary. In summary, barometric pressure changes do have a real effect on salmon behavior. They can detect even slight shifts in

18:29 pressure via their swim bladders. A fast falling barometer will trigger strong, short-lived bite. Fish feeding up before the storm. Prolonged low pressure makes them sluggish and the bite dies until conditions improve. Stable high pressure can bring tough midday bites until it improves. So, while pressure isn't the only factor, it's one of those subtle ingredients behind the scenes that if you're a super savvy angler, paying attention to that little piece of data can make you understand why things are happening a little bit more effectively next time you go out and fish. So, finally, number four, scent and salmon. Does smell matter? And the answer is absolutely yes. It matters in salmon fishing. Salmon have an incredibly keen sense of smell. One of the most acute in

19:15 the animal kingdom. Their olfactory ability helps them navigate back to their home streams. They actually imprint on the smell of their natal waters, which is how they find their way back home when it's time to spond. So, because they have that olfactory superpower, it definitely affects them when they're feeding as well. They can detect odors in concentrations in just a few parts per billion in the water. So, think about that. Think about when you have junk on your gear or bad smell on your gear. But putting in into perspective, it's like being able to smell a single drop of scent in an Olympic size pool. That sense of smell means that they can pick up on very small traces of substances, whether it's amino acids from prey, and we've talked

20:00 about that before. Certain bait fish that are more oily have a stronger amino acid content and salmon are attracted to that. The pherommones of other fish or unfortunately like gasoline or sunscreen. So, if you're touching your gear, you have sunscreen on your hands, maybe you filled up the tank, but it dripped when you pulled the thing out, maybe whatever it may be. If you have chemicals on the boat, you have cleaning agents, the fish can smell it. So, that's the reason you'll see a lot of really seasoned anglers wearing gloves when they're handling their gear or rigging their bait or oftentimes washing their hands to make sure that they're getting all of that scent off before they're messing with their stuff. So, as an example, there's good sense versus bad scents. Because of the sensitivity, some scents can actually repel your

20:45 fish. An Alaska study noted that when salmon detect food-like odors, their behavior changes. It increased their searching activity as they tried to locate food. So many anglers exploit this by using scent attractants. So because of this, using scent attractants is definitely an effective way to increase your bite. As an example, some guys on like their hoochis, they'll put a little strip of herring on that front hook so that there's a level of natural scent that is going to be on that lure. It also could be masking some scent that maybe you got on it by just touching it with your hands. So, herring oil works, krill scent works. On the flip side of that, unpleasant or foreign odors, like we talked about, can definitely turn fish away. So being aware that certain

21:33 scents can affect what is happening, you might want to consider avoiding things like gas, sunscreen, tobacco, sweaty hands, anything that could kind of gross out your fish potentially or turn them away from your lure. Just be cognizant that scent can make a difference even though it's a very minor thing at times. So practical ways to keep things clean is again wear gloves is a really great way. Okay. Also, a fishing towel that's been used to wipe up fish slime and is sitting on the deck and is getting really gross, it can become rank and sour. So, that can also negatively affect the smell of your gear. If it's offensive to humans, it's probably more offensive to the salmon. But, yeah,

22:19 wiping your hands and lures with foul smelling towels is a good way to repel fish. Also, washing your lures in Lemon Joy soap is a trick that was actually borrowed from bass angling, but supposedly it removes any manufactured oils or human scents quite well, and that's a way that you can prevent your scent from being a repellent to the fish. So, scent attractants is a good way to give you an edge like a gel or an oilbased scent, herring or anovroving or krill. You can add that to your lures. One of the problems you'll run into if you get a little too overzealous with scents is it gets all over everything and it can go rank. So you want to make sure that if you do use scents that you clean your gear really

23:05 nicely afterwards. Also, if you get it on the line, it can affect it staying in the clip, which is really frustrating. So it just sense can get really messy. So use it if you're going to do it. Make sure you're pretty careful with how you apply it and how you keep it clean on the boat. And a lot of times a herring strip if you are using something like a hoochie will go a long way. So just throw a little herring strip on there or fish bait. That's one reason I think bait fishes so effectively well is it has the natural scent and amino acids of what a salmon would actually eat. But bottom line, it's not a gimmick. It's a great factor to consider when you're salmon fishing. And if you are not going to be using scent, you just want to make sure that you're not adding any negative repelling scent to your

23:51 lure by keeping your hands washed and and oils and food and sunscreen off of your gear because you're relying on the actual presentation to entice the bite, which is our next and final factor that entices a salmon to bite is the bait and lure presentation. So even when environmental factors are perfect, you still have to make the salmon want to bite your lure or bait. So often anglers will talk about presentation, how the lure moves, its appearance, its speed, its depth. Why does a salmon bite a lure even if they're not hungry at the exact moment? So let's talk about the feeding instinct. Hunger, obviously most straightforward reason that a fish would strike your lure. So, in the ocean, shnook and coo spend a lot of time

24:37 hunting prey, presenting something that looks like their prey, which is why you hear that term match the hatch. If you do catch fish, open up their belly, see what's in there. And more than likely, what you caught them with is going to be a little bit similar to what you find in that gut. And that's because they're feeding on your presentation. So, having something that looks a lot like what they're hunting can entice that fish to bite. The other reason that these guys will bite is aggression/territorial responses. So salmon, specifically coho, can be very territorial and aggressive even when they're not hungry. And they will strike a lure not to eat it, but to attack it. So this is the reason that plugs can be so effective. They make this loud rattling noise and it can

25:24 irritate a salmon into striking. Salmon are opportunistic. So, if a lure is moving like a wounded bait fish and sometimes like when I'm fishing bait, it'll just like do this weird wobble thing. And if the lure looks like that, it will be easy prey and therefore a salmon will strike it. So, even sometimes when my bait does not look like a very tight little barrel roll, I'll send it down and it'll still hook up. And I really think it's that exact reason. It just doesn't quite look like it's something that can get away quickly. So, the salmon will attack it. So, let's talk about speed and movement. Salmon are opportunistic feeders. Something that's slower and kind of looks like it's a wounded bait fish can entice a feeding bite, which is when a salmon is just looking for that easy

26:11 meal. Whereas, if you have something move quickly and maybe it's a sudden dart away, that can entice a chase or an aggression bite. So, if you think about a lot of times when you're out there trolling, have you ever been turning and in the turn your rod on the fast side of the boat will get hit? So, a lot of guys will actually troll crosscurren or do some zigzagging. And the reason for that is it's just changing the pattern of your lure, which is potentially a way to get the fish to aggressively feel like the bait fish is running away from it and it has to go after it and get it. So, that's a really important thing as well. So, in summary, bait and lure presentation works because it triggers the salmon's natural instinct. So, when you're looking at your presentation, a,

26:57 you got to make sure the scent is not going to be detracted on that lure, but also, how does it move in the water when it's just trolling straight, and then what can you do to add a little bit of variability into the way it's moving? And sometimes it's going up and down on the downrigger, it's bouncing the bottom, just doing a little bit of movement, not just sitting there trolling straight and doing nothing. If you're not getting any action, sometimes a little bit more activity on the downrigger can entice that bite. So, something to think about when you are targeting fish. But to sum it up, tides and currents matter a lot. It's probably your biggest factor to be considering when you're choosing where and why fish are going to bite. Moon phase is limited. It could potentially be something that matters or not. We don't really have enough data to figure that

27:43 one out. The barometric pressure changes do affect salmon behavior, which is something pretty cool to start tracking. So you can see how it actually looks where your home waters are and what that does to your actual planning. Scent control and attractants are absolutely crucial. Whether that means eliminating bad scents or adding scents to your products, it's definitely worth considering because of how olfactory salmon are. And also presentation entices bites. So, knowing all these factors, you can use what you know about the species and what you know about the conditions and make more effective choices next time you go salmon fishing. So, I hope you guys have gotten something out of this episode. And if you like these little science nerdy

28:29 research episodes, let me know because I'll keep making them. I I really enjoy the process of creating these. And so, if you guys are getting value out of these, definitely let me know and I'll keep adding them to the roster. So, with that, get out there, have fun, go fishing, and we'll catch you next week at the same time on the Fishing for a Reason podcast.