Mountain Lake Fish: Stocking, Eggs, Geology

0.000000    6.000000     Welcome to everyday explained your daily 20-minute dive into the fascinating house and wise of the world around you.
6.000000    11.000000     I'm your host, Chris, and I'm excited to help you discover something new. Let's get started.
11.000000    12.000000     I'm going to picture this.
12.000000    16.000000     You're way up high in the mountains, maybe on some remote trail, right?
16.000000    21.000000     And you stumble across this absolutely gorgeous pristine lake.
21.000000    24.000000     Looks totally cut off, no rivers flowing in or out.
24.000000    29.000000     But then you look closer and you stop like, "Huh, there are fish swimming around."
29.000000    33.000000     And you just stop and think, "Hang on a second. How on earth did they get here?"
33.000000    34.000000     It's a bit of mystery, isn't it?
34.000000    40.000000     We're talking about lakes that are seriously tucked away, landlocked, with zero obvious connection to anywhere else.
40.000000    46.000000     So yeah, how do fish get into these high altitude spots? I've been curious about this for ages, honestly.
46.000000    51.000000     So today, we're finally going to do a deep dive and get ready for some genuinely surprising stuff.
51.000000    54.000000     Some unexpected players in this whole aquatic puzzle.
54.000000    56.000000     It really is a fantastic question.
56.000000    61.000000     Because, like you said, so many of these bound lakes, they genuinely lack traditional inlets or outlets.
61.000000    64.000000     You look at a map that's just no obvious way in for a fish.
64.000000    68.000000     Geographically, it doesn't seem to make sense, so if they can't just swim there, what is going on?
68.000000    71.000000     Exactly. And it's more than just fish, right?
71.000000    75.000000     It sort of opens a window onto how interconnected things are, sometimes in ways you just don't expect.
75.000000    77.000000     Okay, let's unpack this whole thing.
77.000000    82.000000     We're going to cover, well, quite a bit from surprising human actions way back to ancient history.
82.000000    87.000000     And even touch on some, let's say, debated natural ideas.
87.000000    92.000000     The goal here is to give you real clarity on this without, you know, drowning you in technical jargon.
92.000000    97.000000     Right, let's kick off with probably the biggest and maybe the most surprising piece of the puzzle.
97.000000    99.000000     Us, humans.
99.000000    107.000000     Turns out, people have been deliberately putting fish into mountain lakes for over a hundred years now, mostly for start fishing.
107.000000    112.000000     You know, trout, especially those beautiful fish you imagine in those high lakes.
112.000000    114.000000     Yeah, odds are they didn't exactly find their own way there.
114.000000    119.000000     And what's really striking, ecologically speaking, is what those lakes were like before the fish arrived.
119.000000    121.000000     Many were naturally fish-free.
121.000000    125.000000     Their main residents were often things like aquatic salamanders, various kinds of frogs.
125.000000    128.000000     They thrived because, well, there were no fish predators.
128.000000    132.000000     Ah, okay, so introducing trout completely changed things.
132.000000    135.000000     Completely. The trout basically became the top predator overnight.
135.000000    136.000000     Yeah.
136.000000    140.000000     And in many places, they just decimated those native amphibian populations.
140.000000    141.000000     That's ironic, actually.
141.000000    151.000000     In places like the Sierra Nevada's, some agencies are now encouraging more fishing for trout, basically an open season, trying to remove them to help the original ecosystem recover.
151.000000    154.000000     Wow. Talk about unintended consequences.
154.000000    156.000000     Yeah, exactly. It's a powerful lesson.
156.000000    161.000000     And the effort involved in the early days, getting those fish up there, it wasn't easy.
161.000000    169.000000     We're talking really tough journeys. You had early stalkers, like bass shepherds in the Eastern Sierras, maybe a century or more ago.
169.000000    175.000000     They literally had to carry tiny baby fish, the fry, uphill in whatever containers they could find.
175.000000    178.000000     Sources mention things like teapots and stuff.
178.000000    181.000000     Teapots and milk cans, too, apparently, back in the 1800s.
181.000000    184.000000     Just common tins filled with water and fish fry.
184.000000    188.000000     And you imagine hauling sloshing cans of baby fish up a steep mountain trail?
188.000000    191.000000     That's dedication, or maybe desperation for fishing spots?
191.000000    196.000000     Well, from those back breaking efforts, we've certainly streamlined the process.
196.000000    201.000000     The methods today are much more, shall we say, airborne.
201.000000    203.000000     It's pretty wild, actually.
203.000000    206.000000     Many states, Utah's a good example. Now use airplanes.
206.000000    211.000000     They literally drop tiny trout, like one to three inches long, straight into these remote lakes.
211.000000    213.000000     Just drop from a plane, seriously.
213.000000    220.000000     Yep, you might picture fish just splatting, but apparently the method is considered less stressful for them than, say, a long bumpy truck ride.
220.000000    228.000000     And the reported survival rate, something like 95%, it's incredibly efficient for reaching those really inaccessible spots.
228.000000    233.000000     Speaking of planes and fish, you know who else was apparently a fan of aerial stalking.
233.000000    236.000000     There may be not exactly through official channels.
236.000000    237.000000     Oh, who were talking about?
237.000000    239.000000     The legendary test pilot, Chuck Yeager.
239.000000    244.000000     Oh, right, the Chuck Yeager story. He took gun fishing to a new altitude, didn't he?
244.000000    254.000000     Totally. The story goes, he used his military access, basically commandeered cargo planes to acquire, love that term, and then drop fish into dozens of lakes in the sierra.
254.000000    259.000000     Apparently, just because he wanted to fish in total solitude, away from everyone else.
254.000000    254.000000     And why?
259.000000    267.000000     It's a crazy anecdote, but it really highlights that human urge to, you know, tweak nature for our own purposes, even if it involves bending a few.
267.000000    269.000000     Or maybe quite a few.
269.000000    270.000000     Rules.
270.000000    274.000000     That story, funny as it is, does touch on a more serious kind of contentious point.
274.000000    275.000000     Yeah.
275.000000    279.000000     The real motivations behind official fish stalking programs.
279.000000    286.000000     Some people argue that stalking, especially by agencies like the US Forest Service, is basically just about generating revenue.
286.000000    288.000000     You know, selling fishing permits and licenses.
288.000000    291.000000     Right, like it's just a business venture dressed up as conservation.
291.000000    292.000000     That's one perspective, yes.
292.000000    293.000000     Yeah.
293.000000    295.000000     They see it as a direct money making scheme.
295.000000    297.000000     But there's another side to that coin, isn't there?
297.000000    300.000000     An argument that the money is actually used for good.
300.000000    301.000000     Exactly.
301.000000    304.000000     The counter argument is that the revenue isn't just profit.
304.000000    314.000000     It gets reinvested into broader conservation work, things like anti-poaching patrols, habitat restoration, maybe funding the hatcheries themselves, and research.
314.000000    321.000000     For instance, one source mentioned California's commercial fishing license revenue was around $3 million in 2018.
321.000000    326.000000     That sounds like a lot, but managing vast public lands and waters cost a fortune.
326.000000    328.000000     So that money helps cover those costs.
328.000000    330.000000     Okay, so it's complex.
330.000000    332.000000     Revenue generation versus funding conservation.
332.000000    335.000000     But what happens when these stalking plans go wrong?
335.000000    336.000000     Like, really wrong?
336.000000    339.000000     Yeah, it's crucial we look at both sides impartially.
339.000000    343.000000     Because some plans might work out, or at least the revenue helps fund things.
343.000000    348.000000     There are definitely cases where as one source bluntly put it, they screwed the push.
348.000000    349.000000     Oh, like what?
349.000000    353.000000     Take the example from Washington State Fish and Wildlife, they introduced Tiger Muskie.
353.000000    357.000000     Reports suggest it was largely driven by wanting to sell more fishing licenses.
357.000000    358.000000     Okay.
358.000000    362.000000     But then it turned out these Tiger Muskie's were hammering the native salmon populations.
362.000000    365.000000     Apparently, the department even tried to shift the blame initially.
365.000000    366.000000     Oh, wow.
366.000000    367.000000     So what happened?
367.000000    369.000000     Long story short, the salmon numbers crashed.
369.000000    375.000000     And ironically, the fishing license revenue probably plummeted too because, well, fewer salmon to fish for.
375.000000    379.000000     It really shows how delicate these things are.
379.000000    386.000000     Managing for one species or one goal, like revenue, can have these massive negative ripple effects throughout the whole ecosystem.
386.000000    391.000000     Okay, so humans are clearly a huge factor, probably the main one for many lakes.
391.000000    393.000000     But what about natural ways?
393.000000    398.000000     Surely some fish get into these isolated spots without a plane ride or a milk can.
398.000000    399.000000     It feels like maybe.
399.000000    402.000000     Maybe these lakes weren't always so isolated.
402.000000    403.000000     Does that make sense?
403.000000    404.000000     Absolutely makes sense.
404.000000    408.000000     When we say isolated, we're often just looking at a snapshot in geological time.
408.000000    411.000000     Over millions of years, landscapes changed dramatically.
411.000000    415.000000     A lake that looks totally landlocked today might have been connected to a larger river system ages ago.
415.000000    421.000000     Rivers change course, land-up lifts, valleys form, the slow dance of geology.
421.000000    422.000000     Right.
422.000000    423.000000     And think about ice ages.
423.000000    428.000000     Massive glacial lakes, like the ancient lake Agacies in North America, covered huge areas.
428.000000    433.000000     As glaciers melted and reformed, they would have undoubtedly spread fish far and wide.
433.000000    436.000000     So fish could have been trapped when the water receded?
436.000000    437.000000     Precisely.
437.000000    439.000000     We see echoes of that today.
439.000000    442.000000     Think about the desert pup fish in parts of North America.
442.000000    446.000000     They live in these tiny, isolated springs and water holes now.
446.000000    450.000000     Remnants of a vast lake system that dried up thousands of years ago.
450.000000    454.000000     They're genetically unique little pockets of life.
454.000000    457.000000     Okay, geology makes sense over long time scales.
457.000000    459.000000     What about more sudden events?
459.000000    460.000000     Like floods?
460.000000    462.000000     Can they connect things temporarily?
462.000000    464.000000     Yes, absolutely.
464.000000    468.000000     Major floods can create temporary waterways, linking previously separate bodies of water.
468.000000    471.000000     And this is where we get that amazing story from Australia, right?
471.000000    472.000000     The golf course.
472.000000    474.000000     Ah, yes, the golf course sharks.
474.000000    476.000000     It sounds like something out of a movie, doesn't it?
476.000000    477.000000     Totally.
477.000000    478.000000     Tell us about it.
478.000000    482.000000     Well, the anecdote goes that there was this golf course pond, supposedly landlocked.
482.000000    487.000000     But after some really severe flooding in the area, bull sharks started showing up in it.
487.000000    488.000000     No way.
488.000000    490.000000     Bull sharks in a golf pond.
490.000000    491.000000     Yep.
491.000000    495.000000     Apparently, golfers were officially warned not to go waiting in the water hazards to retrieve their lost balls.
495.000000    497.000000     I bet they weren't.
497.000000    498.000000     That's incredible.
498.000000    504.000000     It really makes you rethink what landlocked even means when nature throws a massive flood your way.
504.000000    507.000000     It does show the power of those extreme events.
507.000000    509.000000     Now, moving on from floods.
509.000000    514.000000     There's another natural theory that gets talked about a lot, maybe too much bird dispersal.
514.000000    517.000000     The old birds carry fish eggs on their feet idea.
517.000000    518.000000     Exactly that one.
518.000000    525.000000     It was proposed way back by famous naturalists, even Charles Darwin, used about it in the 19th century.
525.000000    528.000000     The idea seems plausible on the surface.
528.000000    536.000000     Birds move between wetlands, maybe sticky fish eggs, cling to their feathers or feet, get dropped off in a new lake, and voila fish.
536.000000    539.000000     Yeah, it sounds like it should work. It has that intuitive appeal.
539.000000    545.000000     Like, oh yeah, birds fly everywhere makes sense, but is it actually proven for fish?
545.000000    551.000000     Well, that's the key point. It makes intuitive sense, maybe, but it's pretty much an unproven hypothesis when it comes specifically to fish eggs.
551.000000    553.000000     So no solid evidence.
553.000000    555.000000     Very little, bordering on none.
555.000000    558.000000     There was a significant study actually from the University of Basil.
558.000000    565.000000     They did a big systematic review of scientific literature looking for evidence of bird dispersal and their finding.
565.000000    571.000000     Basically zero robust scientific studies confirming that birds disperse fish eggs effectively.
571.000000    574.000000     Oh, okay. So much for that popular theory.
574.000000    579.000000     It's a great example of how an idea can persist, because it seems logical, even without strong backing.
579.000000    587.000000     Interestingly, the same review did find plenty of evidence for birds dispersing aquatic invertebrates, like tiny crustaceans or snails.
587.000000    591.000000     So the mechanism isn't impossible, just highly unlikely for fish.
591.000000    595.000000     Why, though, what's the specific problem with fish eggs and bird travel?
595.000000    597.000000     There are several major hurdles.
597.000000    602.000000     First, most fish eggs need to stay consistently wet and get enough oxygen to survive.
602.000000    606.000000     Bird feathers, especially on waterfowl, are designed to repel water.
606.000000    608.000000     That's how ducks stay dry.
608.000000    609.000000     Right, they're oily.
609.000000    613.000000     Exactly. And birds are constantly preening, cleaning their feathers.
613.000000    619.000000     It's hard to imagine delicate eggs surviving that, let alone staying stuck and wet for a long flight between lakes.
619.000000    626.000000     Plus, many of the fish species we find in these mountain lakes, like trout, actually don't have sticky eggs.
626.000000    628.000000     Their eggs wouldn't cling easily anyway.
628.000000    630.000000     And you'd need more than one egg, presumably.
630.000000    639.000000     Precisely. For a population to get started, you'd need viable fertilized eggs, or maybe both male and female fry, to arrive in the same place around the same time and survive.
639.000000    641.000000     The odds just get incredibly small.
641.000000    646.000000     While other critters, maybe crayfish or freshwater mussels, might occasionally hitch a ride,
646.000000    650.000000     the fish egg on bird foot theory is largely debunked by scientists today.
650.000000    652.000000     Okay, so let's pull this all together.
652.000000    658.000000     We've talked about humans dropping fish from planes, geological history, rogue sharks on golf courses, and debunked bird theories.
658.000000    662.000000     But beyond just the how, what about the, so what?
662.000000    666.000000     What does it actually mean when fish show up in these previously isolated mountain lakes?
666.000000    668.000000     What are the wider ripple effects?
668.000000    673.000000     Yeah, the ecological consequences are really the crucial part of the story here.
673.000000    675.000000     It raises that question again.
675.000000    680.000000     What are we potentially sacrificing for, say recreational fishing?
680.000000    683.000000     Because almost always, the fish being introduced are non-native.
683.000000    686.000000     They're essentially invasive species in that specific context.
686.000000    688.000000     And that causes problems.
688.000000    692.000000     Big problems. We already mentioned trout wiping out native salamanders and frogs.
692.000000    699.000000     Yeah, that's a huge disruption to an ecosystem that evolves without fish predators for thousands, maybe millions of years.
699.000000    702.000000     But it's not just the intended introductions.
702.000000    705.000000     Think about anglers using live minos as bait.
705.000000    708.000000     If some escape, those minos can become established.
708.000000    709.000000     And what do they do?
709.000000    716.000000     Well, they can be aggressive predators themselves, eating the eggs in young, of native species, or even the trout that were stocked.
716.000000    722.000000     Some studies even show that certain minos can stroke sediment and promote algae growth, making the water less clear.
722.000000    726.000000     So you're fundamentally changing the water chemistry, the food web, everything.
726.000000    729.000000     Often it's not for the better from an ecological standpoint.
729.000000    731.000000     It really does seem like the human element looms large here.
731.000000    739.000000     Whether it's for food, sport, generating revenue, or even just, well, Chuck Yeager wanting his private fishing hole.
739.000000    743.000000     Our desires seem to be the main driver for fish in many of these remote spots.
743.000000    746.000000     It really highlights this ongoing tension, doesn't it?
746.000000    752.000000     Between human activities, recreation, resource management, sometimes driven by economics,
752.000000    757.000000     and the efforts to conserve these often very fragile, unique native ecosystems.
757.000000    764.000000     Understanding how the fish got there is fascinating, sure. But understanding the impact, that's where the knowledge becomes really valuable,
764.000000    766.000000     where we have to think about the choices we're making.
766.000000    770.000000     Okay, so let's quickly recap the main ways fish reach these isolated mountain lakes.
770.000000    773.000000     Number one, overwhelmingly, is human stocking.
773.000000    781.000000     That includes everything from those tough historical tracks with teapots and melt cans, right up to modern airplanes dropping fish from the sky.
781.000000    783.000000     Yep, humans are the biggest factor by far.
783.000000    791.000000     Then, much less commonly, you have the possibility of past geological connections, lakes that used to be part of larger river systems millions of years ago.
791.000000    793.000000     Or connected during glacial periods, exactly.
793.000000    802.000000     And finally, those really rare, extreme natural events like massive floods creating temporary and sometimes dramatic pathways.
802.000000    804.000000     I think sharks on the fairway.
804.000000    806.000000     It paints a complex picture, really.
806.000000    811.000000     It shows how our relationship with nature is often messy, unpredictable.
811.000000    820.000000     Our actions, even ones that seem small or well-intentioned, can ripple outwards and reshape environments in profound ways we don't always foresee.
820.000000    822.000000     So what does all this mean for you, listening right now?
822.000000    827.000000     Well, maybe the next time you find yourself by one of those beautiful quiet mountain lakes and you see a fish,
827.000000    832.000000     you'll know its ancestors might have arrived via a determined shepherd's centuries ago,
832.000000    839.000000     or maybe thanks to shifting continents over millennia, or perhaps just maybe it's descended from a fish that literally fell out of the sky.
839.000000    842.000000     It definitely adds another layer to just looking at the water, doesn't it?
842.000000    843.000000     It does.
843.000000    845.000000     It may be props of final thought.
845.000000    847.000000     Consider the delicate balance.
847.000000    851.000000     A stock lake might offer a great day of fishing, and that has value to many people.
851.000000    857.000000     But those increasingly rare, truly unfished lakes, the ones still dominated by amphibians and insects.
857.000000    863.000000     They hold a different kind of value, an ecological baseline, a glimpse into what was there before we intervened.
863.000000    865.000000     Which kind of value do we prioritize?
865.000000    867.000000     Which one do we really want to protect for the future?
867.000000    870.000000     And that wraps up today's episode of Everyday Explained.
870.000000    873.000000     We love making sense of the world around you five days a week.
873.000000    878.000000     If you enjoyed today's deep dive, consider subscribing so you don't miss out on our next discovery.
878.000000    881.000000     I'm Chris, and I'll catch you in the next one.