Category Archives: Fisheries Science

You’ve been with the Boldness, now nap with the Oldness

guide_serviceScience suggests bold and aggressive trout are likely to dominate their peers, and being carefree extroverts, have the highest likelihood of eating our flies and lures, therefore enjoying a very short dominance …

… and those same scientists have inadvertently bred for aggressive, outgoing, social trout, used to rubbing shoulders in concrete pens, ensuring great numbers of them will be needed to guarantee species survival, as they lack the wily, shy nature of their wild counterparts.

Science also suggests boldness is inheritable – and should the aggressive, outgoing, fearless trout be lucky enough to mount something other than a loose fold of your wader leg, their progeny will also be bold, outgoing extroverts.

It is only reasonable that the last couple hundred years of angling and our relish for killing anything of size, has selected for shy, finicky, and introverted fish. Better yet, similar logic should hold for Mankind, given the bold social extroverts were likely the first ones out of the trench, and war, plague, and saturated fat, has seen fit to thin the ranks of extroverts and ensure species survival lies with “wild” or shy types.

Oracle: I’d ask you to sit down, but, you’re not going to anyway. And don’t worry about the vase.
Neo: What vase?
[Neo turns to look for a vase, and as he does, he knocks over a vase of flowers, which shatters on the floor.]
Oracle: That vase.
Neo: I’m sorry–
Oracle: I said don’t worry about it. I’ll get one of my kids to fix it.
Neo: How did you know?
Oracle: Oh, what’s really going to bake your noodle later on is, would you still have broken it if I hadn’t said anything?

… and is the successful angler so because boldness catches aggressive, and rushing to the creek forgetting to lock the car door, or checking for your license, or remembering lunch, catches more fish than us reserved fellows that use turn signals in traffic, and don’t “low hole” those that arrived before us?

Flies and tackle have certainly become bold as they’ve jettisoned somber and become bright and colorful again. Gone are the drab earth colors and camouflage finishes of the shy, stalking angler – replaced by tinted aluminum and the harsh hues of mini-mall neon.

Fly fishing periodicals are obviously catering to extroverts. Their pages depict an incessant litany of fashion, exotic locales, and eye-searing colors, suggesting boldness and audacity is unaffected by mounting debt, weakening economy, nor the indiscriminant accumulation of gear.

Perhaps their readers have read of their fate and are aware that continually low-holing the riffle, borrowing flies from your pals, or relying on Malaysian 747’s to get to those exotic locales, often ends badly – and both accumulated debt and dominance are erased in the resulting mushroom cloud.

It’s no secret that successful anglers stand little chance of reproduction, given their penchant for inclement conditions, incessant mosquitoes, and taint that follows all blood sports. Left to the female of the species, our extroverts have little chance of passing on their boldness given the only thing romantically linked to fly fishermen are beer and the Law.

… and wardens, being stalkers and introverts, aren’t liable to be attracted to boldness unless it is out-of-season, over limit or undersized.

And all this time I’d assumed fly fishing was merely a place for us antisocial types to pick on things smaller than us. Now I know us wily old guys are critical to the sport, as the outgoing extroverts are systematically eliminated it falls to us to propagate the species.

Which explains our relish for making fools of ourselves attempting to ignite the interest of something half our age … and why our numbers continue to dwindle …

Why you’re a prick if you fish a Copper John

Considering that Science is a stale read, I livened up my research by poring over pages of BASS forum datum, searching for “cable guy” wisdom on the use of scent on baits.

BASS fiends are more fun than fly fishermen, but only because they have so many more hang-ups (and such thin skins) …

Mention to a fly fisherman that he “coaches soccer,” and you get that screwed up face suggesting the joke was lost on him, whereas the bass crowd is already climbing over the bar intent on your arse …

In short, science suggests scent in fish is somewhat synonymous with taste, and it makes perfect sense. In humans scent is particulate matter mixed with air, and taste is particulate matter dissolved in spittle. Each sense being chemically discrete and can be experienced without the data intruding from one to the other.

Fish “smell” particles dissolved in water and their “taste” is the same medium, so the two senses have overlap.

The physics of water and scent is reasonably obvious. The rush of water downstream carries scent and forms a plume from the source of the dissolved solid. Lake water has much less of a current and therefore the scent area is a slowly widening circle from the source of the particulate.

current_scent

Naturally my slow moving ditch water has neither appreciable current nor is it completely stagnant, so the chemical trail of any bait tossed within its banks will be slow in spreading.

That’s the good news.

Science drops the bombshell by suggesting polluted waters affect smell drastically, and even fish exposed in migration can suffer many weeks of scent impairment. Among the most drastic pollutants are metals, heavy or otherwise.

The worst of the worst being copper, which should send a cold chill up any fisherman’s spine …

Copper is most frequently deployed as an algaecide or fungicide. Significant amounts of copper in the water column result from farm field runoff from crops that are water intensive like rice or tomatoes.

As we’re discussing those drainage ditches that bisect California’s Central Valley, we know that copper is deployed wherever there is rice fields, which comprises about half the state.

Naturally its the Northern half – which means all that copper is in the Sacramento, and pushed down to Southern California via the aqueduct, and spat into San Francisco Bay after permeating the Delta.

Copper is apparently linked to the decline of California’s Coho salmon population given its ability to destroy taste and smell in salmonids, making them unable to detect waterborne predators like Pike minnow, Otters, and everything else the southern water districts conjure up as a Jihadist of salmon.

So while you’re buying all that antimony because you can no longer bear to throw lead into the creek, consider your use of copper wire ribbing and how many fish are bumping into things because of your errant back casts and the rusting Copper John’s left in your wake.

Even worse is how Copper is being used to mitigate Didymo … and in so doing, will play havoc on everything downstream.

The Bass crowd are adamant on the merits of Anise, Garlic, Eau D’ Earthworm, Shrimp, Shad, Herring, and Crawfish. Naturally, they don’t spend a lot of time offering science to back up their assertion that Bass adore Garlic, but they can claim it makes their own hammy hands smell less like human.

… and fish hate human … along with tobacco, urine, bubblegum and a smoking fry pan …

In short, scent is among the senses used to detect prey, as bugs and minnows, crayfish and frogs, all have a chemical plume downstream of them, assisting a fish in opaque water to located them by following that plume upstream to its source.

Polluted water means fish can smell less, but as murk water is a fly fisherman’s Achilles Heel, cannot be ignored as a source of attraction.

Bass anglers mention that both aerosol and liquid scents seem to wash off faster than the “sticky jelly” variant, so it sounds like we’ll be getting our hands dirty …

Murk Water and the Vesicles of Savi

Counter to what we’re taught with traditional angling, we don’t run out to buy a vest and a thousand dollar rod simply to fish the vastness that is the murk water.

Rather, we’ll be channeling a lot of Arthur Conan Doyle, and learn the weaknesses of our quarry and his environment, knowing we’re not likely to be holding aces when fishing water with little or no visibility.

“Brown Water” is not brownlining, brown is merely a convenient pseudonym for a body of clay-rich and filthy … the presence of enough suspended sediment to make sight essentially useless.

Our normal fly tying arsenal of eye-searing colors and tinsel Bling is useless when visibility is so scant, as neither the hottest of Oranges nor the flash of iridescence can be seen under any light condition.

Yet those who’ve dipped salted clams for Catfish and other bottom dwelling bewhiskered species can vouch for their being well fed, suggesting fish acclimated to this environment have little issue finding food in opaque water.

It’s plain that something other than visuals draws predators to their prey, and it’s likely that the commotion of a struggling fish might travel further underwater than its visuals. Larger food items are likely to have a signature swimming motion allowing predators to quickly pounce on known items due to their swimming rhythm.

A mud burrowing mayfly may struggle enroute to the surface, but its small size is liable to have a proportional disturbance, which would have an insignificant signature compared to a larger baitfish or swimming frog.

Murk water has plenty of hatching insects, but hatches and surface bugs doesn’t yield the same swarm of opportunistic feeders. The rhythmic dimples we see with clear water species and bug hatches are the result of sight feeding and share no parallels in opaque water.

The science of fish and opaque water (or the impenetrable blackness of low light) is completely fascinating, and suggests that fish have as many as three tools to locate prey without relying on visuals.

First, it may surprise some that fish actually have ears, and their range of hearing (detectable frequencies) varies considerably among species. Scientists classify fish as “hearing specialists” – fish with an ability to hear a greater range of noise frequencies, “hearing generalists” – fish that can hear better than average, and regular fish, like Salmon and Trout with only marginal hearing.

Therefore, for most ?shes that rely on hearing only through particle stimulation mechanism, their hearing ability is limited to a narrow frequency band (less than 1000  H z) with high sound pressure threshold (as high as 120   dB at the best frequency). Such ?shes are hence termed  “ hearing generalist ”  species.

It should be little surprise that many of our dirty water fish like Carp and Catfish are among the hearing specialists.

However, fishes in the superorder Ostariophysi (e.g., cyprinoids, characoids, and siluroids) have a specialized mechanical coupling structure (i.e., the Weberian ossicles) that connect the gas bladder to the inner ear (Furukawa and Ishii 1967 ). Hence, vibrations caused by the passing sound to the gas bladder are transmitted to the ears and hearing abilities are enhanced. Because of their extended hearing frequency range (up to 8000 Hz in certain catfish) and low thresholds (60 dB in goldfish), these fishes are called “ hearing specialist ” species.

In addition to the ears of fish, a fish can also detect vibration in the water around it via its lateral line. It turns out this organ is poorly understood among ichthyologists, and while there is much thought and conjecture, there is a great deal of unknown about its function. What we do know is it is host to numerous types of receptors and its complete range of capabilities is still unknown.

The lateral line has mechanical receptors able to detect vibration in the water around it, akin to a second type of “hearing”. Less well known is the ability of the lateral line to detect electrical fields, the ability to discern the presence of a living organism due the change in their surrounding electrical current.

All organisms produce electrical currents. A variety of aquatic organisms can detect these currents with specialized neurons. Such electrical sense has been found in a number of invertebrates and many aquatic vertebrates including sharks, fish, and even mammals such as the duckbill platypus. Electrical senses are important in turbid waters such as muddy rivers or the vicinity of a bleeding victim after a shark takes its first bite (scarlet billows, through the water ….). Often, the electrical sense neurons are concentrated near the head or in a structure that is placed in contact with a muddy bottom, such as the barbels on the chin of a catfish (which also have chemoreceptors), or the bill of a platypus. Other organisms go so far as to create their own weak electrical currents (modified muscles can do the trick) and actively search out prey.

As turbid water emits “noise” both audible and vibrational, consider your average trout stream to be an exceptionally noisy environment. Water flow around obstacles creates vibration as does current when it scours streambed and propels rocks and debris downstream.

Like light, high pitched noise (high frequency) travels the shortest distance in fluid. So if we’re tiptoeing around the creek and bark our shin on a stone – emitting a girly-nasal-screech will scare less fish than a throaty epithet …

And were we to pull all that murk water auditory science into fly design, we’d want larger beads in the rattle than smaller beads to make the noise as deep (low frequency) as possible, we’d want as many things sticking out of the fly as we could to cause vibrations when yanked through the water, we’d want the thing weedless as we have no idea what peril we’re throwing it at, and we’d want it to throw a dab of static into the water column to alert predators that it has a heartbeat versus some shoddy silicon wiggletail …

… and smell, smell would be nice …

If you peed enough Bacon would trout want a pork chop?

wastwater3It started with the discovery that hot flashes and night sweats lead to wastewater rich in estrogen and other hormones, making everything downstream of our treatment facilities female and completely irrational near a shoe sale.

Now our worst fears are becoming scientific certainty, anything we eat, drink, and pizzle, dips our watersheds and its many residents in a chemical cocktail of human excesses.

That which is excreted by us is swallowed by them. “Them” being fish both common and noble, insects, tadpoles, frogs, newts, and anything else that buries a muzzle in the creek to drink.

As anglers we’ve limited our outdoor competencies to the lifecycles of fish and insects. Entomology is used as the only device to explain both angling phenomena and our good fortune. Everything else, the lack of fish, the presence of Didymo, the absence of trash, the color of the water, its opacity, are all Mysteries of Nature – marginally understood and endured as part of the outdoor discipline.

Bugs and fish alone can’t explain much of what we witness, yet we use them as the “Lee Harvey Oswald” of angling; the guy they caught and hung, and chemically charged sewage ripples through our watershed undetected like a sniper cloaked by the shrubbery of the grassy knoll.

If the essence of everything we eat and drink are marinating fish, the difference is our visual recognition of them as food and conscious choice. We knew what the chili-cheese fries will do to our colon and eat them despite the pleas of the medical profession. Fish are not so lucky, they enjoy the same clogged artery endorphins we’ve released upon completing our sodden meal, but lack any knowledge of the source of this obscene pleasure.

If our excreted chemicals are part of the watershed then its residents are filled with unexplained cravings, unfulfilled deep-seated needs, and both fish and insects hunt for oddities they’ve inhaled but never seen, hoping it’s a Caramel Macchiato, cheese burger, or nicotine-rich cigar butt.

While afield we’ve seen countless fish dart from cover to inhale some current-borne morsel and being dependent on bugs science have assumed it to be a tumbling mayfly or caddis that caused this feeding behavior. Not surprisingly fish behavior has always been attributed to bug theory, and the reality may be our incessant pizzle of hormones have given them all seven cardinal sins; wrath, greed, sloth, pride, lust, envy, and gluttony, and the real motivations are akin to our own.

Flick, Schweibert, Swisher & Richards, all join a Human history full of ardent prophets whose outlandish theories were proven wrong after they were burnt at the stake.

Now that our sport struggles to free itself from its classical roots, and real scientists struggle with the role of human diseases, sexual aids, and dietary shortcomings as they pour into our watersheds – it may be time to rethink our dependence on bug-minnow imitations and upgrade our selection to include flavored and scented patterns that imitate the chemical essence of an Egg McMuffin.

Now that artificial sweeteners coat our stream bottoms and antibacterial soaps are denuding our watersheds of life-giving algae, it’s becoming obvious that the next century of anglers will be mastering sewage-sitology, the predation of innocent hosts using effluent based triggers.

It’s not really that far fetched, as it’s possible all of the great fly fishing mysteries remain so because insect science has never been able to explain them fully …

Why do fish prefer one fly pattern over another?

Entomologist: The #12 Royal Wulff more closely resembles the Ephemera Guttulata, and the trout mistakes the artificial for the real insect.

Sitiologist: The trout cannot recognize a cheeseburger by sight, yet it has inhaled beef byproducts in its water supply since it was an alevin. The Calf Tail emits a faint odor of cow flesh and the trout inhales it, knowing it to be a natural.

Why do bead headed flies work?

Entomologist: We’re not sure, but it sinks like a Son of a Bitch so it must be tasty!

Sitiologist: Normal insect imitations look like real bugs that live in the creek. Real bugs hide under rocks, burrow in the bottom, or simply fall in the water by accident. Despite their origin fish know they taste like shit compared to a Twinkie.

The addition of a big shiny copper bead makes the insect imitation something novel and new, therefore they eat the beaded fly to satisfy their craving for Twinkies (which they’ve never seen, and hope this is). Fish are optimists and something new may be that human thing they crave, yet cannot attain.

fivehourWhy do large fish feed at night?

Entomologist: Large fish are wary of predation and feed on smaller fish which are wary of big fish, and therefore unavailable until black dark.

Sitiologist: Large fish have been in the river far longer than smaller fish and therefore have inhaled a great deal more Five Hour Energy, Starbucks, and Rock Star effluent and have considerable trouble sleeping.

Without much else to do they prowl around for smaller fish that are quietly sleeping so they can bully and eat them.

 

Insect theory suddenly showing itself as quite porous in light of the above …

Unfortunately for the wader industry it appears  front zippers are doomed based on the Fish & Wildlife’s concern about chumming …

The social , gregarious fish are simply too precious to “one hand” or lift out of the water

largemouth_glasses Our study involving largemouth bass provides the
first direct experimental evidence that vulnerability to
angling is a heritable trait and, as a result, that
recreational hook-and-line fisheries can cause evolutionary
change in fish populations.

– via Selection for Vulnerability to Angling in Largemouth Bass

A twenty year study on Largemouth Bass yields an eye-opening conundrum for anglers, as the research suggests that Bass pass the likelihood for being caught from one generation to the next.

A 20-year study, led by University of Illinois research David Philipp, provided the first direct experimental proof that vulnerability to angling is an inherited trait.
Beginning in the 1970s, Philipp and his colleagues tagged and released largemouth bass in a pond in central Illinois. Some fish were caught up to 16 times a year. But when the pond was drained in the 1980s, they found that 200 of the 1,700 bass that were tagged had never been caught.
From that stock, the researchers bred groups of "high-vulnerability" and "low-vulnerability" bass. Then they stocked those fish in the same pond and repeated the experiment. Through three generations, the offspring stayed true to the parents’ tendencies.

– via Red Bluff Daily News

Years ago, US anglers took great exception to the practice of killing wild trout that was common on managed water in Europe and the UK. Angling restrictions required the fish be kept, as the prevailing theory was, “once it’s felt the hook – it’s not likely to eat an artificial again.”

The document mentions that Rainbow Trout have been used in similar research but fails to mention any conclusions of their use as subjects.

While the above conclusion is limited to Largemouth Bass, if it were to hold for most gamefish, then killing fish that take any fly, lure, or bait, ensures only the antisocial, cagey fish are left to breed, thereby ensuring that the fishery is ruined for us beer drinking vacationers …

Of interest is the description of the Largemouth’s vision, it can see about 50 feet with a resolution quality of about 10% that of a human.

Several lure companies have come out with highly touted lures with intricate paint patterns designed to imitate baitfish. But many of those baits proved to be a disappointment and never did sell the way manufacturers hoped they would.

The problem? They might have been too accurate.

Too much realism can make the bait invisible to prowling bass, based on distance and diminished vision quality. A bass might miss the movement should the lure be at sufficient distance (water being murky) whose camouflage was simply too good to be detected.

"The bass uses its eyesight and lateral line in combination when it is feeding," Jones said. "The lateral line is very effective in feeling local disturbances one to two body lengths away."

The full research paper was published in 2009 by the American Fisheries Society, and is available in PDF.

Now that we understand all those “red-state conservatives” no longer believe in Science, we can go down there and kick some tournament ass.

Take that Mister “We’ll just add a hatchery”

There are so many absolutes, so many unequivocating terms in the below as to be downright scary:

A new study has revealed that the impact of a hatchery environment on steelhead trout is so profound that in just one generation genetic traits are developed that cost fish the natural ability to be able to survive in the wild.

Nineteen years of research on the Hood River in Oregon will have both scientists and anglers in an uproar once it’s common knowledge that we’ve been unknowingly selecting for big sea-run trout that like concrete ditches and prefer the taste of dried kibble …

… and will we be able to look that thousand dollar spey rod festooned with black nickle and dripping acres of rare and exotic dander, without feeling less the Man and so very shortchanged … perhaps dirty even?

We’ve known for some time that hatchery-born fish are less successful at survival and reproduction in the wild,” said Michael Blouin, a professor of zoology at Oregon State University. “However, until now, it wasn’t clear why. What this study shows is that intense evolutionary pressures in the hatchery rapidly select for fish that excel there, at the expense of their reproductive success in the wild.

-via Worldfishing & Aquaculture

In short we’ve been catching the social moths, the trollops, and the used car salesmen of the steelhead world.

What’s worse is the potty mouth diet we’ve been catering to … These being the Twinkie eaters, the migrating fish that dine at fish ladders and Chinese takeout rather than forage for a meal, and all those wonderful and intricate patterns that have proven so successful have been a colorful representation of the hatchery ditch followed by a shovel full of desiccated dog chow.

We sure showed them, opposing thumb and big frontal lobe really proving the difference this time.

I’m going back to salmon roe goober and florescent marshmallows, food befitting some fat-bottomed fish struggling for breath on the cobble, trying to gasp out more fart jokes …

Adding extra studs to wading boots, how to tap dance your way to larger fish

wading_stud I’m giggling while Science chides me about noise pollution and fish –hoping to make me feel bad.

I suppose if I owned a boat I’d feel worse, but the article concludes that even short bursts of noise can distract fish while feeding, and they’ll make more errors in judgment and ingest things they shouldn’t …

The foraging mistakes are consistent with a shift in attention when exposed to noise, and in the natural environment these mistakes could be costly: increasing the chances of ingesting harmful items, and affecting the risk of predation if fish have to forage for longer to compensate for reduced efficiency.

I’m not so sure science was expecting to be serving information to the enemy, fellows like myself reading the conclusion and hanging on every word …

… but in elementary school we learned we could unnerve a good hitter at the plate by yelling, “hey batter-batta, SWING ..”, and anyone watching golf has to believe science, given anything louder than a duck fart sends a dimpled ball through someone’s picture window and muttered curses by even the most practiced golfer.

Can we induce a fish to eat something the wrong size, wrong species, and if so – how far away from the fishes maw do we trigger the underwater equivalent of a car alarm?

 

Taking it a step further, if we run out of the hot fly can a tantrum at the precise moment make something less worthy, extra-tasty? It’s certain we swear often enough in critical situations, perhaps we need to do so much louder …

I suppose SIMM’s will break the thousand-dollar barrier when it adds zippers and Sensurround, and then we can race each other out of parking lot to set hook while fiddling with the volume on Walkürenritt …

Is it really Whirling Disease, or did we just make the entire batch spin to the left?

oOPSIe, we didn't know Until recently fisheries biologists have seen the adipose fin as largely superfluous, and have clipped it to visually distinguish planted fish from their wild cousins.

Now they’re not so sure.

Recent studies suggest the adipose fin is crucial to fish, aiding it in navigating turbulent water.

With the tiny fin removed, he says the fish need to use much more energy to maintain position and speed in the water.

– via CBC News Canada

Given that the practice is especially prevalent with salmonids, which re-enter fresh water when it is most turbulent, it may have been one of many reasons why hatchery fish have never adequately replaced indigenous populations.

Makes you wonder whether we’ve been our own worst enemy, accidentally even. 

Fortunately “scoured by Mother Nature” is only Guy Clean

For most of the year I’ve resisted the urge to muck about on the local creek, largely for fear of upsetting the delicate balance of Nature given that once the flood receded I could only count 4 fish in eleven miles of its banks.

Then again, once I saw the hurried exodus of neighbors, hastily packed luggage crammed into idling vehicles, and the vexed expressions of those waiting in the car while [insert_family_member] went one last time, I realized in addition to being the only person home this weekend, I’d have to bring my own glass to the water, as it would be the only surface absent beer cans and a flotilla of V-8’s.

Note that new svelte-ness, soon toes will be visible

And while all those vacationers hoped to rendezvous with the Pristine, be it casino-based or Mother Nature’s Original Recipe, I strode up her seamy underbelly counting noses in sync with the measured beat of tires on bridge seams.

… and the noses were suddenly plentiful and varied, much to my surprise. All that lifeless gravel now colored with a bit of welcome algae, and host to an early morning Trico spinner fall that was twice as thick as year’s past, suggesting all those shifting tons of gravel buried much of the streambed, but has been assimilated and is home for bugs as well as fish.

Shedding last skin before spinner

I landed quite a few Pikeminnow, who have always appeared to bounce back quickly, and both Bluegill and Sunfish, even hooking a holdover bass that shook me free in a deeper pool.

Most importantly, schools of small fish are visible everywhere, and plenty of largemouth and smallmouth bass are among them. The one-inch fry of Spring have turned into the four inch minnow of early fall, and while it’s easy to miss the first, the latter are large enough to be seen at distance.

The science of stream recovery has proven to be much more valuable to the fisherman than you’d suspect. While it’s certain few have any interest in a coarse fishery, plodding all these miles of riverbank is birthing the newer svelte version, and through observation has taught me where fish go when stressed, where they linger if forced from their comfort zone, and what rate can anglers count on for the natural regenerative processes to spread surviving bugs and fish throughout a traumatized watershed.

There’s enough of the Precious left for our generation to frolic in, yet it’s a comfort to know that someone’s child will have a chance to commune with Nature – or at least her coarse black heart – once the Earth’s crust warms those few fateful degrees and trout are an afterthought in the fossil record.

and we do so love our Fisheries and their science

We Love Science Science suggests that it would prefer you not call an invasive species,  invasive …

Firstly, it may hurt their feelings, and secondly, given that it’s successful in outcompeting the local fare means it’s possibly superior (owning Adonis DNA), and may simply be species extincting a weaker occupant of the same resource …

In short, as history is written by the victors, it’s merely a Darwin thing, not a full fledged invasion.

To illustrate the peaks and valleys of successful science allow me to mention how a recent study in Japan illustrates how a terrestrial snail has a 15% chance of survival given their digestion by birds and crapped out after the full tour of the gastrointestinal tract …

This is the first study of its kind to show that the bird’s and their droppings are able to disperse living snails to other geographical locations. One snail managed to show the researchers that entire snail families could be transported by the birds. Not long after being ingested, one small gave birth to juveniles not long after passing through the gut of the bird.

Turn of the century studies have shown that diatoms can pass through a bird gut unharmed, given the armor of snails and their small size it’s not surprising that incomplete digestion might occur and birds might disperse a viable population outside their normal range.

In our continual battle against “Superior Darwin-esque victor-species” birds (ducks especially) may well be responsible for a portion of their travels.

Think didymo, mussels and snails …

… and for the Invasive chuckle of the week …

The Giant Salvinia is one of the more horrific invasives being battled intensely in the Southern United States. It spreads faster than daylight and completely chokes off lakes and waterways – rendering them impossible to navigate due to sheer volume of weed.

Giant salvinia is able to double in number and biomass in less than three days in optimal conditions and forms dense mats on still waters. The plant can regenerate even after severe damage or drying. The explosive growth of giant salvinia not only adversely affects the natural ecological system of the infested region, but it also causes considerable economic damage and sanitation problems.

… and has recently been found to cure cancer in humans, go figure.

I’ll wait until the AMA confirms the finding before grabbing a couple handfuls for my tub, a vain attempt to make up for all them cheap cheroots I sucked down earlier.