Category Archives: science

Peel Rubber, Kill a Salmon

peelrubberCars have been synonymous with pollution for several decades, but for fishermen “tire pollution” may be their worst legacy yet …

Scientists are attributing rubber dust from tire wear as being toxic to Salmon and Steelhead – and when transported into the watershed via rain and runoff, have attributed it to a series of fish kills in Puget Sound and possibly elsewhere.

Treating the runoff to neutralize the chemical would be prohibitively expensive due to the magnitude of paved roads near waterways, so the solution will require a change to tire composition, akin to the replacement of Freon for refrigeration systems.

The chemical is added to rubber to stabilize it from Ozone oxidation and goes by the trade name “6PPD.”

“It’s like a preservative for tires,” Tian said. “Similar to how food preservatives keep food from spoiling too quickly, 6PPD helps tires last by protecting them from ground-level ozone.”

Ozone, a gas created when pollutants emitted by cars and other chemical sources react in the sunlight, breaks the bonds holding the tire together. 6PPD helps by reacting with ozone before it can react with the tire rubber, sparing the tires.

But when 6PPD reacts with ozone, the researchers found that it was transformed into multiple chemicals, including 6PPD-quinone (pronounced “kwih-known”), the toxic chemical that is responsible for killing the salmon.

This chemical is not limited to the Puget Sound region. The team also tested roadway runoff from Los Angeles and urban creeks near San Francisco, and 6PPD-quinone was present there as well. This finding is unsurprising, the researchers said, because 6PPD appears to be used in all tires and tire wear particles are likely present in creeks near busy roads across the world.

YouTube has several videos on the subject from the University of Washington scientists that published the finding.

The question becomes how much 6PPD is found in “sticky rubber” and will the Purists insist we wade barefoot …

Cancel that Alaskan Fishing trip while you can

reefmadnessNow there’s more reason to “Go West, Young Man” – given as how Oregon, Colorado, and California are soon to upstage Alaska, New Zealand, and Argentina as the last bastions of pure angling body count …

While each has its own unique allure, all are “blue” states, home to free thinkers, liberals, men of letters and science, but more importantly – legal Weed.

In an effort to breed Tuna that Tastes Good, scientists have determined that stress-free fish tastes better than those forced to watch their brethren dismembered during processing. Those “fight or flight” endorphins released just prior to death turning grey and tasteless farmed salmon into grey, bitter, and plank-like salmon, which by all accounts – being even worse.

As the Filet of Fish and therefore the culinary health of all America is at stake, scientists have been redoubling their efforts at reducing stress in farmed fish by introducing cannabis extract to the water supply prior to harvest …

… and while it is too early to determine if cannabis in the water was better than issuing blindfolds, it did make the fish eat like a sumbitch.

Well, it did something. Although the fish didn’t appear to be any healthier or happier after the study concluded, the researchers noted that their metabolisms had increased, so they ate and digested food more quickly – a case of the fish munchies, you could say.

-via the Sac Bee 10.24.17

Given how most of California is being reseeded with medicinal hemp, all a canny angler has to do is stuff a couple of wader bags full of his neighbor’s unwanted chaff, stake the bag into the headwaters of his favorite creek, and bask in the benefits of “Trout Tea” and its ability to unlock the watershed – turning even the wiliest fish into a frenzied eating machine.

Hell, it’ll take years for the wardens figure it out, and even then we can blame it on the Sinaloa Cartel, or whatever the latest ill Donald Trump is peddling us to fear …

Before pulling up stakes and selling the homestead, there was a conspicuous lack of infomation on the effects of cannabis extract and the local mosquito population – and while they are wired a bit differently, it could be they never recovered the journals (or the bodies) of the scientists tasked with that bit of errata.

Seduced by the menu Photo

menuburgerEating the damn things has never adequately explained our zest for rising before dawn and spending the day waist deep in icy water.

I’ve always assumed that as our ability to hunt and gather is trodden upon by the more Urbane branch of Homo Metrosexualis,  whose tiny dog barks menacingly from their apartment window, whose owner is indifferent to Nature as the call of handheld electronics is twice as compelling, forces us Outdoorsmen to funnel our aggression into stomping life out of things smaller than us.

An inconvenient truth, given how we’ve attempted to make our sport politically correct with the, “we don’t eat them anymore” mantra.

A decade of reality shows celebrating People Behaving Badly and more recently, Presidential debates that are anything but, suggest Man may have reached a tipping point, his intellect on the wane and his base nature rules the day.

The research into how fish interpret and integrate sensory information, led by School of Biomedical Sciences ARC Future Fellow Dr Ethan Scott, could improve understanding of how humans combine senses like sight, touch and sound to create a complete experience.

With science now examining fish and their senses to understand Man’s interaction with his surroundings, it offers anglers a unique insight into behavior they see from our quarry yet mirrored in society at large.

Like “schooling” on freeways, “bottom feeding”  the Internet for amusement, and “rising” at anything feminine at the bar; first at the unusually well formed insects, and as the hours and drinks pass, the classic “smutting rise” for spin-sters, cripples, and anything else described as,  “… a ten at two.”

Those of us not capable of stalking and killing our own food return from the field to hunt in restaurants.  It should be no surprise that both fish and humans prefer fast food, as a mayfly spun through a riffle is as elusive as the menu picture of a savory meal – both promise much and are elusive to capture …

Turgid tomatoes, lush green lettuce, crisp onion slices, melting cheeses, and bubbling meats buttressed by soft breads; things that exist at the peak of ripeness, rich in color, damp with moisture, and  lure us like a majestically tied artificial. Proportions perfect, torso chiseled and regal, dancing on the water prior to leaping skyward,  wings taut, upright,  and drying rapidly. …

FattyAP

… and like our pellet fed surrogate, we fall for the SOB just just as hard.

Tasty awesomeness rolls over the lip to vanish in a dose of reality, as sodden paper bag borne of plastic tray delivers the congealing  lumpy turd through the driver side window.

Red tomatoes now mushy and pale, lettuce trending into the yellow-olive and drooping into the greasy unmentionable leakage from the patty of meat-like substance.

Our senses are fine, and while we recognize the lumpy thread whip finish or gleaming gold bead isn’t part of a mayfly, like the fish we’ll consume the gelatinous mass anyway. … hoping some hidden spice mixture alters “Powerbait” into a feast fit for royalty.

The rich reds, and damp greens of the menu vanish in favor of the the “well chewed” imitation – which arrives sandwiched between Clinch and Split Shot .. (or the canned peas and imitation Ice Milk.)

Assuming that pollution in streams is a rough approximation of  tomatoes grown for toughness rather than flavor, and vegetables picked green and ripened under the reefer’s fluorescent glare, there’s something fair in all this.

Learning of our willingness to suffer and explaining another’s plight in similar terms may shed light on the way we think, but the visuals aren’t so much the issue. Our willingness to settle may neatly explain both the well chewed fly and how anything made from Dog hair and Owl feathers rivals blister packed cheddar … or the attractiveness of an offshore-tied Parachute Adams.

The Notion of Blood, Angling’s Sacred Cow

imageOne of the things I find fascinating about fishing is how angling success is never a mystery, and how post-trip, prowess afield can be explained by local religion, mythology, or science.

“Science” being only of recent invention, given how religion and mythology were the sciences of angling’s antiquity.

As I young man I was fascinated by full dress Atlantic Salmon flies, how the traditional feather wings of Europe evolved into elaborate rituals of intertwined plumage from rare jungle birds.  I found them both daunting and impressive and spent many hours attempting to master their construction, as they represented the ultimate test of a tier’s skill.

Despite my fascination with their construction, I was never able to rationalize how fish that populated the Northern Hemisphere had such an unbridled lust for feathers or meat of things living South of the equator. As I pored through the hoary tomes of the period;  works by the venerable Pryce-Tannatt and Kelson, it was revealed that the Salmon, being the noblest of all fishes, dined only on Butterflies, which made these lures require such brilliant colors.

While consistent with bug lore, as described by the current angling “scientists” (Swisher and Richards, Schweibert, Caucci and Natasi, etc), none of these old books mentioned the presence of enormous swarms of butterflies necessary to sustain the many thousands of large salmon that spawn in Northern Europe and live to return to the ocean …

… which was my first brush with the mythology of our sport, as I was convinced their “science” horseshit – yet was aghast that an entire generation of anglers would swallow this fanciful explanation without complaint.

As I developed as an angler, I was to learn that despite our notion of “how things work”, popular opinion is often debunked horribly by successive generations and more current Science, and this has been the case since the dawn of time.

I was thinking of this as I read the latest bit of science-fancy on salmonids …

Of our “sacred cows” perhaps the most widely accepted is the notion the color red is irresistible to fish of all species, as it is the color of blood, something that unleashes the predatory nature of fish, making them less wise and much easier to catch.

"We’ve discovered an enzyme that switches the visual systems of some fish and amphibians and supercharges their ability to see infrared light," said senior author Joseph Corbo, MD, PhD, associate professor of pathology and immunology. "For example, when salmon migrate from the ocean to inland streams, they turn on this enzyme, activating a chemical reaction that shifts the visual system, helping the fish peer more deeply into murky water."

While the research is still in its infancy, the ability to shift vision from the blue-green of saltwater to the muddy flows of Winter, may be assisted by this ability to see the shortest wave lengths of light containing  red and the infrared spectrum.

I have wondered about this same phenomenon whenever I see a stream or river turned into a muddy torrent by rainfall, how do they see – and where do they go to avoid logs and debris?

While much of that information still eludes us, the Good News is the “biohacker” community  insists that if you gorge yourself on liver and Paprika you can see in the Infrared spectrum too, the obvious downside is your breath will be reminiscent of a lion’s arse

… Likely it’s the same crowd that said we should smoke banana peels back in the Sixties.

Science provides inspiration and wisdom does the debunking

I’ve always assumed Renoir and Degas had similar issues with us fly tiers; a couple of decades spent on rigorous painting tedium, and saddled with the costs of painting supplies, groceries, and a roof overhead, true masterpieces were sacrificed for the more mundane portraiture … because painting Madame … paid the bills.

Fly fishing, especially during those cold months between Winter fisheries and Spring, endures a similar tedium, where inspiration comes occasionally, and inclement weather and work combine into  books read, magazines thumbed through, and daydreams of future successes.

I used to find inspiration from periodicals, where fresh ideas and the exploration of new fisheries caused me a fit of tying creativity or made me lust after new terminal gear. Unfortunately, fresh ideas are in limited supply, and periodicals eventually yield to the stale yet profitable, and every Bahamian bone fishing article looks like ISIS reconnoitering Mosul, the difference between the two the color of their sun buff …

With the Internet and its ready access to all of the great colleges, organizations, and  sources of fisheries research, the Scientific community is an underutilized source of freshness in angling ideas. Theories abound on fish, bugs, stream dynamics, global warming, and invasive species, and even a casual knowledge of fish and bug behavior allows the reader to follow along from proposal to conclusion.

The volume of research is staggering, and while much is in its infancy (and is best served as simple topics to mull), a great deal more is mature – and for anglers  seeking new insight into their quarry or craft, become a source of ideas and topics that will never be mainstream enough to grace our angling press, or may feature conclusions that counter current ecological practices and are ignored by our conservation organizations.

In short, if you don’t turn over the stone yourself, no one will turn it for you.

This Spring has seen me start down a thread I found interesting, and resulted in many hours of fervor at the vise. What started simply – as a dissertation on Guppies has led through a chain of other papers, physics, and conventional wisdom, and while both conclusions and flies will always be questionable – the enjoyment of discovery and new inspirations have made the journey completely worthwhile.

The April issue of the Royal Society Proceedings B, has an article discussing the notion that patterns, motion, and coloration of prey (flora and fauna) are inheritable in Guppies, a freshwater fish.

After a great deal of rigorous experimentation the authors concluded Guppies prefer red or orange, and don’t particularly care much for blue. What fascinated me was the discussion that like bees, guppies were capable of honing in on patterns exhibited by their prey (both motion and coloration) akin to bees and birds and the specialized pollination coding on flowers.

For those as are unfamiliar, flowers are colored (both primary color and patterns of color on their petals) to attract the unique insects and birds that can best pollinate them. So long necked flowers that bees cannot climb into are coded for Hummingbirds, and anything with a long, thin proboscis that it can wad into the barrel of the flower.

This notion that freshwater fish may have similar tendencies I found fascinating, given that if anglers accept this notion it would likely spawn a bazillion new patterns that resembled (in coloration and pattern) everything from Green Drakes to discarded French fries.

As Mother Nature colors her insects to resemble the stream bottom, the notion of red or blue is a bit far fetched, but it does buttress our notion that color of the natural is worth imitating, in either dry or wet variants. Inheritance would also ensure that planted fish, should they survive, would also trend toward the same food choices of wild fish – as both groups must dine off the same menu.

Color and shape are the most copied trait of the modern fly tier, a reflection of the prevailing  “match the hatch” logic that has dominated fly fishing for the last several decades. Patterns in coloration and motion are the “less traveled” path, given how fly tying materials have dictated how the resultant imitation moves.

Natural materials being a bit more lively than synthetics, but only by accident, as many natural materials can be stiffened by the simple act of attachment to the hook.

Having to use a “J-shaped” bit of steel to contain all the parts of the natural is also a delimiting factor. Any discussion of imitation has to also recognize the limitations of physics on our potential options.

After a couple of weeks ferreting out full motion videos of mayfly nymphs in their natural settings, and viewing them for signatures akin to how a bee might view flowers, it is quickly apparent that there is a couple of patterns of color on a typical mayfly when swimming. The first was due to its carapace and color density imbued by thickness, and the second was due to gill motion, and the lightening effect that lateral gills (and the light-colored cilia attached) and their constant motion have on the surrounding colors of the insect.

Mayfly_Pattern600

Should this wild notion of torso “pattern-key” being the missing ingredient in the complete subjugation of Salmonids, I could expect some lofty company. The thought of my Portly & Brazen suddenly synonymous with Gordon, Skues, or Sawyer was pretty heady, but a couple of decades of wisdom tempered my flirtation with ego.

Tying flies with this type of pattern in their torso had some very obvious shortcomings …Physics being the most sinister, as all of my full motion vignettes quickly displayed.

BellyBackIn moving water most fish face upstream. Insects dislodged due to mishap or swimming to the surface come downstream (roughly) head first. Fish on the prowl for targets likely don’t see anything of the abdomen patterning save the wink of dark top or light belly, and only if the insect is swimming in its customary violent tail-centric, up-down, fashion.

In still water the fish can encounter an underwater insect along any axis, and the predative view may not even involve any signature other than motion, the frantic attempt to evade being eaten triggering the pursuit.

Fish_eye_nymphbutt

Not to mention the notion of the fish’s eye not being the same as our stereo flavor, and the exaggerations of coloration that exist when converting a stereo image to an approximation of what we think fish see …

… and therein lies the beauty of Science and the unending appeal it has for me and my dull Winter months. A constant stream of facts and theorems that promise future success – all of which must be tempered with angling wisdom and experience, in order to determine which theory will fill next season’s fly box.

What’s not important is whether any chain of facts will result in more fish caught, as the angler cannot determine what he would have done had he fished other flies. What is worthy is to continually question the status quo, given the shaky ground all of our current angling truisms are built upon.

It’ll take More than fries and a smile

The title appeared innocent enough, but its import sent a chill down my spine.

Inference and Science are never mixed without trouble, as inference is the opposite of scientific rigor. While I instinctively understood that my “connecting the dots” was a leap of faith, the conclusion was so hellish as to ensure our beloved pastime is threatened …

“ Female bats are fussier than males when it comes choosing where to eat in urban areas …”

Knowing that Mother Nature often shares her constructs across species, and buttressed by my personal experiences that Human Females share the same tendencies as  bats, suggest this behavior is present in  fish as well.

Make_Trout_Want

For most this will be a yawner, but knowing most of the freshwater fish in the world live in environments rich in Estrogen and are steeped in female hormones, and noting Science has indicted the water treatment folks with their callous extermination of gonads of all types, suggests the bulk of our quarry are at minimum transgender … or are already female.

As such they’ll develop the rarified palate and be doubly difficult to catch.

What Science has yet to explain is whether a “sale” tag on the fly will make them eat more often, or whether they’ll simply browse your fly box without touching anything.

For those scoffing at my reach of the available facts, note that like Human males, male bats settle …

Males, on the other hand, seem to be less particular and are just as likely to be found settling for poorer-quality woodland patches next to built-up areas. (Via Physorg)

Both species having low self esteem in common, and don’t pay much attention to the quality of what they stuff in their gob …

In male cuttlefish, mated behaviour was not affected by female receptivity; however, familiarity with the female did affect male mating behaviour. Males exerted a strong preference for unfamiliar females ..  (Via Physorg)

Males settle … and in females, prefer some “Strange” …

I don’t make this stuff up, I infer it, which is way better.

Where we fish from the shores like Gentlemen

tweedWith little to fish for and the only hatch forest fires, I’ve little to hone my skills than science.

“Neovison Vison” is Latin for our pal the Mink, and a study released on the biological implications of Didymo diatoms spread via animal agent has recently concluded in Patagonia, Chile. Mink, like waterfowl, are able to travel much farther than smaller waterborne animals (up to 10 KM overland), making them a poster child for diatom spread given the damp and humid environment their fur represents.

… and how anything liable to rub onto felt soles is likely to do similar when in contact with a Mink’s arse …

Anything immersed in water and coming into contact with damp substrate can carry diatoms, but waders and shoe uppers are an unpleasantness anglers only talk about in hushed circles. We know that were we to point fingers at others with greater fervor would bring into focus our remaining unclean habits and our hypocrisy, and would force us to cast from the shoreline like proper gentlemen.

It’s my opinion our beloved pastime and its many pundits continue to ignore issues associated with waders and wading shoe uppers, having performed their “due diligence” by pointing the finger at felt soles, and ignoring the larger issues of us being the vector for a lot of watershed ills.

Unfortunately true concern for the watershed may have us ensconced in a placental plastic membrane, or Tweed and Deerstalker, as science is proving reluctant to condone anyone or anything’s feet in the water …

“.. wildlife vectors may limit or negate the efficacy of biosecurity measures focused exclusively on the human role in dispersal (e.g. ‘check, clean, dry’ and gear washing stations) to date, management of D.Geminata has not considered wildlife vectors (Reid et al. 2012) a key oversight in terms of conservation planning and efforts to contain or exclude D. Geminata”

Factor in the omnipresent nature of waterfowl and their intercontinental migration patterns, and should diatoms live within damp duck down as they do in Mink fur, they’ll be viable for sixty days flight time, akin to our damp wading gear, yet instead of drying in our garage, landing nightly in a new watershed, and spreading diatoms with each immersion.

Geese were also mentioned as having direct interaction with D. Geminata (swimming, feeding, or touching the bloom).

The article has not yet been released into the public domain, and is available only as a paid download, and therefore cannot be redistributed yet.

IT concludes that 23 mink sampled in two rivers had on average about 3000 live diatoms rinsed from their fur after capture (capture was on dry land), and the kind and type of diatom found roughly matched their occurrence in Nature.

Animals captured near heavy concentrations of D. Geminata had more cells on them than those caught in rivers of weaker diatom density. Which is not surprising at all, and is consistent with common sense.

While humans are one of the animal agents that spread algal cells, and our jets and boats and vehicles make us especially well suited in doing so, our simplistic notion of “our dirty feet” being central to diatom spread and subsequent bloom is growing more holes than a good Swiss cheese.

Dissolved Phosphorus controls the presence of Didymo “bloom” and most of the continents have their own subspecies of the diatom – and have hosted it for some time.

Of particular interest to me is the article’s mention that salmonids are also able to spread D. Geminata. To date we’ve enjoyed an egotistical notion that we are the root of most watershed evil, but even migratory fish scrub the occasional rock – and carry diatoms further up or downriver.

Rainbow trout were mentioned specifically, with a sample of 20 fish having been scraped of mucous yielding no live D. Geminata cells, but Chinook salmon were mentioned as having a better likelihood of harboring live cells in their mucous, but are as yet untested.

This notion I find completely fascinating and potential humorous, given how us anglers flock to salmon streams during migrations, and how our feet may have been blamed coincidentally for spreading the plague our quarry brought with them …

… that ought to bake your noodle.

Part 2: A couple of backhoes and some dampness, right?

Arnold Palmer made a handsome living designing golf courses, and were you lucky enough to get drawn for Powerball and decided not to take the kids out of school, opting instead for a moderate lifestyle replete with small wineries or something private on the lot behind the house, exactly what would it contain?

Considering a large farm complex already owns backhoes and Caterpillars and those skilled in their use, any lull in tomato growth would give you the opportunity to reposition those assets for your dream pond.

A couple thousand gallons of diesel later, and you’ve scraped a big hole in the ground, but it’s dawning on you that’s the easy part …

Above_Pond

Now you’ve got to decide how deep it is, how much will evaporate in a single season, do you want to fish it from shore, do you plant trees, do you want to wade it or use a float tube, and what kind of fish can it support – and how many?

I took the opportunity to interview the fellow responsible, as he was a friendly cuss and proud of his work. This was his third such project, about 1.5 miles in circumference and nearly 12 feet deep at the deepest edge.

No naturally occurring water sources, not large enough to require concrete or reinforcement, just a simple earthen dam as recipient for all the dirt carved out from behind, and a simple spillway system allowing any runoff to meander through a short natural area prior to finding the tomato canal below.

Well water fed the organic tomatoes next door, and a simple ditch dug between the closest well and the pond ensured the area could be refilled as needed (for the price of additional diesel).

With a hole in the ground and a water source you’ve got a muddy liability that in no way resembles a premier fishery, so you’ve got to add weeds, tules, trees, brush, shade, sunken timber, underwater topography, broken branches, brush piles, duck weed, milfoil, algae, grass, and everything else Mother Nature provides naturally.

… and note we’re nowhere near adding fish yet …

pond1

Everything in these pictures, every spec of growth, planted by design to provide the eventual final shade pattern for the water. Every grass bed, every tule clump, every willow seedling, and every tree bordering the periphery, hand selected for the shade it’ll provide and the stabilization it brings to the machined earthworks.

pond2

… every finger pier constructed with its wooden chair and steps leading to the water’s edge. All of them carefully staked off at the high water mark to ensure each pier at constant height to the waterline, and every plant placed in the area chosen to stabilize the dirt walking area so wind erosion wouldn’t erode the topsoil off each bulwark.

The owner is in his eighties and losing mobility, so the design incorporates the ability to seat yourself in productive water with minimal effort. Wooden steps and hand rails allow access to the water’s edge, and seating is provided at each cleared fishing area.

pond3

The dead timber is all staked to the bottom to hold it in place, and branches are sawed halfway through then broken to provide branch snarls in the water. Broken but not severed so they hold their position until years of decay eventually dissolves them.

pond4

After a year or two of hard work on the banks and shade, covering the bottom in life-giving weed is child’s play. Weeds provide the dissolved oxygen in the absence of running water, yet controlling them is not so simple, given that water level, temperature, and ambient sunlight change their growth patterns seasonally.

During summer as evaporation lowers the lake and water temperatures rise, algae and weeds blossom, and quickly cover the impoundment unless treated chemically.

The proceeds of our paid trip were to assist in defraying the costs of another application of weed killer. Dispensed manually, the chemical operates only in the areas its applied, allowing you to sculpt and channelize weed beds.

Bass love to lurk and ambush, and providing the cover to predate is part of a healthy fish ecosystem.

pondpoppy

Wildflowers follow each earthen finger out to its seating area. The flowers anchor the topsoil to the structure as it’s prone to erosion. Each earthwork has a mixture of tules, saplings, and flowers to provide wind cover, initial anchor of soil, and then the long term benefits of reinforcing tree roots, and the wind protection offered by its canopy, and shade.

Now that banks offer cover and shade is available, and a mix of weeds line the bottom, you can introduce bugs and forage fish. Mosquito fish to control the mosquito larva and provide forage for anything larger, then Bluegill to eat those – each introduction needing permits and the blessing of Fish & Game. If you have a creek feeding it you have one set of problems, and if you have a wetlands it’s another set of triplicate. If your thing empties into someone else’s thing, it grows even worse.

… and then finally, when all of that stuff is living and thriving, when you learn the delicate dance between water, its temperature, its life-giving carpet, dissolved oxygen, shade, and tasty fish and bugs to eat, you can introduce the Quarry.

Tomorrow – Part III The part you’re salivating over, the fishing …

Fossil Record shows Didymo Geminata is native rather than invasive

stickey_RubberYou’d think Science, knowing our history of continental land bridges and pre-historic migrants overwhelming natives, would have consensus on how many thousands of years it takes something to dominate its surroundings to become the new “native” – but you’d be wrong …

The latest science involving Didymo rethinks the “invasive” label, as examination of the fossil record of lakes and streams afflicted by the diatom are finding the Didymo has been resident on five of seven continents for many thousands of years.

The Delaware River shows Didymo having been present for tens of thousands of years, rather than recently introduced by fishermen. Dissolved Phosphorus can dip below its normal threshold via numerous temporal phenomena, and with that change in water chemistry, triggers the visual “blooms” that gives the infestation its characteristic unappealing blanket. As quickly as water chemistry is restored, the blooms vanish, explaining one of the great mysteries of Didymo infestation.

Moreover, fossil and historical records place D. geminata on all continents except Africa, Antarctica, and Australia; records place D. geminata in Asia (China, India, Japan, Mongolia, Russia), Europe (Denmark, Finland, France, Germany, Ireland, Italy, Norway, Poland, Portugal, United Kingdom, Sweden), and North America (Canada and the United States), and historical records dating back to the 1960s place D. geminata in South America (Chile; Blanco and Ector 2009, Whitton et al. 2009). The recent blooms of D. geminata are found on each of these continents, where fossil or historical records have been documented, which indicates that attributing all blooms to recent introductions or to range expansion is incorrect.

… and as the last article mentioned, our collective angst in approaching our respective legislatures was a tad premature …

In fact, citing the threat of human-induced translocations of D. geminata or other unwanted organisms, seven US states (Alaska, Maryland, Missouri, Nebraska, Rhode Island, South Dakota, and Vermont), Chile, and New Zealand have passed legislation banning the use of felt soled waders and boots in inland waters (e.g., the 1993 New Zealand Biosecurity Act, Chile’s law no. 20.254, Vermont 2013 Act no. 130 [H.488]). Although such restrictions may reduce introductions of other deleterious aquatic microorganisms, the connection to the spread of Didymo. geminata within its native range seems dubious.

What’s even more interesting is the final definitive science will employ DNA sequencing of the respective colonies to see which continents have unique strains, and which continents may have sourced strains carried by everything from humans to migrating waterfowl.

The assertion that the recent blooms are caused by inad- vertent introductions of D. geminata cells by humans comes from frequent reports of blooms in areas that are used for recreation or monitoring by various agencies (Bothwell et al. 2009). Although Kilroy and Unwin (2011) reported a correlation between the ease of river access and D. geminata blooms in New Zealand, this has not been found in North American studies. In fact, systematic observations at both rivers with frequent human activities and remote rivers not heavily used for recreation or monitoring reveal no association between human activities at a river and blooms in Glacier National Park, in Montana (Schweiger et al. 2011).
Moreover, pathways for introducing D. geminata cells have existed for decades (e.g., felt-soled shoes; the transport of fish, their eggs, and water from areas where D. geminata is determined to be native on the basis of fossil records), making inadvertent introductions by humans difficult to explain, given the recent worldwide synchrony of blooms.

Really good article for the lay person given the science is common sense and easy to follow. I recommend you read it and draw your own conclusions.

As I adore a good conspiracy theory, I find it equally interesting that our fishing media and conservation organizations have published nothing on how scientists are reconsidering earlier theories as more concrete observations accumulate.

I’m sure those that insisted we act responsibly, by first purchasing new wading shoes, donated most generously …

Cut, Slash, and Riposte

I’ve assumed anything I can learn about fish serves me in good stead, and anything known on their feeding habits or behavior will assist me in seducing them to take my fly.

I’ll confess that I’ve wondered just what the “bill” of a billfish is used for – given I‘ve never seen some dolphin or unwary scuba diver skewered prominently on their beak.

Scientists suggest that the bill of a billfish is actually used as a sword, by first inserting the bill into a cluster of tightly packed baitfish, then slashing through the school to wound and disable.

Billfish uses bill to cripple baitfish via slashing motion of head

The above Youtube video shows the action of insertion and then the subsequent slash, and the trailing bits of scale and baitfish that result.

At least I’ll know what to expect when I deploy my “Alabama Rig” in blue water.