Category Archives: Fisheries 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 …

Sell your Rod while YOu Can

My reaction was to slide under the desk and start looking for all that 9mm I had squirreled away for the Zombie Apocalypse.  At this late stage, a life spent torturing fish (and worse, documenting same) have earned me a rarified spot right up there with Osama Bin Laden and Uncle Adolph.

As scientists have been telling us for many years – fish do feel pain when hooked, only now they’ve discovered the worst, that they can remember who done this to them and can recognize human faces from underwater …

(Queue the Jaws soundtrack …)

“… have impressive pattern discrimination abilities, but also provides evidence that a vertebrate lacking a neocortex and without an evolutionary prerogative to discriminate human faces, can nonetheless do so to a high degree of accuracy.

Jesus. We’re screwed. The only truly good news is that fish don’t have either Hellfire missiles or drones, so fleeing the parking lot swathed in Hoodie and sunglasses may get you to the Interstate.

spearedBob

It’s tough to acknowledge that PETA was right all along, and while we’ll walk soft and sheepishly avoid their gaze, their smugness will evaporate when the first near-sighted Salmon detonates itself in the reefer of that Whole Foods delivery truck on the Causeway.

Fly tiers will be the first culled given that Chickens are looking to settle scores for a half-century of heavy handed anglers wrenching hackle off their backside.

“Chickens (Gallus gallus domesticus)19 and jungle crows (Corvus macrorhynchos)23 can also discriminate pictures of human faces”

The upside being all them stuffy “featherwing Salmon guys” are even deeper in the Hurt Locker.

Catch & Release damages the “Delicate Flowers” of the watershed

anxietyI’m thinking the Brits may have been right all along  – and us liberal eco-friendly colonials have been gleefully abusing trout for several generations.

New fish farming research suggests that “dropout fish”, that small percentage of fish that become listless and unresponsive when wadded into pens and fed dry pellets made of horse manure and ground walnut shells, may be “overstimulated” fish – incapable of handling new external stimuli.

“Overstimulated” being the definition of vaccination, excessive handling, predation of really mean Gangsta fish, and having really small gonads (therefore being the laughingstock of gym class). All this unwanted external attention causing a percentage of pen raised fish to withdraw from their sheltered concrete lined lifestyle, suffer chronic depression and essentially will themselves to die.

The researchers suggest that the “drop out” fish came to their condition due to stresses they encountered that were not in their natural environment (overcrowding, aggressiveness from other fish, handling by humans, vaccinations, etc.) Stresses that all of the fish in the fish farm were forced to endure—it was only those that were not able to cope with the highly stressful environment that were overwhelmed and succumbed to depressive-like symptoms. The team further suggests that losses due to “drop out” fish could be reduced by reducing or eliminating the stress inducers that exist as a normal part of aquaculture processes.

Not surprisingly, human psychologists are keen to note the similarities between farmed fish and humans, the difference being our “dropouts” spend the bulk of the day in their phone, ignore parental begging to secure gainful employment, and choose to live with us until they’re forty .. instead.

“Overstimulated” may  be the selfsame reason our progeny are ignoring traditional blood sports and opting for the genteel hobbies consistent with concrete lined lifestyles popularized by our major urban epicenters.

This theory dovetails into fly fishing lore, given how fishing is always worse now than the decade prior, and how the popular “hot spots” on our rivers inevitably turn cool.  An explanation that the gleeful manner by which we repeatedly slam steel into innocent mouths suggests that fish duped many times over may develop feeding anxieties  and lowered self esteem once caught, handled and released.  After numerous encounters with sharp hooks and boorish humans they withdraw from the prime lies, leading to lowered reproduction rates, and eventually extincting the Powerhouse #2 riffle

(that’s a California joke …)

Balance versus Purism, the war continues

purism_suxDry fly purists always insist they practice the One True Calling – and characterize whatever the rest of us do as being coarse and inferior.

Us “normal” fishermen think them perfumed ninnies – whose real ambition is to keep the sport free of common folk and ensure membership is limited to hedge fund managers, bankers, and the monied elite.

Only on matters of conservation can the two factions ever agree on anything, and despite an uneasy alliance, the combined meager vote counts solved little beyond a token attempt at unification and cooperation.

Now Science has vindicated both Dry Fly Purists (DFP) and our Nymph Fishing Insurgency (NFI), as they’ve determined that fish close to the surface are the smartest fish with the biggest brains, and as the water deepens – fish become dumb as fence posts.

Fishes that live very deep are known to have much slower metabolisms than species that live in relatively shallow water and one of the costs of that appears to be a reduction in brain size,” said Dr Iglesias.”

Purists can now achieve the Moral High Ground and insist that dry fly fishing is both akin to godliness AND their fish are smarter …

… and us meat-minded bullies amuse ourselves by tossing cone heads at retards.

There is some solace in our catching twice as many fish as the perfumed dandies, and NFI’ers could care less about which fish is smarter. We know that by the third retelling, our fish are likely to have invented cold fusion – and only our prowess at seduction  saved the entire human race from extinction.

Assuming fish populations are a rough mirror of human diversity, and any morning commute proves there are more ‘tards then Mensa members, suggest there’s little doubt as to why bead headed flies dominate a fly shop’s inventory.

Five to Eleven generations and then there’s Hell to Pay

trouts_Gone360While scientists giggle at us trout and salmon anglers, knowing our fragile quarry and how they’re damned to extinction via Global Warming, they throw us a bone by reassuring us that as climate changes over the coming centuries, we’ll not have to deal with “Quasimodo Trout” or something equally misshapen shuffling about  the muddy bottom …

… and no, they’re not concerned enough to forswear Ebola research in favor of crafting a more resilient Salmonid, they are merely reassuring us that despite the warming of the Earth’s crust and the dwindling water supply, we’ll not have to fret over Carp-Chinook hybrids or Bluegill Rainbows.

(That indignity being somehow so horrific as to make them blanch and stare at their feet hoping we didn’t notice their earlier glee.)

The latest research stems from the Lake Huron archipelago and centers on a recent study of Canadian Brook trout. Wild and hatchery fish were intermingled and the resultant prodigy examined via the genetic microscope, suggesting that while breeding occurs between wild and hatchery fish, natural selection continues to winkle out foreign genomes in favor of those developed for the unique environment and wild populations win in the end.

It turns out that within five to 11 generations of fish (about 25 to 50 years), the foreign genes introduced into wild populations through hybridization are removed by natural selection. That means fish populations previously bolstered by hatchery stock are, genetically speaking, indistinguishable from purely wild populations.

– from Phys.Org

The journal Evolutionary Applications is host to the research and while considerably harder to follow, suggests the findings are preliminary (as population dynamics are a function of time), yet interloper genes are quickly discarded and the resultant strain become genetically identical to the original wild populations over time.

Although we believe that our study demonstrates that salmonid populations can exhibit no effect of hybridization after 5–11 generations, more studies of this phenomenon are still required to aid policy makers when classifying the protection status or management practices for populations known to be hybridized. Our results additionally provide hope for wild populations of high ecological and economical value currently displaying negative effects as a result of human-mediated hybridization with domesticated conspecifics. If the incoming flow of foreign genes can be stemmed and the environment resembles that experienced by the wild population prior to hybridization, there appears to be a considerable chance that populations will recover, and possibly in less time than previously thought. Similar conclusions have recently been made about canid species exposed to hybridization, but that continue to experience the same selective regimes of their nonhybridized ancestors (Stronen and Paquet 2013).

from Evolutionary Applications (Wiley Online Library) 8.27.14

Global Warming aside – it is a bit of welcome good news in light of how much “cross-pollination” our hatchery practices have induced in North America.

While politicians are quick to grasp any photo opportunity, they’re reluctant to pursue most forms of science beyond that practiced by pollsters. Any increase in watershed temperatures is likely to be met with a “doubling down” on stocking – versus solving the issue completely, and it’s nice to know that should we emerge from this scientific abyss, there might be a few “neo-native” fish to survive with us ..

The squeals of outrage will demand a watery Jihad

mule300While the old adage insists, “ … in Spring, a young man’s thoughts turn to Love,” the Global Warming variant may change that antiquated lyric to, “ …in Summer, a young trout’s thoughts turn to Hybridization.”

A recent study of wild trout intermingled with hatchery fish, based on lakes and hydroelectric dams in Norway – suggests that wild fish and hatchery trout rarely inter-breed. It’s thought the high mortality rate of pen-raised, pellet-fed, fish – coupled with the inability of hatchery fish to make use of spawning creeks – means the two strains rarely occupy the same space at the same time, and interbreeding is negligible as a result.

Released trout accounted for nearly 30% of the sexually mature fish in the reservoirs and it was assumed that the prolonged use of non-indigenous and previously released fish in hatcheries posed a risk to the genetic integrity of wild fish. However, it appears that wild fish maintain their natural, genetic structure, principally due to the high mortality of indigenous and released hybrids and to the fact that released fish do not migrate when spawning.

from the Norwegian School of Veterinary Science

My tortured blend of humor and lay science suggests this phenomenon could be due to their “fast food” diet. How inhaling pellets shat from a cannon leaves hatchery trout couch-prone and listless – versus chasing a shapely wild female up the riffle and into the Gravels of Lust.

But Global Warming and its corresponding changes in water temperatures apparently changes this delicate relationship. With elevated temperatures, “Couch Potato” fish suddenly mount everything, including beer cans and sunken grocery carts and the gene pool resulting is a crazy mash up of hybridized fish.

Despite widespread release of millions of rainbow trout over the past century within the Flathead River system5, a large relatively pristine watershed in western North America, historical samples revealed that hybridization was prevalent only in one (source) population. During a subsequent 30-year period of accelerated warming, hybridization spread rapidly and was strongly linked to interactions between climatic drivers—precipitation and temperature—and distance to the source population. Specifically, decreases in spring precipitation and increases in summer stream temperature probably promoted upstream expansion of hybridization throughout the system. This study shows that rapid climate warming can exacerbate interactions between native and non-native species through invasive hybridization, which could spell genomic extinction for many species.

Excerpt from Nature Climate Change, July 2014

As I’m one of those horribly insensitive louts that claim to have tread lightly on his environment, (which we now realize as “having our way with the Old Gal,”) and after leaving what few scraps of the watershed that remains to the New Breed of fly fishermen, can only cackle at your indignity when you see some obese Grass Carp mounting that silvery, noble Rainbow (as it lies panting in the hot water), and how righteous you’ll sound when you insist we kill everything with Rotenone, so the gene pool is kept sacrosanct …

In addition to leaving you whatever we couldn’t eat, along with the discarded plastic wrapper of everything we did consume, we’ve imparted to you our antiquated snooty attitude towards salmonids. No doubt you’ll cling to this last bit of purism despite rising hemispheric temperatures, and with the Trout-centric enviro-lobby’s urging – will launch a Genetic Cleansing, or watery Jihad … whichever Politically Correct term you’ll devise for eradicating all the warm water fish that don’t mind hybridizing with lawnmowers or Salmo Salar …

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.

Hook manufacturers abandon steel hooks adopt “Sticky” Plastic to save Steelhead

SkeletonNow that magnetic fields are thought to be the reason behind a salmon’s unerring ability to return to the river from whence it spawned, similar research finds the same mechanism in Steelhead Trout.

The elation over the discovery is being tempered a bit with further studies, suggesting  reinforcing rebar and steel used in a concrete hatchery pen plays havoc with navigational skills of both species of Parr, and might be making “migrationally challenged” salmonids.

“I would not go out and tell hatchery managers to pull out all the iron pipes and replace them with PVC or aluminum,” said lead author Nathan Putman, a researcher at Oregon State University at the time of the study who is now at NOAA Fisheries Service in Miami working on fish migration questions. “We know it has an effect. What is not clear is whether the fish can recalibrate their magnetic sense after leaving the hatchery, or whether they are confused for the rest of their lives.”

–  ABC News Study: Hatcheries Can Disrupt Steelhead Navigation

Migration skills being synonymous with survival, suggests some scientists may be a bit red faced knowing they’ve been pouring hundreds of thousands of juveniles into ponds containing submerged Toyotas and the debris field associated with decades of lost fishing tackle.

Naturally, we’re going to share the blame with the architects, as it’ll be all the lures we lost as kids that are preventing a long overdue resurgence in salmonid returnees.

… and because YOU insisted they were the penultimate game fish (note my Brownlining sense of moral outrage) we can neither put our feet in the creek NOR use anything but plastic fish hooks and weightless everything.

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

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.