Are cattle destroying our trout streams? (and other ramblings)

The relationship between farmers and fishing lobbyists can be somewhat heated at times. Some areas of conflict include

  • – Stock grazing too close or in waterways
  • – Use of too much water for irrigation
  • – Leaching of fertilizer into waterways

In my opinion, some of these views are valid, while others I struggle to support.

Farming is nothing new, and farmers have been grazing cattle alongside trout streams for decades, even centuries. I keep hearing about the good old days, and how much better the fishing was prior to the 1980s.

Some people even cite further back and speak of angling glory days after WWII, or even further back still.

Many people seem to think, that fishing use to be so much better, and one of the reasons for the decline is modern farming practices. I disagree, farming used to be a lot worse.

I grew up on a small mixed-cropping and livestock farm, just under 200 acres in size. It has been in our family for 3 generations, but we have worked on it for 5.

One thing that is immediately apparent to me, is that farming practices today are orders of magnitude better for the environment than what was practiced historically.

But, trout fishing back then was the stuff of legend, the rivers were full of numerous large trout. I have heard stories, that my great grandfather, using his bamboo fly rod and silk lines used to pull double digits number of trout out of a small local river that is now lucky to even sustain a population of minnows.

My family farm dates back to the mid-1800s, in those early days it was part of a much larger ranch. The land was burnt yearly to stimulate fresh growth. The natural forests and scrublands were cleared and replaced with pastures.

Even until quite recently there was little care for the environment, the stream was both a source of drinking water and an open sewer. Every farmhouse and town use to discharge any waste directly into the streams. In the early days, cholera (a waterborne bacteria) certainly took its toll.

Trash and refuse were thrown straight into the stream. After large floods, I still find antique and vintage bottles from the 1860s to around the 1960s when habits started to change stopped.

Back then, fences were unheard of. They paid someone to follow the stock or arguments broke out between neighbors when the cows wandered too far. In those times, there was little care for the environment.

Cattle, horses, and sheep all drank freely from the streams. Munching and trampling their way through the vegetation. Riverside herbs and willows are much sweeter than the starchy grass that dominates the meadows.

Yet the trout population thrived.

Even in my father’s childhood, some 70 years ago. He always mentioned that the best fishing in town was by the sewage outlet pipes, and the next best was the slaughterhouse discharge. Huge shoals of bait fish will gather feasting on the nutrient-rich outlets, and the larger predatory trout will be there to predate on them.

The site of the original stockyards

Now I want to talk about agrichemicals. The chemical use back then was much less specific than what we have available today.

I want to highlight the site of the original stockyards. While the wooden yards have long since rotten away, the concrete-walled cattle dip (trough) still remains now beneath the shade of ancient elms.

(Cattle dips are long troughs that can be used to fully immerse animals in insecticide treatments to kill parasites such as ticks. They can be deep enough to force cattle to swim)

Anyway, this trough was constructed just a stone’s throw from the edge of a small spring creek.

This location was obviously chosen due to the easy access to water. They needed to haul a lot of water to fill the trough, and probably to allow the animals to drink while waiting in the yards.

As was normal for the time, any leftover chemicals from the bath would have flowed directly into the stream, or leached the few yards through the soil into the adjoining aquifer.

Chemical treatments

So what were the chemical treatments? Some benign organic root juice? No.

I know many people look back to these earlier times with rose-tinted glasses. There is a belief that there were no nasty modern chemicals. Will, the chemicals used back then for the most part are worse than the ones we use today.

Arsenic solutions were extremely popular in controlling ticks. It was highly effective but not at all specific. It also stays in the environment for an extremely long time.

Another popular option for drenching was carbolic acid mixed with petroleum. It was used in liberal amounts to control foot rot and as a drench to control parasitic insects. It was a popular choice because it would kill all vermin, “except for rats and mice”. In other words, it was just as effective in clearing out a lice infestation as a colony of caddisflies. It all ended up in the stream.

So despite the use of such non-selective chemistry and lack of environmental standards, the trout continued to thrive.

So what happened? Why have so many fisheries collapsed?

I think when looking back objectively most people will agree that farming practices were terrible back in the good old days, so why did the trout fisheries continue to thrive?

Is it a case of death by a thousand pinpricks? The rivers and streams could only absorb so much abuse before the ecology collapsed and the fisheries failed. Maybe.

Or are we overlooking other factors? After all, I believe the cows standing in the water are only the tip of the iceberg.

While farming is not without blame, trout have lived and evolved alongside grazing herbivores for their entire existence. A heifer standing in a stream is really no more damaging than a bison or bull elk.

Some fishermen complain that cattle might trample the trout redds, will I have seen more fishermen trampling redds than cattle? Some fishermen need to look in the mirror before blaming cows.

Yes, intensively grazing 1000 head of title in a small wetland will be disastrous for the ecology, but this is certainly not the norm.


If farmers deserve any blame, it is for the amount of water they take for irrigation. So often I will be trout fishing shrinking water in the early summer, and throughout the day will walk past pump after pump.

The demand for irrigation is also usually at its peak when river levels are at their lowest. It is a double whammy for the ecology of the water source.

Enormous amounts of river water is taken to irrigate cropping land to grow grains to supply feedlots. I feel, that discussing the impact of irrigation can be a topic in its own so I will end this section here.


The amount of fertilizer being used has certainly skyrocketed, especially since the synthetic fertilizer boom that followed WWII.

Soil simply lacks the holding capacity to store large amounts of fertilizer, so it eventually leaches through the profile and makes its way into aquifers that erupt as springs into our waterways.

Now, a little fertilizer added to a low fertility stream can actually improve the quality of the fishing, because it stimulates plant growth, which in turn allows the river to sustain a larger population of aquatic insects.

But a little can quickly become too much, and with water levels already low from irrigation and other water uses algae blooms start to develop. For a time riparian strips were all the rage, but in my experience, they only slow the problem, they do not eliminate it.

Riparian strips can also quickly become overgrown, making the river banks impassable by anglers.

Flood control and draining of wetlands

Humans love nothing more than to straighten and control rivers, we want them to flow down predefined channels, and not flow chaotically across private property. In the process, we drain wetlands, and dry bogs that further slow waters and act as reservoirs in times of drought. After all a swamp has little productive value.

A meandering river, as it twists and turns through the landscape flows slowly, the turns create pools, shallows, and ripples. A natural river provides excellent fish habitat.

Flood engineers, on the other hand, want to get the water from point A to point B as quickly as possible. They straighten rivers down diversions and trap them between permanent embankments. Such rivers flow shallow and fast leaving very little room for fish habitats.

Many local areas have lost up to 99% of their wetlands, and we wonder why the fishing has deteriorated.

Dams and impeding river flows

Dams are nothing new, there was even a small mill dam on my farm that operated for a few decades during the 1800s. What is new is the scale and size of the dams. According to Wikipedia, there is now 84,000 dams in America. That is a lot of impeded water.

Dams change waterways, and rarely for the better. They also prevent migratory fish from completing their urns. Fish ladders were one answer, but getting the fish to use them can be easier said than done. Often the fish just accumulate at the base of the dam depriving fresh recruitment to upper portions of rivers.

With every dam constructed, it seems like we lose part of a river and gain a lake. Overall, I feel they do more harm than good.

There is simply more fishing pressure

In the 1850s the world’s population was 1.2 billion, in the 1950s 2.5 billion today it has surpassed 7.7 billion. The growth in America is even more severe, the population climbed from 23 million up to 329 million.

At the same time accessibility to fishing spots has also improved significantly, traveling to the next town used to take all day, and now we can drive 100 miles down the road in under two hours.

So it is simply a numbers game, the fisheries are under more angling pressure than ever. So the trout are spending more time disturbed and less time feeding.

Releasing stock trout can assists in keeping the crowds away from the wild fisheries but it is still only a band-aid solution.

More invasive species – limit the space for trout

Every year invasive species spread to more lakes, and invade more streams. Bass might be a great sportfish, but they do not belong in a brook trout pond. Yet they continue to spread.

One of my local ponds got drained, and ‘sterilized’ because someone introduced perch into it.

Carp continue their march upstream, and Lampreys harass the trout of the great lake.

All over the globe, invasive species are battling for dominance in waterways. In many cases, trout themselves are the invaders, brown trout displacing Brook, while brook trout displace cutthroat.

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