What Really Matters

The survival of any species depends on its ability to reproduce, and upon the survival of its young.  There are many factors that can reduce a population to the point of extinction.

What are some of those factors and how might they apply to the remnant phenotypical Alvord cutthroat trout?

Generally, most cutthroat trout are known to spawn only once in their lifetime.  Females usually mature between 3-5 years and males between 2-3 years of age. Of these mature trout; approximately sixty percent die after spawning. Those that survive their first spawning season generally do not spawn the following year.  It is only a small percentage of trout that actually survive the rigors of life long enough to spawn, again, two years later.  Since not much is known about the spawning habits of the cutthroat trout exhibiting the Alvord phenotype, protecting the mature trout and their opportunity to spawn is an important factor in preserving this species.

Not much is known about the spawning beds of these Alvord phenotypes, but it is commonly known that juvenile cutthroat trout face many impediments as they begin their life.  Unless the water temperature is just right, the eggs often fail to develop and hatch.  If the gravel of the redd is not adequate, or of the right size to offer protection for the eggs, the eggs may be subject to predation both by the parent trout and other fish, especially if food sources are not abundant.  Life in the stream is often all about survival.  Once the eggs hatch, the young are subject to parasites, changes in water flow, temperature fluctuations and, again, predation.  If the water is too cold and the food source sparse, then young trout often fail to thrive and their growth rate is slowed.  While the trout with the Alvord phenotype have a prolific food source during the latter half of the summer, winters are known to be harsh and the food source most likely is limited for both young and mature trout. Perhaps wintertime predation of fingerlings could be one of the reasons so few of the young trout have been observed in the stream.  From research it is estimated that only about 2% of fertilized cutthroat trout eggs actually survive to maturity.

Hybridization with non-native or competing species also affects cutthroat trout populations.  At least one study has concluded that cutthroat trout exhibit a lower growth rate when competing with cutthroat-rainbow trout hybrids.  In fact, the Alvord cutthroat trout was declared extinct soon after rainbow trout were stocked in its native streams.  The rainbows quickly hybridized with the Alvords and the new hybrids became stronger and more dominant, extirpating the native cutthroat.  Fortunately, it appears that the rainbow trout that were stocked in ***** Creek did not gain a foothold in the stream; and therefore, the trout with the appearance of Alvord cutthroat trout have “competed” and “hybridized” primarily with other similar cutthroat trout species, thus allowing the Alvord phenotype to persist; but for how long?

Of course, environmental factors and habitat affect the survival of both adult trout and their young.  Some environmental factors can be controlled, but others cannot.  For example, weather and climate changes can alter a stream and its habitat very dramatically by either drought or flooding.  Pluvial Lake Alvord eventually dried up, driving the Alvord trout into the headwaters of its native range in order to survive.  Although the Alvord’s demise was ultimately a result of hybridization, many other native trout populations have been driven into small streams whose water velocities have diminished such that they are unable today to sustain the trout once known to inhabit their waters.

We cannot control the weather, and may not be able to control the environment or habitat as much as we would like, but we can pay particular attention to how we handle fragile species of trout so that we may preserve the opportunity to enjoy them in the future.  We can do that best by returning them to their habitat unharmed.

It is extremely important to handle endangered and native trout carefully, especially when they are a species of concern.  We have found that small, fine-wired, single hook, barbless flies or lures are the best tackle to use, and it is imperative to not allow the trout to swallow the hook.  This is a critical factor, because if you do not hook a trout properly in the mouth, and in a manner that allows for quick handling and release of the trout, tragic and senseless casualties are bound to occur.  Fish quickly become traumatized from hook injuries and excessive handling and squeezing.

No matter which of the following two methods you use; keeping the trout in cool, oxygenated water while quickly removing your hook is the best way to handle a trout being released.  Keep in mind that while the water is very cold, the surface temperature may be very hot (varying as much as 60 degrees).  Temperature extremes can cause trauma to these trout.  Think of it this way.  Imagine resting and watching a movie in an air-conditioned room and then stepping outside on a 105-degree, 125% humidity day.  Immediately you would start to overheat, sweat and find it extremely difficult to breathe.

Perhaps the inverse comparison might be to imagine relaxing, while sun-bathing, in 105-degree hot desert air—and then suddenly a rope jerks us into a 45-degree pool of water, and forcibly holds us under!  How long would we last before helplessly swallowing water as we gasp for air in shock?  If we can visualize that, then we might be better able to under-stand the stress a trout experiences after being caught and held too long—gasping for life on a 95-degree day, while one casually tries to take the perfect picture to remember it by.

If you plan to take a picture, keep the fish in your net in the water (as much as possible), allowing for good stream flow as you prepare your camera.  If it is a sunny day, position yourself so the light shines over your shoulder to where you plan to hold the fish for the picture.  Then quickly lift your trout out of the net and allow yourself no more than a couple of quick pictures and then either get the fish back into your net in the water, or release it immediately in the stream.

Carrying a collapsible bucket with you is another way to temporarily keep a trout oxygenated and healthy if you plan to take a picture.  Upon arriving at the stream fill the bucket with cool oxygenated water and leave it nearby on the bank.  After catching a trout, you can quickly release it from the hook and put it in the bucket.   Prepare to take your picture, then quickly hold the trout and take just one or two pictures at a time.  Either put it back in the bucket for a few minutes to allow it to recover sufficiently in order for you to take another picture, or release the fish as soon as possible.

Never take so many pictures of any one trout that its life is imperiled!  It is imperative to keep the trout healthy and oxygenated, and be careful in handling, so they can be released unharmed — in truly wholly good condition.

Remember; the native trout you catch and hold in your hand for a picture today, is the mature trout that may have only one opportunity to spawn and produce the progeny you hope to catch in the future.

These desert trout already have so many critical challenges and grave dangers confronting them — let’s not add another level of threat to their already precarious and perilous status.

With thoughtful planning and attention to detail, fishing for such rare, endangered or even “extinct” trout (such as the ***** Creek Alvord cutthroat trout phenotypes), can be a once in a lifetime experience that can be truly enjoyed and preserved as long as it is possible.

Of course, the ultimate solution is the rescue | restoration of this relict remnant of Alvords.

© KOD 6-2011
_______________________________________________________

 

Virtually every region of the Basin and Range will benefit from riparian zone stewardship:

Riparian Improvement

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About kortumofdiscovery

Kortum of Discovery (a slight play on Lewis & Clark's Corps of Discovery) is a family team that is Affirming the Exceptional Beauty of Nature, one Adventure at a Time. With a focus toward rare and endangered species in the Great Basin and American west: discoveries, unique methodologies, and many “tall tales to tell” are continually being shared around the campfire!
This entry was posted in Fisheries Biology and Genetics, Observations. Bookmark the permalink.

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