A Salmon's Life Through A Salmon's Voice
These days, life as a salmon is very rough.
We've been having a lot of problems, especially in the past few decades.
Problems such as water pollution, clear cutting, farming, over fishing,
and the creation of hydroelectric dams have killed off many stocks of different
species of salmon. A stock is kind of like one big family of one species
of salmon that has adapted itself to be able to live and reproduce in a
particular area of a river or stream. A stock of the Sockeye salmon
from Redfish Lake in Idaho is just one example of a stock that has become
extinct. We will never have a family like that one on Earth ever again.
My species isn't doing so well, either. I am a female Chinook salmon, the
biggest species of all the salmon. The Pacific Salmon species are: Chum,
Pink, Sockeye, Coho, and Chinook salmon. There are also two species of
trout that are in the same situation as the salmon, which are the Steelhead
and Cutthroat trout. But what it all boils down to is this: we are
all in danger and are growing closer to extinction everyday.
As I try to tell you what life is like as a salmon,
I'll introduce you to some of the factors that have been the cause of the
decline in salmon. The salmon life cycle is very complex and the state
of the environment in which we live is very critical to our health. Let
me explain.
As I start my life after hatching from an
egg, I'm known as what's called an aelvin. I still have a yolk sac attached
to my belly and this is where I get my nutrients from. I am sheltered in
the stream bed gravel from predators and the sun's UV rays by the home
my mother has made, which is called a redd. She has traveled all the way
from the ocean to come to a river to lay eggs. The female salmon instinctively
knows just the right place to build the redd to give her baby salmon a
better chance of survival. She makes sure to build it in a protected area
of a large river and under or next to some trees and shrubs, which provide
shade, and keeps the water temperature cool. We need cool water. Activities
such as logging or construction causes a few problems in this case. One
problem with clear cutting, is that if thousands of trees are chopped down
along a stream or river, there's no more shade to keep the water cool.
If the water gets too hot, it can kill the baby salmon. Trees along waterways
are also important because they keep a lot of sediment from getting into
the water where there might be a redd. Sediment is sort of like dirt. If
there's a lot of sediment sliding into the water, it can suffocate the
eggs. The redd itself is made of gravel at the bottom of the pool. She
builds it by jetting through the water against the current, kicking and
flapping her tail, and that force causes small rocks and gravel to pile
up on top of each other. When she senses the redd is ready, she'll lay
around 3,000 - 5,000 eggs. And all this time she's doing this, there is
a male salmon waiting nearby to fertilize the eggs so they can hatch. Only
about half of all those eggs will hatch successfully, which is natural.
A few weeks later, the parent salmon will
eventually die near the redd. This entire process of adult salmon going
upstream and reproducing is called spawning. They die due to exhaustion
because of all the effort and energy they put into reproducing. But their
job isn't finished just yet. The salmon carcasses left lying in the water
are very important to the surrounding environment, especially for my siblings
and I. When I use up all of my yolk sac, I have to begin searching for
food on my own. At this stage in my life, I am called a fry, a little free
swimming salmon. The carcasses provide food for me for awhile as I adjust
to having to get my own food. Often times, land animals eat the carcasses,
and they also provide nutrients for the vegetation in the riparian zones,
or stream sides. So, if there are less and less fish carcasses, or even
none at all, which I'll soon explain why that might happen,
it'll effect the abundance of wildlife and quality of vegetation in
the ecosystem.
As I'm growing up and getting bigger in size,
I stay in large rivers. During my "rearing" time in the river, I need pools
of deep, cool water to hide in. These pools are created by logs and woody
debris that fall in the river. Then, after about a year, I make my journey
to the ocean, which is miles and miles away. But I can't go directly from
fresh water to salt water. I have to hang around in an estuary. An estuary
is where the fresh water and sea water mix. Here, I am at a very vulnerable
state to predators because I'm very weak as my body changes to allow me
to swim in salt water. This change is called smoltification. Estuaries
are in danger, too. There's a lot of industrial development along or even
on top of estuaries. Sometimes estuaries will get filled with rocks and
gravel so things can be built on top of them. This is an example of habitat
loss.
Only about half of the salmon actually make
it to the smolting stage after some time spent in the river. At this point,
we're down to about 50 - 100 salmon that make it out to the ocean. The
50 - 100 salmon are the fish from the same redd as I am from. When I finally
get out to the sea, I travel for many, many miles. This is my time to grow
mature so I can spawn just like my parents did. However, I face many dangers
in the ocean, as well. Dangers like predators and commercial fishing take
a toll on salmon populations, although, the fishing isn't as bad as it
used to be now that people have set rules and regulations on it. Only a
handful of the 50 - 100 salmon that went out to the sea actually survive
and can go back to the fresh waters to reproduce.
When I feel I'm ready, I begin my journey
back to the fresh waters to spawn. This is the interesting part. I don't
go back to just any river. I have a good memory and sense of smell, which
leads me right back to the river I was born in. And that is called my natal
river. However, being back in my natal river is one thing, and getting
there is another. There are so many challenging things I have to pass through
to get there, and the thing that makes it even more difficult is that I
don't eat my whole trip home. Jumping up all those waterfalls makes me
grow tired day by day. So, if I have to get past a bunch of obstacles,
it's going to take me much longer than I thought to get back to my natal
river. I may even become so exhausted that I might die before I get to
reproduce more salmon, which actually happens to some adults.
The making and operation of hydroelectric
dams have had a very negative affect on our populations ever since dams
were created. They've killed a lot of salmon.
However, not too long ago, people have been thinking
and designing ways to get the salmon past the dams safely. Even though
they have been and are now able to help some adult salmon pass the dams,
the salmon who are going through the smoltification process have an even
harder time because they're not so familiar with the water routes yet,
so it makes it more difficult for them to
find a path to the sea. Many of them never make it to the sea.
Another problem I haven't talked about yet is water
pollution. We not only need cool water, but clean water, too. There are
many ways the water of streams and rivers get polluted. A lot of the water
pollution is caused by chemicals that are dumped into the water, usually
by big industries that have no where else to put their chemical wastes.
On the smaller scale, pesticides from farms can end up in the water after
a heavy rainfall.
These difficulties that I've mentioned, clear
cutting, water pollution, over fishing, and the operation of dams are just
some of the main problems that have an influence on our population. And
the influence is not good. It's not only bad for us, but bad for everyone
else, as well. People affect salmon, and salmon affect people. While more
and more salmon are being killed in large numbers, not enough salmon are
filling those empty spaces because only a few out of the thousands of eggs
that were laid will eventually grow and be able to spawn. We are a very
strong species but we are extremely sensitive as well.
Thoughts For Consideration:
1. What are a few of the environmental problems that have been affecting
the salmon population?
2. What are some of the requirements that salmon need in order to survive?
3. What kind of problems to hydroelectric dams cause for salmon?
4. What are some of your ideas on how we can help the salmon?