Uploaded by Erika Xim Paola Santos

Aqua Sci Commentary (1)

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Erika Xim Paola Santos
BSBA (Marketing) – III
Aqua Sci – 2
Film Commentary of “Our Planet: Fresh Water”
I’ve always loved watching documentaries about wildlife and ecosystems. As
a kid, I used to appreciate National Geographic more than cartoon channels. While,
watching the film, “Our Planet: Fresh Water”, the kid in me was re-awakened but the
fascination in learning something new about wildlife still remains.
Fresh water is very crucial nowadays, which is why freshwater ecosystems
are valuable. While the earth consists mainly of about 70% water, only a minute
fraction consists of fresh water. As said in the documentary, only 1% is within reach
and still, most of the fresh water are trapped in glaciers. Freshwater ecosystems also
provide as breeding grounds for species of animals like the threatened Pacific
salmon which returns to the rivers of the Andes to lay their eggs. They also thrive
with plants such as the macarenia, as well as seagrass, which manatees and other
aquatic animals graze on. Insect species such as the giant mayfly also stay 3 years
underwater as larvae. Freshwater systems also act as the drinking water source of
animals like elephants. Along with hippos and buffalos, they also rely on these
waters to keep themselves cool. People also use freshwater bodies for their
livelihood as they breed freshwater fishes.
Marine ecosystems do not differ that much as with freshwater ecosystems,
and there are actually marine animals that go to freshwater bodies depending in cold
seasons or during breeding season or until they hit maturity. The main difference lies
in the salinity levels where marine ecosystems have higher salinity levels such as in
the open oceans and seas. The Pacific salmon mentioned earlier lay their eggs in
rivers, after which their young stay in freshwater until they reach maturity and
migrate to the open seas. Manatees also stay in seas during the summer but have
winter homes in rivers during the cold seasons because the waters are warmer.
The basic principles in aquatic systems is that it is composed of thriving living
things such as plants and animals, and there are certain non-living factors in play as
well. These plants like the seagrass are the food sources or sometimes the breeding
ground of some animals. In an ecosystem, there is also a food chain. Just as in the
rivers of Andes where the torrent ducks feed on the larvae of mayflies as their source
of nutrients. The Pacific salmon also visit these waters and leap up waterfalls, or
straight in the mouths of awaiting Alaskan bears. The non-living factors include the
temperature of the water, which are crucial for the adaptation of some notable
species, light for the growth of plants, and nutrients for survival. There is also the
interaction with terrestrial animals, as well as people.
I learned a lot from watching the documentary. I was filled with fascination and
interest as I learn new things I didn’t know beforehand. What I was most surprised
was about the formation of Lake Eyre or the Kati Thanda in the middle of the desert
of Australia. It’s quite a mystery how it only forms once a decade when heavy rains
pour over the desert and flood the lowermost areas. Even more puzzling is how
animals learn about the lake as pelicans travel down to feed on fishes and reproduce
until the lake dries out and not return after another decade has passed.
I was also overwhelmed by the reality of our ecosystems being threatened
due to human activities that contribute to global warming and pollution. It was also
saddening how there is a scarcity of freshwater in wildlife such that elephants have
to dig deeper to drink water since the streams have dried out due to dams built by
people. I’m concerned how they get dehydrated especially since elephant species
are starting to get fewer in number. Buffalos and hippos also have to make do with
mud instead of abundant water to cool themselves. I felt helpless to see how they
are mud-soaked and packed tightly due to the scarcity of water, and their tempers
rising as the temperature also rises.
I hope we get educated about freshwaters ecosystems and how they are
valuable especially to the aquatic plants and animals so we can lessen pollution and
find ways to address global warming. After all, these are the only homes they know
and go to.
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