Mighty water week: Day#2

Greetings everyone and welcome back to the second day of Mighty Water Week here on Biobunch! In today's article we are going to show you how the water is replenished all the time, but that is just a small part the main topic that this post is going to talk about is... FRESHWATER! you need it, we need it, almost every living organism on earth needs it, so we are here to tell you a little more about it.  Here it goes...

The process by which water sources are replenished is summed up in one nice process. This process is the hydrological cycle, also known as the Water Cycle.

Water, water everywhere but not a drop to drink

How accurately put, it sums up the freshwater distribution on our planet perfectly! As mentioned before on the very first blog-post of this week 75% of planet earth is consumed by water, but that doesn't change the fact that, freshwater is rare. A minor 3% of planets water is freshwater making the remaining 72%  pure seawater. 70% of that 3% is locked up as ice and snow, 30% is trapped in soil and rocks and then only 0.3% flows on the Earths surface as rivers and lakes! (that means that we have direct access to only 0.3% of Earths water!). 

Needless to say that the importance of freshwater habitats is huge, we depend on freshwater for drinking water and many other uses. It was found that 40% of all fish species live in freshwater, and that most amphibians, countless insects, reptiles, birds and mammals depend on this vital resource also. When thinking about freshwater habitats think of every lake, river, stream, pond and spring... think of habitats such as the Amazon River, or the River Nile, or Angel Falls for instance all amazing in terms of the wildlife they support and for the magnitude of their beauty, and they are all sources of freshwater. 

On the edge of it...

Angel Fall is so ridiculously high that you are able to parachute of, of the top of it... Ermm no thanks

Within Venezuela there are ancient tepuis (a table top mountain often found in Venezuela) that rise 1000m above the rainforest. This amazing habitat is able to sustain what has been said to be the greatest bog collections of insectivorous plants, a majority of which can only grow at the high altitudes offered by the tepuis. The insectivorous plants that grow here owe their success to the wet conditions that are provided by the areas annual rainfall of 400 cm, just for comparative sake the UK has an average annual rainfall of 60 cm. 

The picture above is of angel falls, the water is fed through to Angel fall by the Devils mountains where the water then plummets down a 979m drop!! this makes this the longest continuous waterfall in the world but we weren't surprised at this with a drop like that anyways. Whilst the water is dropping, it gathers such a force that before some of the water has even hit the Devils Canyon the wind often blows it forming a fine mist.

Moving further upstream before any waterfalls are encountered is where things start getting very quick. You may have been taught in geography that every river has what is called a profile and if you recall this lesson then you may or may not know that the upper section of the river is the most fastest and most dramatic section of the river profile (almost like a hyperactive kid given way to much sugar) it is this feature that offers those white rapids people love so much. But this section of the river is cold, low in nutrients but high in oxygen perfect for invertebrates. 

It is not an easy habitat to live in, the strong currents and nutrient acquisition are just a few of the challenges that life has had to deal with. In term of invertebrates occupying this area  the American hellgrammite nymph has a flattened body in order to reduce drag and have 'grappling hooks' to avoid being swept away. Invertebrates are not the only ones leading the way, specialized fish such as the Tibetan stone Loach is the worlds highest altitude fish, they feed by scraping algae of rocks and avoid being swept away by holding on with their enlarged mouth suckers. In this freshwater habitat predator are few but still present. 

  

This is one of the predators that patrol the upper section of the river. This is a harlequin duck they are found in Alaska and Siberia.

This is a picture of a male and female torrent duck found in the Andes and South America, both the torrent ducks and the harlequin ducks have streamlined bodies and powerful webbed feet.

When trekking up river China or Japan and you are trying to find the predator of this river you will not come across something that looks like a duck, you would be looking for something that looks like the picture above. Say hello to the Giant Salamander, considered to be the largest in the Salamander family they may not be the most attractive of predators but their slow metabolisms are perfect for the cold waters found in the upper regions of the river. They may have poor eyesight but their sensory nodes detect changes in the water pressure i.e what happens when prey moves.

 

Two of natures most amazing freshwater events!

THE GREAT SALMON RUN:

This event was featured in BBC's series 'Natures Great Events', they never failed to stress that this whole annual event was a cause of the freshwater environment. It all goes down in the cool temperate rivers in the northern hemisphere in Spring where 2 million Atlantic Salmon invade over 2,000 river mouths along the coasts of North America and Europe to enter the most dangerous journey of their lives to their spawning grounds. In the northwest Pacific alone all 6 species of Pacific salmon which is around 142-287 million are on the move invading rivers. (Before commercial fishing was a problem and habitat destruction the Pacific Salmon used to number 350 million)

The biggest threat to the salmons success... are the grizzly bears. On average an adult bear consumes a ton of salmon over the six week spawning period, for growing cubs the pressure is on to consume as much fish as possible as this is often the factor that decides whether a bear cub survives its first winter. 

Despite the odds being stacked against them a vast majority escape the bears jaws and using their inherited navigational skills make it to their spawning grounds. During this time their physical transformation from silver to bright red has been completed as the males become more hunched up and develop a kipe and a low overhung mouth for jousting of competitors. 

The Male is resting on the rock in this picture and showing full physical transformation.

Though this is most dangerous journey of their lives those that have survived ultimately meet the same fate as those that didn't make it past the bears. Once both the male and females have successfully spawned they all die forming a mass graveyard of salmon bodies. Even though they have died their death holds a significant ecological purpose. More than 137 species will directly benefit by feeding on this annual lush banquet of food, from the caddisfly larvae to armies of crayfish and from bald eagles to wolf cubs. 

THE GREAT MIGRATION:

This event occurs further down river where the river is slower, warmer and much richer in life. Every year around 1.5 million Wildebeest and 300,000 zebra along with other ungulates begin their trek for greener pastures. Ultimately they end up in the Masai Mara national reserve, along their migration they pass through multiple lion territories and for many of them their journey ends here. Putting lions, hyenas, wild dogs, cheetahs and leopards aside another danger lies, one that marks the migration.

Crocodiles! All the action from this migration occurs at two distinct points in their journey both of which are freshwater rivers, the first time these ungulates meet their number one enemies is at the Grumeti River in Tanzania, and then the Mara River in Kenya. These crocodiles remain concealed waiting for the wildebeest to cross because they know that every muscle in their preys body is telling them to go. To be honest some of the deaths are unrelated to the crocodiles some die from being trampled on, or when the have tried to jump down they have fallen and twisted their neck some way.  Either way it is a banquet for the Crocs!

Freshwater habitats are the drivers behind some of natures greatest events, if it wasn't for the rivers transporting the salmon towards their spawning ground the wildlife would be missing out on a huge energy injection from nature. Freshwater is the water that we drink, that every animal drinks. Freshwater is an amazing spectacle on our living planet and without it well... there would be no us.

We hope you enjoyed today's article, if you have any interesting facts about freshwater leave a comment down below or if you have a question go ahead and ask us we may not know the answer of the top of our heads but we will try our hardest to answer it. 

Biobunch,

Over and out.