Viral videos - Are they harmless?

Check out this link guys.

I've briefly touched on the effects of tourism on animals in the post about elephants and how some go through the process of crushing. This article points out it does not have to just be tourism in the country which effects animals across the world, social media also plays a large role with viral videos sometime bring unwanted attention to threatened and endangered species.

http://www.onegreenplanet.org/animalsandnature/viral-videos-and-pictures-of-exotic-animals-harm/

Thanks for reading

Salmon

With the last post being about dams I believe it appropriate to talk about salmon in this post.

The salmon is an amazing creature, it is born in fresh water before migrating down to the sea and adapting for a salt water life before then returning to fresh water to breed and die. This is not a simple process it requires some serious changes within the physiological structure of the salmon so as they are capable to maintain the composition of their body fluids. To be able to cope with these extreme changes in salinity salmon alternate the amount of fluid they intake, freshwater fish avoid water gain by producing large amounts of urine which they do not excrete to raise their osmotic potential, while fish which are leading a marine existence change their habits and consume more water so as to produce dilute urine leaving their body fluids with a lower osmotic potential which is then filled by the salt water. In addition to this process marine fish are capable of secreting excess salt through their gills while fresh water fish are capable of absorbing salt.

Salmon do not just change their methods of maintaining their body fluid osmolality they also go through changes in their diets throughout their lives. Upon hatching the tiny salmon feed on invertebrates and plankton, once mature however the adult salmon is a large predator located near the top of the food chain, it is capable of catching larger prey such as squid, shrimp and other fish.  Depending on the sub species of salmon they can grow from 4 to 110 pounds and vary in length from 20inches to 5ft, with Cherry salmon being the smallest and Chinook salmon being the largest.

Once salmon reach sexual maturity they begin the long journey back to the same stream they were born in. This journey marks the start of the end for a salmon and it is triggered by day length and water temperature. Once entering fresh water salmon stop feeding and their stomach and the rest of their digestive tr

act begins to disintegrate so as to maximise the space available for egg development. Male salmon also undergo physiological changes and their snouts develop into a longer hooked shape called a kype, they also change colour and become redder.

Once the salmon reach the same area in which they were hatched, which is usually an area of shallow well oxygenated water, they can breed. A female then attach their eggs to vegetation or rocks before males release their sperm into the water for external fertilization, this is a milky fluid and in some areas has been known to fill the streams before dispersing. After spawning the majority of salmon die within the following few days, some females do remain alive long enough to guard their nests for a couple of weeks but none remain alive for the entire gestation period of the eggs which is  around four months.

This process of mating and then dying is not uncommon in the natural world, it is known as semelparity or suicidal reproduction, many plants as well as insects, frogs, lizards and a handful of mammals exhibit this behaviour.  Semelparity is generally the outcome due to complete exhaustion and depletion of resources it an attempt to maximise breeding success, which is the ultimate aim of any organism. The death of the previous generation is also beneficial for the following generation as it means a reduction in competition for resources such as food and shelter.

Finally global climate change has already had effects on migratory fish such as salmon; this is due to the fact that longer hotter and drier summers mean that river levels are lower and so salmon struggle to reach their spawning grounds high upstream.

 Although many of you may have already known a lot of this information I hope you found out a few new things, let me leave you with the fact that the highest recorded salmon jump is 3.7m (12ft) at Orrin Falls.

Thanks for reading

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Dams- The way forward or a step in the wrong direction?

Sorry for the delay in this post as I’ve recently been away in the middle of nowhere for things related to my degree, but I’m back now.

I mentioned about dams in a previous post concerning river health but I did not go into any kind of detail on them, as I believe it to be suck a big topic that it requires a post all of its own. Dams are an extremely controversial topic as they can be seen as both good and bad in different people’s eyes.

There are a number of different reasons dams are built in some cases it’s due to the requirement of water storage for large population, to help drain areas of marshes so as to provide more land for agriculture and development on or to provide a power source which is not dependent on fossil fuel or nuclear power. Now it is the reason for the dam in my eyes which either make it a good investment or not, and also the area which it is going to be built.

It is always important to remember that a dam does not just effect the immediate environment behind it which becomes flooded upon completion of the dams. Dams have repercussions which stretch for hundreds of miles or even for the entire river.

Dams change ecosystems in a number of different ways; the first thing I’m going to bring up is how they disrupt the movement of sediment down the river. This works in two different ways, firstly sediment is held up above the dams and as the water slows the sediment which is held in suspension, settles out of the water and build up. Although this may appear good it’s not all amazing as these sediment can built up and bury aquatic plants and other forms of life and as the water builds behind the dam the bottom of the resulting lake can become baron and lifeless. In fact a study conducted by the World Bank in 1987 estimated that around 1,100 cubic kilometers of sediment was accumulated behind the world’s reservoirs. That amount of

sediment equated to almost 1/5 of global storage capacity at the time. The area below dams is also effected by the loss of the sediment however as a key source of nutrients is lost, the river in some cases tries to replace these lost nutrients by extensive erosion below the dam. Typically this erosion could be anything up to several meters within the first few years of the dam’s first closure.

Now onto a positive though, as if you block a river you capture a lot of potential energy as the water is stopped. This water can then be released and feed through turbines and produce clean electricity, the Three Gorges Dam in central China is the world’s largest power producing facility of any kind. Personally I’m all for alternative energy sources and believe that our dependence on fossil fuels needs to be reduced as fast as possible.  For instance in the UK 21% of its total energy used is produced through renewable energy sources and of that 21% hydroelectric power makes up 21%. That’s the third highest renewable energy source closely following biomass then wind power. This is nothing however compared to places such as Mozambique and Nepal both of which produced over 99% of their energy needs through hydroelectric power in 2012.

A third use of dams or a secondary use of hydroelectric power dams if for water storage, this is of course necessary due to the increasing population numbers and the ‘wasteful’ sort of culture we live in. For instance people within the UK use on average 150 liters of water a day personally; this is a number which has been growing by 1% every year since 1930. Also when the amount of water used to produce food and other products used by an individual each day is factored in you will actually be consuming 3400 liters a day.  This is of course a major issue and so dams are created to feed large populations with water when required. However still in some cases these dams still are not enough to fulfill the demand, this situation has been addressed by things such as reducing the amount of water lost through evaporation. California for instance as filled a number of their reservoirs with thousands of black plastic balls like those found in ball pits so as to shield the water from the heat of the sun to reduce evaporation.

These reservoirs also produce a build-up of sediment like any dam, but along with that they also reduce the amount of water flowing down stream.  Although not all the water is held up and dams are constantly producing a compensation flow, there is still drastically less water going downstream the majority of the time. This affects general health of the ecosystem below reducing both the biodiversity and carrying capacity of river, it will also affect the seasonal residents of the river, for instance migratory fish such as salmon first of all struggle to reach the dam and then being unable to reach their spawning sites. Furthermore the large amount of still water provide efficient breeding grounds for disease vectors, more of which can be read about in the link below which focuses on Malaria.

Finally there are the economical effects of dams. Now hydroelectric dams clearly have a form of economic income through the production of electricity but the creations of dams change a rivers physiology completely. This can result in the loss of river features such as rapids, and meadows and fertile land above the dam which becomes flooded. Uganda has and is still currently building dams across sections of the White Nile which contains several sections of world class white water which attract thrill seekers from across the world to raft and kayak. However the creations of the first and now the second dam have flattened out large sections of the White Nile and reduced income from tourism in that form.  

It’s always a gamble whether the socioeconomic effects of a dam are worth building it and it is not a standard answer. Ever individual case is different and based on a series of variables such as effects to the environment surroundings, human benefit vs human loss and potential of the dam if built.

So if there is a dam being created close to you or anywhere else in the world you cannot simply make a blanket decision, research and knowledge is needed to create sensible opinion. 

I’ve only skated over the pros and cons of dams and extra reading can never hurt, if you have any good sources for or against dams please comment.

(As a side note – It is also important to remember the creation of a dam is extremely costly to the environment. For instance huge machinery is used to divert water courses, and the millions of tonnes used to produce the dam produce vast amounts of CO₂)

Thanks for reading!

Just a few links

http://www.iflscience.com/environment/how-big-dams-are-poisoning-arctic-methylmercury

http://www.iflscience.com/environment/dams-sub-saharan-africa-linked-increase-malaria-rates

http://www.ibtimes.co.uk/california-drought-thousands-black-plastic-balls-released-into-reservoir-stop-water-shortages-1515378

http://www.internationalrivers.org/it/sedimentation-problems-with-dams

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Geckos

A Gecko is a wide term used by many to describe a small lizard when you see them on holiday or around your house. Geckos belong to the infraorder Gekkota and are found across the world in warm climates. They come in many different colours and sizes ranging from 1.6 to 60cm in length when fully grown including the tail.

I will give you a bit more general background into geckos in a bit but the real reason I wanted to bring geckos to your attention is because of their amazing feet. It does not jump to the for front of most people minds but have you ever wondered how they are able to climb walls and glass without any signs of effort and hang from the ceiling stationary for hours? It’s a really cool answer but you have to look incredibly closely at their feet and know a tiny bit of physical chemistry.

When you look at their feet you’ll see that there are microscopic hairs like structures which are the secret to geckos amazing spiderman ability. These microscopic hairs are how the gecko ‘stick’ to the walls, using van der Waals forces which are also known as London forces. These forces are electrostatic interactions between the molecules making up the hairs on the feet and the molecules on the other surface. They occur because of the presence of either two permanent or instantaneously induced dipoles, dipoles are formed by the electron configuration of the molecules due to covalent and ionic bonds drawing electrons to ‘one’ side of the nucleus and uncovering the positively charged protons. The electrons of other molecules in this case the hairs on geckos feet are then attracted to the exposed positive charge nucleus.

This is not the only fact which is interesting with geckos, like many different lizards geckos will throw of their tails in an attempt to escape from predation. This process is not as easy as it sound however; the actual name of this defence mechanism is called autotomy. This defence mechanism is made possible thanks to the geckos tail containing ‘fracture planes’ which are areas within the tail either between the vertebrae or the centre of the vertebrae depending on the species. This is a last resort however because the loss of a tail is extremely costly as they contain the majority of a geckos fat reserves, so once lost juvenile geckos stop growing while a new tail develops and adults cease being reproductively active. The tail is so important in fact that some geckos will return to it after time and proceed to eat it so as to limit the resources lost.

Over a quarter of all known lizard species, 26.8% of the 5600 different species fall under the category of geckos. The majority of them are also nocturnal and have evolved to have specially shaped lenses which help magnify the little available light and allow them to see up to 350x better than a human eye in the dark. Sticking with the eyes no known species of geckos possess an eyelid, instead they has a thin transparent membrane which covers the eyes. This membrane is to help keep the eye clean aided by the tongue.

Thanks for reading

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Plastic food

I've already posted about the waste which is currently circulating in our oceans however I just want to draw this article to your attention to reinforce the message.

Even if you do not read the article just open it up to have a look at the top picture.

It is shocking

http://www.iflscience.com/plants-and-animals/99-all-seabird-species-will-likely-be-eating-plastic-2050

Thanks for reading!