Avifauna of ephemeral ponds: The effect of hydroperiod on bird community structure Supervisor: Prof. P.W. Froneman Abstract Ephemeral ponds are temporary water bodies (Blausten et al.2001). Biotic and abiotic factors affect ephemeral ponds more than normal bodies of water, as being ephemeral they dry up in the dry season. This means that there is limited access to water at certain times of the hydroperiod, causing other factors to come into play. Much is known about ephemeral ponds and their subsequent forms of life such as amphibians – they become rich in animal and insect life when wet, but during the dry phases they force competition onto the living things within them (Blausten et al.2001).
They expel large amounts of salt in their bloodstream through urination (shark saver.org). When bull sharks are in freshwater environments they adapt their process of osmoregulation. Their kidneys can be gradually adjusted to control salt conservation based on the salinity of their surroundings. The kidneys and special glands near their tails recycle the salt within their bodies. They remove more urea from the bloodstream through urination when in freshwater, essentially reversing the regular marine shark method of osmoregultion (jeb.boilogist.org).
Aeromonas hydrophila is a gram negative rod bacterium. This bacterium spreads widely in various environments, especially in fresh water like in fish cultivation ponds, rivers, lakes, even in sparkling chlorinated drinking water reservoirs. This bacterium is known as a dangerous pathogenic bacterium in water biota like shrimps, oysters, frogs, and fishes (Martin-Carnahan & Joseph, 2005; EPA, 2006). The infection caused by this bacterium can lead to mass dead of fish in short period of time, which in turn causing a great loss of fishes. Formally, in a stable condition when the fish are not in stress, A. hydrophila existing in fish intestine has a role as microflora for water creatures (Illanchezian et al., 2010; Mangunwardoyo et al., 2010).
Many individuals’ expresses that frog sound, joined with readings from atmosphere information lumberjacks, and could help enhance our comprehension of the effect of environmental change. Environmental change appears to underlie a considerable lot of the dangers confronting frogs around the world. Frogs great markers of the strength of a biological system since Amphibians make great pointer species since we live in two conditions, land and water, and have thin skin that we in some cases inhale through. Our thin skin can likewise assimilate harmful chemicals, radiation, and infections. In the event that there are bunches of frogs and different creatures of land and water in a natural surroundings, it implies the environment is
Tiger Sharks play a massive role in their environment and it makes them into a keystone species. If The Tiger Sharks were gone from tiger bay there would be less sea grass for organisms due to an increase in turtles and Shark bay would lose many of the organisms who feed off the sea grass. These keystone species impact their environments and habits in many ways ranging outside their direct food web. These species are important in keeping the amount of species high in their habitats and are essential in the health and productivity in each habitat. The African Elephant makes far more abiotic differences in their environment by creating things like lakes while the Tiger Shark has mainly biotic factors and many of there changes in the ecosystem are a result of them eating fish and turtles and less about them shaping the land.
Conclusion & Recommendation Tilapia had a RGL value of 6.666%, as a result of computing its digestive tract's length I therefore conclude that tilapia is an omnivore. It is said that they feed on both aquatic plants and planktons. Tilapias are omnivores, and as such have a low requirement for fishmeal and fish-oil in their diets, making them a net producers of protein and therefore a valuable aquaculture species. For us to be able to dissect successfully , get a bigger fish that is easier to detach the organs out. The size of the species really matters when it comes to identifying its parts.
There are three main parts of an aquaponics system, fish, plants an microbes. Fish produce ammonia and solid waste, when raising fish in tanks these waste products reach high levels, becoming unhealthy for the fish, therefore they must be removed or the water replaced. In an aquaponics system the fish tank water is fed to grow beds. Grow beds do not use soil but use growing medias like pumice stone, clay pebbles, gravel, or the plants are floated directly on the water surface, using rafts often made of polystyrene for buoyancy. Naturally occurring micro-organisms in the plant beds break down the ammonia, first into nitrite then into nitrate.
According to AOAC (1980), paralytic shellfish poisoning (PSP) is a marine toxin disease with both gastrointestinal and neurologic symptoms reported worldwide. It is a serious illness caused by ingesting shellfish polluted with dinoflagellate algae that create harmful toxins. Some of these toxins are 1,000 times more powerful than cyanide, and toxin levels contained in a single shellfish can be deadly to humans. Moreover, there is no antidote, patient need to go for supportive therapy and survivors usually recover fully on their own. The distribution of these toxicants in the environment is caused by herbivorous zooplankton.
Ships act as vectors. While most of the plankton species carried in the ballast water are harmless to a non-indigenous area and may even die off, the process poses a risk to vulnerable ecosystems as a toxic species may potentially be transported. Diatoms and dinoflagellates in their planktonic stages pose a low risk since they show limited survival ability during transportation in the dark ballast tanks. The resting spore (cysts) of these species, however pose a greater risk as they are well adapted to be able to survive the unfavourable conditions of the ballast tanks. One ballast tanks can contain an estimated 300 million of these toxic cysts which can germinate and set off an algal bloom (refer to figure 4) (Hallegraef & Bolch, 1991).
It is therefore often washed out by our water systems into rivers, lakes, dams and oceans. Ammonia is also present in certain fertilizers such as ammonia sulphate fertilizer and in industrial waste-waters; these are other mechanisms that allow ammonia to get into water bodies. Ammonia is a toxic and corrosive substance and therefore can be detrimental to living cells. Ammonia poisoning in humans can be lethal, hence it is classified as a severe pollutant. Duckweeds are a group of plants that are found in ponds lakes and slow-flowing rivers, they are members of the Lemna genus.