Faith Crud Student number 332289 The effects of drought on Aquatic Biodiversity Introduction: Prolonged drought is one of the biggest environmental predicaments we encounter periodically. Australia is a well known dry continent and is potential by low yearly rainfall. As drought progresses, water evaporation increases sharply which then decreases water levels on dams, rivers and creeks threatening the flora and fauna present in those ecosystem.
The augment in water temperature may also result in diminishing levels of Oxygen present in water and as a consequence the salinity of he water increases and could do an immense destruction on fish species" (Bond, , Lake, Irritation,2008 p. 14). The " increase in water temperature may also result in nutrient build up which will intensify algal growth and makes the water poisonous not only to the fish species but also to the livestock and domestic animals in the surrounding area" (Bolton,2003 p 1173).The study on the effects of increased frequency and prolonged period of drought was conducted in order to establish the impact and its adverse effect on living organisms. Purpose: To determine the effects of a droughts duration and frequency upon aquatic flora and fauna.
Hypothesis: It is believed that as drought progresses, the rate at which aquatic living organisms propagate decreases. Method: The data from different ten wetland systems was analyses. These wetland systems has experienced drought in 1950, 2005 and 2008.Each event occurred for the duration of nine, eighteen and ten months respectively refer to figure 1. 1 " Invertebrate richness".
The mean, standard deviation, standard error and variance of the available data given were calculated using the formulas shown in figure 1. 0. The ATA available was also plotted into a line graph (refer to figure 1. 2 "The number of Invertebrate present In can wetland Walt year") to easily determine ten gallants effect of prolonged drought on number of invertebrates.
The data in the table was color-coded to match the graph. Once the mean, variance, standard deviation, and standard error was calculated the answers were placed on a table and then a bar graph was established where the average was plotted against the year in order to determine the extent of damage drought could do to living flora and fauna present in hose ten wetland systems. The Bar graph was a useful tool to compare the trend in averages of the number of invertebrate per annum.It is evident that severe and prolonged drought conditions devastate and cause immense destruction on aquatic flora and fauna in these ten wetlands.
In the early stages of drought we can see that there is a rapid diminution of aquatic life present in wetland areas classified as 1,2,6,5,4,7, and 8 (color-coded dark blue, pink, red, purple, aqua, and green respectively) refer to figure 1. 2 " The number of invertebrates present in each wetland with year" and it is tangible that in the early years of the drought several roofs of invertebrate were severely diminished.However despite the given condition " many native biota in drought prone systems possess adaptations which allow them to either survive the drought by 'sitting out' (resistance traits) or to recession and recruit after the drought breaks" (Bond, Lake, Irritation, 2008 p. 4). This idea is replicated in the graph depicting wetland 3, 9 and 10 (color-code yellow, blue-green, and light-blue respectively).
By further calculating the average, variance, standard deviation and standard error it is evident that there is a significant crease in the number of invertebrate thriving in these wetland systems.
