- Introduction
Aquatic ecology is the study of relationships between organisms and how they interact in aquatic environments such as oceans, lakes, and wet lands. Aquatic ecology provides a habitat for wildlife, purifies water, and recycles nutrients; therefore, it is important to study and understand the basics of aquatic ecology so that humans do not negatively impact the environment. It is useful to compare the community of macroinvertebrate in summer samples of the same pond and winter samples of the same pond so that seasons or specific weather conditions can be tested to see if it affects pond or stream health. A pond or steam is considered healthy if it has a large diversity of aquatic organisms. The water quality of an ecosystem is determined by physical and chemical factors which is directly related to the macroinvertebrate who respond to these factors. In this lab we are taking samples from the retention pond near Tallahassee’s community college. The main objectives of this lab are to determine the pond health based on abiotic and biotic conditions, and to observe if the quality of the pond water varies between season specifically summer and winter. To measure pond health the specific biodiversity metric used is Shannon-Weiner Index and to measure the quality of water between seasons the metrics specific richness and evenness are used.
- Methods
The pond being sampled in the lab is on the corner of progress and century park across the street from the parking garage near the biology building of Tallahassee community college. The abiotic factors of this community are the air temperature at 82 degrees, cloud cover at 0% precipitation, Wind at 8mph, turbidity at 0 JTU, and humidity at 42%. The biotic factors are the Chara green algae in the water, dominant plants on the shoreline are nut sledge and blackberry. The water movement is still, and the bottom of the pond is clay. To collect the ponds organisms a dip net is used to drag through the bottom of the pond and put into a bucket. In the lab room the 16 species are separated and photographed to determine their identity. The water from the pond is the put into 6 test tubes and sealed. With each water samples nitrate, phosphate, pH, and dissolved oxygen is tested.
- Results
Figure 1: Log rank abundance of pond invertebrate species in winter 2020.
Figure 2: Log rank abundance of pond invertebrate species in summer 2020.
| Sample #1 | Sample #2 | Sample #3 | Sample #4 | Sample #5 | Sample #6 | Average | Ranking | |
| Turbidity | 0 | 0 | 0 | 0 | 0 | 0 | 0 | excellent |
| (jtu) | ||||||||
| Water temperature (C) | 21 | 22 | 18 | 18 | 18 | 18 | 19.16666667 | |
| Nitrate | 0 | 0 | 0 | 0 | 0 | 0 | excellent | |
| (ppm) | ||||||||
| Phosphate | 2 | 3 | 2 | 1 | 1 | 1.8 | good | |
| (ppm) | ||||||||
| pH | 7 | 7 | 7 | 7 | 7 | 6 | 6.833333333 | excellent |
| Dissolved oxygen (ppm) | 66% | 88% | 88% | 66% | 77% | 88% | 79% | good |
Figure 3: Water Chemistry of winter 2020
| Sample #1 | Sample #2 | Sample #3 | Sample #4 | Sample #5 | Sample #6 | Average | Ranking | |
| Turbidity | 0 | 0 | excellent | |||||
| (jtu) | ||||||||
| Water temperature (C) | 36 | 36 | ||||||
| Nitrate | 3 | 2 | 2 | 2 | 2 | 2 | 2.166666667 | good |
| (ppm) | ||||||||
| Phosphate | 1 | 2 | 1.5 | 1 | 1 | 1 | 1.25 | excellent |
| (ppm) | ||||||||
| pH | 10 | 10 | 10 | 10 | 10 | 10 | 10 | poor |
| Dissolved oxygen (ppm) | 24% | 24% | 24% | 24% | 24% | 24% | 24% | poor |
Figure 4: Water chemistry of summer 2020
There was a total of 286 organisms and 16 different species found in the Tallahassee community college pond. During winter 2020 the most abundant class of species were the aeshnid and southern leopard tadpole and the least abundant were chironomid, notonectid, red warm, dipteran larva, and caddisfly based on rankings. During summer 2020 snail, notonectid, and coryxid were most abundant and the chironomid, crayfish, and spiders were the least abundant.
In the winter time and summer time the Shannon index is used as a metric to measure biodiversity. The biodiversity of winter 2020 (Figure 1) is 2.577277714. The biodiversity of summer 2020 (Figure 2) is 2.190380029. Based on Figure 3 the Turbidity of the pond during the winter is excellent, nitrate is excellent, phosphate is good, pH is excellent, and dissolved oxygen is good. Based on Figure 4 during the summer time the turbidity is excellent, nitrate is good, phosphate is excellent, pH is poor, and dissolved oxygen is poor.
- Discussion
Based on the results the pond is healthier in the winter time because in the winter time the species have a higher diversity and evenness therefore there is more species present. In the summer time the diversity and evenness are lower meaning there is a smaller amount of species. This could be due to the weather in the summer time the temperature is obviously higher than in the winter. Also the water chemistry in the winter has a better ranking than in the summer.