Experiment Number: 5 Date: December 8,2011. Aim: To assess and analyze man’s impact on the small coralline cay- Lime cay.
Apparatus: boat Introduction: Lime cay is a small coralline cay that is mostly used by humans for their personal entertainment. By visiting this cay, man has had detrimental effects on the environment. In the earlier times, man’s impact was not so prevalent, however, overtime it has increased as agricultural practices and technology has been introduced. The effects can rise from pollution to global deforestation, which results in the death of many organisms.This can lead to species and genetic diversity being lost and also gives rise to extinction of some species. The adverse effects will be discussed later in details.
Procedure: A small boat was used to travel to lime cay where the students walked around the small coralline cay and recorded all observations, which indicated man’s impact on this environment. Observation: Pictures showing the small coraline cay-Lime cay and evidence of the presence of man’s pollution. Picture showing an example of an organism that lives on the cay that is affected by man’s presence (sea urchin).Table showing the organisms present on the cay and their preys Organisms Being Fed On| Organisms Feeding| Flowers| Snails and Bees| Snails and Fish| Turtle| Leaf litter | Earthworm| Phytoplankton| Zooplankton| Algae| Sea Urchin and Fish| Fungi| Crab and Sand Fly| Wood| Wood Boring Beetle| Tree Bark| Termite| Woodlouse and Bees| Spider| Bird| Pelican| Bees and Earthworm | Bird| Discussion Questions: (a) Create a food web of all the organisms present on the cay. Pelican Stingray Shark LizardBird Turtle Spider Fish Wood boring Earthworm Sea urchin Zooplankton Bees Snails Crab Sandfly Beetle Termite Leaf litter Algae Phytoplankton Flowers Fungi Wood Treebark (b) What is the significance of the cay? The significance of the cay is to: (1) provide a habitat for a variety of organisms that were present on the cay (2) to aid in breaking heavy wave and tidal action and (3) to serve as a recreational ground for humans. c) What are the ways that man affects this habitat? Man affects this habitat by pollution when it is used for recreation, by deforestation/slash and burn method, by causing eutrophication, overfishing, oil spills and exposing unwanted predators.
(d) Do you see any animals or evidence of any animals? What organisms are affected by man’s activities and how? Yes, there were animals seen. The animals seen were crabs (their tracks and their holes were spotted) ground lizards, pelicans, birds, fishes, sea urchins, spiders (spider webs were spotted) snails, stingray and a turtle.Generally speaking, with human activities being practiced on the cay, it resulted in habitat destruction. Changes usually take time for the organisms to adjust. However, when changes occur at a fast pace, there is little or no time for individual species to react and adjust to new circumstances. This created disastrous results, and for this reason, the rapid habitat loss causes species to migrate to other areas to live. On the cay there was a lot of garbage left behind from human activities.
These consisted of mainly plastic materials such as cups and bags.Trash like plastic, can cause death to fishes as plastics take a while to biodegrade and therefore remain in the water. Fishes sometimes mistake plastic for food and ingest it, which results in a blockage in their digestive systems killing the fish. Plastic can also get wrapped around their necks and choke them or it could get stuck in their mouths, making it unable for the fish to eat and so it might starve and also die. Another observation made was a traveling cargo ship. This activity released pollutants into the water and also made it prone to oil spills.
An oil spill has the most hazardous effect on aquatic and terrestrial life. The oil coats the fish’s outer layer and kills it. Also, oil affects sea birds as it sticks to their wings rendering them flightless. Oil settles on top of water and so forms a thick layer that is opaque, which prevents sunlight from reaching marine plants, so photosynthesis is obstructed.
Oil spills may result in eutrophication, which feeds algae blooms. When algae dies they sink to the bottom where they are decomposed. The decomposition process uses oxygen and deprives the deeper waters of oxygen, which can kill fish and other organisms.Also the necessary nutrients are all at the bottom of the aquatic ecosystem and if they are not brought up closer to the surface, where there is more available light allowing for photosynthesis for aquatic plants, a serious strain is placed on algae populations.
Growth of algal blooms disrupts normal functioning of the ecosystem, causing a variety of problems such as a lack of oxygen needed for fish and other organisms to survive. Also it may be noted that by human activities, which cause organisms to migrate, makes them more available to predation.Additionally, it can increase competition for food and space between organisms. Another point that was observed was the presence of fishermen. Overfishing decreases the population of fishes in the area, which disrupts the food chain as terrestrial organisms that feed on aquatic life have less food to eat. Also human activities affect turtle nesting, as the turtle was seen moving outwards from the cay.
This suggested that based on the exposure to unwanted predators, turtles might see the cay as unsafe to lay their eggs.There may have also been introduction to pests as a result of the garbage and also pests may come to the cay in boats. Lastly, we can look at the effect of the method slash and burn method. Evidence of the burning of wood was seen which resulted in the various plants and animals that lived there being swept away. This could also have been the area where only one particular species is kept and slashing and burning could result in extinction for that species.
This also affects organisms that live in the soil, like the bacteria, that would result in their death. e) Is the only impact by those who visit the cay? No, the impact is not only by those who visit the cay, the impact of the habitat destruction is also by pests as stated before like rats who come on the cay and create mass destruction to the organisms living there. (f) As a manager, what would you suggest to minimize man’s impact on this environment? There should be provision of proper disposal facilities, where the site can be kept clean of litter and the waste and contaminants are not runoff into the water.Implementing in-situ conversation and management practices to exclude or eliminate pests, so pesticides are unnecessary and the organisms will be protected is another suggestion for minimizing the impact. With the prevention of pollution, eutrophication will decrease.
Plastics can be collected in a container for recycling, so recycling bin can also be put into play. And lastly, rules should be implemented against burning of materials on the cay. Conclusion: Man has significantly impacted lime cay and evidence was there to support this theory, which resulted in many detrimental effects to the organism present on this cay.