Deck 18: The Impact of Humans on the Marine Environment

Question 1

Wastes from duck farms used to wash into two shallow-water bays on Long Island, New York. The wastes, rich in nutrients such as nitrate and phosphate, polluted the water. What do you suppose was the immediate effect of the pollutants? Can you speculate on the likely effects to the commercially valuable shellfish of the area?

Answer 1

Humans are highly dependent on sea for different resources. These resources could be used for obtaining food, oil, and other raw material for industrial and domestic purposes. The greed and carelessness of humans have lead to the mass destruction of different ecologies. They have negatively impacted the ecology of the area.
The running of waste rich in nitrate and phosphate from duck farm in the shallow-water could have extremely negative role on the marine life. Such exposure could lead to the rapid growth of algae in the region, a process known as eutrophication. This algal boom could decrease the concentration of dissolved oxygen, thereby reducing the marine life in the area. In addition, the formation of anaerobic condition in the area could result in the build-up of hydrogen sulphide in the region. This formation of hydrogen sulphide could hamper the growth of commercially important shellfish.

Question 2

It is found that a chemical present in effluents coming from a factory is being stored in the tissues of herring, a plankton-feeding fish. What type of observations and possible experiments would you suggest to find out if the chemical is biodegradable? What is the significance of finding out if the chemical is biodegradable or not?

Answer 2

Humans are highly dependent on sea for different resources. These resources could be used for obtaining food, oil, and other raw material for industrial and domestic purposes. The greed and carelessness of humans have lead to the mass destruction of different ecologies. They have negatively impacted the ecology of the area.
There are certain experiments that can be performed for observing whether the chemical is biodegradable or non-biodegradable. The most common and efficient experiment involves the procedure of growing fresh herring in an artificial condition. These fishes could be exposed to the pollutant under question. After certain period of time, these fishes could be removed and the presence of the pollutant in their tissues could be evaluated. If the pollutant is observed in the tissues, it could indicate the non-biodegradable nature of the pollutant. On the other hand, if the pollutant is not found in the tissues, it could point towards the biodegradable nature of the pollutant.
It is important to evaluate whether the pollutant is biodegradable or not as this could tell us whether the process of biomagnification is occurring or not. Herring is one of the common foods for the larger fishes. These fishes, in turn, are consumed by the humans and can easily enter our food chain.

Question 3

Tourism and its effects (for example, pollution from hotels and the impact of boats and tourists on fragile habitats) often clash with conservation efforts. Sometimes, however, tourism can help. The economic impact of banning the hunting of harp seals in eastern Canada has been compensated for in part by the influx of tourists that now come to see the seals. Can you think of other examples? What recommendations can you make to minimize the impact of tourism on unspoiled marine environments?

Answer 3

Humans are highly dependent on sea for different resources. These resources could be used for obtaining food, oil, and other raw material for industrial and domestic purposes. The greed and carelessness of humans have lead to the mass destruction of different ecologies. They have negatively impacted the ecology of the area.
There are several examples of the benefit of tourists on the unspoiled environment. Some of the common examples are the tours available in the Great Barrier reef, Galapagos islands, etc. These places could be preserved by arranging nature oriented tours that could provide ample information regarding the benefit of such area and the harmful effects of destroying it. Education is the most important method of preserving any area. The visit to specific area could be arranged and may include stays, food, etc. only at specific regions.