Chapter 53, Problem 1Q

Summary Introduction

To review:

The outcome of results of the experiment on relationships between the number of fish species and the species diversity of the corals in their respective habitats. Also, explain the way in which this knowledge would help in maintaining the coral reef ecosystem under threat.

Given:

Figure 1 shows the study area of the experiment in the Indo-pacific region with high coral reef species. The three sites are Kimbe Bay in Papua New Guinea (PNG), Moorea Island in French Polynesia, and Lizard Island in the Great Barrier Reef on the east coast of Australia.

Figure 1: Experimental sites across the Indo-pacific region.

Graph 1 shows the results of the number of the fish species found in the coral species region. A relationship was established between the index of sensitivity and the number of coral species.

Graph 1: Relationship between the index of sensitivity and number of coral species.

Introduction:

An experiment was conducted in the three islands, Kimbe Bay (highest fish diversity), Moorea island (lowest number of fish species), and Lizard island (with an intermediate number of fish species). In the experiment, the coral diversity was manipulated and associated fish species were counted during a 12-month period. Based on this experiment, an index of sensitivity was calculated to evaluate the relationship among the number of coral species and the number of associated fish species that inhabited in the plots.

Explanation of Solution

Corals are coelenterate, which is composed of thin layers of calcium carbonate that is secreted over time by coral polyps. Polyps witness a symbiotic relationship with zooxanthellae. Coral reef ecosystem is the most diverse ecosystem on the earth. It is made up of corals, sponges, molluscs, Fish, sea turtles, dolphins, sharks, and many other aquatic organisms. Corals and fishes have a symbiotic relationship where many fishes depend on corals for their food and habitat whereas the corals depend on grazing by certain fishes for reproduction.

The results suggest that fishes at the Kimbe Bay Island were more sensitive to changes in the number of coral species and they were expected to undergo local extinctions. This happens because the fish species diversity is more in this region. On the other hand, Moorea island, which inhabited fewer number fishes, were not much sensitive to changes in the number of coral species.

These results might be useful in preserving the coral reefs, which inhabit a large number of fish species. As the fishes and simultaneously the coral reefs in the Kimbe Bay are sensitive to any changes, they might face extinction threats from the activities of the nearby human population. Thus, the ecologists must give special attention to this region (Kimbe Bay) while laying down protective guidelines for the coral reefs all across the globe.

Conclusion

Therefore, it can be concluded that decline in the number of fish diversity is directly proportional to the decrease in the coral species. This can help the marine biologists to pay special attention to the sensitive regions of coral diversity.