Course:EOSC270/2023/Group 10
What is the problem?
· Clearly identify what the problem is
· What human actions cause the problem?
· Where does the problem occur?
· How pervasive is the problem?
How does this problem impact marine ecosystems?
· How and why does it impact the identified ecosystems?
· Are their unique characteristics of this habitat that make it vulnerable?
· What organisms does it impact?
· How and why does it impact this organism/s?
· Are their unique characteristics of this organism/s that make it vulnerable?
What is the extent of the problem?
· What are the measurable ecosystem changes that have occurred?
· What is the present status compared to the past?
· What is the prognosis for the future if we continue on our current trajectory?
Case Studies
Two separate case studies, one in which diving had a positive impact on the ecosystem and one exploring negative impacts
Positive-
Negative Case Study
Hong Kong, Hong Kong, eastern reefs near Sharp Island
→ Diving associated with coral breakage
→ Behaviour of divers in these areas
Coral reefs off the eastern coast of Hong Kong have been affected by diving and between two studies within two years, behaviours of the divers and the impacts of diving on the reefs were looked at. Two major conclusions were drawn and can be synthesized in the following points:
- Divers are causing harm to reefs, specifically inexperienced divers with cameras were breaking off bits of coral, and minor tissue damage
- This leads to an imbalance of coral species and dominance of more structurally sound coral
In the first study, Divers in Hong Kong were divided into groups and watched underwater and it was confirmed as seen in the previous case study, that inexperienced divers and photographing divers are often the groups causing the most damage and pushing the reef past the amount of wear and tear it can normally handle. In the study, many divers were not certified, and it is not uncommon for instructors to use reefs as training grounds, which was discouraged given the results. https://link.springer.com/article/10.1007/s00267-013-0023-y#Tab5
| SIte | No. of genera | Distance (min) | No. of divers | Broken coral colonies | % broken colonies |
|---|---|---|---|---|---|
| Sharp Island | 15 | 20 | 2667 | 19 | 21.8 |
| Shelter Island | 13 | 45 | 1259 | 18 | 11.7 |
| Bluff Island | 11 | 60 | 490 | 16 | 10.7 |
| Long Ke | 12 | 90 | 1080 | 13 | 10.4 |
| Hoi Ha | 15 | 150 | 118 | 9 | 6.5 |
| Port Island | 11 | 150 | 138 | 3 | 4.0 |
| Crescent Island | 9 | 180 | 98 | 3 | 3.7 |
Table 1 from https://www.sciencedirect.com/science/article/pii/S0025326X14000253,showing relationships between diversity and damaged coral.
The effects of this can be seen in the second study, which looked at the coral itself and the change taking place in Hong Kong waters. Coral was divided into four types, branching, plate-like, massive and encrusting, and breakage was measured from these four types. Sharp Island was found to have 21% of the total broken coral found among islands. Not coincidentally, it was also the most accessible and popular diving spot in both studies. https://www.sciencedirect.com/science/article/pii/S0025326X14000253
A conclusion that can be drawn from Table one is the more diverse coral reefs are most popular and most susceptible to damage. It is also important to note that most of the damage seen pointed towards divers; small breakage and surface lesions, and only a small portion were from anchor damage. These small damages may not seem like much but they add up over time, and invite attack from predators. Since the coral that is more breakable will be attacked, biodiversity of coral is decreasing and unnatural domination of stronger coral is present. There is evidence of this change already complete in some sites. https://www.sciencedirect.com/science/article/pii/S0025326X14000253
Given the impact, what are the solutions?
· What are the local solutions, if any?
· What are the global solutions, if any?