Summary and conclusion

It seems clear from numerous investigations that human influences are severely harming the health of coral reefs (Reaser et al., 2000; Obura, 2005; Barber et al., 2001). Fishing and sedimentation in particular appear to be having a large impact, with nutrient enrichment seemingly slightly less damaging. More studies into the effects of weapons testing need to be carried out in order to determine their impact, although the discontinuation of nuclear testing in the Pacific atolls could make the results of these studies of less value. However, climate change appears to offer the greatest threat to coral health. Steadily rising SSTs over time have led to stronger ENSO events, and in turn mass bleaching events have increased. Bleaching events brought about by the climate are much more widespread and directly affect far more corals than any of the other human factors mentioned, which apply to more local areas of coral. Although the timescale being studied is a small one, it seems as though the rising temperatures are a result of climate change and not one-off events. Whether or not global warming as a result of increasing greenhouse gases in the atmosphere is occurring is unproven and open to speculation, but it seems likely in my opinion that there is a significant human aspect to this phenomenon.