Disappearing Sharks
A kind of underwater archaeology is telling us how important sharks were - and still are - to healthy reefs. Dr Anjani Ganase looks at a recent study based on shark scales collected in the sediment on coral reefs. In my fifteen years of diving on reefs of Tobago and the Caribbean, I can count the number of sharks that I’ve encountered on one hand. This is a tragic reflection of the impact of mismanaged fishing pressures. Over decades, we have decimated the shark communities regionally. This decline is also an alarming trend in other parts of the world. Even on reefs with a management system, sharks are declining because of loss of reef habitat and the ravages of climate change. In 2012, when I first surveyed the far-northern reefs of the Great Barrier Reef (GBR) in Australia, our team would encounter dozens of reef sharks on every reef we visited. Four years later, after two major bleaching events hit the GBR, we were lucky to encounter a single shar...