Sharks In Pacific Ocean Reefs Dwindling, Less Than 10 Percent Remain

Sharks along the Pacific Ocean reefs have seen a huge decline in recent years, which American and Canadian researchers attribute to human fishing pressure.

In an analysis of the population, published Friday by Conservation Biology, researchers state that the closer a shark population is to people, the worse off they are, even if the human population is less than 100 residents.

The study estimates that as many as 90 percent of reef sharks have vanished. The authors wrote that:

“Our results suggest humans now exert a stronger influence on the abundance of reef sharks than either habitat quality or oceanographic factors.”

The study was comprised of a team of eight scientists, who examined the results of ten years of underwater surveys across 46 Pacific islands and atolls.

They discovered that the densities of reef sharks (including gray, whitetip, blacktip, Galapagos, and tawny nurse sharks) “increased substantially as human population decreased.” The populations increased as productivity and temperature of the ocean increased as well.

The published study claims that near places like the Hawaiian Islands and American Samoa, there were about 36 sharks per square mile. In remote reefs, however, such as the Northwestern Hawaiian Islands and the Johnson Atoll, about 337 sharks could be seen per square mile.


Mark Nadon, the study’s lead author and a scientist at the University of Hawaii’s Joint Institute for Marine and Atmospheric Research, said in a statement that, “In short, people and sharks don’t mix.” He went on to say that:

“We estimate that reef shark numbers have dropped substantially around populated islands, generally by more than 90 percent compared to those at the most untouched reefs.”

Julia Baum, assistant professor at the University of Victoria, Canada, and one of the co-authors of the study stated that:

“We show that, as one would expect, these factors also are important. The greatest reef shark densities are on Jarvis Island: that’s because it is the perfect convergence of all the factors reef sharks like — warm water, high productivity, and no people!”

Check out the following video, courtesy of shark defenders: