Saturday, March 24, 2012

Native Hawaiians Provide Lessons In Fisheries Management

Roughly three-quarters of the Earth’s surface is covered with water. As I stand on a beach in Hawaii and look out over the vast, blue expanse in front of me, I am overwhelmed by the immensity of the Pacific Ocean. My brain wrestles with numbers far beyond its capacity to visualize. In that moment, it is incomprehensible that even seven billion humans could deplete such a boundless and unimaginable resource. Yet, I know that we are. We are emptying the oceans of their fish, one species at a time.

Today, 85 percent of the world’s fisheries are either fully exploited, overexploited or have already collapsed. Combined, the world’s fishermen catch 2.5 times the sustainable number of fish every year. Scientists predict that if current trends continue, world food fisheries may collapse entirely by 2050. “We are in the situation where 40 years down the line we, effectively, are out of fish,” explains Pavan Sukhdev, special advisor to the UN Environment Programme.

What we need are better management strategies. Now, researchers from the Center for Ocean Solutions at Stanford University are turning to the past for advice. Loren McClenachan and Jack Kittinger used historical records to reconstruct fish catches for the past seven hundred years to see if earlier civilizations did a better job than we are at managing their fisheries. The authors were able to characterize historical catch rates in the Florida Keys and Hawaii by reviewing a variety of historical sources, including species-specific catch records from the 1800s and archaeological reconstructions of population densities and per-capita fish consumption.

“Seven hundred years of history clearly demonstrate that management matters,” said Loren McClenachan, co-author of the study and assistant professor of environmental studies at Colby College. In Florida, fisheries were characterized by years of boom and bust through sequential collapse of high-value species, many which are still endangered or extinct today. The Keys fisheries were set up for failure – unlike other historical island communities, the Keys were highly connected to other markets, increasing fisheries demand. Furthermore, they have historically lacked a centralized management system. But, while fisheries in the Florida Keys have always been poorly supervised, fisheries in Hawaii were once far better than they are today.

“Before European contact, Native Hawaiians were catching fish at rates that far exceed what reefs currently provide society,” said Kittinger, co-author and early career fellow at the Center for Ocean Solutions. Native Hawaiians pulled in over 15,000 metric tons of fish per year, and these high yields were sustained over several hundred years, despite a dense Hawaiian population. “These results show us that fisheries can be both highly productive and sustainable, if they’re managed effectively.”

by Christie Wilcox, Scientific American |  Read more: