When it comes to protecting Earth’s oceans, looking into the successes and failures of past generations can provide valuable lessons, as well as urgent warnings.
Researchers at the University of Exeter analyzed the long-term trends of fisheries, and found that few of the most successful ocean management strategies are being used today.
The investigation was focused on 20 historical examples of fisheries and aquaculture dating back as far as the 12th century.
The experts identified consistent patterns that resulted in “blue growth,” the development of sustainable ocean economies that benefit entire communities.
At the same time, the study revealed “common recipes for failure” that could serve as valuable lessons for resource managers today.
“Our aim was to see if we could learn from past successes and failures,” said Dr. Ruth Thurstan.”We often assume our problems are new, but a look at the past shows societies have faced similar issues before – though many of our challenges today are on a bigger scale.”
Dr. Thurstan explained that some past societies failed at blue growth, while others succeeded in balancing economic growth, social equity, and sustainability for various lengths of time.
“In basic terms, success came when societies managed to achieve fair – rather than unlimited or open – access to resources, and when they were responsive to change,” said Dr. Thurstan.
“Basing decisions on evidence, getting all parties involved and planning for the long-term were also key. Failure occurred when short-term gains were prioritised over long-term sustainability.”
The study was conducted by an international team of historians, environmental scientists, and marine ecologists. The experts analyzed ocean management strategies in countries such as Ireland, Italy, Japan, and the United States over the last 800 years.
In Japan, the team found that blue growth was achieved from the 1600s forward. Access to seaweed resources that benefited the majority rather than a minority of people, use of traditional knowledge systems, and enhanced seaweed cultivation techniques helped achieve a balance between market demand and ecological sustainability.
On the eastern coast of the United States, oyster reefs collapsed after two centuries of over-exploitation and worsening water quality. While oyster production remains far lower than historical levels, many communities are working to restore coastal reefs.
“Worryingly, the recipes for success that we discovered are rarely included in even the most advanced blue growth agendas today,” said Dr. Bryony Caswell.”The seas are destined to play an ever-more vital role in food security. If we don’t take this chance to learn from history, we may be condemning ourselves to repeating past mistakes.”
The study is published in the journal Fish and Fisheries.