New findings reveal that global conservation initiatives are responsible for around 10 percent of fish populations found on coral reefs.
Recent research from the University of Sydney indicates that international conservation initiatives account for roughly 10 percent of fish populations found on coral reefs.
The worldwide study, published in Proceedings of the National Academy of Sciences, was conducted by Professor Joshua Cinner from the School of Geosciences and principal analyst Dr Iain Caldwell from the Wildlife Conservation Society. This international team also included researchers from the US, UK, Kenya, France, and Germany, among others.
By analyzing fish survey data from nearly 2,600 tropical reef sites, the researchers created a model demonstrating that around 10 percent of fish biomass (which refers to both the number and size of fish in a given area) can be linked to existing protective measures.
Professor Cinner, who directs the Thriving Oceans Research Hub, stated: “Millions rely on reef fish for their livelihoods and nutrition. However, overfishing poses a serious threat to the well-being of coastal communities worldwide. Implementing protective measures can help replenish fish populations and provide additional benefits for people.”
“Our research rigorously tested the effectiveness of global coral reef conservation efforts. On one hand, we found that these conservation initiatives have contributed positively to fish populations on global coral reefs, which is encouraging. However, on the other hand, this contribution is relatively modest, indicating that there is significant potential for improvement.”
Globally, coral reefs face immense pressure from various human-induced challenges including climate change, pollution, and overfishing.
Marine Protected Areas (MPAs) are designated sections of the ocean where governments impose restrictions on human activities, serving as a widely supported method for conserving marine environments. At present, MPAs protect only a small portion (approximately 8 percent) of the world’s oceans, but this coverage is expected to increase significantly in the coming years.
During the UN Biodiversity Conference in 2022, 196 nations endorsed the Global Biodiversity Framework, committing to protect 30 percent of the world’s terrestrial, freshwater, coastal, and marine zones by 2030—an initiative commonly referred to as 30×30. The researchers hope their findings will enhance the outcomes of this initiative.
Professor Cinner noted: “Our model suggests that by increasing the coverage of fully protected reefs to 30 percent, we could achieve up to a 28 percent increase in fish populations on coral reefs worldwide—but this would depend on choosing these areas wisely.”
Dr Iain Caldwell from the Wildlife Conservation Society emphasized: “No-take zones are effective, particularly when adhered to well, but they are not the only means of enhancing fish populations. Although banning fishing provides the most significant increase in fish biomass for the protected area, other fisheries management strategies can also be effective and may be more agreeable to those who rely on reef fish for their sustenance and livelihood.”
More than 50 percent of the coral reefs studied had no fishing restrictions whatsoever, prompting the research team to evaluate the impact of implementing fishing limits—such as banning the use of nets or spearguns—on currently unregulated coral reefs.
The predictive model indicated that globally, fish populations in coral reefs could rise by an additional 10.5 percent—effectively matching the total contributions of all past conservation efforts.
Professor Cinner stated: “While fisheries restrictions are not as effective as no-take MPAs on a per-area basis, they tend to face less opposition from fishermen, which can improve compliance, and can be applied on a much larger scale. Sustaining coral reef fish populations will require utilizing every available strategy.”
