Is the ocean broken? Headlines about the environment have been pessimistic for years and Carlos Duarte, King Abdullah University of Science and Technology (KAUST), Saudi Arabia, pulled one such headline, “Earth's sixth mass extinction event under way, scientists warn" (The Guardian), up at the beginning of his keynote lecture at ICES Annual Science Conference 2021.
The world has already lost thousands of species. And while the majority have been landbased, marine biodiveristy has also been negatively affected. "20 species extinct in historic times, 830 species of conservation concern, an 89 % decline in exploited marine megafauna abundance, one third of fisheries overexploited , and two thirds of fisheries below targets", Duarte continued, as he asked, "Who’s next?".
Twenty years ago, Duarte admits, he may have perpetuaed the pessimistic views of the ocean that abound but something has changed and Duarte spent the remainder of his lecture providing inspiration and hope to his audience. Referencing his 2020 Nature article Rebuilding marine life, Duarte presented the documented recovery of marine populations, habitats, and ecosystems that has occured worldwide following past conservation interventions and from this research suggests that, "substantial recovery of the abundance, structure and function of marine life could be achieved by 2050, if major pressures—including climate change—are mitigated", stating that, "Rebuilding marine life represents a doable Grand Challenge for humanity, an ethical obligation and a smart economic objective to achieve a sustainable future".
How should this be achieved? The health of the ocean depends on protecting species, protecting spaces, harvesting wisely, removing pollution, mitigating climate change and, most importantly, stated Duarte, by not giving up. Handing a healthy ocean over to future generations depends on this.
Positive trends
Recovery is already evident. Duarte preented evidence of policies on whale hunting and the trade in endangered species contributing to 42% of 92 marine mammal populations increasing, and marine habitats, such as seagrass, making unprecendented gains in comparison to losses throughout the twentieth century.
Not all ecosystems have as postive an outlook and Duarte impressed on the audience that "rebuilding coral reefs carries the highest risk of failure as cumulative pressures (for example, overfishing and pollution) that drove their historical decline are now increasingly compounded by warming-induced bleaching". Many have indeed lost hope and already accepted coral loss. Not so for Duarte, who stated that we should not accept the loss of coral reefs and grieve. Instead, he says quoting Joan Baez, "We must act, for Action is the Antidote to Despair”.
One such action is the newly established Global Coral Reef R&D Accelerator Platform created by the G20 leaders in 2021, of which Duarte is acting executive director.
Rebuilding Marine Biodiversity by 2050
To conserve and sustain what is left is no longer acceptable states Duarte. Marine biodiversity can be rebuilt to 1860 levels by 2050, we have the knowledge and a window of opportunity to do this before damage is irreversible but we can do it with the international collaboration of scientists, governments, businesses, NGO’s and opinion leaders and investment.
