A study by the University of Tasmania reveals the critical importance of fish size diversity in maintaining healthy oceans. Led by Dr. Asta Audzijonyte, a Pew Marine Fellow at the Institute for Marine and Antarctic Studies (IMAS), the research highlights the drastic decline in large fish populations over the past century and the resulting impact on marine ecosystems and global food security.
Dr. Audzijonyte explained, “The ocean’s big fish are disappearing. Despite advanced fishing technology, data, and historical evidence show today’s fish populations are younger and smaller, destabilizing ecosystems and threatening sustainability.”
Selective harvesting of larger fish and increased recreational fishing—sometimes accounting for half the total catch—have significantly altered fish population structures. During the COVID-19 pandemic, recreational fishing surged and remains high, exacerbating the problem.
Dr. Audzijonyte advocates Marine Protected Areas as essential to restoring fish populations, promoting biodiversity, and preserving genetic diversity. She notes that collaborative efforts among anglers, communities, and policymakers could recover big fish populations within 10 to 20 years.
To engage communities, her team developed an educational card game, “Big Fish,” launching on Kickstarter. IMAS Technical Officer Matthew Teston explained, “Players compete to maximize points while maintaining a healthy fishing environment, teaching sustainable practices.”
Through education, research, and conservation, this initiative emphasizes the vital role of fish size diversity in ensuring marine resilience to climate change and fostering healthier oceans.