Scientists tied plastic bottles to fishing nets – and couldn't believe what happened next…

Marine researchers recently tested a low-cost method to protect dolphins from accidental entanglement in fishing gear. By attaching common plastic bottles to gillnets, scientists hypothesized that the air-filled containers would act as acoustic reflectors. This allows dolphins to detect the nets using their natural echolocation, which often fails to pick up the thin nylon filaments currently used in commercial fishing.

The initiative involved testing these modified nets in diverse locations, including Zanzibar, Peru, and Brazil. Results varied by region, largely due to the differences between surface-level nets and those anchored to the seafloor. In surface waters, environmental noise interferes with the acoustic reflection, providing less protection for marine life. However, results from bottom-set nets tell a different story.

Trials using bottom-set nets in Brazil demonstrated an 88 percent reduction in dolphin bycatch. Researchers noted that the bottles did not negatively impact the volume of target fish captured, suggesting this is a viable solution for the fishing industry. The approach provides a dual benefit by repurposing plastic waste found in the ocean to prevent the loss of protected species.

Professor Per Berggren of Newcastle University emphasized the accessibility of this solution for local fishers globally. The low cost and ease of implementation mean that the practice could be adopted without significant investment or operational changes. Ongoing research is expanding these trials to include coastal waters in Cambodia and the Congo.

This simple intervention highlights how practical engineering often yields the most effective conservation outcomes. By modifying existing gear with recycled materials, the industry can take a meaningful step toward reducing the unintended mortality of coastal dolphins and porpoises.