(NewsNation) — New research on declining shark populations shows that more than 500 species of sharks play a critical role in maintaining ocean ecosystems.

To beachgoers reading the news of recent shark attacks, the idea of an ocean without sharks may be appealing. However, a new study examines the decline of shark populations, which have decreased by more than 70% since 1970.

While recent conservation efforts have shown some promise, shark populations are still at risk due to human activity, primarily overfishing.

Researchers who examined the impact of fewer sharks found that healthy shark populations protect seagrass from grazing by sea turtles and sea cows, which in turn provides a habitat for young fish and shellfish. Sharks also help preserve kelp forests and coral reefs, which are critical for ocean habitats.

Sharks also play a crucial role in food chains, and not just as predators that can keep other populations under control.

While many people view them as one of the top ocean predators, even large sharks like white sharks are prey for predators like killer whales.

Scientists say the study confirms long-standing beliefs about the role sharks play in the ecosystem and means conservation efforts are important.

The researchers recommended targeting key shark populations for conservation, limiting the most harmful fishing equipment and creating safe zones that allow sharks to live and grow without the risks from overfishing.