The “inhabitants” of the underwater world can “speak”: Benthic organism identification—silent sentinels safeguarding aquatic ecosystems.

Have you ever gazed at a body of water, wondering what kind of world lies hidden beneath its surface? Beyond the swimming fish, at the bottom of the water—where light struggles to reach—dwells a group of mysterious yet vital “inhabitants”: these are benthic organisms.

Who are benthic organisms?

Benthic organisms constitute a vast “kingdom” of underwater inhabitants, including familiar species such as snails, clams, mussels, and cockles, as well as inconspicuous aquatic insect larvae (such as dragonfly nymphs), worms, and tiny shrimp and crabs. Some of these creatures spend their entire lives buried in the mud; others crawl slowly across the bottom; and still others make brief, temporary stops. Their most distinctive feature is their limited mobility—unlike fish, they can’t swiftly escape pollution. It’s precisely this “steadfastness” that has made them the most faithful “recorders” of aquatic environments.

The Significance of Benthic Organisms—The “Chief Diagnostician” of Aquatic Ecosystems: Environmental Monitoring and Health Assessment

1. Natural indicators: Different species exhibit vastly varying tolerances to pollution. Some are “cleanliness enthusiasts” (such as mayfly larvae and stonefly larvae), preferring to live only in clear, pristine waters; others are “pollution-tolerant experts” (such as tubifex worms and chironomid larvae), capable of thriving even in oxygen-depleted and heavily polluted water bodies.

2 Decoding the community’s “code”: Once we find that all the “cleanliness enthusiasts” have vanished from a particular river section, replaced instead by a landscape teeming with “pollution-tolerant experts,” it’s as if our body has issued a powerful alarm signal, telling us that the water body has fallen ill.

3 Quantifying health values: Based on this characteristic, scientists have developed various biological indices (such as...). BI Biological indices transform biological information into intuitive numerical values, precisely quantifying the health status of water bodies and providing robust data support for environmental management.

Identifying benthic organisms is not merely a scientific exploration—it is also a profound sense of responsibility and commitment. It’s a way for us to decipher nature’s language and listen to the Earth’s heartbeat, and it marks an important starting point for us to safeguard our green mountains and clear waters and jointly build a community of life. Protecting our aquatic environment means protecting these silent sentinels—and, more importantly, ensuring the future on which we humans ourselves depend for survival.