How did conservationist Aristide Kamla clear Lake Ossa's invasive weed to protect African manatees?

Cameroonian conservationist Dr Aristide Kamla said giant salvinia had spread across Lake Ossa, smothering the plants manatees eat, blocking them from surfacing to breathe and hurting local fishing. His team used biological control, releasing the salvinia weevil, a tiny insect that feeds only on that weed. Within about two years almost all of it was gone and manatee sightings became more common.

• Kamla says manatees help fertilise the water, which means more fish for local fishermen.
• His citizen-science app SIREN lets fishermen log wildlife sightings and holds over 40,000 observations.
• The data supports a catalogue of 46 shark and ray species, including one thought extinct.

Source: our own transcription of the episode. The full conversation is on Global News Podcast (2026-10-31). Read the whole episode summary →

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