资源环境科技发展态势分析平台

Today, like every year, we celebrate the world's five remaining species of river dolphins, writes Daphne Willems, WWF Lead River Dolphin Initiative.

From China via South and South East Aais to Brazil, we shine a spotlight on these iconic species, the top-predators in some of the world's mightiest rivers (I would happily tell you all about them but the best way for you to find out more is to watch our wonderful short videos - you can find one per species here).

But this year, today is also World Fish Migration Day - a day we normally celebrate in April but it was postponed due to the Covid-19 pandemic since so many field events had to be cancelled.

I feel this “coincidence” is a blessing in disguise: migratory fish are after all the main food source for river dolphins. While migratory fish can migrate thousands of kilometres, dolphins follow them as far as they can and cover hundreds of km themselves. Living in the same rivers - think of the Amazon, Ganges, Indus, Irrawaddy, Mekong and Yangtze - river dolphins face many of the same challenges  as migratory fish: hydropower dams blocking their migratory routes, illegal fishing and pollution to name a few. It feels right to celebrate them all on the same day.

But there has actually been a whole week of river dolphin events with a series of global webinars and some major news. We saw the launch of the first Amazon Dolphin Dashboard, bringing all river dolphin data together in one place. It's an incredible achievement and will make a huge difference to river dolphin conservation in South America and I am so proud of the team that made that happen! It's already shown us - via satellite tagging of 29 individuals - that dolphins migrate up to 300 km. This proves how important it is to keep rivers free flowing so that dolphins and migratory fish can thrive.

We also saw the latest numbers of Irrawaddy river dolphins in Mekong, the rarest river dolphin in the world. With 89 individuals, this population has stabilized, but we were disappointed that the slight increase over the last few years did not continue. But after decades of decline, stabilisation is still success. However, everyone agrees that even more collective action is needed from government, communities and WWF, especially to fight illegal fishing, which is the main direct cause of dolphin deaths in the Mekong.

But we've also seen alarming news recently about declines in fish catch in the Mekong. This is very serious for all the people along the river who rely on freshwater fishes for food security and livelihoods. But is also another concern for river dolphins, since they rely on the fish of the Mekong as well.

And this shows how we are all connected: people, river dolphins and migratory fish - because hundreds of millions of people depend on these mighty rivers. And there are no better indicators of the health of these rivers than their dolphins and migratory fish. If they are struggling to survive, if their numbers are declining - which sadly they are in most cases - then the rivers will not be healthy enough to sustain people either.

But there is hope. As this week has shown, concerted conservation efforts can halt the decline in river dolphin populations and new data is being produced and shared, which will drive even more effective conservation in future. And critically, awareness about the plight of river dolphins and migratory fish is growing as well as the realisation of how important they are to people and nature.

Indeed, the longer I work to protect river dolphins, the more I become convinced I am working to protect people as well. And that if we can save the world's wonderful river dolphins, we can save so much else.