2. It’s the story of the fishers who learned to gather the clam as children, and the scientist who spent decades studying them and their catch – until the moment when everything changed.
3. And it’s a story about vulnerability – how people can build their lives around a feature of the natural world that seems fixed and reliable, like a clam fishery, only to see it all upended as the climate shifts.
4. After much research, @vanhoutenphoto and I went to Uruguay to meet with Omar Defeo, the scientist, and travel with him to the border with Brazil, where the yellow clam fishery that he studies is now under extremely tight government regulations.
6. It’s beautiful, but it is not a happy scene. That’s because a once abundant clam resource has been devastated by mass-dieoffs and many other negative physiological impacts.
7. These are changes that Defeo and his colleagues have linked, across multiple studies, to rapidly warming ocean waters.
int-res.com/articles/meps_…
int-res.com/articles/meps_…
8. There are still cold water clams on Uruguay’s beaches, buried under the sand, but not nearly so many. Much of their habitat is now crowded with invaders that prefer warmer waters.
9. We met with the community of fishers – now, a pretty small one – who still pursue the clam under the stringent regulations that now exist.
Or, at least, still remember the earlier pursuit.
Or, at least, still remember the earlier pursuit.
10. They remember above all when everything changed – a series of mass clam mortalities swept southward from Brazil, to Uruguay, to Argentina, leaving shorelines strewn with dead clams.
This was in the mid-1990s.
This was in the mid-1990s.
11. “Kilometer after kilometer, as far as our eyes could see. All of them dead, rotten, opened up,” remembered one of the fishers, Ramón Agüero (in translation).
12.We couldn’t find an image from a clam dieoff in Uruguay but here is one from a related event in the same species, in nearby Argentina, in 1995. Courtesy of Sandra Fiori. 
13.In Uruguay, the fishery was shut down for 14 years. Everyone had to find an alternative source of work. If they could.
14. And that was just in the 1990s – since then, the temperature increase has been relentless in the waters along this coastline and even more intense offshore.
15. Data provided by Defeo’s student, @IgnacioGianelli, show a 1 degrees C rise in water temperatures in the last 20 years alone. In my prior thread, I explained why this is happening -- a major shift in a warm current called the Brazil Current.
16. Our story establishes that, over a longer period, this region has warmed by 2 degrees Celsius, or more, over preindustrial levels. It’s one of the fastest warming parts of the ocean.
17. The clams are not extinct but the allowed catch is tiny, just a few tons. And it’s not clear what the future holds.
18. Meanwhile, the impacts are spreading. An ocean heat wave reaching temperatures 1.7 degrees C over anything measured before struck in 2017, killing fish and closing beaches in the capital city of Montevideo. agupubs.onlinelibrary.wiley.com/doi/abs/10.102…
19. More recently, Defeo and @IgnacioGianelli documented that the entire catch of fish in Uruguay has undergone a predictable and even expected shift towards more warm water species. This has happened in a tight relationship with warming waters. int-res.com/abstracts/meps…
20. And we don’t even know what else is happening. Probably a lot. The largest fishery – Argentine hake – has plummeted, even as far south of here, in Patagonia, they are now catching hundreds of thousands of tons of Argentine red shrimp, suggesting a population explosion.
21. But the causes of the changes aren’t fully understood. It is all so new.
22. This is what happens when a rapid ocean warming event strikes your shores. If not for Defeo, who was essentially in the right place at the right time, we would surely know even less.
23. The clam dieoff also says something about the unequal distribution of climate change damage.
24. Clams can’t move, Defeo pointed out to me. They are stuck along this stretch of beach, whatever comes. They are sort of like corals, rooted in place. So when something changes, there’s no escape.
25. These are the kinds of species that will be hit hardest by rapid ocean changes – and that impact will ripple to the human communities that depend upon them.
26. In the end I am left wondering – where else has something like this already happened, but we just haven’t even heard about it yet? I imagine lots of places.
27. Across the world people are dependent on oceans and fisheries. Sometimes for subsistence, sometimes to eke out a living. And if they happen to be working in an ocean hot zone – well, all that they were used to and depended up on can be quickly taken away.
28.This is what a fast warming planet – with hot zones now exceeding 2 degrees C – means. /end
Our story: washingtonpost.com/graphics/2019/…
Our story: washingtonpost.com/graphics/2019/…
