These mini-ecosystems existed under the dinosaurs’ feet, but our parking lots may drive them to extinction

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This is episode four of the 4 part Enchantment of Vernal Pools. You can listen to Episode One here, Episode Two here and Episode Three here.


Christopher carved: It is Scientific American‘c Science, fast. I’m Christopher Carved.

When I first started working on this Vernal Pools series and convinced myself that I needed to go see them myself, one of the most surprising things was when people kept telling me to go see them.

Chuck Black: This landmark is the largest and most pristine concentration of vernal pools remaining in San Diego County and possibly California.

Carved: A preserve of hundreds of acres of wild land containing more than 1,000 vernal pools—it’s also part of a Marine Corps base outside San Diego: Marine Corps Air Station Miramar. And my tour guide was a wildlife biologist employed by the Department of Defense, a man named Chuck Black.

Carved (ribbon): I never thought that … for this story, I would come to a military base to find … the natural resource.

Black: yes yes Well, many people don’t associate military bases with… conservation efforts, but…

Carved: It’s true – when I think of conservation, I think of roadless stretches of the Sierra Nevada or remote stretches of the Mojave Desert.

Here, the natural wonder is sandwiched between a highway, a dump and a track. And there’s a reason this military base is the largest remaining bastion of vernal pools along the Southern California coast. Many other things were developed here.

Black: Flat tops of mesas like this were the main areas for development in the 18th, 19th and 20th centuries.

Carved: Vernal pools turned into farmland, houses, shopping centers.

Black: It is estimated that over 98 or 99 percent of the vernal pools that used to exist in San Diego are now no longer here due to development.

Carved: And if you look across the country, the numbers aren’t all that different, and vernal pools are believed to be among the most threatened ecosystems in the state.

Sean O’Brien: Many people know that 90 percent of the vernal pools were lost from the Central Valley after European colonization. But what people don’t know much about is that these losses continue. This is not just a historical problem.

Carved: This is Sean O’Brien. He is a senior wildlife biologist at ICF, a consulting firm. And he does biological studies of the vernal pools before development and tries to recommend ways to avoid damage to the vernal pools — and if that can’t be avoided, he advises ways to compensate for the loss elsewhere.

And he says there are a number of factors today that threaten the vernal pools and the animals there, but one stands out among the rest.

O’Brien: I think it’s safe to say that habitat loss is the number one problem in a landslide.

Carved: A recent study by vernal pool consultant Carol Whitham found that between 2005 and 2018, 9 percent of the remaining vernal pool habitat in the Central Valley, 76,000 acres worth, was destroyed.

And more than 90 percent of those losses were not mitigated. This means that the pools were destroyed without complying with regulations that require documentation of the loss or preservation of the pools or restoration elsewhere to compensate.

The Witham report says that most of the pools are being destroyed to make way for vineyards and orchards.

Witham: And there are some consultants who make a lot of money helping people do this.

Carved: Witham explains that much of the habitat loss documented in her report is achieved through something of a complex solution.

Witham: It seems that in many cases they at least avoided the larger vernal pools and planted only around them and not through them. But for all intents and purposes this endangered species habitat, if it isn’t already gone, will be gone in very short order.

Carved: Vernal pools tend to be in low places – right where pools of water gather. It is also where polluted water from agriculture flows, which can kill the animals in the basins. And if the checkers were “mistakenly” eliminated that way… well, she says that’s a lot harder to enforce.

Witham: This is part of the reluctance of regulatory agencies to take enforcement action. Because they can’t prove that the activity killed endangered species because they didn’t actually go in and intentionally damage the vernal pools at the time they put the trees in. But in a very short period of time all their activity around the vernal pools will destroy the vernal pools.

O’Brien: You also have to feel for those ranchers who…see how their neighbor just made an orchard and became a millionaire, while they did the right thing and didn’t turn their vernal pool complex into an orchard, and they’re, they are not making money out of it. They have no incentive to keep their land.

Carved: Private ranchers are the largest landowners of the remaining vernal pools in the Central Valley. And to be fair, some ranchers actively protect pools on their land through various types of conservation agreements.

But even when they’re not, and the vernal pools turn into orchards, O’Brien says the fairy shrimp seem to follow Jeff Goldblum’s famous lineage of Jurassic Park …

[CLIP: Jeff Goldblum in Jurassic Park: “I’m simply saying that life, uh, finds a way.”]

O’Brien: You will still see shrimp hatching in these plowed fields. They are certainly hardy creatures.

Shannon Blair: Yes, from zooming in on a very, very long view, I think the fairy shrimp as a group will be fine.

Carved: I talked to Shannon Blair about it. She is a molecular ecologist at the University of Idaho who has done a lot of work on fairy shrimp as an undergraduate and graduate student at the University of California, Davis.

Blair: I think the dangers of losing vernal pools are that they are not just isolated habitats. They are deeply connected to the region’s agricultural productivity, the area’s wildlife and migratory birds, and protect and support native amphibians. So you lose a lot more than just a pond when you lose a pond.

Carved: But just by looking at the fairy shrimp, she says they’ve survived — despite what humans could throw at them.

Blair: They survived the breakup of Pangea. They have survived the extinction of CT. They survived the meteor that killed the dinosaurs. They’ve lived through… multiple ice ages and still are – as an order, they’re found all over the globe: in the desert, in the Arctic…, on rocky outcrops. They are found in the rich jungles of South America. They are found on islands.

They represent the ability to survive in very difficult, very variable conditions. And they do this by sort of waiting for things to become perfect before they re-emerge and change quickly and adapt quickly to new environments as they arise.

Carved: Her thought reminded me of something Chuck Black had said to me as we wandered the vernal pools of Miramar.

Black: I’ve even seen fairy shrimp in the pits of the track that are as big as your hands.

Carved: They can survive in small puddles of runway. This stuff is really hardcore.

And I should emphasize that no one told me that we shouldn’t be worried, even worried, that the vernal pools are disappearing right now, today.

But perhaps there is reason to hope.

Black: Fortunately, they are a very hardy species. They withstand anxiety and other things. So if you dig a hole that holds water long enough, most of the plants and fairy shrimp will do just fine. If you asphalt it with a parking lot, there is no way. So… [laughs]

Carved: If we don’t completely destroy the remaining vernal pools, it seems that the unusual creatures that call them home may just find a way to hang on.

For Science, fast“I’m Christopher Carved.”

Science, fast was produced by Jeff Del Vicio, Tulika Bowes and Kelso Harper. Music by Dominic Smith.

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