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March 21, 2014

Urban Foraging: Carp Caviar from the L.A. River!

Ask me where my favorite spot to explore urban nature is in Los Angeles, and I'll almost always say the river. This is particularly true during, and after, our seasonal rain storms. We're used to extreme heat episodes, wildlfires, and the odd earthquake* or two. But, by and large, us Angelenos are unaffected and unimpressed by the elements. Going down to the river after a good rain, you get a rare chance to see, hear, and feel the raw power of nature.

*Anyone else wake up abruptly last Monday morning after the 4.4 trembler, wondering how much water you could salvage from your toilet's holding tank?

River patrol after the El Nino rains in January 2010

During our most recent rain storms (February 28-March 2) I, along with a number of other people, ventured down to the river to watch all that water flowing through the concrete channel.

 

View of the river and the Fletcher avenue bridge March 1, 2014

Unfortunately, the above pictures just don't do it justice. They don't let you feel the power of that much water flowing past you. Maybe this photo collage, created by Damian Robledo, can do a better job?

Damian works right next to the river in Elysian Valley (aka Frogtown), and was able to duck outside his office at RAC Design Build, to document the dramatic change.

As you can see, the river filled the channel almost to the very top. Which, according to The River Project, means a flow rate of about "183,000 cubic feet of water per second," or in terms easier to understand that's, "40 million garden hoses going full blast," or, "14 times the flow of New York's Hudson River!" Whoa, that is one heck of a lot of water flowing through the heart of Los Angeles and on out to the Pacific Ocean. While watching this spectacle, I couldn't help but wonder about the animals that live in the river. What happens to them when 14 Hudson rivers are forced between the river's banks?

Obviously, some creatures, like the white egret pictured above (long-necked bird hanging out in the middle of the frame), can just fly out of the river and hole up until the storm is over. Other fauna native to California, have evolved different strategies to deal with our sudden influxes of water. According to Dr. Greg Pauly, our curator of Herpetology, amphibians are much better than we are at sensing changes in barometric pressure. When they sense cues that a storm is coming (i.e. a drop in barometric pressure), frogs and toads will hop out of the watercourse and find a place to shelter, like under a nice big bush, or down an abandoned ground squirrel burrow. Some amphibians even thrive after massive disturbances like winter floods. Greg told me that after the Mount Saint Helens eruption, Western Toad, Bufo boreas, populations exploded.

But, what about the water-bound creatures, do they fare as well? In the case of this introduced carp species, Cyprinus carpio, not so well:

I found this fish while exploring the river on March 2nd, during an ethnobotany tour put on by River Wild. Although, we were focusing on urban foraging of edible plants, none of us could help taking time to marvel at this massive fish. As you can see, it was was lying there dead, with much of its insides spilling out, including the roe (all those orange bits are fish eggs)! Apparently, carp roe are sold as a caviar substitute, but I just wasn't willing to try them early on a Sunday morning. Yes, a part of me worried that they could be contaminated with toxins present in stormwater*, but mostly it was because I grew up vegetarian in England and accidentally ate taramasalata at a friend's birthday party. Incidentally, taramasalata, is a Greek or Turkish dip made from vinegar, olive oil, lemon juice, and taramas (aka preserved roe). As you can imagine, this has permanently affected my taste for carp caviar!

*In 2008 FoLAR (Friends of the L.A. River) commissioned a fish study to determine species presence and toxicity levels. They sent five L.A. river carp to a lab to be tested for mercury and polychlorinated biphenyls (PCBs) levels. All the fish tissue tested came back with mercury and PCB levels below those designated by the Office of Environmental Health Hazard Assessment's for fish contaminants.

But, how did this impressive creature die, and how did it end up in a dry side channel of the river? I think, one of two things happened. Either, the carp was battered around and killed by debris during the flood, and was then deposited in the side channel as the water receded. Or maybe, the water receded so quickly that the fish was stranded and then, unfortunately suffocated. Either way, post-mortem, it seems that another animal came along to have a snack, apparently wild creatures are into carp caviar too! Then, for some reason (maybe we disturbed them), the epicurious scavenger fled the scene of the crime and left this mighty fish to decompose on the river bank.

 



Posted by:Lila Higgins

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