365 Urban Species. #130: Common Carp

[urbpan]

Urban species #130: Common carp Cyprinus carpio


Photos by cottonmanifesto

The common carp is a well-known, fairly large Eurasian fish that tolerates poor water quality, feeds on organic material in mud, and reproduces prolifically. It seems like a natural choice for artificial introduction, to provide a sustainable food source in an urban environment. Unfortunately, in the United States, the sport of carp-fishing is not popular, and the meat of this fish is not much sought after. Those few who do fish for urban carp are warned that these animals may have high levels of carcinogenic pcbs in their tissues. In the absence of human predation, urban waterways have become havens for common carp. Their bottom-feeding habits stir sediments into the water, making their habitat unsuitable for other fish that require cleaner water, or higher oxygen levels.

In some urban areas, such as Boston's Jamaica Pond, there are introduced Japanese Koi, which are common carp that have been bred in captivity for their bright orange and white colors. A 20 pound koi was caught there in 2005. Goldfish are carp relatives, and the same hobby of captive breeding produced the baffling variety of goldfish as well as koi.

Mature common carp are so large that they have no urban predators. The largest carp recorded have been over three feet and over eighty pounds. They can be fascinating to watch from urban bridges as they glide below the surface, or burst out of it, displaying their spawning behavior.

Comments

[sheridankm.livejournal.com]

I've always wanted to do a study of what one could actually eat in Boston (or any city), should one be forced to it. Ignoring the carcinogenic effects, these would be a pretty good source indeed.

[urbpan.livejournal.com]

The authorities only warn against children or pregnant women eating more than 3 meals of carp a week per month (if I recall correctly), with no warnings for people in other demographics. So yes, if I had to collect my own food in Boston, I would definitely consider carp (after canada geese and pigeons).

[ex-wellread.livejournal.com]

When I've gone fishing in Colorado, I've seen people who would fish for carp just to pull them out and let them rot on shore. That seems just mean and wrong. I just throw them back in the water. Anything I will not eat goes back. Carps and bullheads. And of course fish that are too small.

I would have to be pretty hungry to eat carp. They just look nasty to me.

[ankhanu.livejournal.com]

All three would be so easy to catch too :)

[ankhanu.livejournal.com]

I've always wanted to catch a carp, for some reason. They haven't been introduced to our waterways though, so they aren't available to be caught. Seems kind of odd that they hadn't been introduced though, I'm not sure why... I'm pretty sure that they've been introduced to locales with similar winters.

Of course, that they're not introduced here is a positive thing, so I'm not complaining. Plus I haven't gone fishing in a few years :P

Fens Carp

[ssejooz.livejournal.com]

Due to the pollution in the Fens, there are signs all over warning people not to eat the fish. You can see a ton of carp in there, and turtles. I once tredged in there, coaxed by my father, to free a turtle from a fishing line... gross!

If you head over there- check out the Victory Gardens for birds. Kinglets every year- lots of cool stuff. Just avoid the areas by the phragmites.

:)

[ex-wellread.livejournal.com]

Good question. Carp seems so plentiful I don't think you can fish them all out. And I have met people who do keep them to eat. Letting them rot on the shore can create an unpleasant environment.

[ex-wellread.livejournal.com]

Well, it is a big fish and you get a bit of a fight. But it's disappointing when you pull it out and it's a carp and not a trout or bass.

1, 2, 3

[shellynoir.livejournal.com]

I wonder if there's any explanation for why they're so tolerant of low oxygen levels. Bigger gills? Better hemoglobin?

In WA they use bounties to reduce numbers of undesirable fish:
http://news.search.yahoo.com/search/news?p=bounty+fishing+salmon&x=wrt
It boggles the mind that some people make a living that way.

I love the advertisement for Mazuri Koi Platinum Wheat Nuggets at the bottom of the article. Hey Mikey! Koi wheat nuggets taste good in milk!

[ankhanu.livejournal.com]

I don't eat fish anyway, so it doesn't matter what it is that comes out of the water, it's just going back in. Pretty much all I have to catch around here are trout and the occasional perch... unless I hit the salt water. I really should start fishing again; just requires actually doing it.

Re: 1, 2, 3

[urbpan.livejournal.com]

I wonder if there's any explanation for why they're so tolerant of low oxygen levels.

A quick search of the literature suggests that they have a better ability than other fish to sustain anaerobic metabolism, and tolerate lactic acid building up on their skeletal muscle.

They also can gulp air from the surface.

[turil.livejournal.com]

I didn't realize that these former pet fish (one of which was mine) were destructive to the habitat. It never occured to me that anything actually lived in the muddy river! I wonder if the monster one they caught in 2005 was mine...

[apathy.livejournal.com]

in teh southwest.. like in lake Mead or Powell or alone the Co. River.. there are so many carp at the docks, theyre laying on eachother!!!.. hehe.. fun to feed them.. pigs.

[karma-apple.livejournal.com]

Do you have grass carp up there?

[urbpan.livejournal.com]

It appears so far that the northern range of grass carp Ctenopharyngodon idella in North America stops at the Ohio river. But it looks to me like they could survive in New England if they were introduced.

[karma-apple.livejournal.com]

*nods* In the South, triploid (sterile) grass carp are often released by the thousand into lakes that have hydrilla problems. I hear that hydrilla isn't much of a problem up north... milfoil and other invasives cause much more damage.

Fens Goldfish

[(Anonymous)]

Back in the seventies I was walking through the Boston fens on a hot summer's day. The water was evidently oxygen depleted as the surface was simply chock-a-block with either large goldfish or koi. These fish were not gray carp, but multi-colored like koi, and of course, all different. They looked well fed and seem to average around 17 or 18 inches or so. I don't know if there is still a population of these fish in the fens, but it made for quite a site.

Good Will

Re: Fens Goldfish

[urbpan.livejournal.com]

You still can see the occasional giant orange carp in the fens and the riverway! :)

kill all carp

[(Anonymous)]

i kill all the carp i catch because in minnesota it is ilegal to catch and release carp