Can fish populate a lake without human help?

And if they can populate a lake, how? And how long does it take? And how big does a lake have to be to support fish (not pet-store fish; I’m thinking of native-to-the-area fish)?

Have the fish that currently exist in lakes been there since the lake was connected to some other large body of fresh water? I have trouble believing they walked from one lake to the next.

Thanks.

Eels can (and do) migrate across land, especially when it rains.

Other fish can get to remote bodies of water in those rare instances when a serious flood links them (or turns the entire landscape into one big lake).

I’m not sure about the rest, but it is something I’ve often wondered about - can fish eggs get transported intact on the legs of wading birds?

It is my understanding that Mangetout is correct in that fish eggs can become attached to duck feet and transfer from one body of water to another.

My wife had a student two years a go who lived on a farm in western Illinois. They decided to dredge out a pond on their property. This pond is nowhere near any other bodies of water and the did not stock it with fish. They told my wife that they were catching bluegills three years after the pond was filled.

They get quite a lot of waterfowl activity so I believe the ducks and geese transfer the fish eggs to these ponds.

From here:

(although this particular article goes on to rule this possibility out for the body of water and species in question.

Doesn’t take much to support fish. When I was a kid I lived in a subdivision that had been carved out of a swamp in Mississippi. (It reverted to swampland in heavy rainstorms, too, heh. Some rich developer down there prolly belongs in jail.) Anyway, there was a drainage ditch off a plot of land that had been cleared but not built on. It was about 30 feet long by about two feet wide by about a foot deep (on average). One day I went out there with a fishing rod and some bread crumbs just to see what was in it. Caught 17 catfish and two sunfish in about an hour.

Also, would it be possible for fish to survive being sucked up in a water spout and ‘rained’ down into a new body of water in the style of rains of frogs?

Birds can catch a fish they mean to eat and accidently drop it in a new body of water too. Unlikely but possible.

All the more so when you consider that they would have to do it twice (and with one being a male and the other a female)…

Zev Steinhardt

Not really. One gravid female would work. If that’s too improbable for you then two females would work for many species, since they can easily switch gender as required.

I have a quarry right down the road from me that is full of perch, no other fish, no snakes no turtles, just perch. I always wondered how they got there.

http://www.dnr.state.md.us/fisheries/snakeheadinfosheet.html

http://www.fearmongers.com/article.php?sid=158

http://www.cbsnews.com/stories/2002/07/03/eveningnews/main514182.shtml

http://news.nationalgeographic.com/news/2002/07/0702_020702_snakehead.html

True about needing two fish being dropped by birds (there are actually very few fish that can switch sexes), but it wouldn’t be that hard to have happen. In a productive area a single bird, even a non-fishing bird, can take dozens to hundreds of fish from the water per day, every day for weeks (I worked at a fish hatchery where birds were very unwelcome). If there’s a lake between the fish source and their nest or eating spot, accidents can happen.

In addition to that that a full-grown fish (even with some injuries) stands a much better chance at survival than an egg. And you won’t be getting whole nests with hundreds of eggs on a duck’s foot, more like 1-5. Remember the eggs still have to land in a suitable spot, not get eaten, hatch, have food for the fry, not get eaten, grow up for a year or more, not get eaten, and meet another fish with a similar fate. The other way you just have to have two fish dropped.

Are there any fish that have extremely durable eggs like those freshwater shrimp whose eggs can lay in desert sands for years, but when there’s a rainstorm you get a breeding population of shrimp wherever there’s a puddle of water? I would imagine they are quite rare outside desert areas, but in desert areas they could get around, blown by the wind, etc.

Some fish live in rivers, so they can move into lakes.

However the eggs or fish get moved, it happens quickly. I’ve seen snapping turtles in enclosed man dug lakes in urban areas. Herons (has a picture of a blue in flight)–not to mention all the other wading birds–in Florida are a likely candidate. They wade around in lakes hunting fish. They spear them and sometimes take the fish with them. It’s not hard to imagine one regurgitating a clutch of fish eggs into the next lake, as herons usually move around to several or more.

I once saw a “bloom” of jelly fish in a strip mine pond in southern Ohio, several hundred miles from the Atlantic coast, there were many thousands of them. A biologist I talked with later said the eggs or what ever she calld them were probably carried there on the legs and feet of birds.