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Freshwater sharks

Started by Guest_Moontanman_* , Jan 21 2009 10:30 PM

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#1 Guest_Moontanman_*

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Posted 21 January 2009 - 10:30 PM

I just read an article on line that stated that bull sharks were found in large numbers in Lake Ponchartrain after hurricane Katrina and bull sharks had been found in lake Michigan. does anyone know if these claims are factual? The article can be found here. http://fish.suite101.../the_bull_shark

#2 Guest_Newt_*

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Posted 21 January 2009 - 10:40 PM

There was a bull shark spotted in Lake Michigan at Chicago in 1955. It actually bit a swimmer. I don't know of any other shark reports from the Great Lakes. Juvenile bull sharks do enter Lake Pontchartrain in large numbers; I hadn't heard that Katrina had any effect on this.

Edited by Newt, 21 January 2009 - 10:40 PM.

#3 Guest_brian1973_*

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Posted 21 January 2009 - 10:43 PM

Growing up in cincinnati and frequently boating on the Ohio I heard plenty of stories of bull sharks being found in the Ohio river but I dont know how true they are but I do know(Discovery Channel) they have been found hundreds of miles inland in the mississippi river.

#4 Guest_rjmtx_*

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Posted 21 January 2009 - 11:30 PM

Bull sharks are supposedly all over Lake Nicaragua, and I've heard of them swimming up into Texas Rivers. Here's a link to a shark story on the Trinity River a couple of years ago http://www.i-dineout...dk.6.20.06.html. I'm still more wary of bipedal mammals than I'll ever be of sharks in rivers or saltwater.

#5 Guest_Moontanman_*

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Posted 21 January 2009 - 11:44 PM

Thanks for the info guys, all this is connected to a thread on another forum about a guy who is keeping Bamboo sharks in freshwater. This lead me to freshwater sharks in general which of course led to Lake Nicaragua and bull sharks and bull sharks in North American waters. One thing I've found that information about lake Nicaragua seldom makes much sense and is fragmented as far as i have found so far. I've seen reports of two different species of shark in Lake Nicaragua, tuna, swordfish, sawfish, rays, other elasmobranchs, giant gars and even sturgeon. I have no idea which if any of these reports of unusual freshwater fish in Lake Nicaragua are accurate and I can't find official reports on the species of fishes of that lake.

Edited by Moontanman, 21 January 2009 - 11:47 PM.

#6 Guest_fundulus_*

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Posted 22 January 2009 - 08:42 AM

The bull sharks in Lake Nicaragua were once considered to be a separate species because of supposed adaptations to fresh water. But research starting in the 1950s (if I recall correctly) banded many of these sharks, and some were recovered as far away as England. The lake is connected to the Caribbean by a river which allows passage to the sharks (and figured in some early pirate history too, another subject...). I'll try to find my one good book on the subject and post the title/author. So bull sharks as far inland as the Ohio River is not impossible, although probably unusual even before the modern industrial era.

#7 Guest_bpkeck_*

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Posted 22 January 2009 - 09:56 AM

Fishes of Alabama lists the most inland record of a bull shark on the Mississippi R. from Alton, IL. When I was working on the Hatchie River in west TN a few locals told me of their 'buddy' that caught one on the Hatchie, but got away (of course).

#8 Guest_Moontanman_*

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Posted 22 January 2009 - 12:37 PM

Sharks do make for great tall tales, I once had a guy tell me about seeing a shark in a small stream in the middle of town where i live, we are just a few miles from the ocean so it's possible, lots of popeyed mullet come up stream and pogies. I think it's interesting that some sources say bull sharks reproduce in salt water because their young cannot tolerate freshwater and others say they do reproduce in Lake Nicaragua. At the point the claims of Billfish and tuna and other normally marine fish is what I am interested in. I have burnt google up but I cannot find a study on the fishes of lake Nicaragua. The best I've found just tells about a few and then goes on to other things. I did read, oh so many moons ago, about a species of shark in the lake other than bullsharks, it was a small brown shark that never left the lake. But billfish and tuna? And other marine fish, not to mention alligator gar and sturgeon, sounds like a wild lake to be sure!

#9 Guest_mzokan_*

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Posted 22 January 2009 - 07:34 PM

Billfish and tuna cannot tolerate freshwater, so they wouldn't be found in the lake. However, there is a population of sawfish that does use the lake and river, this may be where the billfish confusion comes in

Sharks do make for great tall tales, I once had a guy tell me about seeing a shark in a small stream in the middle of town where i live, we are just a few miles from the ocean so it's possible, lots of popeyed mullet come up stream and pogies. I think it's interesting that some sources say bull sharks reproduce in salt water because their young cannot tolerate freshwater and others say they do reproduce in Lake Nicaragua. At the point the claims of Billfish and tuna and other normally marine fish is what I am interested in. I have burnt google up but I cannot find a study on the fishes of lake Nicaragua. The best I've found just tells about a few and then goes on to other things. I did read, oh so many moons ago, about a species of shark in the lake other than bullsharks, it was a small brown shark that never left the lake. But billfish and tuna? And other marine fish, not to mention alligator gar and sturgeon, sounds like a wild lake to be sure!

#10 Guest_Ouassous_*

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Posted 22 January 2009 - 07:53 PM

There are also tarpon (Tarpon atlanticus), snook (Centropomus parallelus), and grunt (Pomadasys sp.) in the lake.

#11 Guest_Moontanman_*

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Posted 22 January 2009 - 08:36 PM

Billfish and tuna cannot tolerate freshwater, so they wouldn't be found in the lake. However, there is a population of sawfish that does use the lake and river, this may be where the billfish confusion comes in

Tuna and billfish were mentioned at the same time as sawfish and a sawfish was shown so I don't think they had them confused. On the other hand I really didn't expect to see tuna or billfish in the lake. It's was probably a tale tall inspired by other fish that live in the lake and the need to draw attention to the fishing in the lake, it was a fishing type show I saw that on. Lots of tall tales turn out to just be hype.

#12 Guest_Moontanman_*

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Posted 22 January 2009 - 08:39 PM

There are also tarpon (Tarpon atlanticus), snook (Centropomus parallelus), and grunt (Pomadasys sp.) in the lake.

What I am gathering here is most of the fish in the lake that are from the ocean are brackish water fishes or fish that do frequent brackish water. Does anyone know if this is true?

#13 Guest_fundulus_*

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Posted 22 January 2009 - 08:58 PM

Here's one reference for bull sharks in Nicaragua: Savage Shore, Life and Death With Nicaragua's Last Shark Hunters by Edward Marriott, copyright 2000, published by Metropolitan Books. It's a somewhat gonzo travel account by a young British writer who has done a lot of research on the history of shark fishermen and pirates in the system defined by Lake Nicaragua, the San Juan River that connects it to the Caribbean and the Miskito Coast. The zoologist who researched bull sharks in the sixties and seventies was Thomas Thorson. He was able to demonstrate that the Lake Nicaragua bull shark is not a landlocked species.

#14 Guest_kzimmerman_*

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Posted 06 March 2009 - 12:09 PM

We have alot of bull sharks here in the chesapeake bay, and i have seen them as far north as annapolis. I've heard of them being further north, but have never seen it documented. That area is very brackish, some years it is almost fresh.

#15 Guest_Brooklamprey_*

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Posted 06 March 2009 - 02:19 PM

Here is an interesting paper on this...

Long-term Declines
in Two Apex Predators, Bull Sharks (Carcharhinus leucas) and Alligator Gar
{Atractosteus spatula), in Lake Pontchartrain

#16 Guest_MDSoares_*

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Posted 01 April 2009 - 08:34 AM

Here are a couple good published articles on this subject. I have provided the name nd relevant information only, as these are generally only available online if you have a subscription to a journal database

If anyone would like a copy, I can provide it in PDF format, just PM me.

-The Bull Shark, Carcharhinus leucas, from the Upper Mississippi River near Alton, Illinois
Jamie E. Thomerson, Thomas B. Thorson and Ronald L. Hempel
Copeia, Vol. 1977, No. 1 (Mar. 16, 1977), pp. 166-168

=Additional Comments on Adult Bull Sharks Carcharhinus leucas (Müller and Henle), from Chesapeake Bay.
Frank J. Schwartz
Chesapeake Science, Vol. 1, No. 1 (Apr., 1960), pp. 68-71

This paper deals specifically with the issue of whether or not the Bull Sharks in Lake Nicaragua are disctinct species as once thought:

Carcharhinus nicaraguensis, a Synonym of the Bull Shark, C. leucas
Henry B. Bigelow and William C. Schroeder
Copeia, Vol. 1961, No. 3 (Sep. 22, 1961), p. 359

The Status of the Freshwater Shark of Lake Nicaragua
Thomas B. Thorson, Donald E. Watson and C. Michael Cowan
Copeia, Vol. 1966, No. 3 (Sep. 7, 1966), pp. 385-402

#17 Guest_Carptracker_*

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Posted 27 April 2009 - 09:53 PM

Bull Sharks and Tarpon have been tagged in lake Nicaragua and followed back to the Caribbean and recaptured there. I don't know why bull sharks would care about salinity for reproduction, since they are viviparous. But I don't know if they do breed or give birth there or not. Interesting question, though.
Tarpon are probably salt-only spawners, though - they have the leptocephalus larvae, which apparently migrate toward fresh water.

A bull shark was captured in the Missouri River near Saint Louis a long time ago, I think the fifties. Mullet occasionally come up that far and also have been caught pretty far up the Ohio.