Well, you do live by the ocean. If sharks ever get spotted in the Great Lakes I’m moving to colder climes.
If you routinely swim and fish in Lake Erie, I think you have better things to worry about than sharks. Personally, mercury poisoning would top my list (unless you’re just doing catch-and-release).
The harvesting of sturgeon (at least in the Midwest) is heavily controlled and regulated. They require a special separate tag (I think it’s $100 in Wisconsin), and you can only harvest one a year. Most of the species are endangered,so there isn’t really a lucrative market for their eggs.
Mostly kayak, occassionally swim, (followed by a Silkwood when I get home) and even less often fish in it anymore. Christ I wouldn’t dare eat anything I caught in the Maumee River.
Unless I caught me a really big great white. 
Some whales have a hair or two, and there were elephants in those woods- in the very early days.
I won’t mention the piranha they found in Professor’s Lake in Brampton (near Toronto) a couple of years ago, then. 
It would be a bitch having to wait at the locks, though. In Canada you need a Green Card to be Predatory Megafauna?
Slippery the Sea Lion.
In 1958 he escaped from London’s Storybrook Gardens, swam down the Thames, made his way down into Erie, and was eventually captured near Sandusky by a Toledo zookeeper.
" Cage goes in the water. Hooper goes into the cage. Shark’s in the water. Heeeeeeeeeeeeeeeeeee. "
I blame it for mine as well. I was swimming off the shore of Cape May, NJ last summer. Dolphin pods not THIRTY FEET away from me, frolicking. FROLICKING, I TELL YA. And what did I do? Did I swim around, so I could say I swam ( swum. Swimmed. ) in the proximity of a pod of dolphins? No. I did not.
I treaded water and kept an eye out for a triangular fin. Like I always do. Great whites love killing dolphins, you know. Goddamned brilliant book. And movie. 
Cartooniverse
Whale hair ain’t whale fur.
But not when Uncle Harko was a kid!
And the Sturgeon protection patrols are out during spawning season in the Fox River Valley, to prevent evildoers from poaching sturgeon for their eggs. Lotsa sturgeon still in Lake Poygan, Lake Butte des Morts, and Lake Winnebago, and in the Fox river.
I miss 'em in Lake Michigan, tho. The elders used to talk about seeing them spawn on the sandbars.
I also miss the days before zebra mussels and alewives.
I don’t remember the days before lampreys.
I just pray I don’t see the day of the Asian Carp arrive in my waters!!! Shark might be preferable.
I think the only way a shark is going to get into, say, Lake Michigan is if some irresponsible acquarium owner dumps his critters into the water. I wouldn’t be surprised if it’s happened in the past. But most species of sharks wouldn’t last long in fresh water.
“We’ve drained Lake Michigan and filled it with Fresh Milk”
Any other Dopers old and warped enough to remember that?
“I’m gonna need a milk-proof watch, though…”
…
Well, they’re only called that if they are found in Lake Nicaragua.
When I was a wee lad, Lake Nicaragua was thought to be landlocked, and researchers thought that the sharks in the lake were a unique species, related to bull sharks. They’ve since found that the sharks can migrate in and out of Lake Nicaragua.
For the record, I would much rather meet good ol’ Mr. Great White than mean ol’ Mr. Bull. Bull sharks are very aggressive in comparison to Great Whites. Bull sharks are also much more likely to be found in shallow water. However, Great Lakes denizens needn’t overly worry themselves; bull sharks prefer warmer waters, and Great Whites, which are found in all temperature zones, are not known for travelling far upstream into brackish/fresh water.
There’s a river not too far from here that produces some interesting catches for local fishermen every year, the Fox River. I might be mistaken, but I believe that a few piranha have been caught, along with some exotic aquarium species as well. They’re cast offs dumped into the water by owners who don’t want them anymore. Some of the more regular anglers aren’t surprised at catching anything anymore. A few years back someone caught a cayman that mustn’t have been in the water too long.
Bottom line, you never know what’s swimming in those waters out there…
Well, of course only Freberg could pull that off, although there was a cartoon knock-off several years later in an ad for Cap’n Crunch that was simply not as good.
Okay, oftentimes I tell my roomate about these topics and read some aloud to him. I did this topic and he immediatly raised the issue that Niagra Falls isn’t on he St Lawerance Waterway directly in any way…
He says that it’s probably possible to trace them someway, but that coming from the sea and on the way to the great lakes, they would not have to pass through Niagra Falls.
True or not? Cause if he’s right and it hasn’t been mentioned yet, then…heh, well I dunno.
(for the record, I think that if he was right, then the Dopers would have pointed the fact out by now, but just humor me cause he’s insisting he’s right)
Until the canal was built, one definitely had to go up Niagara Falls to get from Lake Ontario to the rest of the great lakes.
Don’t you guys have maps?
Well, strictly speaking, the St. Lawrence Seaway is a navigable waterway for shipping, and since Niagra Falls is only navigable in one direction some of the time while equipped with a proper barrel, then no, it doesn’t qualify as part of the shipping route. It is the natural course of the water that flows along what people consider the general route of the seaway, though.
Hence, as mentioned above, the navigable, manmade route provides plenty of opportunity for waterborne stowaways in any case.
Oh I do…you need to know my roomate a bit. He’s very stubborn.
I dunno what he’s on about, but he’s still saying he’s correct. shrug whatcha gonna do? I even pulled up a map and showed him but he’s saying that the falls are a dranage off of the lakes and river and not in the way from the great lakes to the sea at all.
Shave the whales!!
But speaking of saving, I will go against the current and mention that the sharks of Nicaragua are becoming extinct, that may sound good to many, but there are serious ecological implications about that, those who wish the sharks may be gone are not thinking this carefully.