Great white sharks in the pacific N.W., British Columbia??

[smellzlikefish]

Crowley-Great description! Great whites have arterial beds that lead to their extremities. These beds allow heat to pass from vein to artery and preserve heat gained through their metabolism, and thus operate at a body temperature that is slightly elevated to that of their surrounding water (I believe it is something like 10 degrees warmer or even more!). Most Mackeral Sharks can do this, including the mako, porbeagle, and salmon sharks. This gives them two advantages. First, they can move much faster due to faster chemical reactions. Second, they can operate in much colder waters, which is why most mackeral sharks are found in temperate zones or even colder. I believe makos are the only mackeral sharks that are commonly found in tropical waters. Whites are much more commonly found in temperate zones. Even when they are found in tropical areas such as Hawaii, researchers believe that they probably travel using the deeper cooler waters and ascend only to feed.

 

[Bill Fisher]

I believe that is called "counter current heat exchangers"

...or something similar

 

[RAD Diver]

LIVES4SHARKS,

You have seen many GW's on the East Coast ???
WOW..where did you see them?

There was 1 caught in a fishing net 3 years ago right at the mouth of the Chesapeake Bay, although a juvenile I believe just 6-8 ft long.
2 years ago I was diving the Ocean Venture off the Va. Beach coast & on our 40ft stop we spotted a LARGE Shark in the distance, I thought Thresher at 1st, but the tail was not long enough & another diver says it was a White, from the distance we saw it from, about 60-80ft away it looked every bit 12 ft long which means it was probably bigger.
Part of me wanted it to get closer for a picture op, but a quick glance at my slate & bottom timer showed I still had 40 min of DECO left.:shocked2:
That thought went away quick.

 

[OnceLoyal]

You guys have to rememebr that Great Whites are one of the few sharks that can regulate their own temperature. About 10 years ago one was caught in Tampa, spotted in the Bahamas, and yes they go all the way up with the Orcas.
If I am not mistaken a Bullshark is another one that can also somewhat preserve it's body temp to an extent.

 

[OnceLoyal]

Makos, and salmon sharks can regulate body temps as well, I thought for sure bulls could, but I can't find anything to back up that claim yet. Just incase anyone wanted to know.

 

[welder]

My friemd just got back from his tour of duty as a Salmon / Halibut fishing guide in Queen Charlotte Islands BC Canada and reported to me that they founds hundreds of Blue Sharks in the 10 Ft Range all over the surface congregating in the same area of Salmon Sharks which is uncommon on our coast.

 

[AfterDark]

LIVES4SHARKS,

You have seen many GW's on the East Coast ???
WOW..where did you see them?

I read / heard somewhere that the waters off Cape Cod have the most GW's of anywhere in the world, they are just not as active as they are in other places. Don't know the truth of that but I do know Georges Banks and other places off the east coast are rich in the foods sharks like. Fish! GW's can regulate their body temps more than most other fish. They can be found in very cold water.