Hell
I need an expert. Looking for a movie title from my childhood. 60s or 50s ?Horror/monster movie. It takes place on an island. The island has villagers, a town and a very private research center that is off limits. The research lab is doing cancer research, I think, and their experiments go wrong and that creates creatures that are turtle like with long necks. They latch onto you and suck the life out of you.
At the end, the villagers inject their cattle with strontium 90 and the creatures die after sucking on the cattle.
Then someone says it is a good thing that this happened on an island or the outbreak could not have been contained.
Movie cuts to a Japanese research center, I think, just as the same horrible cancer reseach result is occurring.
Thanks...

You could be talking about "I eat your skin" where a scientist working on a cure for cancer inadvertently creates ZOMBIES not turtles (1961)

If that's not it I don't know what to tell you.

Or "island of terror?" >>> I think there are cattle in that 1.

I'll have to check Island of Terror out.

From IMDB Island of Terror (1966)

Island of Terror is a great little flick produced by Richard Gordon who also gave us the cult favourite "Fiend Without a Face". Directed with the expertise Hammer director Terence Fisher offers, Gordon has produced a similarly obscure "herd" of creatures to terrorize a high-class cast. The 'Silicates' looks rather silly, like huge turtles with a trunk instead of a head with which they grab their victims, and moves around with the speed of a snail. Like zombies, they are not really a threat when spotted coming, but make up for it with their ability to be anywhere you least expect them. (like up in trees, waiting for passers-by, or underneath cars waiting for someone to enter it). This does get a bit, if not more than a bit, corny, but the ever deadly presence of these creatures, and the nasty way of killing (dissolving the bones, and sucking them out of the body) keeps the fun-bad aspect at bay. There are some great attack sequences at different cast members, and some disgusting slurping when they are "devoured".

And turtle things with long trunk necks. I remember the movie you are describing. But I might be confusing the title with another film.

SOLVED... SOLVED

And the winner is... ISLAND OF TERROR

THANKS TO YOU ALL