Why are shells on the West coast thicker than shells on the East coast?

Question

A friend told me that this is the case, and I was wondering why it is. I know that temperatures fluxuate more in on the East coast, but I dont know how this effects shell formation. Thanks!

Answer 1

Are you sure your friend didn't misinform you? Shells do tend to get thicker and more spiny as you go north to south, due to resource availability and increased predation. However, I've never heard anything about thicker shells on the west coast.

If they are thicker, though, it;d probably be due to:
1. higher predation levels on the west coast driving speciation
2. more upwelling on the west coast due to the narrower continental shelf generating a higher nutrient flux, and allowing quicker and thicker shell formation
3. warmer overall temperatures on the west coast, which if this is the case, would allow the waters to carry more dissolved CaCO3 which could be secreted as shell material.
4. different, thicker shelled species present on the west coast

Those are the best four reasons I could think of to explain this phenomenon, if it is true!

Answer 2

There is more salt content in the pacific ocean than there is in the Atlantic ocean. This causes the shell developement process to produce a thicker shell.

Answer 3

I don't know.