Be very careful, just because your LFS said you could HAPPILY collect from
your waters, doesn't mean that it is legal to do so. You had better enquire
from your authorities first, It's not legal here in Australia where I am...

Collecting Sea water from the Ocean always has its dangers, just in the last
few days we have heard on our local News that the place where we collect our
water from now has reported cases of Red Spot disease.
About 10% of fish caught there have the disease and I have a feeling this
may have been what killed one of my fish just recently.
So to answer of your question "YES" you can introduce sickness to your
tank..

Cheers
Microbot

"Peter Lee" wrote in message
...
Hi All,

I have recently purchased my first marine tank, 63 gallons give or take,
and
it is about 10 days into its cycle. I live very close to the ocean so it
is
relatively easy for me to hunt around and pick up interesting little
creatures along the water line and in rock pools at low tide.

I asked the chap at the store where I bought my setup and he assured me
that
I could happily collect things like hermit crabs and live rock (from
deeper
water). He also said that I should have no problem using some sea sand I
collect there as a base in the tank.

Is this a safe thing to do? I initially thought that this would introduce
all manor of pathogens, parasites, etc.

If it is safe are there any precautions I should take? I've heard that
starfish can be quite destructive.

Thanks in advance.