Here is how to catch copepods:

Sandy beaches work, but the best is mud flats if you have them nearby. Look for "wrack", a term for washed up seaweed if you are unfamiliar. The stuff on mud flats at low tide is the best. It has to be somewhat moist. When you find a good amount, (maybe a storm or high wind earlier in the week), brush your hand through it, when you see things jumping off it congrats you found copepods. Stick the entire bit of wrack in a bucket and pull out the seaweed bits one by one, and give them a brush on the way up, it will get the copepods off. Living by the gulf will give you a lot of good spots, as the wind will bring things in but the waves aren't as bad as what we get on the Atlantic, and there are plenty of mudflats I am sure.

Happy hunting!