~diving birds are often indicators of baitfish~

Bay Anchovies: Also known as 'Glass Minnows' are the only saltwater species of minnows that remain in local waters year round. Schools of glass minnows from barely visable up to 3 inches or more can be seen around most pilings and other structure. Very small mesh nets are required to capture glass minnow in mass. Snatch rigs work well with sizable minnows... Glass minnows do not survive well in bait keepers,. to fish with 'hot' baits it is best to use freshly snagged or netted baits. (more)

 

White Bait: The common name for 'Scaled Sardines' (pilchards) white bait is available from the smallest 'Fry' to the giant 'Horse Minnows' and everything in between, whenever the water temp. is 68 degrees and above. ( more) Can be found in all inshore waters and along beaches.
Castnet mesh size will determine the minimum size baits (choose your nets wisely and return unwanted sized bait unharmed)...Chumming works well to herd up white bait for netting and jigging...All sized white baits can be caught or snagged with standard bait rigs or manufactured types (Sabiki etc.) minnow rings can also be used to catch white bait.

Threadfins are very similar to the scaled sardines only their coloration is greener and they have a distinct feather trailing the dorsal fin... threadfins of all sizes can be caught the same way as scaled sardines...