A great Kiwi pastime. I’ve taken my youngster to the very popular wharf at Mangonui, up north, Orakei in Auckland, and Kauri Pt in Tauranga, and he had a great time. I put him in a life jacket which I think is a good idea if the current is strong.

You haven't said where you live, but assuming North Island, you can expect anything from kingfish to 'sprats'. Most wharves have good populations of baitfish such as piper, yellow-eyed mullet (sprats), jack mackerel (yellow tail). Next most likely fish is a kahawai of various sizes (no size limit), and under-sized (less than 30cm in the northern region) snapper. In some areas, john dory hang around, but you're unlikely to get one on bait unless it's a live bait. Sometimes you'll get 'spotties' or similar fish which hang about the wharf piles. Most people return them. 

From time to time, kingies will do a lightning raid, and all hell breaks loose! Houhora and Mangonui are famous for them, ditto Kauri Pt. When we were at Orakei, something big snapped off our sabiki, possibly a big kahawai grabbed a hooked and struggling mackerel.

If you want to use a fish for a live bait, it must be legal catch. You can't use a baby snapper on a hook for a john dory, for example.

My biggest tip is to use suitable gear for the type of fishing you want to do - usually, for small fish catching at a wharf, that means light line, small hooks, bait that stays on the hook etc.

I get frustrated when I see parents taking their kids out to a wharf trying to catch sprats and mackerel etc with overhead boat reels, 50lb trace and 7/0 hooks, and a bit of last night’s ham for bait. A recipe for disappointment and a real shame.

Yes, if your line has been left in the sun or is showing signs of wear, cut off some from the end. Make sure your reels are working well, and hooks are sharp etc.

Using lures typically involves a lot of casting, and potential line tangles, so I wouldn't make that my first choice for the kids. A light spin reel with a half sabiki rig, sweetened with a little bit of bait, is likely to result in some nice catches of mackerel or yellow eyed mullet. At Mangonui kids get legal snapper on them too.

Piper are suckers for a tiny bait hung below a float. I've had good success on little balls of dough mixed with flour and the juice from a can of tuna. Try to let the float drift out a bit, as piper can be shy. If they are around, there's likely to be a skilled Asian fisho making the most of their presence with specialist gear. Watch what they do.

A berley bag/basket is often a great idea to keep fish swarming in your spot.

Try to fish at the best times of day - change of light, and when the tide is running. That’s more likely to result in success.

Depending on the wharf, casting away from it can be a detriment because fish are attracted to the structure for shelter and food. That in turn attracts the predators. Dropping a bait directly under the wharf is often more productive than casting for the horizon. Usually, just letting the bait disappear out of sight is a good start for mackerel, rather than dropping it to the bottom.

Although, if you can cast to a channel from a wharf that is sitting in shallower water, it is also productive to cast out.

Try to fish on the down current side, so your lines aren’t disappearing under the wharf.

If you think larger kahawai and keeper snapper are a prospect (which is likely on many of our wharves), use some of the fresh mackerel or other decent bait, and use comparatively heavier gear.

Take a chilly bin with some ice bottles for looking after your catch, sufficient rags to keep hands clean, something to sit on, and plenty of sustenance (for the kids as well!!).

It’s a great opportunity to teach kids about respect for under-sized fish, how to look after them before returning to the water (not leaving them flapping about on a hot concrete wharf), how to respect rays or other ‘rubbish’ fish you catch etc. And for teaching them the right thing to do with rubbish. 

Have fun.