I used to fish there as a kid in the 70's before the Jericho beach pier was repaired. You could only get to it during low tide and had to scramble across rocks and 2 x 4's. Then you had to fish from the skeleton of the old pier.
It used to be amazing. Crabbing was phenomenal, and it wasn't unheard of to get a skate, ling or a salmon. And the flounder...let me tell you about the flounder!
Then in the early 80's, after they repaired the pier, it became a mecca for people who would come down and keep everything they caught. Totally brutal.
They have also closed most of the fishing off the rocks in West Vancouver (lighthouse park, whytecliff, piccadilly place), and I believe the reason is the same. People would leave with everything that they hooked. Completely brutal. It was like watching a drag net fishery operation.
If you want to have some fun catching flounder, go at about an hour before low tide on west Spanish banks and walk out to the navigation markers. A good cast will take you to a drop off point about 5 meters from the marker. Best bait is ghost shrimp dug in the mud flats. Just watch for the incoming tide...
There are also some good beaches to coho fish later in the summer.