For years the herring were hammered by commercial and recreational fisheries, to the point it is illegal to harvest or use for bait these herring. One problem that I have come to learn is that river herring swim in the ocean with ocean herring and have been decimated through by-catch. For years strong spawning grounds had been destroyed by the building of dams, which blocked the fishes full migration. River like the Raritan have seen key dams being removed, or along the shore like Wreck Pond, fish passages or ladders have been constructed.
Herring have been mainstay in peoples, and predators, diet throughout the last centuries. Herring smoked, stewed, pickled, broiled, steamed air fried. They also have been harvested for use as bait
for lobster and other crustaceans, as well as for fish like striped bass. I have seen anglers using sabiki rigs on the Delaware at Trenton before that fishery was shut down in 2013. The bots would be lined up along the channel and it was a quick drop down, reel up a few, then live line them, and then reel in a large striped bass. I looked into the NJ Fish and Wildlife river herring surveys. The last I found was in 2017 where gill and seine net sampling occurred. Between the overfishing and floods and droughts the numbers have been just about decimated.
one below looks pretty big. Alewives are also broader built, while the bluebacks a little stealthier, like the one above. What is known is that alewives like to spawn in slow moving water at night and the bluebacks over faster rocky structure during the day, so they are active around the clock, perfect for the nocturnal striped bass. In doing some digging around ;looking for good patterns I found Ian Devlin's tie. He's another mad scientist. He is from Connecticut and if you ever want to talk fly rods, lines or skiffs, he's your go to guy. Like Steve Farrar, Ian also has a live of blends, called Devlin Blends. He has developed a pattern he likes for matching the herring. Like most big flies, its a mix of Hollow, and something, and his, and hers, and whoever. But what I like is the tail, and if you look at the link