Why not? Ban fish from unsustainable and environmentally unfriendly sources. 10 million New Yorkers represent enough buying power to marginally change the economic incentives for fishing companies worldwide.
Considering for cities like NY and SF the majority of seafood served is not what is advertised, despite existing legislation to the contrary, I think enforcement is the problem.
I imagine the only substantial course of action would be to ban ocean fishing vessels from the entire coast.
i think banning ocean fishing would be a disaster actually. what we need is responsible fishing with proper management of the fishing nets (i.e. huge penalties for mismanaging/dumping/abandoning the fishing nets)
also the elephant in the room is that an individual in the US has little to no control over huge sources of pollution apart from feel good activism (look at this! i'm using a paper straw! I saved 2 turtles this morning y'all! what? can i drink though the paper straw? naaaw dog - it's mushy after 5 seconds but the turtles)
Plastic straws are such a red herring for climate change. If you want to make an impact on your individual contribution, then you can get an EV (at very least a plug-in hybrid) and (if you own a home) get a solar roof or a heat pump instead of gas (everyone has pretty much replaced their incandescents, which is the cheapest thing to do). The marginal costs of these things are relatively low to neutral (and sometimes can save you money), and all of them have several orders of magnitude bigger impact on climate change than straws.
And it's contagious. Several of my peers (who aren't ultra-green types) bought electric cars or installed solar roofs after I talked about my EVs, and even some of their peers bought electric cars after talking to them. Individual action builds consensus on the importance of political action, too, as it is tangible proof that a transition to a low-carbon economy isn't just possible but attractive.
As far as plastic waste:
We can just replace drink straws with biodegradable plastic of the same performance. Techno solutions work. It's how we fixed ozone depletion.
"US has little to no control over huge sources of pollution"
Not trying to suggest you can create structural change here, but just as a product of being an American consumer you have a larger power to reduce GHG emissions than most of the other 6.6 billion people on the planet.
I don't disagree, but as an individual taking action, it sure feels futile.
On plastic waste specifically, I think there is far more consumer awareness and consciousness than where I am now, Japan. Everything is in bags in bags in bags.
