I'm not seeing any mention of the drastically lower tourism for 2020/21 due to Covid. Is there any hypothesis for how this might effect things? Sunscreen? Boat

I'm not seeing any mention of the drastically lower tourism for 2020/21 due to Covid. Is there any hypothesis for how this might effect things? Sunscreen? Boat emissions? They mention the tourism drives a ton of dollars, but it also has to drive a ton of contaminants. Does anyone see any explanation beyond just weather?