Here's the solution. Fans can donate money to buy a balloon to be released at the game. For every balloon, a donation is made to the loggerhead turtle foundation for habitat renewal or hatchery/replenishment operations - whatever.
It is a WIN/WIN.
The actual negative (albeit trivial) impact to the environment and wildlife solely from the balloons released at 7 football games per year would be HUGELY offset by the positive impact this money would have (not to mention public opinion).