The inland waters fishing season officially begins Saturday morning. Officials said anglers should watch-out for invasive species, and –if you are 16-years-old or older– make sure you have your fishing license. Muskie anglers will have to wait until muskie season on May 25. More than two million anglers spend about $1.5-million in Wisconsin every year. Twice as many Wisconsin adults fish, compared to the national average. Wisconsin has more than 15,000 lakes and 44,000 miles of flowing streams.