I'm sorry but I have to agree with Rowdy. Since I do receive a couple of 1099's which show the US Government I am having taxable income and I have to report these amounts every year---then you can show how you offset this income by the expenses you incur to receive that money.
Now, I only account for the tournaments I actually get a 1099 form. Most tourneys don't even report your income, but if you fish BFL/FLW's and or B.A.S.S events or even Renegade Circuit, you will get a 1099 and you have to report this at tax time. So like any other place you make an income, you can show your expenses to get that income.
To each his own.