The simple answer to your question is No, your parents do not need to know how much you made, as long as you do not claim your own exemption (claim yourself) on the tax return you file. And with $8000 of income, you are required to file a tax return.
But the great American tax system is complicated and convoluted and there may be exceptions. One common exception is if your parents are custodians of a UTMA in your name and that account earned more than $1050 of interest, dividends or capital gains.
