I bought some fishing poles and reels there seriated and in a bag along with tackle box all are sealed in plastic. What is required in order for my friend to take to El Salvador

In checked bag only

According to the TSA - What Can I Bring? website (https://www.tsa.gov/travel/security-screening/whatcanibring/all), fishing poles and small fishing lures are allowed in checked and carry-on luggage. Sharp fishing tackle that may be considered dangerous, such as large fish hooks, should be sheathed, securely wrapped, and packed in your checked bags. Like other high-value objects, you may wish to pack expensive reels or fragile tackle that does not pose a security threat (small flies) in your carry-on bags. Please contact you airline directly to find out their requirements for transporting these items. Every airline has their own rules.

Unfortunately I can't help you there, sorry

Contact the TSA or the airlines directly