As a lifetime resident of Lake Tarpon I have seen a lot of changes to th elake since the mid 70's. It's always been a real finicky lake and with temperatures rising, we all know the jet skiers and water skiers will be out in force making for an even tougher bite.
Unless you absolutely have to fish during the day, the lake sports a very good evening, and night bite that makes a world of difference from the lake in the day time. A night trip to the lake will also better than average chances for a double digit fish. Leave the spinning gear at home if you venture out at night because the menu should consist of 7.5" to 12" worms in black/blue, Tequila Sunrise, or flat black. Another great night time lure is a heavy buzz bait with a black painted blade and matching skirt. I have caught a lot of 5+ lb'ers on this bait and have one 10.8lb'er on the bait in the sparse cattails located on the eastern side of the lake.
During this time of the year you can try the many main lake points for flipping reeds, tules, and working eel grass. If you have nothing against live bait fishing you'll find fish anywhere there may be eel grass. In the north end of the lake you will find eel grass in as deep as 7' of water, all the way up to the 2' shallows. For the most part the spawn is but a memory, but the fish are hanging around shallow to bust tilapia and bluegill, who are making their way onto beds.
Lake Tarpon is also a noteworthy crappie (speckled perch) fishery with a lot of fish in the 1-2lb range. Drifting open water with white Hal-Flies, Beetle Spins, or live minnows are the ticket.
Average depth of the lake is about 11' deep with a couple holes around 14-16' range. Also, the lake has a few good main lake points that are good places to work with Texas rigged worms and shallow running crankbaits.