Loosing Oil, Help.

[Anton Faicchio]

I have a Suzuki df70 four stroke 2000. I recently got the upper crankshaft oil seal replaced cause i noticed i was loosing a little oil after i would do a long time or a few. I finally got my engine back and after a few times i notice the oil levels down again from originally being at the second dot on the dipstick to now half. the only visible thing i noticed was oil on this part of the engine (shown in the pic) does anyone know what this is or how to fix