Credits to Vast @ Arlong Park forums
Yeah, it's their position in the crew. From right to left:
-Doctor (医者)
-Cook (コック)
-Poet (詩人) and Musician (音楽家)
-Navigator (航海士)
-Vice-captain (副船長) and Sniper (ソゲキ手)
-Captain (船長)
-Probably Helmsman?, I'm not sure, it doesn't say 操舵手, which is what Jimbei was called in chapter 976. But it could be another word for helmsman, maybe かじとり?
-Fighter (戦闘員)
-Something about plants? (植物----) (headband guy)
-Shipwright (船大工) (small guy)
Also, for some reason it says "Bolero" (ボレロ) in the bottom left corner.
Credits to Solid @ Arlong Park forums
"Bolero refers to two distinct genres of slow-tempo Latin music and their associated dances."
and we know Oda is a fan of Buena Vista Social Club.