Ark Nova: Marine Worlds, an expansion for Ark Nova, adds multiple new elements to the game, such as sea animals that each have to be played in new special enclosures that must be built adjacent to water.

Roughly half the sea animals are reef dwellers, and whenever you add a reef dweller to your zoo, you will trigger the ability of all reef dwellers in your zoo. In order to deal with the dilution of the deck, naturally caused by adding more cards, all sea cards feature a wave icon, and whenever it is revealed in the display, you will discard the first card in the row, then replenish.

A new fourth university is available on the association board, and if you take it, you will claim one of six special universities from the reserve that feature one research icon and one of six animal icons. When you take this registry, you will reveal cards from the top of the deck and keep the first revealed card with an animal icon that matches your chosen university.

For each of the five action cards, four alternate versions with a little twist will also be available. Players will draft action cards at the start of play, replacing two of their standard action cards with these new ones, increasing the asymmetry in the game.

New bonus tiles and final scoring cards are also included.

Also the expansion will comes with alternate wooden markers for the 3 tracks and cute animals to mark the conservation projects you support instead of using your regular player markers.