The "Sea of Crabs" is the nickname for the eighth level in the Ecco 2 Alpha which, as the moniker suggests, is saturated with crabs. Tethercrabs and Crabsnakes, along with Crabworms abound. A baby Orca as well as an adult Orca also reside in the level. This adult Orca shows an early version of the death of the Asterite, the queen using star-shaped projectiles instead of the inverted red boomerang-shaped pulses in the final version of the game.
This level was a testbed for Vortex Future enemis such as the Vortex Snake or the Vortex Dragon.
The Sea of Crabs has lots of Crabsnakes.
Tethercrabs, there be many.