CHARLESTON, S.C. (AP) — Two underwater robots will check the water off Myrtle Beach later this week, investigating a big flounder catch along the South Carolina coast several years ago.

Something caused a low level of dissolved oxygen in the water in 2004, resulting in a big catch.

The robots are to be launched Wednesday as part of a program of the South Carolina Sea Grant Consortium.

One will collect information such as dissolved oxygen and temperatures offshore down to more than 300 feet. The other will check the nearshore waters, down to about 66 feet.

The idea is to be able to forecast low oxygen events which could help fishermen.