This is the first episode with Rocky's tugboat to be aired in the United States. The first episode with it ("Pups Save a Stinky Flower") had only been shown in Canada at the time "Merpups Save the Turbots" premiered in the U.S.
Marshall came the closest to his demise (after being accidentally sucked into the sea slug's mouth during its sleep, he was exhaled in a bubble to safety).
During the first few scenes, a direct flashback to "Pups Save a Mer-Pup" can be seen. This is the second time in the series a previous scene is replayed, after "Pups in a Fix".
Since Marshall was absent for the elevator sequence, Rubble wiped out with the pups instead.