Goofs

Near the end, a beer keg rolls by one female character three times between shots.

When the creatures are attacking the townspeople while celebrating at the Salmon Festival (about 1h 05m into the film), you can hear the screams are being played on a loop at approximately 10 second intervals.

After Johnny Eagle takes the couple back to his cabin to help clean the fish for dinner, it's already dark. When Slattery and crew are coming upriver to his cabin, it's still dusk.

When the Salmon Queen bashes the skull of one of the sea mutants right after her bikini top is yanked off, she ends up fully topless, but in one shot, her 'beauty pageant' sash and her bikini top strap can be seen on her back.

Jerry jumps out of the water to scare Peggy. However, in the very next shot when they're kissing, his hair is nearly dry.

Mispronunciation of the fish name. Coelacanth is pronounced see-la-canth not co-e- lacanth.

The first attack scene on the boat when the winch engine is heard running then runs out of fuel during the conversation with the boy there is no spark plug wire going to the engine's spark plug, so being out of fuel is the least of the problems.

The radio DJ at the festival keeps mispronouncing the word "salmon" with a vocalized L instead of a silent one.

Once the humanoids break through the bottom of the dock, the commotion starts. And the first eight or nine seconds of screaming is "looped" and continually heard throughout the rest of the attack at the carnival.

In the first boat sequence, the winch is supposedly under a lot of strain but all of the lines are loose. They would be tight if the winch motor was working to attempt to pull in the net.

When the humanoid is lying in the road after he fell off the truck's hood, he presumably starts to roll over. But it's just recycled film in reverse from a few seconds earlier.

When Jackie is pulled underwater by a humanoid, you can see that the film was merely run in reverse, (hence the water rolling UP his head) from the first time he emerged after falling in.

When seen from the outside, Linda's pickup truck clearly has a large center section of the windshield cut out for the camera to do interior shots of Linda inside the truck.

As a creature looks into a woman's bathroom window, she comes to open the door. No bathroom should have a door to the outside in a regular house.

Dr. Blake incorrectly pronounces Ceolacanth as "cola-canth", not "seela-canth".