SCP-7204 and trainer, prior to her demise during Incident 7204-β.

Item #: SCP-7204
Object Class: Keter
Special Containment Procedures: The aquatic mammal containment tank housing the anomaly must contain no portals through which it could observe any space outside of its tank. The drainage and plumbing systems servicing the tank are to operate independently of all other adjacent infrastructure with pressure monitors being checked once every four hours.
It has been determined that the continued deterioration of SCP-7204's mental faculties presents a danger to those personnel responsible for its care. To maintain its mental health, SCP-7204 is to be placed within a tank containing other non-anomalous dolphins on a bi-weekly basis. During socialization and feeding times, all lighting within the tank is to be dimmed in order to prevent SCP-7204 from making visual contact with Foundation marine biologist personnel.
Description: SCP-7204 is a male adult dolphin, estimated to be approximately fifteen years old. It has a scar on its dorsal fin from a boat strike which took place prior to initial containment.
When placed in an artificial habitat with a drainage system, an anomalous link forms between its blowhole and any drains or other comparable plumbing inside the tank. SCP-7204 is able to forcefully absorb matter within its visual perception field into its blowhole, after which the object will be transported through a spacetime portal before reappearing, miniaturized, inside the drainage system. This effect was originally noted by trainers at the [REDACTED] aquarium, who reported miniaturized versions of missing property appearing in the dolphin tank.
The effect does not apply to everything in SCP-7204's visual perception, it appears to activate randomly or possibly based on SCP-7204's preferences1. Prior to the effect's activation, SCP-7204 will expel water from its blowhole. Objects or persons previously affected by its anomalous effect or which were present in the drain may be launched from SCP-7204's body during these blowhole expulsions.
Foundation assets first became aware of SCP-7204 after four [REDACTED] aquarium trainers were reported as missing persons. Subsequently, biological matter believed to be trace human remains were found inside the dolphin tank drainage filter. Reports to law enforcement authorities alerted local Foundation agents, who secured SCP-7204 after verifying its anomalous properties.

Excerpt from the Police Interview of [REDACTED] aquarium dolphin trainer Willard Stephens

Record of Incident 7204-β Accessed

OFFICER REYNOLDS: Is it normally your job to check the filters?
STEPHENS: No. Allyson did that before she stopped showing up. But I was the only one left who knew how to change a cartridge without contaminating everything.
OFFICER REYNOLDS: You did this alone?
STEPHENS: Yeah, I usually do. I know what I'm doing and I don't appreciate people breathing down my neck who think they know better than I do.
OFFICER REYNOLDS: Let's stay focused. You were changing the filters, it's something you do a lot. What was different this time?
STEPHENS: I used to do freelance work for the school board. It looked like when the girls would flush their used… products, down the drains and get 'em clogged.
OFFICER REYNOLDS: But this wasn't connected to the bathroom plumbing, correct?
STEPHENS: That's when I saw them. I thought maybe they were the toys they sell in the gift shop. Little un-articulated plastic people, like army men wearing the blue wet suits. But these ones all had blood oozing out the mouth and eyes. But they weren't toys. I wish they'd been toys. They weren't toys.
OFFICER REYNOLDS: So what were they?
STEPHENS: Four one-inch corpses. They were stiff and cold and they smelled horrible.
OFFICER REYNOLDS: Are you sure you're not mistaking it, maybe you saw something that smelled like death and imagined something in the moment?
STEPHENS: I could still recognize their faces. I know them, I knew them. Allyson was my friend. Peter, we, everyone pitched in together to buy a cardboard cutout of him when he went on vacation to surprise him with when he came back, because we missed him so much. Gabe, Alex, what's crazier? That they were there, or someone made them again small and put real gore inside.
OFFICER REYNOLDS: You've been through some serious trauma. We can pause for a moment if you need to ground yourself, maybe get a glass of water.
STEPHENS: Yeah, sure.
All subjects involved were amnesticized during the enactment of containment.

Footnotes
1. Further research is necessary to determine whether or not SCP-7204 is capable of consciously creating the portal.