Yes dolphins do poop or release feces or excrement depending on how you’d like to phrase it.
As a species dolphins make up about half of the 80 – 90 or so cetaceans that have been recorded so far.
In fact all cetacean species (cetaceans include all species of whale, dolphin and porpoise) release toxic waste from their bodies in one way or another either through vomiting or pooping, however pooping is one of the most common ways to remove toxic waste and non nutrient matter from the body and a common characteristic of all animal species.
The amount of food a dolphin can eat varies with some species consuming between 2% – 10% of their body weight in food on a daily basis.
As dolphins consume fish, squid, octopus, krill, shrimp and other sources of food their body needs to break down the food and separate the nutrients from the waste in order to excrete toxic substances from the body while also allowing their body to receive and absorb the proper nutrients it needs to grow healthy.
At birth baby dolphins consume their mother’s milk which they receive from her nipple for the first 6 months to 2 years or until the baby dolphin is able to hunt, consume solid foods and survive on its own.
Note: Depending on the type of dolphin that is being observed these marine mammals can range anywhere from 4 ft. long and 90 lbs. (maui’s dolphin) up to 30 ft. long and 10 tons or more (the killer whale)!
Once eaten the food that these marine mammals consume makes its way through the dolphin’s digestive system where enzymes and acids break down the food into proteins and sends those nutrients to the correct areas of the body where it can be stored and/or used; the rest of the non nutrient waste goes through the anal tract and is excreted as poop.
When a dolphin poops or releases its excrement the dolphins poop comes out as an almost liquid like form of fecal matter (often in a plum like cloud) which is sometimes light enough to float across the top of the sea water or near its surface.
Dolphin poop is very important for the oceans ecosystem (up to 50% of an animals poop may contain a large amount of energy) and for the healthy growth and production of a variety of organisms such as phytoplankton and/or fish that survive off of eating these organisms.
Studies detailing the effects of how sperm whale poop affects phytoplankton have shown that as phytoplankton grows from the nutrients found in sperm whale poop it pulls more and more carbon from the atmosphere cleaning up the environment and creating a healthier ecosystem for both land and oceanic animals.
While not as much information has been collected regarding the effects of dolphin poop in regards to how it affects the oceans ecosystem there is a good possibility that dolphin poop may serve a similar role/function in maintaining the balance of the oceans ecosystem and aquatic life.
Note: In addition to pooping dolphins are also capable of vomiting and peeing just like most animals.