The photo received a lot of backlash, with Instagram users writing things like, "those animals are being enslaved for your entertainment, just saying @brielarson," "dolphin shows are torture. I hope you never support this again, Brie," and "don't support dolphins in captivity please, it's just like #Roomthemovie but for dolphins. You better than that guuuuuurl."
The 26-year-old actress then shared a makeup-free selfie, accompanied with a lengthy message apologizing for her actions.
"Yo - it's me again. I posted a photo previously that encapsulated a silly moment in my weird life," Larson wrote. "I forgot that through social media and random interviews you do not know all the facets of me and what my concerns are. We should be concerned about the well being of all animals. Yes, Dolphins. Along with every other creature."
"There are problems with animals in captivity," she continued. "There are problems with animals living in the wild. It has always been a priority of mine to speak for those who cannot speak for themselves. I apologize if the photo appeared to endorse animal cruelty. I don't believe any living thing deserves miss treatment."
"In the comments section feel free to discuss your thoughts, concerns, articles ANYTHING that can turn this into a moment of education for myself all who are interested," she concluded. "We gotta remember that we will make mistakes but we can learn from them, together. Much love."
According to the World Animal Protection website, "dolphins are perfectly evolved to live and flourish in their wild ocean home, not within the confines of a human-made concrete tank or artificial lagoon. Statistics of dolphin deaths during capture and confinement prove that dolphins do not belong in captivity. Wild dolphins can swim more than 40 miles a day -- they engage in mating, foraging, fighting and play behavior with their pod members: and they use their echolocation to explore their diverse ocean environment."
The site also states that in contrast, "captive dolphins are forced to swim in endless circles in artificial habitats, interact with unfamiliar dolphins and other species and perform behaviors that are unnatural and in some cases painful. Captive dolphins also face exposure to human infection, bacteria and chemicals and suffer from stress-related illnesses."
In happier news, Larson is officially joining the Marvel Universe -- she's set to star as female heroine Captain Marvel in the superhero flick of the same name.
ET caught up with Ant-Man star Paul Rudd last month, where he had nothing but good things to say about Larson's exciting new gig and welcoming her into the Avengers family. Watch the video below to hear more!