The singer, 40, posted a photo on social media that features the star fishing plastic out of the Tyrrhenian Sea off the island of Capri.
Wearing a yellow bikini, the "Masked Singer" judge used a long pole to gather plastic garbage that was floating near her boat.
Along with the photos, Scherzinger told her 3.8 million followers: "In America alone we throw away 100 BILLION plastic bags each year! It only takes 1 to kill an endangered sea turtle that has confused it for a jellyfish to eat."
"There are tons of ways to get involved and support cleaning up our oceans - local charities where you live, like @sustainablecoastlineshawaii in my native Hawaii through to global campaigns with @wwf, @skyoceanrescue & @leonardodicapriofdn!" she added.
"You don’t need plastic bags, straws and water bottles. Save our stunning oceans! 'The world is changed by your example, not your opinion.'"
Scherzinger has been on vacation for the last week and also sent an inspiring message to her fans about body image.
"Another year around the sun is approaching and I share these pictures in grace, gratitude and voluptuous celebration!" she wrote.
"I have struggled with my weight and image my whole life and I still do, but I’m just realizing as the moons go by to take it easier on myself. Life is too short. We spend too much time beating ourselves down as opposed to talking ourselves up," the former "X-Factor" judge continued.
"I realized I’m too grown up and need to not to be so hard on myself, I have to choose to embrace me and my body through all of its stages and seasons! This season I’m grateful for the body I’ve worked so hard for in the gym. Now I am rewarding myself by eating my weight in pasta here in one of my favorite places."
Scherzinger regularly posts videos of her grueling workouts which include lots of squats, machine work, and cardio.