It’s your turn, you place a paper with a word on your forehead and people start yelling clues for you to guess: “Ketchup bottle! Your glasses! Glitter! Legos! Tea bags! But then the clues take a turn: “Gets stuck in trees! Floats in the ocean! Lies in gutters!” Realization hits and you yell “Plastic!” Plastic, a global riddle that inundates our daily lives yet also is the source of a growing waste and pollution crisis. Single-use plastic packaging and containers generate 300 million tons of plastic waste each year and between 4.8 to 12.7 million tons of it leaks into the ocean annually, from a variety of land-based sources like stormwater runoff, construction sites, and poor waste management systems. Moreover, nearly invisible pollution from plastic-derived chemicals and microplastics are also on the rise in the oceans. These plastics end up in the guts of birds, oysters, and fish, and entangle sealife, posing a threat to the health of ocean ecosystems, food security, and the planet.

Picture this: It’s a warm, spring day in May 2021. You are at a local seafood restaurant overlooking the Chesapeake Bay and your order of raw oysters arrives delicately placed on a layer of ice. Your waiter reviews the type of oysters you ordered. He says, “Running clockwise, you have Pemaquid, Blue Point, and PEI.” Before the waiter steps away, he asks, “Would you like extra microplastics added to your oysters?” Dumbfounded, you reply, “Extra?”

This Twilight Zone-like scenario is not totally fictional. Oysters are a keystone species in the environment, meaning they are the backbone of ecosystems. They are heroes in a small shell. In addition to where they sit on the food chain, oysters can filter up to 50 gallons of water per day, cleaning the surrounding water of chemicals and pollutants. However, this means they inevitably suck up more than they bargained for. Scientists have discovered that oysters contain microplastics, plastic pieces that measure less than 5 mm in size in one dimension (similar to the size of a sesame seed). Oysters suck in microplastics and, sometimes, they never pass them out.

Marmite, a popular food spread developed from yeast at the Burton on Trent brewery in west-central England, is a by-product of brewing beer. The sticky brown food paste adopted the marketing slogan “love it or hate it,” hinting that its strong flavor is an acquired taste. For centuries, Burton on Trent brewed beer, but it has now gained another valuable brewing by-product in addition to Marmite—methane biogas. In 2008, the brewery built an anaerobic digester that converts the beer waste to methane, which is then burned to heat boilers to make beer.