Deep-sea sponges, particularly the species _Calyx_, inhabit the dark depths of the ocean, forming vast ecosystems that are crucial for marine biodiversity. These sponges utilize unique survival strategies, relying on symbiotic microorganisms to thrive in an environment devoid of sunlight. A recent study published in the journal Microbiome reveals that about 16% of the microbial partners in these sponges engage in chemosynthesis, using ammonia as an energy source to convert carbon dioxide into biomass. The remaining 84% of microbes are heterotrophic, consuming organic matter, which is scarce in the deep sea. These microbes possess specialized enzymes that allow them to break down complex organic compounds, providing essential nutrients to their sponge hosts. Despite their ecological importance, deep-sea sponge gardens are under threat from human activities such as trawling and mining, which can devastate these habitats. The United Nations has recognized these ecosystems as vulnerable, highlighting the need for conservation efforts to protect them before their roles in the carbon cycle are fully understood.