The deep sea, despite comprising the largest biome on Earth, remains a frontier defined by its inaccessibility. While coastal surface communities are routinely monitored, the mesopelagic zone is typically studied only through sporadic, resource-intensive ship-based expeditions using nets or ROVs. This logistical disparity creates a significant knowledge gap regarding the high-frequency temporal dynamics of deep-sea biodiversity and its connectivity to the surface. In this presentation, we explore how Environmental DNA (eDNA) metabarcoding can bridge this divide, offering a scalable solution for the simultaneous, weather-independent monitoring of contrasting marine environments. In this presentation we also evaluate an infrastructure-based sampling methodology: the utilization of industrial deep-sea water (DSW) intake pipelines as permanent, terrestrial-based biological observatories.