Hidden in plain sight: The giant deep-sea discovery that caught California scientists by surprise

The deep sea is commonly thought to be the ultimate mystery waiting to be explored; it is a place that requires us to go many miles ahead before we discover anything new. However, in some cases, what we do not know is always closest to us; we find answers where least expected to – in those places that we believe we know best. Such was the case for a part of the world near Southern California, which is believed to be one of the best-known marine areas in the world.While doing routine surveys between two very well-known marine protected areas, a research team from the federal government lowered a camera into a very deep underwater valley. They expected to see something very predictable in the way of a dirty and muddy seafloor area. What happened was they came across an enormous, sprawling complex of unusual sponge mounds.Beneath our day-to-day routinesWhy the sudden discovery of these sponge mounds managed to surprise everyone? The answer lies simply in human assumptions. These mounds turned up right in the middle of two very well-known undersea locations called Footprint Ridge and Piggy Bank. Due to years of analysis of these neighbouring areas, no one could ever have imagined anything important lying in between.How the problem of this particular blind spot was discovered is described in detail in an official research report released by NOAA Fisheries titled, Researchers Find Massive Rare Sponge Mounds Hiding in the Deep Sea. The critical breakthrough came when the exploration team realised that deploying a highly sophisticated remotely operated vehicle into deeper waters at around 600 meters below the surface would be essential.This area lies slightly beyond the usual area covered by past explorations. As the remotely controlled vehicle descended towards the seafloor, its lights revealed an alien landscape of giant sponge mounds that seemed more like something straight out of a movie than real life. Clearly, the ocean was not concealing this feature; we were simply failing to look at the right depth levels. The silent graveyards, building a futureAfter the discovery was made, the scientists who worked on the project realised that they were up against a set of truly bizarre environmental paradoxes. The sponge mounds are highly significant ecological structures which have come to be known as rainforests in the deep sea since they serve as shelters and nurseries for hundreds of marine species, such as fish and crabs.The vital role these structures play in the broader ocean ecosystem is explored in an educational study published by the NOAA Office of Ocean Exploration and Research titled Deep-Sea Corals: Rainforests of the Deep. But when scientists steered the robotic camera closer to examine this newly found patch, they noticed something highly unusual. A massive portion of the sponges making up these mounds appeared to be completely dead, leaving behind a sprawling landscape of ghostly white skeletons.Such a strange phenomenon has resulted in a very interesting research topic. Instead of signifying the end of past catastrophes, the layers of skeletons that lie beneath the surface prove to be the secret to the success of the entire mound. The solid skeletons deposited through time by now-extinct sponges work well as sediment catchers and create a good base for further development.The huge discovery in California brings to our attention one of the lessons in modern-day exploration – the fact that declaring an area in the ocean to be mapped in no way means we have understood all of its secrets. As it turned out, a unique and valuable ecosystem can exist unexplored even close to the most active coastline, which shows there is much left to explore on Earth.