Kim Fulton-Bennett: Uncovering the ocean’s deep secrets
Through September 2, Monterey Bay Aquarium and Monterey Bay National Marine Sanctuary host Big Blue Live – an unprecedented series of live natural history broadcasts from PBS and the BBC. Big Blue Live highlights the remarkable marine life that gathers in Monterey Bay each summer, and celebrates an ocean conservation success story of global significance. We’re publishing guest commentaries about conservation efforts that contribute to the health of the bay and our ocean planet. This comes from Kim Fulton-Bennett, who coordinates external communications for the Monterey Bay Aquarium Research Institute.
Lunging humpbacks and frolicking otters are potent symbols of the abundance of marine life in Monterey Bay. But the vast majority of animals in the bay, and in the ocean as a whole, live below the surface. To fully appreciate and protect the wonders of the bay, we need to find ways to map, explore and understand this invisible world.
For almost 30 years, researchers at the Monterey Bay Aquarium Research Institute (MBARI) have explored the depths of the bay using high-tech tools such as robotic submersibles equipped with high-definition video cameras. Over the years we’ve progressed from simply looking around in awe to amassing vast databases of marine observations, conducting complex underwater experiments and documenting threats to deep-sea life.
We still see as-yet-unnamed species almost every time we dive in the bay—a reminder of how little we know about life in the depths. In a 2010 research paper, MBARI biologist Bruce Robison pointed out, “Deep-sea animals probably outnumber all others on Earth, but they are so little known that their biodiversity has yet to be even estimated.” Thus, changes in the numbers and diversity of deep sea animals may already be occurring without our knowledge.
Biodiversity hot spots
MBARI’s research has revealed many previously unknown hot spots of biodiversity in the deep sea. In 2002, MBARI’s robotic vehicle Tiburon first explored the crest of Davidson Seamount, an underwater mountain range about 60 miles off the Big Sur coast. Flying over the rocky seafloor, 4,000 feet below the surface, Tiburon’s video cameras captured stunning images of massive corals growing over nine feet tall.
Over the next 10 years, MBARI conducted additional expeditions to Davidson Seamount in collaboration with the Monterey Bay National Marine Sanctuary. Video and data from these expeditions eventually convinced federal government officials that Davidson Seamount held unique animals and habitats that deserved protection. In 2009, the Sanctuary was expanded to include Davidson Seamount.
After almost 20,000 hours of deep-sea dives, MBARI researchers have compiled a unique database documenting not only deep-sea biodiversity, but also physical conditions in the ocean. By “mining” this database, researchers have made many discoveries, including the fact that oxygen concentrations deep in the bay have been gradually declining over the past 25 years. Scientists are still trying to figure out what this means for animals in the bay. It’s possible that some deep-sea animals could be forced to live closer to the surface, leaving certain depths more sparsely populated.
Tracking deep sea trash
This same database contains records of every piece of human debris and trash that MBARI researchers observed on the seafloor. In a 2013 paper, MBARI researchers used this unique data set to show for the first time where and how much trash was collecting in the depths of Monterey Canyon. This information has helped environmental organizations convince decision-makers and the public to reduce the amount trash that ends up in the ocean.
One of the biggest pieces of debris that MBARI discovered on the seafloor was a shipping container that was lost from a cargo vessel during a storm in February 2004. Using MBARI video, staff from the Sanctuary traced the origin of this container. Fines paid by the shipping company supported additional dives and research that showed how the container is affecting deep-sea animals—the first study of its kind in the world.
A more acidic ocean
MBARI researchers have also been at the forefront of research on ocean acidification, which poses a threat not just to marine animals in Monterey Bay, but around the world. Many researchers have tested the effects of acidified seawater on animals in the laboratory. MBARI’s efforts have focused on the more challenging task of measuring and studying the biological effects of pH shifts on animals in their natural habitat.
In the early 1980s, MBARI marine chemist Peter Brewer was one of the first researchers to suggest that carbon dioxide from human activities was dissolving into the ocean, making it more acidic. Brewer has spent the last 10 years working on automated systems for creating slight changes in the pH of seawater over a small patch of seafloor, superimposed on the natural daily and seasonal pH fluctuations in the surrounding seawater. Experiments based on MBARI’s system have been carried out in the Mediterranean, on the Great Barrier Reef, in Antarctica, and in the deep waters of Monterey Bay.
Because deep-sea animals are seldom seen, it’s easy to think of them as being relatively immune to effects of human activities. In his 2010 paper, Robison noted that overfishing, ocean acidification, and expanding low-oxygen zones in the ocean could potentially wipe out key organisms and cause irreversible changes in deep-sea food webs. Such shifts in deep-sea biodiversity could directly impact marine mammals, human fisheries, or even Earth’s climate. By keeping an eye on the invisible world below the surface, MBARI researchers are providing essential information about the health of Monterey Bay and of the world ocean.
Featured photo of deep sea marine life courtesy Steve Haddock/MBARI