People are curious by nature and drawn to frontier settings. Marco Polo, Davey Crockett, Ernest Shackleton, Jacques Cousteau, and Captain James Kirk are testimony to the human desire to go where no man has gone before. This desire is no different in regards to the deep sea, a place of mystery and isolation. It is, with good reason, often referred to as “inner space.”
We are naturally drawn to the strange and wonderful creatures of the deep sea. We can now view them in ways never before possible thanks to remarkable close-ups, zoomed-in cameras, and telepresence beaming the images to our home computers. Despite this curiosity and technological advances, we still have not seen most of the animals or sampled most of the microbes in the deep ocean. We often do not know where animals live, what they eat, how they reproduce, and their role in greater ocean processes like carbon cycling.
Why might we want to know these things? I would argue that curiosity about the natural world could be most important. But often, there are more applied motivations driving ocean exploration and scientific study. The growing human population has led to greater demand for food, energy, pharmaceuticals, and minerals. As we deplete these resources on land, we have sought them in the ocean and, in recent decades, in the deep ocean. The continued discovery of novel biodiversity in the deep ocean is often accompanied by discovering new resources – the push to extract these is termed the ‘blue economy.’ Technology has enabled us to fish deeper, drill for oil and gas deeper, discover new marine genetic resources, and probe deep seabed minerals. Although there is no place we cannot reach, when we extract resources without careful study, we risk damaging or destroying life before we have discovered it. At the same time, we are intentionally and unintentionally introducing new chemicals and materials into the water – contaminants, debris, and plastics. These end up in deep water, but with unknown consequences.
The deep sea has the potential to offer us new sources of food, cures for diseases, climate solutions (e.g. enzymes that can remove carbon dioxide), novel sources of energy, and more.
But we need to find a way to take advantage of this potential without disrupting the important services that the ocean provides – absorption of carbon and heat from the atmosphere, productivity, and fisheries. To be responsible caretakers of our planet, we need to understand what lives in the deep ocean and how deep-sea ecosystems function.
The research planned for this expedition to mineral-rich settings in the deep waters off southern California is a small step on this road to deep ocean sustainability. So too is our plan to study the influence of DDT on microbes and animals, spread from barrels deposited in deep waters off Los Angeles. We hope to learn what animals and microbes live on or avoid phosphorites and Fe-Mn crusts that form on the banks, seamounts, and ridges at 100-2000 m and how they are affected by low-oxygen waters. Although deep seabed mining is not currently an issue in southern California, phosphorites are increasingly being targeted for fertilizer and the Fe-Mn crusts for rare earth and other elements elsewhere in the world. Our studies of animal and microbial biodiversity associated with these resources should help inform society’s management and decision-making in the deep ocean.
