A trio of changes in ocean conditions coupled to climate change, ocean warming, ocean acidification, and declining oxygen levels in deep waters, are affecting marine organisms from the surface to the seafloor. Although action to reduce fossil fuel emissions has increased, emissions are rising and atmospheric CO2 levels are far beyond the range of variation known to occur for millions of years. Climate-related changes occur first in surface waters, and then slowly penetrate to deep ocean depths, where animals may already be ‘living on the edge’ due to cold, low oxygen conditions, and limited food availability. We are using field and laboratory studies to assess the response of marine animals to changes in ocean conditions linked to climate change, particularly ocean warming, ocean acidification, and declining oxygen levels in deep ocean waters.

To assess species responses to ocean change, we perform experiments exposing animals to expected future conditions. In the laboratory, we’ve developed an “Upwelling Simulator” that controls the temperature, oxygen levels, and acidity of waters fed to experimental aquaria. We can mimic the sort of environmental variation that nearshore animals off California experience naturally, and under more severe future conditions, and measure how it affects the reproduction, growth, and survival of organisms (e.g., black abalone).

For our deep-sea studies, we are using a robotic metabolism study system (Benthic respiration system – BRS) to measure the metabolism of deep-sea animals (snails, corals, urchins). We deploy the BRS over the side of the ship and it sinks to the seabed where we use a remotely operated vehicle to place individual organisms in up to eight small metabolic chambers that measure rates of oxygen consumption under current deep-sea conditions. Waters simulating future conditions (e.g., lower oxygen, more acidic) are then injected into chambers to detect species’ responses to ocean change. Together, these laboratory and field studies will advance our understanding of the sensitivities of key marine organisms to changing ocean conditions.