CoasTal Ocean Monitoring

​The coastal ocean is one of the most dynamic and ecologically important regions of the world. As the lead institution in the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO), our lab is particularly interested in ocean dynamics in the inner-shelf region of the California Current Large Marine Ecosystem (CCLME). This region extends approximately 5-10 km offshore and is one of the most productive and diverse components of the nearshore ecosystem. It is critical habitat for many marine organisms and is strongly affected by a variety of oceanic processes and human conditions such as winds, currents, upwelling, temperature, phytoplankton blooms, climate change, ocean acidification, hypoxia/anoxia, coastal development, pollution, and commercial and recreational harvesting of marine resources.
​
The overarching goal of our study of the inner-shelf is to increase our understanding of oceanic processes, their linkages to larger-scale processes in the middle, outer shelf, and open ocean, and how these vary through time. To accomplish this goal, we have conducted long term monitoring of oceanic conditions utilizing inner-shelf moorings deployed annually since 1998. Instruments mounted on or near the moorings collect information on temperature, salinity, fluorescence, dissolved oxygen, pH, pCO2, and currents. Two major areas of current interest are ocean acidification and hypoxia, both potentially able to cause dramatic alterations in marine systems, particularly in the coastal ocean of the CCLME.

Ocean Acidification

Historically, the earth’s oceans have absorbed nearly one-third of atmospheric carbon dioxide. However, as global levels of carbon dioxide rise, oceans are becoming increasingly more acidic and the consequences for many important marine species remain uncertain. Research indicates that many species making calcium carbonate hard parts, such as corals, mussels, calcifying algae, and plankton will be negatively impacted. These organisms rely on naturally occurring carbonate ions in ocean water to form protective shells and other hard parts necessary for survival. With increasingly acidified seawater, fewer of these ions are available for organisms because they are diverted to form bicarbonate, as a product of CO2 uptake, instead of calcium carbonate.
Ocean acidification is a global phenomenon, but it can be especially pronounced off the western coast of the United States where upwelling carries acidified, deep ocean waters to the surface. Recent surveys have revealed that pH varies non-linearly in the inner shelf of the CCLME, forming an ocean acidification mosaic. In particular, the coasts of Oregon and northern California are the epicenter of acidified coastal waters, with pH readings in the inner-shelf already reaching levels not expected in the ocean in general until 2100. In partnership with PISCO, our lab utilizes a combination of shipboard water sampling and state-of-the-art moored oceanographic instruments to monitor pH and pCO2, providing insight into the effects of ocean acidification and its long term consequences.

Hypoxia

​Hypoxia refers to conditions in which seawater dissolved oxygen (DO) drops too low to support most marine life. Specifically, hypoxia occurs when DO is less than 1.4 milliliters of oxygen per liter of water (ml/l). Areas affected by hypoxia are commonly referred to as “dead zones” as most of the organisms within them either flee the area or suffocate. In the Pacific Northwest, DO in deep, offshore waters has historically been low (this is termed the oxygen minimum zone or OMZ). In 2002, coastal Oregon experienced severe hypoxia, and event without precedent. Since then, hypoxia and associated inner shelf dead zones have persisted, creating an annual summer hypoxia “season.” The size, severity, and duration of these events have varied from year to year, reaching an extreme anoxic (no oxygen) state in 2006.
Our research on hypoxia and its impacts include extensive shipboard water sampling, the use of moored oceanographic instruments, and collaborations with state, federal, and local partners including the Oregon Department of Fish and Wildlife (ODFW), the National Oceanic and Atmospheric Administration (NOAA), and the Oregon Coastal Ocean Observing System (OrCOOS).