A Preliminary View of the 2016 NOAA West Coast Ocean Acidification Cruise Results

Introduction

The NOAA Ocean Acidification Program (OAP) West Coast Cruise was conducted in the coastal waters of Baja California, California, Oregon, Washington, and British Columbia during the spring of 2016 (5 May – 7 June; Figure 1). The oceanographic conditions during this cruise varied significantly from those observed in this region during our last NOAA ocean acidification cruise in the summer of 2013 (Figure 2). Starting in late 2013, open-ocean surface waters in the northeast Pacific began to warm up by as much as 2–3 °C above normal due to the lack of strong storms and subsequent cooling. This warm pool, commonly known as “the Blob,” lasted throughout all of 2015 and into early 2016. Within the “Blob” pCO2 values were generally about 40–50 µatm higher than normal. In the coastal region, the surface SST values were generally lower in the latter half of 2013 and early 2014 due to coastal upwelling but that changed in the late summer and fall of 2014 when the coastal waters also had anomalously high SST values because the Blob moved ashore. By spring of 2016, the large SST anomalies had dissipated but the surface waters generally remain warmer than normal by 1–2°C (Figure 3).

Figure1
Figure 1. Locations of transect lines and stations of the  2016 NOAA West Coast Ocean Acidification Cruise along the west coast of North America (5 May – 7 June 2016).

Also occurring during the 2015–16 timeframe was a very strong El Niño in the tropical Pacific that caused warm waters to propagate northward along the coasts of Central America and Mexico. These two oceanographic phenomena led to lower overall productivity of phytoplankton and zooplankton and increases in numbers of warm-water zooplankton species relative to cold-water species. Coupled with the ever-increasing acidification due to anthropogenic CO2 emissions, the region was under the strong influence of the combined stressors of warming and acidification. Our present cruise will address how these new conditions affect the distribution and health of a variety of marine species that are known to be sensitive to these combined stressors.

Figure2
Figure 2. Contoured regional image of blended 5 km sea surface temperature (SST) analysis, May 30, 2016.  From NOAA Office of Satellite and Product Operations, National Environmental, Satellite, Data, and Information Service (OSPO/NESDIS): http://www.ospo.noaa.gov/data/sst/contour/uspacifi.c.gif


Baja California

The 2016 OAP West Coast Ocean Acidification cruise began in the warm, salty waters of Baja California near Laguna San Ignacio. The SST data products derived from the NESDIS contoured regional image of blended 5 km sea surface temperature fields yielded high temperature (14–20° C) water throughout the coastal region with salinities >34.5. These waters have an Equatorial Pacific origin and show evidence for upwelling in the northern part of the region south of Punta Baja (Figures 2 and 3). Relatively warm, saline, low oxygen water, characteristic of the poleward-flowing undercurrent, was found over the upper continental slope (200–350 m depth). The signature of undercurrent water dissipated to the north, and was not apparent north of the Southern California Bight. Corrosive waters (Ωar <1.0) were generally found below 80 m in this region, which was deeper than observed in 2007. This may be due, in part, to the impact of the recent strong El Niño in the tropical Pacific. When upwelling occurs, it is usually upwelling of waters with Ωar > 1.0 (Figure 5). However, these low saturation state waters would be within the range that would affect calcification in several species of bivalves and pteropods. The pteropods we found living there were exclusively the warm-water species.

Figure3
Figure 3. Maps of AVHHR Daily Optimum Interpolation SST anomalies fields for A) Lines 1 through 9 of Mexico and California, May 21, 2016, and B) Lines 10 through 16 off Oregon, Washington, and British Columbia, May 26, 2016 (Images provided by Charles Kovach, from https://coastwatch.pfeg.noaa.gov/erddap/griddap/).


California

In the California region (lines 4 thru 9), near-surface waters were comprised of both Equatorial Water and Pacific Subarctic Water (Figure 4). Upper slope waters off southern California showed a relatively weak influence of Pacific Equatorial Water that diminished to the north. There were large east-west gradients in SST due to upwelling along the coast, particularly along northern California. Corrosive waters off California were shallower than 75 m in all near-shore waters north of Monterey Bay. However, corrosive, low pH waters (Ωar < 0.9; pH < 7.7) reached the surface at the innermost station of line 7 near the entrance to San Francisco Bay due to strong winds favorable to upwelling at the time of sampling (Figures 5 and 6). Elsewhere on line 7 surface pH values were generally < 8.0.

Figure4
Figure 4. Potential temperature (θ)-salinity diagram comparing data from 2007 (gray dots) and from 2016 (dots colored by sampling lint).  A general freshening of waters occurs from south to north.  Contours of density (black) and spice (gray) are included.  Labels indicate nominal water masses in the region including Pacific Equatorial Water (PEW), Pacific Deep Water (PDW), and Pacific Subarctic Water (PSW).

 

Figure5
Figure 5. Preliminary maps of a) surface aragonite saturation; and b) surface pH for lines 1 through 10 along the west coast of North America from Baja California to Heceta Bank.

This is the first time we observed corrosive waters at the surface this far south on our OAP cruises. These results suggest that many species of calcifying organisms, such as oysters, clams, scallops, pteropods, crabs, and mussels may be experiencing significant stress due to the combined effects of warming and acidification. Zooplankton species were generally small and, in most cases, the cold-water pteropod species, Limacina helicina, was absent on these transect lines.

Figure6
Figure 6. Vertical sections of a) aragonite saturation, and b) in-situ pH along the line 7 transect off Pt. Reyes seaward of San Francisco Bay.  Note the innermost station indicates upwelling of corrosive water all the way to the surface.


Oregon

In the Oregon region, surface waters were generally warmer and fresher than normal, with a strong influence of the Columbia River plume over the outer shelf and slope. The river flows outward into the coastal region as a surface plume that is a source of corrosive waters affecting marine organisms that live in the upper reaches of the water column. It also acts as a stratification barrier for the upward movement of the denser CO2-rich upwelled water from below. In late spring and early summer, the Columbia River plume waters are at their maximum volume and flow southward along the mid- to outer-shelf region, forced by local winds from the northwest. In the wintertime, the plume flows northward toward the Strait of Juan de Fuca under the influence of winds from the south.

Figure7
Figure 7. Vertical sections of a) aragonite saturation, and b) in-situ pH along the line 12 transect seaward of the mouth of the Columbia River.  Note that the innermost two stations indicate the outflow of corrosive waters from the Columbia River.

The upper extent of the upwelled, corrosive waters along the Oregon Coast was generally within 20-40 m of the surface near the coast and at depths ranging from 50 to 130 m offshore (Figure 7). Cold-water zooplankton species were found to be significantly more abundant in this region than off the California coast. We collected enough cold-water pteropod samples from this region to conduct experiments onboard the ship and provide samples for future laboratory studies of dissolution and genomics. Copepod samples (Calanus sp. and Eucalanus bungii) were also collected and frozen for further analyses measuring gene expression and biomarkers of oxidative stress.

Pseudo-nitzschia cells were abundant in Columbia River plume water over Heceta Bank. Cell morphology indicated a different species than that seen in California waters with the Oregon samples having a dominance of the P. multiseries/P. pungens type species. At present, it is unclear if this species originated from the north and was advected south in the plume, or if a localized bloom in the Heceta Bank region (a documented source of Pseudo-nitzschia blooms) was mixed into plume water. Concentrations of the neurotoxin, domoic acid, produced by Pseudo-nitzschia species were measurable but lower than the Monterey Bay samples. Experimental studies onboard the ship will determine how key environmental factors such as temperature, salinity, and pH control the production and concentrations of domoic acid under high-CO2 conditions. Offshore of the Columbia River is a region of high productivity in surface waters and high respiration rates at depth. The near-bottom waters have very low oxygen, and as a result, some of the bottom waters are hypoxic and have very low pH and aragonite saturation state conditions.

Washington

The surface waters off the Washington coast ranged from about 12 to 14°C (Figure 2). Temperatures were slightly higher than the average to the south and slightly lower than average in the near-coastal waters to the north (Figure 3).

There appeared to be moderate upwelling in the Juan de Fuca Eddy region where there are higher levels of chlorophyll in the surface waters (Figure 8). Carbonate chemistry data indicate low aragonite saturation state and pH values near the Strait of Juan de Fuca, with corrosive waters found as shallow as 10 m (pH < 7.8). Zooplankton species and crab larvae abundances were high in this region as large numbers of pteropods, copepods, and euphausiids were found in all net tows.

Crab larvae were highly abundant in the near-shore surface net tows. Sampling was conducted in close proximity to an in situ robotic early warning monitor for Pseudo-nitzschia species and domoic acid, providing an opportunity for analysis comparison with and context for observations by the robot. Pseudo-nitzschia species were observed in the majority of samples from the Washington coast. Relative concentrations were low in all samples with the exception of the Juan de Fuca Eddy region off northern Washington and southern Vancouver Island. The highest concentrations of cells recorded on the cruise to date were seen in the eddy samples, and the assemblage was dominated by the small-sized species of Pseudo-nitzschia. Domoic acid concentrations at the eddy site were low however, indicating the species present at the time were not producing high amounts of the neurotoxin.

Figure8.png
Figure 8. Chlorophyll concentration composite satellite image for month of May 2016 from the SNPP-VIIRS courtesy of NOAA/STAR Ocean Color team.  For interactive display of data, click here.


British Columbia

Sampling on the British Columbia continental margin consisted of two survey lines extending southwest from Vancouver Island (in collaboration with the Department of Fisheries and Oceans, Canada) and from the mainland through Queen Charlotte Sound (Figure 1). In addition to the sample lines, near-shore stations were occupied off Calvert Island (in conjunction with the Hakai Institute), in Queen Charlotte Strait, Johnstone Strait, and in the Strait of Georgia. Stations 144 and 149 were co-occupied with Hakai Institute research vessels as part of a cross-institution data inter-comparison study. Over the entire British Columbia region surveyed, surface waters exhibited evidence of strong biological activity. Satellite surface chlorophyll retrievals showed high concentrations in excess of 15 mg m-3 along both survey lines and in the Strait of Georgia (Figure 8). SSTs generally ranged from 11 to 13°C (Figure 2), which is close to normal for this time of year. Surface water pH values averaged about 8.1, and the corrosive waters were generally deeper than 100 m in Queen Charlotte Sound. Cooler surface water with high pCO2 was observed in Johnstone Strait. Warmer waters were observed inside the Strait of Georgia, presumably due to the influence of the Fraser River and other local river outflow. Saturation states were higher than those observed during the previous OAP cruise in 2013 throughout the water column on most stations, presumably due to a combination of higher water temperatures and strong primary productivity. Surface expressions of undersaturated water with respect to aragonite only occurred in Johnstone Strait due to the intense mixing there. Zooplankton species and crab larvae abundances were high in this region, as large numbers of pteropods, copepods, euphausiids, and crab larvae were found in the all of the net tows. Low concentrations of Pseudo-nitzschia and domoic acid were observed in British Columbia waters, however, the harmful algal bloom species Alexandrium, was observed in relatively high numbers on the northernmost transect.

Summary and Some Initial Scientific Perspectives

The 2016 West Coast Ocean Acidification cruise was designed from the beginning to integrate physical, chemical, and biological studies of the California Current Large Marine Ecosystem at a time when the ecosystem was responding to rapid change. The remnants of the warm “Blob” and the most recent El Niño yielded higher than normal surface and subsurface temperatures that had a significant impact on the chemistry and biology of the region, with elevated pCO2 levels and cold-water zooplankton species being significantly more abundant in the northern parts of the study area as compared with stations further to the south. Experiments conducted onboard the ship were developed to determine how these combined stressors of increased temperatures and increased CO2 levels affect the immediate responses of the organisms. Further studies in our shore-based laboratories will assess other molecular and genomic responses of these same organisms. The results of this particular field study will be integrated with other ongoing field, laboratory, and modeling studies and satellite observations for the region to provide a better understanding of the relative sensitivity of the marine ecosystem to these natural and anthropogenic stressors.

From a scientific perspective, the cruise demonstrated how natural variability, climate change and ocean acidification combine to effect large-scale chemical and biological changes over the various sub-regions we studied. It also demonstrated the great extent to which the Columbia River, Juan de Fuca Eddy, and Fraser River influence the local chemistry and biology of the sub-regions. Future studies are recommended to focus on how these local drivers are changing in a high-CO2 world, and how the ecosystem responds to those changes.

It is the consensus opinion of the scientists on this cruise that we have accomplished all of the objectives of the cruise, and that our integrated approach to ocean acidification research through national and international cooperation was indeed a great success. However, it cannot be overstated that a large portion of the credit for the success of this cruise is the direct result of the outstanding cooperation of NOAA Commanding Officer Captain Robert A. Kamphaus, Acting Commanding Officer Nicole Manning (cruise leg 1), Operations Officer Lieutenant Brian Elliot, and other officers and crew of the NOAA Ship Ronald H Brown. Their professionalism and devotion to supporting the mission of the project were exemplary.  Finally, Commander Tom Peltzer, Lieutenant Francisco Fuenmayor, and Wendy Bradfield-Smith were instrumental in assisting the science party with logistical and international research permit requirements and planning.

This scientific report was prepared with the input and collaboration of all in the scientific party listed below.

2016 NOAA West Coast Ocean Acidification Research Cruise Scientific Party

Scientific Party Leadership
Dr. Simone Alin, Chief Scientist, NOAA Pacific Marine Environmental Laboratory
Dr. Richard Feely, Chief Scientist, NOAA Pacific Marine Environmental Laboratory
Cathy Cosca, NOAA Pacific Marine Environmental Laboratory
Dana Greeley, NOAA Pacific Marine Environmental Laboratory
Julian Herndon, Joint Institute for the Study of the Atmosphere and Ocean, University of Washington

Scientific Party Members
Dr. Nina Bednarsek, University of Washington
Brian Bill, NOAA Northwest Fisheries Science Center
Dr. Brendan Carter, Joint Institute for the Study of the Atmosphere and Ocean, University of Washington
Erin Cuyler, University of South Florida
Marty Davelaar, Department of Fisheries and Oceans, Canada
Nora (Katie) Douglas, University of South Florida
Zelalem Engida, University of Victoria, British Columbia, Canada
Dr. Jonna Engström-Öst, Novia University of Applied Sciences, Finland
Dr. Wiley Evans, Hakai Institute, British Columbia, Canada
Dr. Olivier Glippa, Novia University of Applied Sciences, Finland
Dr. José Martín Hernández-Ayón, Autonomous University of Baja California, Mexico
Emma Hodgson, University of Washington
Dale Hubbard, Oregon State University
Chris Ikeda, San Francisco State University Romberg Tiburon Center
Kevin Johnson, University of California – Santa Barbara
Charles Kovach, NOAA National Environmental Satellite Data and Information Service (NESDIS) Center for Satellite Applications and Research (STAR)
Dr. Sherwood Liu, University of South Florida
Dr. Ryan McCabe, Joint Institute for the Study of the Atmosphere and Ocean, University of Washington
Anna McLaskey, University of Washington
Lisette Mekkes, University of Amsterdam, Netherlands
Dr. William Nilsson, NOAA Northwest Fisheries Science Center
Dr. Remy Okazaki, Joint Institute for the Study of the Atmosphere and Ocean, University of Washington
Morgan Ostendorf, Joint Institute for the Study of the Atmosphere and Ocean, University of Washington
Katrina Radach,  University of Washington
Dr. Linda Rhodes, NOAA Northwest Fisheries Science Center
Sigrid Salo, NOAA Pacific Marine Environmental Laboratory
Jonathan Sharp, University of South Florida
Meghan Shea, Stanford University, NOAA PMEL
Spencer Showalter, Boston University, NOAA Northwest Fisheries Science Center
Melissa Ward, University of California-Davis, San Diego State University
Carrie Weekes, Oregon State University

Principal Investigators and Other Collaborators on Land
Dr. Burke Hales, Oregon State University
Dr. Debby Ianson, Institute of Ocean Sciences, Department of Fisheries and Oceans, Canada
Dr. Robert Byrne, University of South Florida
Dr. Vera Trainer, NOAA Northwest Fisheries Science Center
Dr. Bill Peterson, NOAA Northwest Fisheries Science Center
Dr. Bill Cochlan, San Francisco State University Romberg Tiburon Center
Dr. Brook Nunn, Genome Sciences Department, University of Washington
Dr. Emma Timmins-Schiffman, Genome Sciences Department, University of Washington
Dr. Gretchen Hofmann, University of California – Santa Barbara
Dr. Julie Keister, School of Oceanography, University of Washington
Dr. Michael Ondrusek, NOAA National Environmental Satellite Data and Information Service (NESDIS) Center for Satellite Applications and Research (STAR)
Dr. Veronica Lance, NOAA National Environmental Satellite Data and Information Service (NESDIS) Center for Satellite Applications and Research (STAR)
Dr. Steve Fradkin, NPS Olympic National Park
Dr. Jonathan (Johnny) Jones, NPS Cabrillo National Monument
Dr. Meg Chadsey, Washington Sea Grant
Jennifer Fisher, NOAA Northwest Fisheries Science Center
Liam Antrim, NOAA Olympic Coast National Marine Sanctuary
Eva DiDonato, National Park Service
Mary Miller, San Francisco Exploratorium

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