Chan, P., Halfar, J., Hetzinger, S., Adey, W., Zack, T., Moore, G.W.K., Wortmann, U.G., Williams, B., and Hou, A. “Multicentennial Record of Labrador Sea Primary Productivity and Sea-Ice Variability Archived in Coralline Algal Barium.” Nature Communications, 8, 2017, 15543.
Abstract: Accelerated warming and melting of Arctic sea-ice has been associated with significant increases in phytoplankton productivity in recent years. Here, utilizing a multiproxy approach, we reconstruct an annually resolved record of Labrador Sea productivity related to sea-ice variability in Labrador, Canada that extends well into the Little Ice Age (LIA; 1646 AD). Barium-to-calcium ratios (Ba/Ca) and carbon isotopes (Î´13C) measured in long-lived coralline algae demonstrate significant correlations to both observational and proxy records of sea-ice variability, and show persistent patterns of co-variability broadly consistent with the timing and phasing of the Atlantic Multidecadal Oscillation (AMO). Results indicate reduced productivity in the Subarctic Northwest Atlantic associated with AMO cool phases during the LIA, followed by a step-wise increase from 1910 to present levels--unprecedented in the last 363 years. Increasing phytoplankton productivity is expected to fundamentally alter marine ecosystems as warming and freshening is projected to intensify over the coming century.
Dassié, Emilie, Kristine DeLong, Hali Kilbourne, Branwen Williams, et al. “Saving Our Marine Archives.” EOS, 98, 2017.
Abstract: A concerted effort has begun to gather and preserve archives of marine samples and descriptive data, giving scientists ready access to insights on ancient environments.
Prouty, Nancy G., E. Brendan Roark, Allen Andrews, Laura Robinson, Tessa Hill, Owen Sherwood, Branwen Williams, Thomas P. Guilderson, and Stewart Fallon. “Age, Growth Rates, and Paleoclimate Studies of Deep Sea Corals.” The State of Deep‐Sea Coral and Sponge Ecosystems of the United States, print edition, edited by Thomas F. Hourigan, Peter J. Etnoyer, and Stephen D. Cairns, NOAA Technical Memorandum NMFS‐OHC‐4, 2017, pp. 297-319.
Abstract: Deep-water corals are some of the slowest growing, longest-lived skeletal accreting marine organisms. These habitat-forming species support diverse faunal assemblages that include commercially and ecologically important organisms. Therefore, effective management and conservation strategies for deep-sea corals can be informed by precise and accurate age, growth rate, and lifespan characteristics for proper assessment of vulnerability and recovery from perturbations. This is especially true for the small number of commercially valuable, and potentially endangered, species that are part of the black and precious coral fisheries (Tsounis et al. 2010). In addition to evaluating time scales of recovery from disturbance or exploitation, accurate age and growth estimates are essential for understanding the life history and ecology of these habitat-forming corals. Given that longevity is a key factor for population maintenance and fishery sustainability, partly due to limited and complex genetic flow among coral populations separated by great distances, accurate age structure for these deep-sea coral communities is essential for proper, long-term resource management. The importance of accurate age and growth characteristics has another important utility in marine sciences. Many deep-sea corals have been useful as biogeochemical proxies that provide a unique view of marine climate and environmental change over time (e.g., Adkins et al. 1998, Robinson et al. 2005, LaVigne et al. 2011). Similar to trees on land, many corals have concentric growth rings that allow scientists to track growth patterns, which can be used to look back into climate history over the coral’s lifespan using stable and radio-isotope techniques. Here we summarize recent developments in determining age and growth characteristics for structure-forming deepsea corals, many of which are vulnerable to disturbance, with highlights on recent advances in paleoclimate reconstruction efforts using deep-sea corals.
Williams, B., Halfar, J., DeLong, K.L., Smith, E., Steneck, R., Lebednik, P., Jacob, D.E., Fietzke, J., and Moore, G.W.K. “North Pacific Twentieth Century Decadal-Scale Variability is Unique for the Past 342 Years.” Geophysical Research Letters, vol. 44, issue 8, 2017, pp. 3761-3769.
Abstract: Reconstructed sea surface temperatures (SSTs) derived from Mg/Ca measurements in nine encrusting coralline algal skeletons from the Aleutian archipelago in the northernmost Pacific Ocean reveal an overall increase in SST from 1665 to 2007. In the Aleutian SST reconstruction, decadal-scale variability is a transient feature present during the 1700s and early 1800s and then fully emerging post-1950. SSTs vary coherently with available instrument records of cyclone variance and vacillate in and out of coherence with multicentennial Pacific Northwest drought reconstructions as a response to SST-driven alterations of storm tracks reaching North America. These results indicate that an influence of decadal-scale variability on the North Pacific storm tracks only became apparent during the midtwentieth century. Furthermore, what has been assumed as natural variability in the North Pacific, based on twentieth century instrumental data, is not consistent with the long-term natural variability evident in reconstructed SSTs predating the anthropogenic influence.
Rooper, Chris, Robert Stone, Peter Etnoyer, Christina Conrath, Jennifer Reynolds, H. Gary Greene, Branwen Williams, Enrique Salgado, Cheryl Morrison, Rhian Waller, and Amanda Demopoulos. “Deep-Sea Coral Research and Technology Program: Alaska Deep-Sea Coral and Sponge Initiative Final Report.” National Oceanic and Atmospheric Administration Technical Memorandum NMFS-OHC-2, 2017.
Abstract: Deep-sea coral and sponge ecosystems are widespread throughout most of Alaska's marine waters. In some places, such as the central and western Aleutian Islands, deep-sea coral and sponge resources can be extremely diverse and may rank among the most abundant deep-sea coral and sponge communities in the world. Many different species of fishes and invertebrates are associated with deep-sea coral and sponge communities in Alaska. Because of their biology, these benthic invertebrates are potentially impacted by climate change and ocean acidification. Deep-sea coral and sponge ecosystems are also vulnerable to the effects of commercial fishing activities. Because of the size and scope of Alaska's continental shelf and slope, the vast majority of the area has not been visually surveyed for deep-sea corals and sponges. NOAA's Deep Sea Coral Research and Technology Program (DSCRTP) sponsored a field research program in the Alaska region between 2012-2015, referred to hereafter as the Alaska Initiative. The priorities for Alaska were derived from ongoing data needs and objectives identified by the DSCRTP, the North Pacific Fishery Management Council (NPFMC), and Essential Fish Habitat-Environmental Impact Statement (EFH-EIS) process. This report presents the results of 15 projects conducted using DSCRTP funds from 2012-2015. Three of the projects conducted as part of the Alaska deep-sea coral and sponge initiative included dedicated at-sea cruises and fieldwork spread across multiple years. These projects were the eastern Gulf of Alaska Primnoa pacifica study, the Aleutian Islands mapping study, and the Gulf of Alaska fish productivity study. In all, there were nine separate research cruises carried out with a total of 109 at-sea days conducting research. The remaining projects either used data and samples collected by the three major fieldwork projects or were piggy-backed onto existing research programs at the Alaska Fisheries Science Center (AFSC).
External Grant: Henry Luce Foundation’s LIASE (Luce Initiative on Asian Studies and the Environment) Program: “Environmental Infrastructure in Asia: Nature, Networks and People in the Anthropocene.” Albert Park (lead-PI), Branwen Williams, and Marc Los-Huertos (co-PIs). $1,400,000, 2017–2021.
EnviroLab Asia is a laboratory for cross-disciplinary research and experiential learning that links knowledge with practice. We aim to engage communities and explore what comes out of the intellectual exchange between the humanities and social sciences, environmental analysis, and various other fields to generate new scholarship about environmental issues in Asia. This is an initiative at the Claremont Colleges funded by the Henry Luce Foundation's LIASE (Luce Initiative on Asian Studies and the Environment) Program and is anchored at Claremont McKenna College. In May 2017, the Henry Luce Foundation awarded EnviroLab Asia a $1.4 million grant to expand its activities at the Claremont Colleges for the next four years.