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Stable oxygen isotopic ratios in corals (δ¹⁸O_coral) are commonly utilized to reconstruct climate variability beyond the limit of instrumental observations. These measurements provide constraints on past seawater temperature, due to the thermodynamics of isotopic fractionation, but also past salinity, as both salinity and seawater δ¹⁸O (δ¹⁸O_sw) are similarly affected by precipitation/evaporation, advection, and other processes. We use historical observations, isotope‐enabled model simulations, and the PAGES Iso2k database to assess the potential of δ¹⁸O_coralto provide information on past salinity. Using ‘‘pseudocorals’’ to represent δ¹⁸O_coralas a function of observed or simulated temperature and salinity/δ¹⁸O_sw, we find that δ¹⁸O_swcontributes up to 89% of δ¹⁸O_coralvariability in the Western Pacific Warm Pool. Although uncertainty in the δ¹⁸O_sw‐salinity relationship influences the inferred salinity variability, corals from these sites could provide valuable δ¹⁸O_swreconstructions. Coordinated in situ monitoring of salinity and δ¹⁸O_swis vital for improving estimates of hydroclimatic change.

 

Climate (in)stability can manifest in the size of mollusks attesting to variable impacts on growth, seasonal exploitation, and cultural persistence. We present population statistics of the height of a bivalve species (Donax obesulus) collected from sites dating to the Early Horizon (EH, 900?200 BCE) in the Nepeña Valley and the Middle Horizon (MH, 600?1000 CE) in the Jequetepeque Valley of northern coastal Peru and compare them with a paleoclimate record and a sample of modern shells (collected in 2012, 2014, and 2016) from the Nepeña Valley. We observe diachronic variation in the size of D. obesulus with larger bivalves during the EH and smaller shells during the MH and in the modern sample. D. obesulus size remains relatively static during the MH at one site through two sub-phases. These bivalve populations were likely impacted by both climate and cultural circumstances. A proxy for runoff from El Niño related rainfall (%lithic flux) from a previously published nearby marine sediment core is elevated during the EH and Late Moche phase of the MH and correlates with shell height. During the Transitional phase of the MH and the modern interval, however, there are periods of comparatively reduced El Niño activity and shell height compared to the EH. 

This archived Paleoclimatology Study is available from the NOAA National Centers for Environmental Information (NCEI), under the World Data Service (WDS) for Paleoclimatology. The associated NCEI study type is Other Collections. The data include parameters of paleoceanography with a geographic location of Peru. The time period coverage is from -61 to -65 in calendar years before present (BP). See metadata information for parameter and study location details. Please cite this study when using the data. 

Michael Moseley emphasized the importance of maritime resources to the development of social complexity in the Andean region in his theory of the Maritime Foundations of Andean Civilization (1975), which became a central (and controversial) text in the field. This volume builds on his and others’ foundational work and asks, “how did ancient Andean coastal communities build themselves, and their identities, around their proximity to the Pacific Ocean”? 

Are the islands off the coast of California “marginal” environments? How could seemingly “depauperate” places have sustained human settlements for thousands of years? In An Archaeology of Abundance: Reevaluating the Marginality of California’s Islands, edited by Kristina M. Gill, Mikael Fauvelle, and Jon M. Erlandson, archaeologists and other scholars argue that our understanding of the resource bases of the California islands is biased by years of Euroamerican impacts. By integrating archaeological and ethnohistoric data with paleoecological reconstructions, the authors reexamine life on these islands before European contact and subsequent environmental degradation.