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Abstract. Global trends of ocean warming, deoxygenation, and acidification are not easily extrapolated to coastal environments. Local factors, including intricate hydrodynamics, high primary productivity, freshwater inputs, and pollution, can exacerbate or attenuate global trends and produce complex mosaics of physiologically stressful or favorable conditions for organisms. In the California Current System (CCS), coastal oceanographic monitoring programs document some of this complexity; however, data fragmentation and limited data availability constrain our understanding of when and where intersecting stressful temperatures, carbonate system conditions, and reduced oxygen availability manifest. Here, we undertake a large data synthesis to compile, format, and quality-control publicly available oceanographic data from the US West Coast to create an accessible database for coastal CCS climate risk mapping, available from the National Centers for Environmental Information (accession 0277984) at https://doi.org/10.25921/2vve-fh39 (Kennedy et al., 2023). With this synthesis, we combine publicly available observations and data contributed by the author team from synoptic oceanographic cruises, autonomous sensors, and shore samples with relevance to coastal ocean acidification and hypoxia (OAH) risk. This large-scale compilation includes 13.7 million observations from 66 sources and spans 1949 to 2020. Here, we discuss the quality and composition of the synthesized dataset, the spatial and temporal distribution of available data, and examples of potential analyses. This dataset will provide a valuable tool for scientists supporting policy- and management-relevant investigations including assessing regional and local climate risk, evaluating the efficacy and completeness of CCS monitoring efforts, and elucidating spatiotemporal scales of coastal oceanographic variability. 

Abstract. The shells of marine invertebrates can serve as high-resolution records ofoceanographic and atmospheric change through time. In particular, oxygen andcarbon isotope analyses of nearshore marine calcifiers that grow byaccretion over their lifespans provide seasonal records of environmental andoceanographic conditions. Archaeological shell middens generated byIndigenous communities along the northwest coast of North America containshells harvested over multiple seasons for millennia. These shell middens,as well as analyses of archival and modern shells, have the potential toprovide multi-site, seasonal archives of nearshore conditions throughout theHolocene. A significant volume of oxygen and carbon isotope data fromarchaeological shells exist, yet they are separately published in archaeological,geochemical, and paleoceanographic journals and have not been comprehensivelyanalyzed to examine oceanographic change over time. Here, we compiled adatabase of previously published oxygen and carbon isotope data fromarchaeological, archival, and modern marine mollusks from the CaliforniaCurrent System (North American coast of the northeast Pacific, 32 to55∘ N). This database includes oxygen and carbon isotope data from 598modern, archaeological, and sub-fossil shells from 8880 years before present(BP) to the present, from which there are 4917 total δ13C and7366 total δ18O measurements. Shell dating and samplingstrategies vary among studies (1–345 samples per shell, mean 44.7 samplesper shell) and vary significantly by journal discipline. Data are fromvarious bivalves and gastropod species, with Mytilus spp. being the most commonlyanalyzed taxon. This novel database can be used to investigate changes innearshore sea surface conditions including warm–cool oscillations, heatwaves, and upwelling intensity, and it provides nearshore calcium carbonateδ13C and δ18O values that can be compared to thevast collections of offshore foraminiferal calcium carbonate δ13C and δ18O data from marine sediment cores. Byutilizing previously published geochemical data from midden and museumshells rather than sampling new specimens, future scientific research canreduce or omit the alteration or destruction of culturally valued specimensand sites. The dataset is publicly available through PANGAEA athttps://doi.org/10.1594/PANGAEA.941373 (Palmer et al.,2021). 

We compiled a database of previously published oxygen and carbon isotope data from archaeological, archival, and modern marine molluscs from the North American coast of the Northeast Pacific (32oN to 50oN). This database includes oxygen and carbon isotope data from over 550 modern, archaeological, and sub-fossil shells from 8880 years before present (BP) to the present, from which there are 4,845 total δ¹³C and 5,071 total δ¹⁸O measurements. Database includes the following parameters: paper of original publication, publication year, unique shell identification, unique subsample identification, sample number (given by original authors), subsample number (given by original author), number of subsamples per shell (added here), age in years before present, species, source (midden or modern), latitude, longitude, calculated sea surface temperature (only if published by original authors), tidal height, life mode, habitat, archaeological trinomial (when applicable), oxygen isotope value, and carbon isotope value. Shell dating and sampling strategies vary among studies (1-118 samples per shell) and vary significantly by journal discipline. Data are from various bivalves and gastropod species, with Mytilus spp. being the most commonly analyzed taxon. This novel database can be used to investigate changes in nearshore sea surface conditions including warm-cool oscillations, heat waves, and upwelling intensity, and provides nearshore calcite δ¹³C and δ¹⁸O values that can be compared to the vast collections of offshore foraminifera calcite δ¹³C and δ¹⁸O data from marine sediment cores. By utilizing previously published geochemical data from midden and museum shells rather than sampling new specimens, future scientific research can reduce or omit the alteration or destruction of culturally valued specimens and sites. 

Marine protists are integral to the structure and function of pelagic ecosystems and marine carbon cycling, with rhizarian biomass alone accounting for more than half of all mesozooplankton in the oligotrophic oceans. Yet, understanding how their environment shapes diversity within species and across taxa is limited by a paucity of observations of heritability and life history. Here, we present observations of asexual reproduction, morphologic plasticity, and ontogeny in the planktic foraminifer Neogloboquadrina pachyderma in laboratory culture. Our results demonstrate that planktic foraminifera reproduce both sexually and asexually and demonstrate extensive phenotypic plasticity in response to nonheritable factors. These two processes fundamentally explain the rapid spatial and temporal response of even imperceptibly low populations of planktic foraminifera to optimal conditions and the diversity and ubiquity of these species across the range of environmental conditions that occur in the ocean. 

Abstract. Microfossil assemblages provide valuable records to investigatevariability in continental margin biogeochemical cycles, including dynamicsof the oxygen minimum zone (OMZ). Analyses of modern assemblages acrossenvironmental gradients are necessary to understand relationships betweenassemblage characteristics and environmental factors. Five cores wereanalyzed from the San Diego margin (32∘42′00′′ N, 117∘30′00′′ W; 300–1175 m water depth) for core top benthic foraminiferalassemblages to understand relationships between community assemblages andspatial hydrographic gradients as well as for down-core benthic foraminiferalassemblages to identify changes in the OMZ through time. Comparisons ofbenthic foraminiferal assemblages from two size fractions (63–150 and>150 µm) exhibit similar trends across the spatial and environmental gradient or in some cases exhibit more pronouncedspatial trends in the >150 µm fraction. A range of speciesdiversity exists within the modern OMZ (1.910–2.586 H, Shannon index),suggesting that diversity is not driven by oxygenation alone. We identifytwo hypoxic-associated species (B. spissa and U. peregrina), one oxic-associated species (G. subglobosa) andone OMZ edge-associated species (B. argentea). Down-core analysis of indicator speciesreveals variability in the upper margin of the OMZ (528 m water depth) whilethe core of the OMZ (800 m) and below the OMZ (1175 m) remained stable inthe last 1.5 kyr. We document expansion of the upper margin of the OMZbeginning 400 BP on the San Diego margin that is synchronous with otherregional records of oxygenation. 

Abstract In the face of ongoing marine deoxygenation, understanding timescales and drivers of past oxygenation change is of critical importance. Marine sediment cores from tiered silled basins provide a natural laboratory to constrain timing and implications of oxygenation changes across multiple depths. Here, we reconstruct oxygenation and environmental change over time using benthic foraminiferal assemblages from sediment cores from three basins across the Southern California Borderlands: Tanner Basin (EW9504‐09PC, 1,194 m water depth), San Nicolas Basin (EW9504‐08PC, 1,442 m), and San Clemente Basin (EW9504‐05PC,1,818 m). We utilize indicator taxa, community ecology, and an oxygenation transfer function to reconstruct past oxygenation, and we directly compare reconstructed dissolved oxygen to modern measured dissolved oxygen. We generate new, higher resolution carbon and oxygen isotope records from planktic (Globigerina bulloides) and benthic foraminifera (Cibicides mckannai) from Tanner Basin. Geochemical and assemblage data indicate limited ecological and environmental change through time in each basin across the intervals studied. Early to mid‐Holocene (11.0–4.7 ka) oxygenation below 1,400 m (San Clemente and San Nicolas) was relatively stable and reduced relative to modern. San Nicolas Basin experienced a multi‐centennial oxygenation episode from 4.7 to 4.3 ka and oxygenation increased in Tanner Basin gradually from 1.7 to 0.8 ka. Yet across all three depths and time intervals studied, dissolved oxygen is consistently within a range of intermediate hypoxia (0.5–1.5 ml L⁻¹[O₂]). Variance in reconstructed dissolved oxygen was similar to decadal variance in modern dissolved oxygen and reduced relative to Holocene‐scale changes in shallower basins. 

Abstract Fire is an integral component of ecosystems globally and a tool that humans have harnessed for millennia. Altered fire regimes are a fundamental cause and consequence of global change, impacting people and the biophysical systems on which they depend. As part of the newly emerging Anthropocene, marked by human-caused climate change and radical changes to ecosystems, fire danger is increasing, and fires are having increasingly devastating impacts on human health, infrastructure, and ecosystem services. Increasing fire danger is a vexing problem that requires deep transdisciplinary, trans-sector, and inclusive partnerships to address. Here, we outline barriers and opportunities in the next generation of fire science and provide guidance for investment in future research. We synthesize insights needed to better address the long-standing challenges of innovation across disciplines to (i) promote coordinated research efforts; (ii) embrace different ways of knowing and knowledge generation; (iii) promote exploration of fundamental science; (iv) capitalize on the “firehose” of data for societal benefit; and (v) integrate human and natural systems into models across multiple scales. Fire science is thus at a critical transitional moment. We need to shift from observation and modeled representations of varying components of climate, people, vegetation, and fire to more integrative and predictive approaches that support pathways towards mitigating and adapting to our increasingly flammable world, including the utilization of fire for human safety and benefit. Only through overcoming institutional silos and accessing knowledge across diverse communities can we effectively undertake research that improves outcomes in our more fiery future.