Recent and projected seasonal changes to river flows combine with human pressures to restructure the base of the marine food web in Puget Sound

Quantifying large-scale climate impacts, ecosystem responses, and human pressures requires sustained ecosystem monitoring and data integration. The Salish Sea is influenced by oceanic processes and hydrological cycles on land. The interplay of processes across the land-ocean continuum benefits the Puget Sound ecosystem by extending the productive cold-water food web of the upwelling system off Washington’s coast into Puget Sound during summer while buffering water temperatures in winter. Circulation patterns that drive water exchange between Puget Sound and the ocean are responding to climate and the timing of river flows. Historically the freshet and coastal upwelling coincide in summer and allow the productive foodweb to thrive in Puget Sound. Recent years have seen warmer winters causing both earlier snowmelt and therefore reduced summer flows. This temporal separation of upwelling and the freshet results in reduced ocean water renewal, increased water residence time, warmer water, and amplified human impacts during summer. In winter, however, water exchange is increased and keeps Puget Sound water warmer by importing heat from the ocean. These effects combine and have potential ecosystem-wide implications. Coastal eutrophication indicators (large algae blooms, red tides, macro-algae, and jellyfish) are already common place in Puget Sound. These changes in the timing of circulation patterns and nutrient characteristics alter the base of the marine food web while expanding the winter range of cold sensitive species into Puget Sound. In this presentation we conceptually lay out mechanisms, spatial connectivity, observations and hypotheses connecting the dots of climate impacts across the land-ocean continuum and the combined effects on ecosystem processes

Recent conditions highlight regional differences in temperature, salinity and dissolved oxygen between Strait of Juan de Fuca and Puget Sound sites under anomalous 2014-2017 climate patterns

Understanding impacts of climate change on Salish Sea water quality is critical yet challenging due to the complexity, strength and diversity of influences on circulation and mixing. Different extreme climate conditions in recent years (2014-2017) include record warm temperatures with reduced snow pack in 2014-2015 followed by a few years of alternating summer droughts with record rainy seasons. These conditions influenced marine water temperature, salinity and dissolved oxygen (DO) throughout the Salish Sea. Analyses reveal distinct differences in these key physical and chemical characteristics between Strait of Juan de Fuca sites and sites within Puget Sound basins. Extremely low DO water in the Strait not observed at neighboring sites in Puget Sound. This indicates that Puget Sound water exchange and circulation are responding to climate change impacts on the regional hydrological cycle. Lower stream flows are effecting seasonal exchange of ocean water masses under drought conditions, while extremely wet and stormy springs are changing the average salinity of Puget Sound basins and impacting the density structure. Following these physical fluctuations, DO conditions vary from season to season, with new anomalous lows occurring in the Strait and the extreme reaches of South Puget Sound. These conditions could reveal how biophysical drivers of Puget Sound water quality impact food web dynamics during adverse climate and ocean regimes. Local water quality issues that are exacerbated due to reduced circulation may be influencing distinct populations in different basins. We can use these basic biophysical properties to inform us about key drivers of regional differences in the Puget Sound food web

Using ferry monitoring data to explore the importance of isotherms on the winter survival of Northern anchovy in Puget Sound

The Salish Sea displays strong seasonality in water temperature which can impose physiological limits on temperature sensitive species. Puget Sound, in winter, relies on ocean water as a heat source whereas in summer, the gradient is reversed. The dynamic exchange of Puget Sound with coastal water dictates the spatial and temporal patterns of isotherms that are relevant to temperature sensitive species. Recent winters with increased water temperature may expand the range of certain species to be able to survive in Puget Sound over the winter. Northern anchovy (Engraulis mordax) are pelagic spawners and survive in between 8 and 25 °C water. We examine near surface isotherms to describe the dynamic of Northern anchovy access to spring plankton blooms using continuous, geo-referenced data from physical and bio-optical sensors from an 80-mile long en route ferry system between Seattle, WA and Victoria, BC. Spatial and temporal patterns reveal which part of the year near-surface temperature conditions may be favorable for anchovy exploitation of the spring plankton blooms. If filter-feeding prey species such as Northern anchovy can reside in Puget Sound during winter, then they can exploit the spring plankton blooms and potentially change the structure of the food web

How did large scale climate anomalies impact 2015 phytoplankton blooms in Puget Sound?

The Washington State Department of Ecology has been routinely monitoring marine water quality throughout the Puget Sound since 1973. An established historic baseline from 1999 to 2008 allows us to examine how water quality varies year to year as a result of both natural and human influences. The recent large scale climate anomaly, the Blob, impacted this region when a mass of warm water entered Puget Sound in fall 2014. In conjunction with higher than normal air temperatures, patterns of estuarine circulation and stratification were regionally altered in Puget Sound. Changes to these physical patterns affect ecosystem functions starting at the base of the food web with phytoplankton. The water quality data collected monthly in 2015 allows us to gain a better understanding of how large-scale climate anomalies affect the timing and amplitude of phytoplankton biomass (chlorophyll a) in different regions of Puget Sound. Exploring the regional changes in phytoplankton biomass in response to the Blob provides us with insight into how future climate impacts could effect ecosystem functioning in different regions of Puget Sound

Eyes Over Puget Sound: Producing Validated Satellite Products to Support Rapid Water Quality Assessments in Puget Sound

Eyes Over Puget Sound (EOPS) is a rapid communication and outreach product developed by the Washington State Department of Ecology that provides a concise synthesis of near real-time data sources in Puget Sound, WA. Monthly EOPS reports summarize aerial photographic surveys, in-situ ferry observations, satellite products, CTD profiles, and mooring data within 2-days of completing each aerial survey. To facilitate the rapid development and synthesis of satellite information products, EOPS developed a framework for producing regionally-tuned products; validated using coincident ferry-based measurements of chlorophyll fluorescence, turbidity, CDOM fluorescence, temperature, and salinity. Daily ferry transects provide a consistent suite of high-resolution measurements necessary to characterize small-scale spatio-temporal variability across the large optical gradients that are present. Ferry data are made available within 24 hours and allow validation efforts to be performed on a daily-, sensor-, and image-specific basis. This framework has been used to validate and merge satellite products from a variety of platforms including MERIS, MODIS, HICO, and Landsat. Future efforts will utilize EOPS-validated satellite products to refine coupled 3-D hydrodynamic/water quality models currently being developed for the region

Regional and temporal variability in Puget Sound zooplankton: bottom-up links to juvenile salmon

We use data from the Puget Sound Zooplankton Monitoring Program to explore patterns of spatial and interannual variability in zooplankton communities in response to environmental change during 2014-2017. This program is a collaborative effort involving 10 tribal, county, state, federal, academic, and nonprofit entities initiated via the Salish Sea Marine Survival Project with the goal of understanding the key role of zooplankton in food webs and ecosystems. Large interannual differences in the environment over this period strong effects on zooplankton community structure and abundance. 2014 began as a fairly normal year in Puget Sound until the Pacific Warm Anomaly event nicknamed “The Blob” began to affect the region during late summer and fall. Unprecedented warm anomalies occurred in summer 2015, persisting through 2016. Off the coast of Washington and Oregon, clear effects on zooplankton community structure were observed, with rare oceanic species occurring in coastal samples concurrent with decreased overall biomass. In sharp contrast, few rare species were collected in Puget Sound, and zooplankton increased in 2015 and 2016 relative to 2014, including increases in nearly all taxa that are important juvenile salmon prey. A few taxa, most notably the dinoflagellate Noctiluca and numerous species of small jellyfish, decreased during the warm years, and shifts in the seasonal phenology of some taxa were observed. These and other findings from the Puget Sound Zooplankton Monitoring Program will be presented in the context of the implications of environmental change for juvenile salmon growth and survival

Reconstructing historical patterns of primary production in Puget Sound using growth increment data from shells of long-lived geoducks (Panopea generosa)

Bottom-up hypotheses predict that changes in primary production affect marine survival of species like Pacific salmon. Long term records of primary production would provide important data to test these predictions. However, direct observations of primary production (in situ fluorometers, water chemistry, and satellite observations of color back-scatter) have relatively short time series (\u3c 30 years). We investigated whether growth increments of geoduck clams (Panopea generosa) are correlated with primary production in different sub-basins of greater Puget Sound. Geoduck are long-lived (older specimens live \u3e100 years), widely distributed throughout the Salish Sea, and deposit annual growth rings in their shells. Shell samples from aged geoducks were by the Washington Department of Fish and Wildlife in four sub-basins within greater Puget Sound (Strait of Jan de Fuca, Southern Strait of Georgia, South Puget Sound, and Central Basin). Geoduck shells from Saratoga passage were provided by the Tulalip Tribe. Using growth indices, the known correlation of growth indices with sea surface temperature and other long-term measurements, and existing basin-level records of temperature and primary production, we modeled historical patterns of primary production in different regions of greater Puget Sound. Analyses show that the relationship between geoduck growth, temperature, and primary production varies between sub-basins, and stable isotope analysis suggests that geoducks may be more than just primary consumers. These issues make reconstruction of a historical record of primary production from growth increments challenging. Nevertheless, analyses suggest that residual growth (after accounting for temperature variation) can explain variation in annual marine survival of local coho and chinook salmon stocks. This indicates the method has promise for retrospective hypothesis testing

Recent climate patterns are affecting seasonal water residence times and water temperatures in Puget Sound

At the end of 2014 water temperatures in Puget Sound rapidly increased in response to The Blob and persisted into 2017. Climate anomalies on land caused premature snow melt and freshening of Puget Sound. The seasonal shift in freshwater delivery increased winter estuarine circulation allowing greater import of heat from the ocean but decreased summer circulation, retaining more heat in Puget Sound in summer. In both seasons, Puget Sound temperatures increased affecting water quality and ecosystem performance. We contrast salinity, temperature, and density records from 2014-2017 to infer residence time and changes in water masses during the extreme climate years. Increased winter temperatures \u3e8C might have promoted overwintering for temperature sensitive species such as anchovy

Can long term-nitrogen increases affect pelagic food web processes and the vertical structure of biogeochemical processes in Puget Sound?

Analyses of Ecology’s longterm monitoring data has indicated that in the pelagic zone of Puget Sound, nutrient concentrations have significantly increased, and nutrient ratios and phytoplankton biomass have steadily changed over the last 14 years. We have also documented a wide-spread decline in benthic community abundance. The cause and impacts of these trends have potential implications for marine food web structure, energy transfer, particle export, vertical structure of biogeochemical rate processes, and oxygen drawdown at depth. Puget Sound, because of its proximity to the cold, nutrient-rich Pacific Ocean, is thought of as a diatom-dominated marine food web supporting higher trophic levels via a productive, short food chain with high export production to benthic communities. Phytoplankton species respond to the nutrient composition, physical character of the water column, and zooplankton grazers. Through Ecology’s long-term marine monitoring program and aerial surveys, we frequently document extensive algal blooms, Noctiluca blooms at the surface. Many of the phytoplankton blooms show high abundances of autotrophic flagellates. Depth-integrated algal biomass, on the other hand, revealed a steady decline from 1999 to 2013. These seemingly opposing observations – increasing nutrients and high algal biomass at the surface and decreasing phytoplankton biomass below the surface - could provide clues to phytoplankton species and food web shifts resulting in reduced organic material export and weaker benthic-pelagic coupling that could explain the long-term decline in deeper-water benthic communities in Puget Sound by 45%. We will conceptually draw these different and opposing observations into a larger cohesive hypothesis and connect changes in Puget Sound’s nutrient balance to larger scale processes of material and energy cycling in Puget Sound