If you build it, they will come: marine habitat provided by a wastewater outfall

King County built a new marine outfall in 2008 that discharges treated wastewater effluent to the Puget Sound Central Basin about 1.6 kilometers offshore at a depth of 183 meters (m). The outfall consists of two 1.6 m diameter HDPE pipes weighted with concrete anchors. To assess the artificial reef effect of the exposed pipes and its use as habitat by marine organisms, underwater video has been collected annually since 2009 at the shallower depths (to -91 m MLLW). Initial video showed rapid colonization by barnacles and other invertebrates. Several rockfish species have routinely been seen on the pipes, particularly at the -24 to -37 m MLLW depth range. Most of the typically solitary rockfish species appear to be subadults that are schooling together, suggesting the pipes might serve as transitional habitat. In 2014, WDFW observed a bocaccio rockfish near the pipes, the first confirmed Central Basin sighting in at least 12 years at that time. During the same survey, over 50 canary rockfish were also seen and canaries were also seen in 2017. To assess biological colonization of the pipes, ten pieces of pipe-material were deployed in 2012 at four depths near the pipe: 30, 91, and 183 m, with a 183 m reference site. Three replicates of these “settlement plates” will be collected at each site after 2, 5, and 10 years. The percent cover of non-motile organisms and counts of motile species will be assessed from photographs taken of each plate and species identified to the lowest practical taxonomic unit. The first sets of plates were retrieved in September of 2014, the second set in October 2017. The pipes provide complex, hard substrate in an area otherwise devoid of rock and cobble and observations from the underwater video and findings from the settlement plates will be presented

Long-term monitoring in Central Puget Sound: Are local climate anomalies impacting phytoplankton populations?

Puget Sound is a large and productive estuarine system at the southern end of the Salish Sea. King County’s comprehensive, long-term marine monitoring program tracks water quality in Puget Sound’s Central Basin through year-round collection of data for a suite of physical, chemical and biological parameters. Phytoplankton monitoring began with traditional microscopy methods in 2008, and expanded to include a particle imaging system in 2014. These data are critical to assess how changes from climate, physical conditions and other stressors linked to anthropogenic activity from the region’s growing population may impact the Sound’s biodiversity and trophic structure. Currently, twice-monthly surface water samples from 10 Central Basin locations (Point Wells to East Passage) are analyzed year round by FlowCAM, an imaging particle analyzer operating in the 10–300 µm particle range. Phytoplankton particle size, abundance and biovolume are quantified for sixty taxonomic categories. Additionally, zooplankton composition and abundance data are available at select stations. Given the considerable changes in physical conditions recorded for the Salish Sea in the last several years, such as higher than normal temperatures beginning in late 2014, data analysis has focused on key water column indicators (temperature, salinity, nutrients) and weather/climate patterns as drivers of phytoplankton abundance and community composition. Our data reveal important spatial differences within the Central Basin as well as inter-annual differences in seasonal succession patterns of phytoplankton species. These findings contribute to our understanding of the dynamics of Puget Sound phytoplankton communities in relation to environmental and biological drivers

Extending observations further: using historic biogeochemical data to understand trends in Puget Sound

Fluctuations in Puget Sound water quality reflect a combination of natural variability and anthropogenic influence. Predictions of how future changes will unfold requires an understanding of the complex interplay between these factors. Recent and ongoing measurement of water quality parameters allow a thorough assessment of variability over short time scales, but understanding changes over longer (e.g., decadal) timescales is critical for forecasting future changes. Examining long term trends requires the use of historical data, however, measurements that pre-date modern monitoring programs can be scarce, and the detection limits are often higher than newer analytical techniques. Here, we will consider several possible methods to stitch together modern and historical data records of dissolved oxygen and nutrient concentrations while accounting for differences in sample rate, temporal coverage, and sensitivity of analytical techniques. To test different data analysis methods, data records with good temporal coverage that show discernible trends and/or high covariance with other environmental parameters will be used as the basis for simulating data with spotty temporal coverage (as might be expected for less commonly measured biogeochemical parameters like deep dissolved oxygen). Selected trend analyses will then be applied to these simulated time series records to assess method effectiveness in identifying a known feature. Top performing methods for trend analysis will then be applied to key biogeochemical parameters such as nitrate and deep dissolved oxygen. We report on the major covariates and trends identified and the associated statistical confidence intervals. These results will be part of a larger effort to determine how existing trends might play out under different anthropogenic input scenarios

Nutrient dynamics and ties to environmental conditions and drivers in central Puget Sound

Real-time and near-continuous in-situ measurements can provide new insights into variability and patterns of a marine system that would otherwise be undetected by sampling at a lower temporal resolution. King County has a comprehensive long-term marine water quality monitoring program in the Central Basin of Puget Sound that currently includes: bi-monthly water column vertical profiles, discrete sampling, near-surface real-time moored sensors, and new quantitative phytoplankton and zooplankton components. These data can assist with identifying changes and linkages in biogeochemical and ecological processes as well as changes in climate patterns. Recently, new moored and profiling optical nitrate sensors were added to existing monitoring systems to better understand nutrient dynamics. The mooring provides data at 15-minute intervals and the profiling sensor provides data throughout the water column at multiple sites. Nitrate data from 2016-17 are explored and tied to diurnal and seasonal patterns in physical conditions and phytoplankton dynamics. Our data show that variations in nitrate are tightly coupled to in-situ chlorophyll observations. During the phytoplankton growing season, near-surface nitrate may vary up to one order of magnitude in a short time period, such as from 0.03 to 0.32 mg/L in a day. Interannual differences are largely influenced by changes in river flow and oceanic inputs, weather, and climate. These data are framed in historical context of the long-term status and trends in nutrients from discrete sampling over the past two decades. By increasing our understanding of changes and drivers in nutrient patterns, these types of data records can help to inform models and management decisions, and better apply effective remediation targets for Puget Sound marine water quality

Central Puget Sound Phytoplankton and Nutrient Dynamics

Puget Sound is a large, geographically complex, and highly productive estuarine system. The Central Basin is the largest of the four deep basins comprising Puget Sound. Primary producers (phytoplankton) serve key ecosystem functions as their abundances and taxonomic composition can impact higher trophic levels. Several factors can influence phytoplankton dynamics, including nutrient availability, water column mixing, climate, and grazing by zooplankton. In this system, coastal upwelling contributes the largest amount of nutrients. Localized watershed and anthropogenic sources also contribute nutrients to the system. King County (Seattle, WA) implements a long-term monitoring program with physical, chemical, and biological components designed to assess water quality in the Central Basin. Nutrients and chlorophyll-a have been consistently sampled at multiple locations since 1997 and quantitative phytoplankton abundance and taxonomic composition assessed since 2014. Although not an exact measure, chlorophyll-a is often used as a proxy for phytoplankton biomass due to its ease of measurement. Phytoplankton analysis was added to the sampling program to address a significant data gap for lower trophic levels, particularly with regard to taxonomic composition which cannot be determined from chlorophyll-a measurements. Results presented will focus on long-term seasonal and inter-annual trends based on the \u3e20 year data record for nutrients and chlorophyll-a, in addition to the shorter-term phytoplankton data. This analysis explores the influence of physical factors and local and large-scale climate patterns on the dynamics between phytoplankton and nutrients

Puget Sound weather, phytoplankton, and nutrients

As part of a long-term marine water quality monitoring program, the King County Dept. of Natural Resources & Parks has collected nutrient and chlorophyll-a data for almost 20 years at multiple locations in the Puget Sound Central Basin. This monitoring program has yielded a unique dataset for evaluating the impact of climatic conditions on the phytoplankton and nutrient dynamics within the Central Basin. Samples collected from multiple depths at each of 14 sites, including wastewater treatment plant and combined sewer overflow outfalls, are analyzed monthly. Samples are also collected and analyzed bi-weekly from March through October at three of these sites. Phytoplankton species and relative abundance data have been collected at the three bi-weekly sites since 2008. In addition, in situ moorings have been deployed at three locations to collect data (chlorophyll-a, dissolved oxygen, salinity, temperature) at 15-minute intervals since 2008. A nitrate sensor was added at one location in 2009. It is apparent that weather and climate conditions have played a large role in the timing and extent of phytoplankton blooms in Puget Sound, particularly over the last two years. Long-term nutrient and chlorophyll data, together with the more recent phytoplankton community data, were analyzed in conjunction with local weather and large-scale climate patterns in order to determine key climatic factors regulating the interplay between nutrient and phytoplankton dynamics over different temporal scales. Over the last two years, phytoplankton seasonal bloom events were influenced by unusually cold and wet spring weather patterns, with a subsequent effect on nutrient concentrations. This type of analysis underscores the importance of factoring in weather patterns when assessing the association between phytoplankton and nutrients

The Ecology of the Dall Porpoise (Phocoenoides dalli) and Interaction With Japanese Fisheries in the North Pacific Ocean

90 pagesThe Dall porpoise (Phocoenoides dalli True) is a small, deep-bodied and easily identifiable cetacean found in the northern North Pacific Ocean and adjacent waters including the Gulf of Alaska, Bering Sea, Sea of Okhotsk, and the Sea of Japan