Research

This request is for a student cruise for the SIO280 Biological Oceanography course. SIO280 is required for all PhD students. The cruise is intended to expose PhD and MS students to scientific activities at sea.

Puget Sound has been observed to host large fields of active methane venting from the seafloor. Although present throughout the Sound, the majority of gas emission sites are co-located over three major fault zones that fracture the entire forearc crust of the Cascadia Subduction Zone (CSZ). Multibeam and single-beam sonar data from cruises conducted between 2011- 2021 identified the acoustic signature of over 350 individual bubble plumes. Fluid samples from adjacent terrestrial hot springs and deep-water wells surrounding the estuary contain a helium-3 isotope signature, suggesting a deep fluid source arising from the underlying CSZ plate interface. However, limited data from our previous pilot study suggests that Puget Sound emission sites appear to lack similar helium isotope signatures expected from a deep plate-interface reservoir. As an alternative hypothesis, a shallow reservoir beneath the Holocene sediments that cover Puget Sound Eocene basement, with horizontal transfer to the thinly-sedimented Alki Point and Kingston Arch anticlines, is also possible. The origin of vigorous marine methane plumes arising from areas of thin sediment cover and associated with deeply-penetrating forearc fault zones but still presenting no thermal or chemical anomalies found in other similar forearc environments, remains an important unresolved scientific paradox.

Organism aggregation, resource patchiness, and layering have long been recognized as fundamental ecosystem properties, especially in dynamic marine pelagic systems. However, integrating fine-scale (1-10 m) water column structure into our understanding of the forces that regulate marine ecosystems has proved challenging. Specifically, an overwhelming majority of marine organisms (plankton) experience their environment at fine spatial scales, which are difficult to sample, yet most measurements of chemical and biological parameters that define the structure of food webs and the flow of energy are averaged over much larger portions of the water column. This mismatch hinders our ability to understand the trophic consequences of fine-scale variability. Addressing this challenge will help to resolve key, and potentially predictable, sequences of events that change community structure and have trophic consequences that propagate throughout the food web in productive continental shelf environments. The trophic consequences of layers and patches depends on the proliferation of the zooplankton groups that exploit them. Conversely, other groups may proliferate in environments lacking vertical structure. One key trophic link on continental shelves is occupied by grazers such as doliolids and copepods – the relative abundance of these groups can determine if carbon is vertically exported or recycled within the microbial loop. Our long-term goals are to understand the ecological role of doliolids and the conditions that favor their proliferation (compared to copepods and other crustaceans). Because doliolids aggregate on fine spatial scales in several ecosystems, biological measurements need to be made on similar spatial scales and through time. Obtaining these measurements within different oceanographic contexts can answer several fundamental questions. For example, what are the trophic consequences of fine scale structure? Do these structures favor particular zooplankton communities above and below, and over what temporal and spatial scales do these structures persist or extend? Answering these questions requires sampling with complementary techniques, and will advance the fundamental understanding of how ecosystems will respond to changes in oceanographic structure, placing seemingly chaotic zooplankton communities into a predictive framework. We propose an ambitious field campaign in two shelf ecosystems with similar zooplankton taxa yet contrasting oceanographic regimes where doliolids are known to form blooms. The sampling will encompass two seasons (summer and winter) with contrasting degrees of stratification. Innovative molecular and stable-isotope measurements will allow for a robust coupling to oceanographic features and zooplankton abundance and community composition, elucidating the trophic consequences of vertical structure, layering, and mixing. In addition to primary research cruises, the multi-cruise plan will also include cruises that will be focused on optimizing the use of novel and proto-type equipment (sea trials) and several education cruises for graduate students and K-12 educators.

Annual survey using trawling and hydroacoustics to survey the health of the fisheries in Minnesota waters of Lake Superior

We will deploy an internal-wave-resolving (IWR) array to measure the propagation of the displacement and velocities signals of low-mode internal waves, which contain most of the internal wave SSH variability. The IWR Array deployment focuses on the SWOT Cal/Val site off the coast of California with partial-array deployment in early 2023 (2 PIESs) to coincide with the 90-day fast repeat SWOT orbit. Thereafter, the deployment of the full IWR Array from Fall 2023 through mid-2024 will capture the seasonal variability in the tidal and near-inertial internal waves, extending the NOPP measurements for a full year beyond the 3-month SWOT cal/val period.

Ship time dedicated to facilitate experiential learning for UGA and USG graduate and undergraduate students.

SEARCH will complete a maritime, remote sensing survey.

Characterization of oceanic primary production is key to characterize the carbon cycle and determine the metabolic state of global oceans over time and space. However, our current understanding of productivity patterns is limited to sparse bottle incubations and satellite models, both of which are known to be biased and inaccurate. We propose to estimate daily rates of production and respiration by particles over a full seasonal cycle using high frequency measurements of oxygen and optical proxies for carbon concentration. We will deploy several autonomous profiling floats equipped with state of the art instruments. These will remain at sea for ~ 1 year, supporting validation of satellite estimates of production across biomes dominated by different ecosystem characteristics. We will conduct ship-based experiments to identify drivers of the spatial temporal patterns in production and respiration. These efforts address the critical need for in situ estimates of production and respiration to better understand the ocean’s food web and biological pump.

The SO-PACE project is a multi-year effort to collect optical and flow cytometry measurements on ships of opportunity. Our project aims to collect high-quality in situ measurements with broad spatial coverage in support of evaluating NASA PACE satellite mission science data products. The PACE mission launched in February 2024, and our team will use ships of opportunity to collect data for PACE product validation during 2024-2026. The primary measurements to be collected by SO-PACE are hyperspectral water-leaving reflectances (commonly referred to as remote-sensing reflectance; Rrs) and inherent optical properties (IOPs) of surface waters. In addition, phytoplankton metrics derived from flow cytometry measurements will be made using instruments that run continuously via connection to shipboard flowing seawater systems. The instruments that will be used in SO-PACE can be installed on opportunistic cruises to target regions poorly represented by existing optical observations and thus will improve the ability to assess and effectively use satellite data products. All instruments run continuously and thus provide data at relatively high spatial and temporal resolution. Data collected continuously also enable calculation of sub-pixel variability for determining uncertainties in satellite products. The SO-PACE team is experienced in deployment of instruments to be used in this project.

We propose to collect high-frequency in situ measurements that can resolve the energy flux associated with internal waves propagating through the deep ocean by combining high vertical-resolution moorings to resolve the waves# modal structure with an antenna of vertically-integrated measures of variability to resolve the speed and direction of beam propagation. This proposal will instrument one internal-wave resolving (IWR) array that is re-deployable to multiple locations. The IWR Array proposed here comprises two pressure-sensor equipped inverted echo sounders (PIESs) and five PIESs with an additional current-sensor on each (CPIESs) and a densely instrumented, full-depth mooring. The C/PIES antenna will allow for the detection and separation of low-mode internal waves propagating from multiple directions, while the mooring will measure velocity and vertical displacement signals of five or more vertical modes. The array has been designed, and the data will be examined, in cooperation with a numerical modeling team (see the Buijsman et al. NOPP submission from our collaborators at USM, University of Michigan; U-M, and the Naval Research Laboratory; NRL) allowing for skill-testing and direct comparison with the global internal-tide resolving models that serve as inputs to regional models of the coastal ocean.

This award provides an additional three years of support for the Oceanic Flux Program (OFP). This program was first established in 1978 to measure the export flux of particles from the surface to the deep ocean in the deep Sargasso Sea and represents the longest and most continuous particle flux time-series of its kind. This program and the time-series record will continue to help the oceanographic community to answer questions about the relationship between deep ocean particle flux and climate and biological, physical, and chemical oceanographic processes. In the past, the OFP has provided evidence for coupling between the upper and deep ocean processes linked to seasonal, episodic (e.g., physical and meteorological forcing) and climate patterns. Looking to the future, this program will utilize increasingly advanced instrumentation and analytical tools to address questions about the material that sinks from the surface to deep ocean and its controls. The OFP provides education and training for students from the high school to Ph.D. level and supports early career researchers. The OFP time-series represents a 43-year, nearly continuous record focused on particle fluxes in the deep ocean. With increasingly more data available from the lengthening record, investigators can put observed biogeochemical patterns into perspective to understand the interplay between climate and ocean functioning. The availability of data from complementary nearby Hydrostation S, the Bermuda Atlantic Time-Series (BATS), the Bermuda Testbed Mooring (1994-2007), the Tudor Hill atmospheric tower and other Bermuda sampling programs provide additional opportunities to study upper ocean physics and biogeochemistry coupled with deep ocean biogeochemical processes. The OFP record is becoming long enough to study deep flux linkages with gyre circulation and advective processes. The OFP’s archive is an unparalleled resource for retrospective studies of temporal trends and the biogeochemical consequences of a changing ocean, including future impacts of ocean acidification. As the OFP heads into the future, increasingly sophisticated OFP mooring instrumentation (ADCP current profiling and backscatter; MicroCAT temperature, salinity, and oxygen measurements) and advances in digital imaging and analytical tools (both chemical and genomic) to probe the recovered flux materials continue to reveal novel, fundamental information about the oceanic particle flux and its controls.

Sediment trap and McLane pumping work for microplastics

Autonomous benthic landers are widely used in the deep sea. Capable of long-term deployments in some of the most remote benthic habitats, landers provide valuable information about the physical environments that deep-sea organisms experience through time. They operate on the principle of a drop weight, often acoustically triggered, and an appropriate amount of buoyancy to enable its retrieval at the surface following release of the weight. Their design and operation, despite the simplicities in principle, require a nuanced understanding of ocean technology, including metal behavior and corrosion, buoyancy and weight, as well as accurate understanding of how the lander will behave both in the water column and on the seafloor. The core of the Davies Lab ALBEX lander is depth-rated to 6000 m, stands 7 ft tall x 7 ft wide, and weighs nearly 2500 lbs in air when fully outfitted with a suite of instruments, including an acoustic current profiler, optical fluorometer/turbidity sensor, oxygen sensor, CTD, sediment trap and camera system. In this project, we will undertake testing and trials of the lander system, test new sensor integrations and establish real-time tracking and telemetry using a Sonardyne Ranger 2 USBL system.

The mesopelagic region of the ocean, between 200 and 1500 meters deep, is home to a complex mixture of physical processes, biological environments and animal communities that interact over a range of temporal and spatial scales. The mesopelagic remains poorly sampled due to the inherent limitations and asynchrony of measurements collected with ship-based instruments, acoustic surveys, remotely operated and towed vehicle systems. This project will develop a novel autonomous robotic instrument to collect physical, visual and acoustic data that will provide concurrent environmental, abundance, taxonomy and size structure data for animals ranging from 100 microns to 10 centimeters in size. The suite of sensors, coupled with a non-disruptive propulsion system and the operational flexibility of the new system will address critical knowledge gaps in our understanding of the ecology of the ocean's mid-water zone. The vehicle will be tested on several cruises in the North Atlantic. The researchers will leverage the ongoing Bermuda Atlantic Time Series (BATS) datasets for cross-comparison and validation. This project will also create research opportunities for undergraduate and graduate students at the University of Rhode Island, Stony Brook University and the Bermuda Institute of Ocean Sciences (BIOS). Public outreach will be facilitated through a partnership with the William M. Davies, Jr. Career and Technical High School, the Rhode Island Teacher-At-Sea program and the BIOS Mid-Atlantic Robotics IN Education (MARINE) program. These activities will develop activities to support STEM education and Next Generation Science Standards. The proposed instrument will be a stealthy vertical profiling vehicle. The sensor suite will consist of steerable multiple-frequency (38/70/200 kHz) broadband acoustics, stereo low light imaging, an Underwater Vision Profiler (UVP6), and environmental sensors for temperature, salinity, oxygen, chlorophyll, turbidity, beam attenuation and photosynthetically active radiation (PAR). Vertical propulsion will be achieved by an internal pumped volume ballasting system, which will create minimal disturbance around the vehicle to reduce avoidance behaviors known to bias observations from net tows and thruster-powered vehicles. Low light cameras will enable taxonomic documentation and size discrimination of larger organisms and gelatinous animals not quantitatively captured in net tows. The concurrent acoustics and environmental data will provide more complete habitat information than is possible with shipboard systems alone. With these capabilities the instrument will occupy an unfilled niche for sensing in the mesopelagic.

One day Sproul cruise to sample fishes for SIO class Biology of Fishes (SIO 188/294) during Fall Quarter 2023

Ship time dedicated to facilitate experiential learning for UGA and USG graduate and undergraduate students.

UW Oceanography Dept. Ocean 230 (and ESS 230) Student Cruise for Fall Quarter 2024.

Ship time dedicated to facilitate experiential learning for UGA and USG graduate and undergraduate students. Educational day awarded to Erv Garrison - UGA faculty.

The western North Pacific is the most active tropical cyclone basin in the world, with an average of 40 storms per year. Efforts to understand the driving mechanisms responsible for modulating tropical cyclone activity are significantly hampered by a short instrumental record. The abbreviated observational record does not permit the identification and characterization of climate forcings that may influence storm activity on centennial and longer timescales, including climate conditions for which there are not analogous historic observations. Instrumental archives in the western North Pacific only extend back to the middle 20 th century and the often incomplete historic record extends back to European colonization of the region. Over the past decade, proxy reconstructions have been developed, elucidating millennial and centennial-scale patterns in tropical cyclone activity. Coarse-grained storm-induced deposits, preserved in coastal sedimentary basins, are particularly effective proxies for intense tropical cyclone impacts at a site. Previously published work and preliminary data show that deep coastal depressions with rapidly accumulating sediments contain high-resolution records of the passage of intense tropical cyclones. These extraordinary sedimentary basins provide a means of extending documentary records of tropical cyclone strikes back millennia, and allow for i) the examination of climate/tropical cyclone interactions that lack modern analogs, ii) the generation of more accurate reoccurrence rate estimates, and iii) assessment of variations in storm activity on sub-millennial time scales. We propose to build on our previous work by exploiting archives of intense tropical cyclone passage across a geographic array of sites in the western North Pacific aimed at examining how tropical cyclone activity there may have varied over the last two millennia. These reconstructions can then be used to begin to explore the climatic drivers of changes in tropical cyclone activity in the western North Pacific. For example, as some of our recent work shows, shifts in the position of the intertropical convergence zone and the evolution of El Niño Southern Oscillation variability over the last millennium may have played a significant role in driving dramatic changes in intense tropical cyclone activity at Jaluit Atoll in the Marshall Islands. The results of this study will provide essential data on past patterns of tropical cyclone activity in the western North Pacific, and offer broader insight into climate factors that modulate tropical cyclone frequency, intensity, track, and area of development.

The research objectives of this project include investigating three-dimensional (3D) propagation, scattering and ambient sound of the acoustic field in the low to mid-frequency range around the Atlantis II Seamounts using an integrated network of sensors.

Large-scale deforestation of the U.S. East Coast during the 19th century increased runoff, amplifying floods as well as coastal sediment delivery. Much of the landscape has since been reforested but flood risk assessments (e.g., FEMA 100-yr flood maps) are often skewed by large floods from this earlier, high-runoff, regime. Likewise, environmental conditions in downstream ecosystems shaped by flood derived legacy sediment and freshwater inputs may not be sustained in the future. This research cruise will address the need for more accurate forecasting by assessing: (1) the dependence of flood frequency on landcover and (2) how land-use and storms have shaped coastal environments. A comprehensive record of past floods on Chesapeake Bay Rivers and land use will be compiled from historic records and sediment cores. Land-use changes will be reconstructed from analyses of downcore pollen assemblages. Grain-size variability and changes in the oxygen isotope fractionation of benthic foraminifera will be used as proxies for past flooding and salinity change, respectively. Incorporation of these data into flood frequency analyses using USGS Bulletin 17C guidelines will be used to improve risk forecasts for partners tasked with flood mitigation such as FEMA, the Army Corps of Engineers, the National Park Service and local governments.

Long-term observations over several decades are a powerful tool for investigating ocean physics, biology, and chemistry, and the response of the oceans to environmental change. The Bermuda Atlantic Time-Series Study, known as BATS, has been running continuously since 1988. The research goals of the BATS program are: (1) to improve our understanding of the time-varying components of the ocean carbon cycle and the cycles of related nutrient elements such as nitrogen, phosphorus, and silicon; and, (2) to identify the relevant physical, chemical and ecosystem properties responsible for this variability. In addition, the BATS program has strong and diverse broader impacts, contributing to the field of ocean sciences by providing high quality ocean observations and data for seagoing scientists and modelers, and a framework through which researchers can conceive and test hypotheses. This award will support the operations of the BATS program for five more years. The primary BATS research themes are as follows: (1) Quantify the role of ocean-atmosphere coupling and climate variability on air-sea exchange of CO2, and carbon export to the ocean interior; (2) Document trends and the controls on the interannual to decadal scale variability in carbon and nutrient cycles to their coupling in the surface and deep ocean via the Redfield Ratio paradigm; (3) Quantify the response of planktonic community structure and function, and impact on biogeochemical cycles to variability in surface fluxes and dynamical processes; (4) Facilitate development, calibration and validation of next generation oceanographic sensors, tools and technologies; and, (5) Generate a dataset that can be utilized by empiricists, modelers and students. This research integrates ocean physics, chemistry and biology into a framework for understanding oceanic processes and ocean change in the North Atlantic subtropical gyre. The existing 29 years of BATS data provide robust constraints on seasonal and interannual variability, the response of the Sargasso Sea ecosystem to natural climate variability, and signal detection of potential ocean changes. This project would extend the BATS program through years 31-35 to address a series of ten interlinked questions through integrated research approaches and a multitude of collaborative efforts. In addition to the themes above, and embedded into the ten questions and approaches, the BATS team will focus on, for example, coupling of particle production and biogeochemistry; revisiting the complexities of the biological carbon pump; oxygen decline; and changes in the hydrography, physics, ocean carbon cycle and biogeochemistry of the Sargasso Sea. The highest quality data observation and collection will be maintained and used to address these questions. Importantly, a wide range of collaborations at the BATS site, spanning the physical and biogeochemical disciplines, will aid these broad goals. Strong links to community stakeholders, and close collaboration (including methods intercomparisons and personnel exchanges) with the Hawaii Ocean Time-series are proposed. This work will extend the research findings of the project into educational and training opportunities within and beyond the oceanographic community, including training and mentorship of both undergraduate and graduate students.

One of the longest open-ocean hydrographic stations in the world is maintained at the Hydrostation S site (formerly known as the Panulirus site) located ~25 km southeast of Bermuda in the North Atlantic Ocean. This program of repeat biweekly hydrographic observations began in 1954 (by Hank Stommel) and now, in its seventh decade, has proved to be the catalyst for numerous studies of ocean physics, biological processes and biogeochemistry. Hydrostation S continues to be recognized as one of the most important sustained ocean time–series. The renewal of the Hydrostation S program is proposed herein, extending this invaluable time–series of ocean hydrography to almost 70 years. The upper ocean warming trend has strengthened (about +1.4° C since the 1970's; ~+0.8°C in last decade) with significant salinification (+0.16). Deeper waters such as the Labrador Sea Water has cooled by a few tenths of a degree and freshened with a marked decadal oscillation. The signature of deoxygenation has been observed at Hydrostation S in the upper ocean (about 4 µmoles kg -1 decade -1 decrease in dissolved oxygen) as well as the oxygen minimum zone (~2.5 µmoles kg -1 decade -1 ). Hydrostation S also supports the longest global ocean CO 2 and acidification time-series (from 1983 to present) The major objective of the proposal is to continue Hydrostation S into the eighth decade with numerous questions related to warming and cooling, salinification and freshening, deoxygenation and insights on biogeochemical changes over time. This program constitutes frequent water column sampling of temperature, salinity, and dissolved oxygen (and indirectly, sampling of important ocean carbon time–series) of the North Atlantic subtropical gyre at the Hydrostation S site. Such work is complementary to other sustained observations such as the Bermuda Atlantic Time–series Study (BATS) and Ocean Flux Program (OFP). We propose to carry out a similar sampling format that has been followed for the past 68 years. As for the past ten years, we would continue to conduct two CTD profiles to better capture the deep–water variability while maintaining all the previous discrete depths. The first CTD cast will profile to full ocean depth (3,300–3,500 m) while the second CTD cast will profile to 500 m (to allow for instrumentation not rated for full ocean depth such as a PAR sensor). One indirect objective will be to continue to collaboratively evaluate a BIOS-based glider program with Hydrostation S data as critically important ground truthing data. The existing glider program has challenging issue, and the aim of this effort is to use robust and highly accurate Hydrostation S data to test the capability of emerging technologies over the next five to ten years.

The Southeast Area Monitoring and Assessment Program (SEAMAP) Shrimp/Groundfish trawlsurveys are conducted throughout the Gulf of Mexico to provide fishery-independent monitoring andassessment information on shrimp and groundfish assemblages associated with low relief softbottomhabitats. These data are essential to the management of the fisheries resources in the Gulf of Mexico.Louisiana Department of Wildlife and Fisheries (LDWF), as well as SEAMAP state partners, sample inconjunction with the National Marine Fisheries Service (NMFS) to provide a Gulf-wide trawl surveyeach summer and fall.

FOCUS will investigate the relationship between sea-level changes in coastal Florida and variations in Gulf Stream transport of water and heat through Florida Straits. To address this goal, the project will use in-situ measurements of velocity, pressure and sound signals along a cross-section between Florida and The Bahamas. These measurements will lead to a better understanding of how 'sunny-day' flooding events in South Florida are linked to oceanic conditions offshore. Results will also illuminate links between variations in different components of Gulf Stream transport and the gyre and overturning circulation and heat content at basin scale. Investigators will interact closely with resilience program managers of a county in southeast Florida that is affected by increasingly frequent flooding from the ocean.