Kevin D Kroeger, PhD
Kevin Kroeger has studied coastal ecosystems since 1990, with focus on a range of topics including fluxes and biogeochemistry of nitrogen in groundwater discharge to estuaries and wetlands, estuarine water quality, and carbon and greenhouse gas cycling and fluxes in coastal wetlands.
Biography
Kroeger is lead of the Biogeochemical Processes group at Woods Hole Coastal and Marine Science Center, and lead of a new project titled: Biogeochemical Drivers of Wetland Persistence and Feedbacks on Coastal Hazards The objectives of this Project are to provide guidance to federal (National Park Service, Fish & Wildlife Service, Army Corp of Engineers), state, local and private land owners and managers regarding stability and persistence of coastal wetlands under a range of hydrological management conditions and changing environmental conditions. Tidal wetlands provide critical services to society, including protection of infrastructure from coastal hazards, and habitat provision for economically important species. A large fraction of U.S. tidal wetlands, however, has been lost or degraded during recent centuries due to human actions, largely related to development and utilization of coastal lands. Feedbacks and interactions among natural and anthropogenic drivers have altered the stability and persistence of coastal wetlands. Decisions regarding hydrological management can alter the balance of organic matter production, retention and preservation, and thus management actions can either promote wetland persistence and resilience, or cause catastrophic loss of elevation, putting coastal infrastructure at increased risk of flooding or storm damage. This project impacts wetland management decisions. The contiguous U.S. has close to 2 million hectares of estuarine and marine wetlands. Nearly all of that area is under some level of management, with the federal government being the largest single manager. Land managers at FWS and NPS, and flood managers at ACOE, must make decisions regarding whether to spend substantial funds to maintain, repair and enhance water control structures under increasing rates of sea level change, or alternatively whether to reduce or remove hydrological management, to restore managed wetlands to more natural hydrology and enhance the capability of wetlands to build elevation over time, and to migrate landward. Society needs guidance and predictions regarding the result of those decisions for continued elevation gain, migration, and ongoing persistence of the wetlands.
Science and Products
Wetland Carbon Working Group: Improving Methodologies and Estimates of Carbon and Greenhouse Gas Flux in Wetlands
WARC researchers are working to quantify the impacts of future climate and land use/land cover change on greenhouse gas emissions and reductions.
Submarine Groundwater Discharge
We define submarine groundwater discharge (SGD) to consist either of fresh groundwater, re-circulated seawater, or a composite thereof. We evaluate and present SGD in terms of a vector for nutrient delivery to coastal waters.
NASA-USGS National Blue Carbon Monitoring System
The NASA-USGS National Blue Carbon Monitoring System project will evaluate the relative uncertainty of iterative modeling approaches to estimate coastal wetland (marsh and mangrove) C stocks and fluxes based on changes in wetland distributions, using nationally available datasets (Landsat) and as well as finer scale satellite and field derived data in six sentinel sites.
Global Science and Data Network for Coastal Blue Carbon (SBC)
The Global Science and Data Network for Coastal Blue Carbon (SBC) brings together scientists from a wide range of disciplines. Our goal is to increase the accuracy of and confidence in local, regional, and global estimates of carbon cycle processes, fluxes, and storage as well as greenhouse gas emissions from coastal ecosystems, and to allow global access to quality controlled coastal...
Environmental Geochemistry
Coastal Environmental Geochemistry research at the Woods Hole Coastal and Marine Science Center spans multiple ecosystems and topics, including coastal wetlands, aquifers, and estuaries, with the goal of providing data and guidance to federal, state, local, and private land owners and managers on these vital ecosystems.
Advancing understanding of ecosystem responses to climate change with warming experiments: what we have learned and what is unknown?
Advancing our mechanistic understanding of ecosystem responses to climate change is critical to improve ecological theories, develop predictive models to simulate ecosystem processes, and inform sound policies to manage ecosystems and human activities. Manipulation of temperature in the field, or the “ecosystem warming experiment,” has proved to be a powerful tool to understand ecosystem...
Collection, analysis, and age-dating of sediment cores from Herring River wetlands and other nearby wetlands in Wellfleet, Massachusetts, 2015–17
U.S. Geological Survey collected fourteen sediment cores from different ecosystems within the tidally restricted Herring River estuary (four sites) and an estuary in Wellfleet Harbor near the Herring River dike (three sites) between 2015 and 2017. Collected cores were up to 70 cm in length with dry bulk density ranges from 0.03 to 2.39 grams per cubic centimeter and carbon content 0.23% to 46....
Collection, analysis, and age-dating of sediment cores from natural and restored salt marshes on Cape Cod, Massachusetts, 2015-16
Nineteen sediment cores were collected from five salt marshes on the northern shore of Cape Cod where previously restricted tidal exchange was restored to part of the marshes. Cores were collected in duplicate from two locations within each marsh complex: one upstream and one downstream from the former tidal restriction (typically caused by an undersized culvert or a berm).
Nearshore groundwater seepage and geochemical data measured in 2015 at Guinea Creek, Rehoboth Bay, Delaware
The U.S. Geological Survey and the University of Delaware measured rates of SGD and concentrations of dissolved constituents, including nitrogen species, from recirculating ultrasonic and manual seepage meters, and in nearshore groundwater, on the southern shore of Guinea Creek, an estuarine tributary of Rehoboth Bay, in Millsboro, Delaware, in June, August, and October of 2015.
Geochemical data supporting investigation of solute and particle cycling and fluxes from two tidal wetlands on the south shore of Cape Cod, Massachusetts, 2012-19
The U.S. Geological Survey and collaborators collected surface water and porewater geochemical data from a tidal wetland located on the eastern shore of Sage Lot Pond in Mashpee, Massachusetts, within the Waquoit Bay National Estuarine Research Reserve, between 2012 and 2019.
Continuous Monitoring Data From Herring River Wetlands, Cape Cod, Massachusetts, 2015 to January 2020
The Herring River estuary (Wellfleet, Cape Cod, Massachusetts) has been tidally restricted for over a century by a dike constructed near the mouth of the river. The U.S. Geological Survey collected continuous monitoring data (including water level, soil temperature, air temperature, and meteorological parameters). These datasets can help evaluate key ecosystem drivers.
Collection, analysis, and age-dating of sediment cores from salt marshes on the south shore of Cape Cod, Massachusetts, from 2013 through 2014
Elevation of the marsh surface was measured with RTK-GPS to evaluate where the marsh falls within the current tidal frame. The historic marsh surface elevation was then reconstructed using the calculated age of each depth interval and its elevation, assuming that elevations within this shallow zone (less than 30 cm) have been preserved for the past century.
Collection, analysis, and age-dating of sediment cores from salt marshes on the south shore of Cape Cod, Massachusetts, from 2013 through 2014
Elevation of the marsh surface was measured with RTK-GPS to evaluate where the marsh falls within the current tidal frame. The historic marsh surface elevation was then reconstructed using the calculated age of each depth interval and its elevation, assuming that elevations within this shallow zone (less than 30 cm) have been preserved for the past century.
Data compilation of soil respiration, moisture, and temperature measurements from global warming experiments from 1994-2014
This dataset is the largest global dataset to date of soil respiration, moisture, and temperature measurements, totaling >3800 observations representing 27 temperature manipulation studies, spanning nine biomes and nearly two decades of warming experiments. Data for this study were obtained from a combination of unpublished data and published literature values.
Continuous and optimized 3-arcsecond elevation model for United States east and west coasts
This data release contains the compilation of multiple elevation products into a continuous digital elevation model at a resolution of 3-arcseconds (approximately 90 meters) from the terrestrial landscape to the seafloor for the contiguous U.S. and portions of Mexico and Canada, focused on the coastal interface.
Coastal Groundwater Chemical Data from the North and South Shores of Long Island, New York
Groundwater data were collected in the spring and fall of 2008 from three sites representing different geological settings and biogeochemical conditions within the surficial glacial aquifer of Long Island, NY.
Oxygen-controlled recirculating seepage meter reveals extent of nitrogen transformation in discharging coastal groundwater at the aquifer–estuary interface
Nutrient loads delivered to estuaries via submarine groundwater discharge (SGD) play an important role in the nitrogen (N) budget and eutrophication status. However, accurate and reliable quantification of the chemical flux across the final decimeters and centimeters at the sediment–estuary interface remains a challenge, because there is...
Brooks, Thomas W.; Kroeger, Kevin D.; Michael, Holly A.; York, Joanna K.
Assessment of water quality and discharge in the Herring River, Wellfleet, Massachusetts, November 2015 to September 2017
The U.S. Geological Survey, Cape Cod National Seashore of the National Park Service, and Friends of Herring River cooperated from 2015 to 2017 to assess nutrient concentrations and fluxes across the ocean-estuary boundary at a dike on the Herring River in Wellfleet, Massachusetts. The purpose of this assessment was to characterize environmental...
Huntington, Thomas G.; Spaetzel, Alana B.; Colman, John A.; Kroeger, Kevin D.; Bradley, Robert T. Pore water exchange-driven inorganic carbon export from intertidal salt marshes
Respiration in intertidal salt marshes generates dissolved inorganic carbon (DIC) that is exported to the coastal ocean by tidal exchange with the marsh platform. Understanding the link between physical drivers of water exchange and chemical flux is a key to constraining coastal wetland contributions to regional carbon budgets. The spatial and...
Tamborski, Joseph; Eagle, Meagan; Kurylyk, Barret L.; Kroeger, Kevin D.; Wang, Zhaoihui; Henderson, Paul; Charette, Matthew Plant biomass and rates of carbon dioxide uptake are enhanced by successful restoration of tidal connectivity in salt marshes
Salt marshes, due to their capability to bury soil carbon (C), are potentially important regional C sinks. Efforts to restore tidal flow to former salt marshes have increased in recent decades in New England (USA), as well as in some other parts of the world. In this study, we investigated plant biomass and carbon dioxide (CO2) fluxes at four...
Wang, Fanning; Eagle, Meagan; Kroeger, Kevin D.; Spivak, Amanda C.; Tang, Jianwu An important biogeochemical link between organic and inorganic carbon cycling: Effects of organic alkalinity on carbonate chemistry in coastal waters influenced by intertidal salt marshes
Organic acid charge groups in dissolved organic carbon (DOC) contribute to total alkalinity (TA), i.e. organic alkalinity (OrgAlk). Its effect is often ignored or treated as a calculation uncertainty in many aquatic CO2 studies. This study evaluated the variability, sources, and characteristics of OrgAlk in estuarine waters exchanged tidally with...
Song, Shuzhen; Wang, Zhaohui Aleck; Gonneea Eagle, Meagan; Kroeger, Kevin D.; Chu, Sophie N.; Li, Daoji; Liang, Haorui Tidal wetland gross primary production across the continental United States, 2000–2019
We mapped tidal wetland gross primary production (GPP) with unprecedented detail for multiple wetland types across the continental United States (CONUS) at 16‐day intervals for the years 2000–2019. To accomplish this task, we developed the spatially explicit Blue Carbon (BC) model, which combined tidal wetland cover and field‐based eddy covariance...
Feagin, R.A.; Forbrich, I.; Huff, T. P.; Barr, J.G.; Ruiz-Plancarte, J.; Fuentes, J.D.; Najjar, R.G.; Vargas, R.; Vazquez Lule, A.; Windham-Myers, L.; Kroeger, Kevin D.; Ward, E. J.; Moore, G.W.; Leclerc, M.; Krauss, K. W.; Stagg, C.L.; Alber, M.; Knox, S. H.; Schafer, K. V. R.; Bianchi, T.S.; Hutchings, J. A.; Nahrawi, H.; Noormets, A.; Mitra, B.; Jaimes, A.; Hinson, A.L.; Bergamaschi, Brian; King, J.S.; Miao, G. Phytoplankton community structure response to groundwater-borne nutrients in the inland bays, Delaware
To determine the impacts of groundwater-borne nutrients on phytoplankton biomass and community structure, we conducted a series of mesocosm experiments in the Inland Bays of Delaware. Four treatments were tested, including mesocosms coupled directly to submarine groundwater seepage, mesocosms with the addition of pumped submarine groundwater,...
Torre, Daniel; Coyne, Kathryn; Kroeger, Kevin D.; York, Joanna K. Water salinity and inundation control soil carbon decomposition during salt marsh restoration: An incubation experiment
Coastal wetlands are a significant carbon (C) sink since they store carbon in anoxic soils. This ecosystem service is impacted by hydrologic alteration and management of these coastal habitats. Efforts to restore tidal flow to former salt marshes have increased in recent decades and are generally associated with alteration of water inundation...
Wang, Faming; Kroeger, Kevin D.; Gonneea Eagle, Meagan; Pohlman, John; Tang, Jianwu Salt marsh ecosystem restructuring enhances elevation resilience and carbon storage during accelerating relative sea-level rise
Salt marshes respond to sea-level rise through a series of complex and dynamic bio-physical feedbacks. In this study, we found that sea-level rise triggered salt marsh habitat restructuring, with the associated vegetation changes enhancing salt marsh elevation resilience. A continuous record of marsh elevation...
Gonneea Eagle, Meagan; Maio, Christopher V.; Kroeger, Kevin D.; Hawkes, Andrea D.; Mora, Jordan; Sullivan, Richard; Madsen, Stephanie; Buzard, Richard M.; Cahill, Niamh; Donnelly, Jeffrey P. Passive experimental warming decouples air and sediment temperatures in a salt marsh
Open top chambers (OTCs) are a commonly used passive warming technique in experimental warming studies. OTCs have been shown to be effective in multiple types of terrestrial systems, but their utility in wetland environments remains uncertain. The objective of this work was to evaluate the effectiveness of using OTCs to warm a temperate salt marsh...
Carey, Joanna C.; Kroeger, Kevin D.; Zafari, Babak; Tang, Jianwu Uncertainty in United States coastal wetland greenhouse gas inventorying
Coastal wetlands store carbon dioxide (CO2) and emit CO2 and methane (CH4) making them an important part of greenhouse gas (GHG) inventorying. In the contiguous United States (CONUS), a coastal wetland inventory was recently calculated by combining maps of wetland type and change with soil, biomass, and CH4 flux data from a literature...
James Holmquist; Windham-Myers, Lisamarie; Blanca Bernal; Byrd, Kristin B.; Steve Crooks; Gonneea Eagle, Meagan; Nathan Herold; Sara Knox; Kroeger, Kevin D.; John McCombs; J. Patrick Megonigal; Lu Meng; James Morris; Ariana Sutton-Grier; Tiffany Troxler; Donald Weller Natural climate solutions for the United States
Limiting climate warming to <2°C requires increased mitigation efforts, including land stewardship, whose potential in the United States is poorly understood. We quantified the potential of natural climate solutions (NCS)—21 conservation, restoration, and improved land management interventions on natural and agricultural lands—to increase...
Fargione, Joseph E.; Bassett, Steven; Boucher, Timothy; Bridgham, Scott D.; Conant, Richard T.; Cook-Patton, Susan C.; Ellis, Peter W.; Falcucci, Alessandra; Fourqurean, James W.; Gopalakrishna, Trisha; Gu, Huan; Henderson, Benjamin; Hurteau, Matthew D.; Kroeger, Kevin D.; Kroeger, Timm; Lark, Tyler J.; Leavitt, Sara M.; Lomax, Guy; McDonald, Robert I.; Megonigal, Patrick; Miteva, Daniela A.; Richardson, Curtis J.; Sanderman, Jonathan; Shoch, David; Spawn, Seth A.; Veldman, Joseph W.; Williams, Christopher A.; Woodbury, Peter B.; Zganjar, Chris; Baranski, Marci; Elias, Patricia; Houghton, Richard A.; Landis, Emily; McGlynn, Emily; Schlesinger, William H.; Siikamaki, Juha V.; Sutton-Grier, Ariana; Griscom, Bronson W.
How We Respond: Community Responses to Climate Change
The American Association for the Advancement of Science just launched “How We Respond: Community Responses to Climate Change” – an initiative that highlights the innovative ways communities are using science to respond to climate change at a local level through a series of multimedia stories and an accompanying report.