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David Zawada, Ph.D.

David Zawada is a Research Oceanographer at the St. Petersburg Coastal and Marine Science Center in St. Petersburg, Florida.

Dr. Zawada is a research oceanographer specializing in underwater imaging and seafloor elevation change.  

Professional Experience

  • Research Oceanograher, USGS, 2005-Present

  • Principal Scientist, Physical Sciences Inc., 2003-2005

  • Research Engineer, WET Labs, 2002-2003

  • Graduate Research Assistant, Scripps Institution of Oceanography, 1995-2002

  • Research Engineer, Argonne National Laboratory, 1987-1995

Education and Certifications

  • Ph.D. Oceanography, Scripps Institution of Oceanography, 2002

  • B.S. Chemical Engineering, University of Notre Dame, 1987

Affiliations and Memberships*

  • Executive board member, Association of Marine Laboratories of the Caribbean

Science and Products

Filter Total Items: 25

Subsampling large-scale digital elevation models to expedite geospatial analyses in coastal regions

Large-area, high-resolution digital elevation models (DEMs) created from light detection and ranging (LIDAR) and/or multibeam echosounder data sets are commonly used in many scientific disciplines. These DEMs can span thousands of square kilometers, typically with a spatial resolution of 1 m or finer, and can be difficult to process and analyze without specialized computers and software. Such DEMs
Authors
Kelly Ann Murphy, David G. Zawada, Kimberly K. Yates
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

Improving ESRI ArcGIS performance of coastal and seafloor analysis with the Python multiprocessing module

Coastal research frequently involves the use of a GIS to analyze large areas for changes in response to major weather events, human action, and other factors. The GIS workflows used to conduct these analyses can be complex and sometimes require multiple days to complete. Long runtimes often exist even on modern high-powered workstations if the GIS software does not use parallel computing technique
Authors
Jonathan Andrew Zieg, David G. Zawada
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

Rigorously valuing the impact of projected coral reef degradation on coastal hazard risk in Florida

The degradation of coastal habitats, particularly coral reefs, raises risks by increasing the exposure of coastal communities to flooding hazards. In the United States, the physical protective services provided by coral reefs were recently assessed, in social and economic terms, with the annual protection provided by U.S. coral reefs off the coast of the State of Florida estimated to be more than
Authors
Curt D. Storlazzi, Borja G. Reguero, Kimberly K. Yates, Kristen A. Cumming, Aaron Cole, James B. Shope, Camila Gaido L., David G. Zawada, Stephanie R. Arsenault, Zachery W. Fehr, Barry A. Nickel, Michael W. Beck
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, St. Petersburg Coastal and Marine Science Center, Hurricanes

Accurate bathymetric maps from underwater digital imagery without ground control

Structure-from-Motion (SfM) photogrammetry can be used with digital underwater photographs to generate high-resolution bathymetry and orthomosaics with millimeter-to-centimeter scale resolution at relatively low cost. Although these products are useful for assessing species diversity and health, they have additional utility for quantifying benthic community structure, such as coral growth and fine
Authors
Gerry Hatcher, Jonathan Warrick, Andrew C. Ritchie, Evan Dailey, David G. Zawada, Christine J. Kranenburg, Kimberly K. Yates
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, St. Petersburg Coastal and Marine Science Center, Supplemental Appropriations for Disaster Recovery Activities

Hydrodynamics and sediment mobility processes over a degraded senile coral reef

Coral reefs can influence hydrodynamics and morphodynamics by dissipating and refracting incident wave energy, modifying circulation patterns, and altering sediment transport pathways. In this study, the sediment and hydrodynamic response of a senile (dead) barrier reef (Crocker Reef, located in the upper portion of the Florida Reef Tract) to storms and quiescent conditions was evaluated using fie

Authors
Legna M. Torres-Garcia, P. Soupy Dalyander, Joseph W. Long, David G. Zawada, Kimberly K. Yates, Christopher Moore, Maitane Olabarrieta
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

Divergence of seafloor elevation and sea level rise in coral reef ecosystems

Coral reefs serve as natural barriers that protect adjacent shorelines from coastal hazards such as storms, waves, and erosion. Projections indicate global degradation of coral reefs due to anthropogenic impacts and climate change will cause a transition to net erosion by mid-century. Here, we provide a comprehensive assessment of the combined effect of all of the processes affecting seafloor accr
Authors
Kimberly K. Yates, David G. Zawada, Nathan A. Smiley, Ginger Tiling-Range
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center, Supplemental Appropriations for Disaster Recovery Activities

Investigación del USGS sobre el ecosistema de arrecifes de coral en el Atlántico

Información General Los arrecifes de coral son estructuras sólidas, biomineralizadas que protegen comunidades costeras actuando como barreras protectoras de peligros tales como los huracanes y los tsunamis. Estos proveen arena a las playas a través de procesos naturales de erosión, fomentan la industria del turismo, las actividades recreacionales y proveen hábitats pesqueros esenciales. La conti-n
Authors
Ilsa B. Kuffner, Kimberly K. Yates, David G. Zawada, Julie N. Richey, Christina A. Kellogg, Lauren T. Toth, Legna M. Torres-Garcia
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

USGS research on Atlantic coral reef ecosystems

Overview Coral reefs are massive, biomineralized structures that protect coastal communities by acting as barriers to hazards such as hurricanes and tsunamis. They provide sand for beaches through the natural process of erosion, support tourism and recreational industries, and provide essential habitat for fisheries. The continuing global degradation of coral reef ecosystems is well documented. Th
Authors
Ilsa B. Kuffner, Kimberly K. Yates, David G. Zawada, Julie N. Richey, Christina A. Kellogg, Lauren T. Toth
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

A comparison between boat-based and diver-based methods for quantifying coral bleaching

Recent increases in both the frequency and severity of coral bleaching events have spurred numerous surveys to quantify the immediate impacts and monitor the subsequent community response. Most of these efforts utilize conventional diver-based methods, which are inherently time-consuming, expensive, and limited in spatial scope unless they deploy large teams of scientifically-trained divers. In th
Authors
David G. Zawada, Rob Ruzicka, Michael A. Colella
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

Breeding loggerhead marine turtles Caretta caretta in Dry Tortugas National Park, USA, show high fidelity to diverse habitats near nesting beaches

We used satellite telemetry to identify in-water habitat used by individuals in the smallest North-west Atlantic subpopulation of adult nesting loggerhead turtles Caretta caretta during the breeding season. During 2010, 2011 and 2012 breeding periods, a total of 20 adult females used habitats proximal to nesting beaches with various levels of protection within Dry Tortugas National Park. We then u
Authors
Kristen M. Hart, David G. Zawada, Autumn R. Sartain-Iverson, Ikuko Fujisaki
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Fluorescence-based classification of Caribbean coral reef organisms and substrates

A diverse group of coral reef organisms, representing several phyla, possess fluorescent pigments. We investigated the potential of using the characteristic fluorescence emission spectra of these pigments to enable unsupervised, optical classification of coral reef habitats. We compiled a library of characteristic fluorescence spectra through in situ and laboratory measurements from a variety of s
Authors
David G. Zawada, Charles H. Mazel
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

Comparing bacterial community composition between healthy and white plague-like disease states in Orbicella annularis using PhyloChip™ G3 microarrays

Coral disease is a global problem. Diseases are typically named or described based on macroscopic changes, but broad signs of coral distress such as tissue loss or discoloration are unlikely to be specific to a particular pathogen. For example, there appear to be multiple diseases that manifest the rapid tissue loss that characterizes ‘white plague.’ PhyloChip™ G3 microarrays were used to compare
Authors
Christina A. Kellogg, Yvette M. Piceno, Lauren M. Tom, Todd Z. DeSantis, Michael A. Gray, David G. Zawada, Gary L. Andersen
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center
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View of beach from roof top, edge of roof in foreground, pier extending from beach out over water in center, park in background.

Remote Sensing Coastal Change

We use remote-sensing technologies—such as aerial photography, satellite imagery, structure-from-motion (SfM) photogrammetry, and lidar (laser-based surveying)—to measure coastal change along U.S. shorelines.
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Big Sur Landslides
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Remote Sensing Coastal Change

We use remote-sensing technologies—such as aerial photography, satellite imagery, structure-from-motion (SfM) photogrammetry, and lidar (laser-based surveying)—to measure coastal change along U.S. shorelines.
Learn More
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Equipment attached to a metal frame floats in the water on two buoys while dolphins frolic nearby.

SQUID-5 camera system

The SQUID-5 is a Structure-from-Motion Quantitative Underwater Imaging Device with 5 cameras.
By
Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, St. Petersburg Coastal and Marine Science Center
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SQUID-5 camera system

The SQUID-5 is a Structure-from-Motion Quantitative Underwater Imaging Device with 5 cameras.
Learn More
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Along-Track Reef Imaging System

Fine-scale Benthic Habitat Mapping

Both ATRIS configurations were deployed in Dry Tortugas National Park (DRTO) to fill information gaps in the spatial coverage of existing habitat maps.
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center
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Fine-scale Benthic Habitat Mapping

Both ATRIS configurations were deployed in Dry Tortugas National Park (DRTO) to fill information gaps in the spatial coverage of existing habitat maps.
Learn More
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Image: Flat Cays, U.S. Virgin Islands Coral Reef

Coral Reef Ecosystem Studies (CREST)

The specific objectives of this project are to identify and describe the processes that are important in determining rates of coral-reef construction. How quickly the skeletons of calcifying organisms accumulate to form massive barrier-reef structure is determined by processes of both construction (how fast organisms grow and reproduce) and destruction (how fast reefs break down by mechanical...
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center, Coral Microbial Ecology Laboratory
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Coral Reef Ecosystem Studies (CREST)

The specific objectives of this project are to identify and describe the processes that are important in determining rates of coral-reef construction. How quickly the skeletons of calcifying organisms accumulate to form massive barrier-reef structure is determined by processes of both construction (how fast organisms grow and reproduce) and destruction (how fast reefs break down by mechanical...
Learn More
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Fuorescent image of a Montastrea cavernosa 

Applications of Coral Fluorescence

Fluorescence is an often overlooked property of reef-building corals that can improve the classification of reef habitats from imagery and provide diagnostic information on corals.
By
St. Petersburg Coastal and Marine Science Center
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Applications of Coral Fluorescence

Fluorescence is an often overlooked property of reef-building corals that can improve the classification of reef habitats from imagery and provide diagnostic information on corals.
Learn More
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Location and submerged topographic map of the study site

Modeling Seafloor Structural Complexity

This effort focused on understanding the patterns and scalability of roughness and topographic complexity of marine habitats, such as coral reefs.
By
St. Petersburg Coastal and Marine Science Center
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Modeling Seafloor Structural Complexity

This effort focused on understanding the patterns and scalability of roughness and topographic complexity of marine habitats, such as coral reefs.
Learn More
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Along-Track Reef Imaging System

Along-Track Reef Imaging System (ATRIS)

ATRIS is a benthic-survey tool that simultaneously acquires geo-located, color, digital images with corresponding water depths.
By
St. Petersburg Coastal and Marine Science Center
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Along-Track Reef Imaging System (ATRIS)

ATRIS is a benthic-survey tool that simultaneously acquires geo-located, color, digital images with corresponding water depths.
Learn More
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bathymetry plotted in 3D

Advanced Remote Sensing Methods for Coastal Science and Management

This project focused on developing algorithms for quantifying benthic habitat complexity from images, modeling the structural complexity of the seafloor, and using fluorescence signatures to classify coral reef habitats.
By
St. Petersburg Coastal and Marine Science Center
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Advanced Remote Sensing Methods for Coastal Science and Management

This project focused on developing algorithms for quantifying benthic habitat complexity from images, modeling the structural complexity of the seafloor, and using fluorescence signatures to classify coral reef habitats.
Learn More
Filter Total Items: 46

Overlapping seabed images and location data acquired using the SQUID-5 system at Looe Key, Florida, in July 2021, with structure-from-motion derived point cloud, digital elevation model and orthomosaic of submerged topography

Underwater images were collected using a towed-surface vehicle with multiple downward-looking underwater cameras developed by the U.S. Geological Survey (USGS). The system is named the Structure-from-Motion (SfM) Quantitative Underwater Imaging Device with Five Cameras (SQUID-5). The raw images and associated navigation data were collected at Looe Key, a coral reef located within the Florida Keys
By
Pacific Coastal and Marine Science Center

Overlapping seabed images and location data acquired using the SQUID-5 system at Eastern Dry Rocks coral reef, Florida, in May 2021, with derived point cloud, digital elevation model and orthomosaic of submerged topography

Underwater images were collected using a towed-surface vehicle with multiple downward-looking underwater cameras developed by the U.S. Geological Survey (USGS). The system is named the Structure-from-Motion (SfM) Quantitative Underwater Imaging Device with Five Cameras (SQUID-5). The raw images and associated navigation data were collected at Eastern Dry Rocks, a coral reef located within the Flo
By
Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, St. Petersburg Coastal and Marine Science Center

Seafloor Elevation and Volume Change Analyses from 2016 to 2019 Along the Florida Reef Tract, USA

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted research to quantify bathymetric changes along the Florida Reef Tract (FRT) from Miami to Key West within a 939.4 square-kilometer area. USGS staff calculated changes in seafloor elevation and volume from 2016 to 2019 using light detection and ranging (lidar)-derived digital elevation models (DEMs) acquire
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

Flooding extent polygons for modelled wave-driven water levels in Florida with and without projected coral reef degradation

This data release presents projected flooding extent polygon (flood masks) shapefiles based on wave-driven total water levels for the State Florida (the Florida Peninsula and the Florida Keys). There are 12 associated flood mask shapefiles: one for each of four nearshore wave energy return periods (rp; 10-, 50-, 100-, and 500-years), the current scenario (base) and each of the degradation scenario
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Hurricanes

Seafloor Elevation Change From 2002 to 2016 in the Upper Florida Keys

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted research to quantify bathymetric changes in the Upper Florida Keys (UFK) from Triumph Reef to Pickles Reef within a 242.4 square-kilometer area. USGS staff calculated changes in seafloor elevation from 2002 to 2016 using light detection and ranging (lidar)-derived data acquired by the USGS in 2001 and 2002
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

Seafloor Elevation Change From 2016 to 2017 at Looe Key, Florida Keys-Impacts From Hurricane Irma

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted research to quantify bathymetric changes at Looe Key coral reef near Big Pine Key, Florida, within a 19.7 square-kilometer area following Hurricane Irma in September 2017. USGS staff used light detection and ranging (lidar)-derived data acquired by the National Oceanic and Atmospheric Administration (NOAA)
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

SQUID-5 structure-from-motion point clouds, bathymetric maps, orthomosaics, and underwater photos of coral reefs in Florida, 2019

The new structure-from-motion (SfM) quantitative underwater imaging device with five cameras (SQUID-5) was tested in July 2019 at Crocker Reef in the Florida Keys. The SQUID-5 was developed to meet the unique challenges of collecting SfM underwater imagery, including multiple cameras with different perspectives, accurate geographic locations of images, accurate and precise scaling of derived surfa
By
Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, St. Petersburg Coastal and Marine Science Center

Seafloor Elevation Change From 2004 to 2016 at Looe Key, Florida Keys

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted research to quantify bathymetric changes at Looe Key coral reef near Big Pine Key, Florida, within a 16.4 square-kilometer area between 2004 and 2016. USGS staff used light detection and ranging (lidar)-derived data acquired by the U.S. Army Corps of Engineers (USACE) Joint Airborne Lidar Bathymetry Techni
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

Projected Seafloor Elevation Along the Florida Reef Tract From Big Pine Key to Marquesas Key, Florida-75 Years From 2011 Based on Historical Rates of Mean Erosion

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted research to quantify the combined effect of all constructive and destructive processes on modern coral reef ecosystems by projecting future regional-scale changes in seafloor elevation for several sites along the Florida Reef Tract, Florida (FL) including the shallow seafloor along Key West, FL. USGS staff
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

Projected Seafloor Elevation Along the Florida Reef Tract From Port St. Lucie to Marquesas Key, Florida-100 Years From 2001 Based on Historical Rates of Mean Erosion

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted research to quantify the combined effect of all constructive and destructive processes on modern coral reef ecosystems by projecting future regional-scale changes in seafloor elevation along the Florida Reef Tract, Florida (FL). USGS staff used historical bathymetric point data from the 1930's (National Oc
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

Projected Seafloor Elevation Along the Florida Reef Tract From Port St. Lucie to Marquesas Key, Florida-50 Years From 2001 Based on Historical Rates of Mean Erosion

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted research to quantify the combined effect of all constructive and destructive processes on modern coral reef ecosystems by projecting future regional-scale changes in seafloor elevation along the Florida Reef Tract, Florida (FL). USGS staff used historical bathymetric point data from the 1930's (National Oc
By
St. Petersburg Coastal and Marine Science Center

Projected Seafloor Elevation Along the Florida Reef Tract From Port St. Lucie to Marquesas Key, Florida-75 Years From 2001 Based on Historical Rates of Mean Erosion

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted research to quantify the combined effect of all constructive and destructive processes on modern coral reef ecosystems by projecting future regional-scale changes in seafloor elevation along the Florida Reef Tract, Florida (FL). USGS staff used historical bathymetric point data from the 1930's (National Oc
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center
a green and white research boat on the water towing an object with two yellow pontoons
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R/V Sallenger Tows SQUID-5 for 3D Seafloor Mapping
A scientist on the back of the R/V Sallenger tows the SQUID-5 system behind the boat.
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R/V Sallenger tows SQUID-5 near Looe Key
Infographic: Studying Seafloor Erosion in the Florida Keys. Images of 3D map of coral reef and floating mapping equipment
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Studying Seafloor Erosion in the Florida Keys
A collection of equipment is mounted on yellow catamaran in the bay. In the background: a pier & skyline with tall buildings
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SQUID-5 test near the St. Pete Pier
Two men deploy scientific equipment mounted on yellow tanks into the bay
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SQUID-5 deployment in Tampa Bay
A man sits at a computer inside the cabin of a boat with water visible through the window in the background.
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Gerry Hatcher controls SQUID-5

Multi-grid Analysis of Point Stability Tool

Elevation-change datasets can also be used to identify stable and unstable areas of the seafloor. The Multi-grid Analysis of Point Stability (MAPS) program was created to automate this process. This program is used to locate persistent areas of user-defined seafloor stability and/or instability at common geographic locations from multiple elevation-change datasets (grids) representing different ti
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center

Seafloor Elevation Change Analysis Tool

The Seafloor Elevation Change Analysis Tool (SECAT) is a Python script intended to be run as a script tool by ArcMap or ArcGIS Pro that automates their intricate methodology.
By
Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center
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New USGS technology provides three dimensional benefits: assessing coastal hazards, seafloor stability, and coral restoration efforts

USGS team invented a new camera system to create highly detailed 3-dimensional models of the seafloor that are proving to be invaluable for coastal...

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Science and Products

*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government