Mary McGann
Science and Products
Sediment Transport in Coastal Environments
Our research goals are to provide the scientific information, knowledge, and tools required to ensure that decisions about land and resource use, management practices, and future development in the coastal zone and adjacent watersheds can be evaluated with a complete understanding of the probable effects on coastal ecosystems and communities, and a full assessment of their vulnerability to...
U.S. West Coast and Alaska Marine Geohazards
Marine geohazards are sudden and extreme events beneath the ocean that threaten coastal populations. Such underwater hazards include earthquakes, volcanic eruptions, landslides, and tsunamis.
Devastating earthquakes in Japan (2011) and Chile (2010) that spawned pan-oceanic tsunamis sent a sobering reminder that U.S. coastlines are also vulnerable to natural disasters that originate in...
Transport of invasive microorganisms
This research is part of the project “Sediment Transport in Coastal Environments”
Sediment core data from the northern flank of Monterey Canyon, offshore California
The five files included in this U.S. Geological Survey data release are data from a set of sediment cores acquired from the continental slope, north of Monterey Canyon, offshore central California.
Sediment core data from offshore Palos Verdes, California
The seven files included in this U.S. Geological Survey data release are data from a set of sediment cores acquired from the continental slope, offshore Los Angeles and the Palos Verdes Peninsula, adjacent to the Palos Verdes Fault, in 2009 and 2010.
Potential use of the benthic foraminifers Bulimina denudata and Eggerelloides advenus in marine sediment toxicity testing
The benthic foraminifers Bulimina denudata and Eggerelloides advenus are commonly abundant in offshore regions in the Pacific Ocean, especially in waste-discharge sites. The relationship between their abundance and standard macrofaunal sediment toxicity tests (amphipod survival and sea urchin fertilization) as well as sediment...
McGann, Mary Preconditioning by sediment accumulation can produce powerful turbidity currents without major external triggers
Turbidity currents dominate sediment transfer into the deep ocean, and can damage critical seabed infrastructure. It is commonly inferred that powerful turbidity currents are triggered by major external events, such as storms, river floods, or earthquakes. However, basic models for turbidity current triggering remain poorly tested, with few...
Bailey, Lewis; Clare, Michael; Rosenberger, Kurt J.; Cartigny, Matthieu J.B.; Talling, Peter J.; Paull, Charles K.; Gwiazda, Roberto; Parsons, Daniel; Simmons, Stephen; Xu, Jingping; Haigh, Ivan; Maier, Katherine L.; McGann, Mary; Lundsten, Eve M. Focused fluid flow and methane venting along the Queen Charlotte fault, offshore Alaska (USA) and British Columbia (Canada)
Fluid seepage along obliquely deforming plate boundaries can be an important indicator of crustal permeability and influence on fault-zone mechanics and hydrocarbon migration. The ~850-km-long Queen Charlotte fault (QCF) is the dominant structure along the right-lateral transform boundary that separates the Pacific and North American tectonic...
Prouty, Nancy G.; Brothers, Daniel; Kluesner, Jared; Barrie, J. Vaughn; Andrews, Brian D.; Lauer, Rachel; Greene, Gary; Conrad, James E.; Lorenson, Thomas; Law, Michael D.; Sahy, Diana; Conway, Kim; McGann, Mary; Dartnell, Peter What determines the downstream evolution of turbidity currents?
Seabed sediment flows called turbidity currents form some of the largest sediment accumulations, deepest canyons and longest channel systems on Earth. Only rivers transport comparable sediment volumes over such large areas; but there are far fewer measurements from turbidity currents, ensuring they are much more poorly understood. Turbidity...
Heerema, Catharina; Talling, Peter J.; Cartigny, Matthieu J.B.; Paull, Charles K.; Bailey, Lewis; Simmons, Stephen; Parsons, Daniel; Clare, Michael; Gwiazda, Roberto; Lundsten, Eve M.; Anderson, Krystle; Maier, Katherine L.; Xu, Jingping; Sumner, Esther J; Rosenberger, Kurt J.; Gales, Jenny; McGann, Mary; Carter, Lionel; Pope, Ed Shallow-water foraminifera and other microscopic biota of Clipperton Island, tropical eastern Pacific
The recent foraminiferal fauna and associated microbiota of Clipperton Island (10.2833°N, 109.2167°W) were investigated at 20 sites collected in the intertidal zone around the perimeter of the island and from the edge of the inner brackish-water lagoon. Due to the island’s geographic location in a low productivity zone, a lack of variable habitats...
McGann, Mary; Schmieder, Robert W; Loncke, Louis-Philippe A ship's ballasting history as an indicator of foraminiferal invasion potential--An example from Prince William Sound, Alaska, USA
We investigated the potential role of ballast sediment from coastal and transoceanic oil tankers arriving and de-ballasting in Port Valdez as a vector for the introduction of invasive benthic foraminifera in Prince William Sound, Alaska. Forty-one ballast sediment samples were obtained in 1998-1999 from 11 oil tankers that routinely discharged...
McGann, Mary; Ruiz, Gregory M.; Hines, Anson H.; Smith, George D. Sediment and organic carbon transport and deposition driven by internal tides along Monterey Canyon, offshore California
Submarine canyons provide globally important conduits for sediment and organic carbon transport into the deep-sea. Using a novel dataset from Monterey Canyon, offshore central California, that includes an extensive array of water column sampling devices, we address how fine-grained sediment and organic carbon are transported, mixed, fractionated,...
Maier, Katherine L.; Rosenberger, Kurt J.; Paull, Charles K.; Gwiazda, Roberto; Gales, Jenny; Lorenson, Thomas; Barry, James P.; Talling, Peter J.; McGann, Mary; Xu, Jingping; Lundsten, Eve M.; Anderson, Krystle; Litvin, Steven; Parsons, Daniel; Clare, Michael; Simmons, Stephen; Sumner, Esther J; Cartigny, Matthieu J.B. Linking direct measurements of turbidity currents to submarine canyon-floor deposits
Submarine canyons are conduits for episodic and powerful sediment density flows (commonly called turbidity currents) that move globally significant amounts of terrestrial sediment and organic carbon into the deep sea, forming some of the largest sedimentary deposits on Earth. The only record available for most turbidity currents is the deposit...
Maier, Katherine L.; Gales, Jenny; Paull, Charles K.; Rosenberger, Kurt J.; Talling, Peter J.; Simmons, Stephen; Gwiazda, Roberto; McGann, Mary; Cartigny, Matthieu J.B.; Lundsten, Eve M.; Anderson, Krystle; Clare, Michael; Xu, Jingping; Parsons, Daniel; Barry, James P.; Wolfson-Schwher, Monica; Nieminski, Nora M.; Sumner, Esther J Discovery of an extensive deep-sea fossil serpulid reef associated with a cold seep, Santa Monica Basin, California
Multi-beam mapping of the Santa Monica Basin in the eastern Pacific has revealed the existence of a number of elevated bathymetric features, or mounds, harboring cold seep communities. During 2013-2014, mounds at ~600 m water depth were observed for the first time and sampled by Monterey Bay Aquarium Research Institute’s ROV Doc Ricketts. Active...
Georgieva, Magdalena N; Paull, Charles K.; Little, Crispin TS; McGann, Mary; Sahy, Diana; Condon, Daniel; Lundsten, Lonny; Pewsey, Jack; Caress, David W; Vrijenhoek, Robert C Initial dispersal (1986-1987) of the invasive foraminifera Trochammina hadai Uchio in San Francisco Bay, California, USA
A time series of three closely-spaced data sets are used to track the early expansion of the invasive Japanese benthic foraminifera Trochammina hadai in the southern portion of San Francisco Bay known as South Bay. The species initially appeared in 1983, comprising only 1.5% of the assemblage in one of four samples that were dominated by the...
McGann, Mary The occurrence of the invasive foraminifera Trochammina hadai Uchio in Flamengo Inlet, Ubatuba, São Paulo State, Brazil
The agglutinated foraminifera Trochammina hadai Uchio (1962), a dominant species in Japan, first appeared as an invasive species in San Francisco Bay, US, in 1983. Trochammina hadai's first appearance in the Brazilian coastal waters of Flamengo Inlet, Ubatuba, Sao Paulo State, is recorded nearly three decades later, in two of thirty-four sediment...
Eichler, Patricia P. B.; McGann, Mary; Rodrigues, Andre R.; Mendonca, Alison; Amorim, Audrey; Bonetti, Carla; Cordeito de Farias, Cristiane; Mello e Sousa, Silvia H.; Vital, Helenice; Praxedes Gomes, Moab Faunal and stable isotopic analyses of benthic foraminifera from the Southeast Seep on Kimki Ridge offshore southern California, USA
We investigated the benthic foraminiferal faunal and stable carbon and oxygen isotopic composition of a 15-cm push core (NA075-092b) obtained on a Telepresence-Enabled cruise to the Southeast Seep on Kimki Ridge offshore southern California. The seep core was taken at a depth of 973 m in the vicinity of a Beggiatoa bacterial mat and vesicomyid...
McGann, Mary; Conrad, James E.