Pamela J Schofield, Ph.D.
Science and Products
In November 2018, USGS researchers joined partners in South Florida where they sampled freshwater bodies for non-native fishes. The bi-annual Fish Slam event helps monitor new introductions and document range expansion of known non-native fishes.
The Florida apple snail is a critical component of the state's wetland food webs. USGS scientists assess the effects of native and non-native fishes on the native snail populations.
Development of a Quantitative Risk Assessment Tool to Predict Invasiveness of Non-native Freshwater Fishes in Everglades National Park
The introduction of non-native fishes is a problem across the United States, particularly in Florida. USGS scientists are developing a decision support tool to help natural resourece managers prioritize which species to focus prevention, detection, rapid response, and control efforts.
The Hunt For The Southernmost Snakehead. Thirty-one fishery biologists from eleven agencies participated in a two-day Fish Slam event. Thirty-five sites in Broward and Miami-Dade counties were sampled for non-native fishes.
22-23 March 2017 - Ten teams of fishery biologists sampled 28 sites amid unexpected wildfires in the Big Cypress National Preserve over the two day period. On the second day a reporter from the Miami Herald accompanied a ground crew team.
Dozens of species of non-native fishes are present in the freshwaters of Florida, and new species are discovered each year. Maintaining current information on the geographic ranges of all non-native fishes is a daunting task, as many jurisdictions are involved at the state, federal, and municipal levels. There is a need to coordinate sampling, research and management across jurisdictional...
November 1 - 2, 2016 – Eight teams of fishery biologists from the US Geological Survey (USGS), US Fish and Wildlife Service - Peninsular Florida Fisheries Office and Welaka National Fish Hatchery (USFWS), the National Park Service (NPS), Florida Fish and Wildlife Conservation Commission (FWC), Florida International University (FIU), and Zoo Miami sampled 20 sites for non-native fishes in Palm...
May 23, 2016 – Five teams of fishery biologists from the U.S. Geological Survey (USGS), Florida Fish and Wildlife Conservation Commission (FWC), the National Park Service (NPS), Florida Museum of Natural History (FLMNH), University of Florida (UF), and Florida International University (FIU) sampled 12 sites for non-native fishes in Broward and Miami-Dade counties in southeastern Florida.
Thirty-four species of non-native marine fishes have been documented in Florida, and their distributions are currently being tracked via the US Geological Survey’s Nonindigenous Aquatic Species (USGS-NAS) database.
Many aspects of lionfish biology are studied at the USGS Wetland and Aquatic Research Center. As part of the U.S. Geological Survey Nonindigenous Aquatic Species database, the distribution of lionfish is tracked over time.
The Florida Everglades is the largest wetland ecosystem in the United States and supports a diverse flora and fauna, including many rare species.
In this project, USGS scientists are developing a new genetic technique – Trojan Y – to help eradicate invasive species. Although the methodology has been well-developed in theory, this is the first test of its practical application.
Introduction and dispersal of non-native bullseye snakehead Channa marulius (Hamilton, 1822) in the canal system of southeastern Florida, USA
An established population of bullseye snakehead (Channa marulius), a large predatory fish from southeastern Asia, was identified for the first time in North America from waters in southeastern Florida, USA, in the year 2000. Since then, it has dispersed throughout the extensive canal system in the area from West Palm Beach south to Miramar....Benson, Amy J.; Schofield, Pamela J.; Gestring, Kelly B.
Salinity tolerance among three freshwater mussels (Bivalvia: Unionidae) from Gulf Coastal Plain drainages
An important physiological constraint influencing distributions of coastal freshwater organisms is their tolerance for saline conditions. We experimentally evaluated salinity tolerance for three freshwater mussel species (Utterbackia imbecillis, Elliptio jayensis, and Glebula rotundata). Mussels were transferred abruptly from well water to one of...Johnson, Nathan A.; Schofield, Pamela J.; Williams, James D.; Austin, James D.
Non-native fishes of the central Indian River Lagoon
We provide a comprehensive review of the status of non-native fishes in the central Indian River Lagoon (from Cape Canaveral to Grant-Valkaria, east of I-95) through literature review and field surveys. Historical records exist for 17 taxa (15 species, one hybrid, one species complex). We found historical records for one additional species, and...Schofield, Pamela J.; Loftus, William F.; Reaver, Kristen M.
Salinity tolerance of non-native suckermouth armoured catfish (Loricariidae: Pterygoplichthys sp.) from Kerala, India
Loricariid catfishes of the genus Pterygoplichthys are native to South America and have been introduced in many localities around the world. They are freshwater fishes, but may also use low-salinity habitats such as estuaries for feeding or dispersal. Here we report results of a field survey and salinity-tolerance experiments for a population of...Kumar, A. Biju; Schofield, Pamela J.; Raj, Smrithy; Satheesh, Sima
Osmoregulation and muscle water control in vitro facing salinity stress of the Amazon fish Oscar Astronotus ocellatus (Cichlidae)
Specimens of Oscar Astronotus ocellatus from a fish farm were abruptly submitted to salt stress of 14 ppt and 20 ppt, for 3 and 8 h to determine their plasma osmolality. Muscle wet body mass change in vitro was analyzed from control freshwater animals. Fish in 14 ppt presented no osmolality distress even after 8 h. In...Gutierre, Silvia M. M.; Schulte, Jessica M.; Schofield, Pamela J.; Prodocimo, Viviane
Lionfish (Pterois spp.) invade the upper-bathyal zone in the western Atlantic
Non-native lionfish have been recorded throughout the western Atlantic on both shallow and mesophotic reefs, where they have been linked to declines in reef health. In this study we report the first lionfish observations from the deep sea (>200 m) in Bermuda and Roatan, Honduras, with lionfish observed to a maximum depth of 304 m off the...Gress, Erika; Andradi-Brown, Dominic A; Woodall, Lucy; Schofield, Pamela J.; Stanley, Karl; Rogers, Alex D.
Invasive species: Ocean ecosystem case studies for earth systems and environmental sciences
Marine species are increasingly transferred from areas where they are native to areas where they are not. Some nonnative species become invasive, causing undesirable impacts to environment, economy and/or human health. Nonnative marine species can be introduced through a variety of vectors, including shipping, trade, inland corridors (such as...Schofield, Pamela J.; Brown, Mary E.
Small but tough: What can ecophysiology of croaking gourami Trichopsis vittatus (Cuvier 1831) tell us about invasiveness of non-native fishes in Florida?
Trichopsis vittata (Cuvier, 1831) is a small, freshwater gourami (Fam: Osphronemidae) native to southeast Asia. It was first detected in Florida in the 1970s and seems to have persisted for decades in a small area. In this study, we documented T. vittata’s ecophysiological tolerances (salinity and low-temperature) and qualitatively...Schofield, Pamela J.; Schulte, Jessica
Modeling suitable habitat of invasive red lionfish Pterois volitans (Linnaeus, 1758) in North and South America’s coastal waters
We used two common correlative species-distribution models to predict suitable habitat of invasive red lionfish Pterois volitans (Linnaeus, 1758) in the western Atlantic and eastern Pacific Oceans. The Generalized Linear Model (GLM) and the Maximum Entropy (Maxent) model were applied using the Software for Assisted Habitat Modeling. We compared...Evangelista, Paul H.; Young, Nicholas E.; Schofield, Pamela J.; Jarnevich, Catherine S.
Salinity and temperature tolerance of an emergent alien species, the Amazon fish Astronotus ocellatus
Astronotus ocellatus (oscar), is native to the Amazon basin and, although it has been introduced to many countries, little is known regarding its tolerances for salinity and temperature. In this report, we provide data on the tolerance of A. ocellatus to abrupt and gradual changes in salinity, its high and low temperature tolerance, and...Gutierrel, Silvia M M; Schofield, Pamela J.; Prodocimo, Viviane
Survival and growth of invasive Indo-Pacific lionfish at low salinities
Invasive Indo-Pacific lionfish [Pterois volitans (Linnaeus, 1758) and P. miles (Bennett, 1828)] are now established throughout the Western North Atlantic. Several studies have documented negative effects of lionfish on marine fauna including significant changes to reef fish community composition. Established populations of lionfish...Schofield, Pamela J.; Huge, Dane H.; Rezek, Troy C.; Slone, Daniel H.; Morris, James A.
The role of citzens in detecting and responding to a rapid marine invasion
Documenting and responding to species invasions requires innovative strategies that account for ecological and societal complexities. We used the recent expansion of Indo-Pacific lionfish (Pterois volitans/miles) throughout northern Gulf of Mexico coastal waters to evaluate the role of stakeholders in documenting and responding to a rapid marine...Scyphers, Stephen B.; Powers, Sean P.; Akins, J. Lad; Drymon, J. Marcus; Martin, Charles M.; Schobernd, Zeb H.; Schofield, Pamela J.; Shipp, Robert L.; Switzer, Theodore S.
The Fish Slam event discovered two nonnative fish species never seen before in Big Cypress National Preserve.