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At least 757 records · Page 42Linked to original sources
USGS2023

Predatory impacts of invasive Blue Catfish in an Atlantic coast estuary

Objective Predatory invasive fishes may consume species of management interest and alter food webs. Blue Catfish Ictalurus furcatus is a large-bodied, salinity-tolerant species that exhibits broad diet breadth and preys on species of both conservation concern and fisheries management interest. To better understand the ecological consequences of the establishment of Blue Catfish fisheries, estimates of predatory impacts are needed. Methods Using a Monte Carlo simulation, we integrated abundance estimates, diet information, and consumption-to-biomass ratios to estimate population-level Blue Catfish predation for a large Chesapeake Bay tributary along the mid-Atlantic coast of the United States, the James River. Result Population-level annual predation estimates by Blue Catfish exceeded 100 metric tons for several species or taxa of interest, including an estimated 400.7 metric tons (95% CI = 272.6–613.2) of blue crab Callinectes sapidus . Prey species abundances were unknown and thus limited opportunities to evaluate prey population responses. For instance, effects of Blue Catfish on blue crab populations remain unknown without tributary-specific estimates of blue crab abundance, but comparisons to landings data suggests that Blue Catfish predation on blue crab in the James River may be low compared with harvest. Conclusion Estimation of Blue Catfish predatory effects may inform development of management goals and objectives that balance diverse stakeholder interests. This work provides beneficial information to assess trade-offs of Blue Catfish fisheries and their effects on coastal aquatic resources.

Virginia↗
USGS2014

Using SPMDs for monitoring hydrophobic organic compounds in urban river water in Korea compared with using conventional water grab samples

We aimed to verify the effectiveness of semi-permeablemembrane devices (SPMDs) formonitoring hydrophobic organic compounds, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), that are not easy to detect using conventional grab samples (because of their low concentrations), in water.We used SPMDs and grab samples to monitor PCBs and PBDEs upstream and downstream of a sewage treatment plant (STP) in the Suyeong River in Busan, Korea. Concentrations in three different phases (freely dissolved, apparently dissolved, and particulate) were measured, to investigate the aquatic fate of PCBs and PBDEs. The freely dissolved (SPMD) concentrations were 2–3 times higher than the apparently dissolved and particulate phase (grab sample) concentrations. No meaningful relationships were found between the total PCB and PBDE concentrations of the grab sample and SPMD sample because of the different partitioning behaviors and detection frequencies of the individual chemicals. However, the summed concentrations of specific PCB and PBDE congeners (that were abundant in all samples) in the grab and SPMD samples correlated well (r 2 = 0.7451 for PCBs 28 + 52 + 153, r 2 = 0.9987 for PBDEs 28 + 47 + 99). The PBDE concentrations measured using SPMDs decreased with increasing distance from the STP, but no apparent dilution effect was found in the grab samples. Our results show that SPMDs could be used to support grab sampling for specific chemicals, or to trace chemical sources (such as STPs) to the aquatic environment.

Science of the Total Environment↗
USGS2019

Predicting the occurrence of chemicals of emerging concern in surface water and sediment across the U.S. portion of the Great Lakes Basin

Chemicals of emerging concern (CECs) are introduced into the aquatic environment via various sources, posing a potential risk to aquatic organisms. Previous studies have identified relationships between the presence of CECs in water and broad-scale watershed characteristics. However, relationships between the presence of CECs and source-related watershed characteristics have not been explored across the Great Lakes basin. Boosted regression tree (BRT) analyses were used to develop predictive models of CEC occurrence in water and sediment throughout 24 U.S. tributaries to the Great Lakes. Models were based on the distribution of both broad-scale and source-related watershed characteristics. Twenty-one upstream watershed characteristics, including land cover, number of permitted point sources, and distance to point sources were used to develop models predicting the probability of CEC occurrence in surface water and bottom sediment. Total accuracy of BRT models ranged from 66% to 94% for both matrices. All 21 watershed characteristics were important predictor variables in at least one surface-water model; twenty were important in at least one bottom-sediment model. Among the model variables, developed land use and distance to point sources were important predictors of the presence of CEC classes in both water and sediment. Although limitations exist, BRT models are one tool available for assessing vulnerability of fisheries and aquatic resources to CEC occurrences.

Great Lakes basin↗
USGS2024

Exploring spatial and temporal symptoms of the freshwater salinization syndrome in a rural to urban watershed

The freshwater salinization syndrome (FSS), a concomitant watershed-scale increase in salinity, alkalinity, and major-cation and trace-metal concentrations, over recent decades, has been described for major rivers draining extensive urban areas, yet few studies have evaluated temporal and spatial FSS variations, or causal factors, at the subwatershed scale in mixed-use landscapes. This study examines the potential influence of land-use practices and wastewater treatment plant (WWTP) effluent on the export of major ions and trace metals from the mixed-use East Branch Brandywine Creek watershed in southeastern Pennsylvania, during the 2019 water year. Separate analysis of baseflow and stormflow subsets revealed similar correlations among land-use characteristics and streamwater chemistry. Positive associations between percent impervious surface cover, which ranged from 1.26 % to 21.9 % for the 13 sites sampled, and concentrations of Ca 2+ , Mg 2+ , Na + , and Cl − are consistent with road-salt driven reverse cation exchange and weathering of the built environment. The relative volume of upstream WWTP was correlated with Cu and Zn, which may be derived in part from corroded water-conveyance infrastructure; chloride to sulfate mass ratios (CSMR) ranged from ~6.3 to ~7.7× the 0.5 threshold indicating serious corrosivity potential. Observed exceedances of U.S. Environmental Protection Agency Na + and Cl − drinking water and aquatic life criteria occurred in winter months. Finally, correlations between percent cultivated cropland and As and Pb concentrations may be explained by the persistence of agricultural pesticides that had been used historically. Study results contribute to the understanding of FSS solute origin, fate, and transport in mixed-use watersheds, particularly those in road salt-affected regions. Study results also emphasize the complexity of trace-metal source attribution and explore the potential for FSS solutes to affect human health, aquatic life, and infrastructure.

Pennsylvania↗
USGS2021

A seasonally dynamic model of light at the stream surface

Light is a primary constraint on primary production and drives many ecological processes in stream ecosystems, yet light regimes have received considerably less attention than other factors of the stream environment, such as hydrology or nutrient cycling. Light received by streams can be highly heterogeneous in both space and time resulting from changes in topography, channel characteristics, and riparian vegetation. Both the structure and phenology of riparian vegetation can be important determinants of the seasonality and magnitude of light reaching the stream surface, particularly in smaller forested streams. Despite the importance of riparian phenology on temporal patterns of stream light availability, existing models do not account for the seasonal dynamics of canopies. We developed a dynamic, biophysically based model ( StreamLight ) that incorporates canopy structure and phenology to predict light reaching the stream surface. We compared StreamLight to an existing model at 21 sites across the USA and found that, across sites, our biophysically based model produced light estimates that were more strongly correlated to observations and reduced the magnitude of errors in comparison to the existing model, particularly for streams that were relatively narrow compared to the height of riparian vegetation. Because smaller streams represent most global stream length, we expect that, in many smaller forested streams, the inclusion of canopy structure and phenology will enhance our ability to predict light regimes. We also used model simulations to examine the importance of controls on stream light environments and found that channel width was the strongest control on light environments. StreamLight represents an important incremental step forward in developing mechanistic models of river network productivity and in linking shifts in terrestrial vegetation structure and phenology to aquatic ecosystem productivity and thermal regimes.

Freshwater Science↗
USGS2013

Hydrologic monitoring and selected hydrologic and environmental studies by the U.S. Geological Survey in Georgia, 2011–2013

This compendium of papers describes results of hydrologic monitoring and hydrologic and environmental studies completed by the U.S. Geological Survey (USGS) in Georgia during 2011–2013. The USGS addresses a wide variety of water issues in the State of Georgia working with local, State, and Federal partners. As the primary Federal science agency for water resource information, the USGS monitors the quantity and quality of water in the Nation’s rivers and aquifers, assesses the sources and fate of contaminants in aquatic systems, collects and analyzes data on aquatic ecosystems, develops tools to improve the application of hydrologic information, and ensures that its information and tools are available to all potential users. During 2011–2013, the USGS continued a long-term program of monitoring stream and groundwater resources, including flow, water quality, and water use. In addition, a variety of hydrologic and environmental studies were completed to assess water availability, hydrologic hazards, and the impact of development on water resources. Information on USGS activities in Georgia is available online at http://ga.water.usgs.gov/ .

Georgia↗
USGS2015

Oil-particle interactions and submergence from crude oil spills in marine and freshwater environments: review of the science and future research needs

Oil-particle interactions and oil submergence are of much interest to oil spill responders and scientists, especially as transportation of light and heavy crude oils increases in North America’s coastal marine and freshwater environments. This report contains an up-to-date review of the state of the science for oil-particle aggregates (OPAs), in terms of their formation and stability which may alter the transport, fate, and toxicity of the residual oil and, hence, its level of ecological risk. Operational considerations—detection, containment, and recovery—are discussed. Although much is known about oil-particle interactions in coastal marine environments, there remains a need for additional science on methods to detect and quantify the presence of OPAs and to understand their effects on containment and recovery of oil spilled under various temperature regimes and in different aquatic habitats including freshwater environments.

Open-File Report↗
USGS2024

Wildlife health capacity enhancement in Thailand through the World Organisation for Animal Health Twinning Program

There is an increasing need for robust wildlife health programs that provide surveillance and management for diseases in wildlife and wild aquatic populations to manage associated risks. This paper illustrates the value of a systematic method to enhancing wildlife health programs. The U.S. Geological Survey and Mahidol University, Faculty of Veterinary Science, Thailand National Wildlife Health Center formally twinned under the auspices of the World Organisation for Animal Health to enhance wildlife health capacity in Thailand and the Southeast Asia Region. We used a system-wide approach to holistically and interdependently enhance capacity. The project commenced with a wildlife health program needs assessment, and capacity enhancement focused on strengthening the general wildlife health surveillance network and improving wildlife health information management. Activities included partner surveys, interactive and didactic workshops, and individual personnel training. Topics included development of wildlife health information management systems, analysis of the current surveillance network, development of a Theory of Change for a strengthened surveillance network, planning workshops to create a wildlife health network, training on wildlife disease outbreak investigation and field sample collection, leading networks, and individual training on bioinformatics and laboratory techniques. Engagement of stakeholders at all levels, continuous communication throughout the project, use of both strategic planning tools and pedagogical methods, and using iterative and adaptive approaches, were key factors to the success of this project.

Frontiers in Veterinary Science↗
USGS2011

Setting limits: Using air pollution thresholds to protect and restore U.S. ecosystems

More than four decades of research provide unequivocal evidence that sulfur, nitrogen, and mercury pollution have altered, and will continue to alter, our nation's lands and waters. The emission and deposition of air pollutants harm native plants and animals, degrade water quality, affect forest productivity, and are damaging to human health. Many air quality policies limit emissions at the source but these control measures do not always consider ecosystem impacts. Air pollution thresholds at which ecological effects are observed, such as critical loads, are effective tools for assessing the impacts of air pollution on essential ecosystem services and for informing public policy. U.S. ecosystems can be more effectively protected and restored by using a combination of emissions-based approaches and science-based thresholds of ecosystem damage. Based on the results of a comprehensive review of air pollution thresholds, we conclude: ??? Ecosystem services such as air and water purification, decomposition and detoxification of waste materials, climate regulation, regeneration of soil fertility, production and biodiversity maintenance, as well as crop, timber and fish supplies are impacted by deposition of nitrogen, sulfur, mercury and other pollutants. The consequences of these changes may be difficult or impossible to reverse as impacts cascade throughout affected ecosystems. ??? The effects of too much nitrogen are common across the U.S. and include altered plant and lichen communities, enhanced growth of invasive species, eutrophication and acidification of lands and waters, and habitat deterioration for native species, including endangered species. ??? Lake, stream and soil acidification is widespread across the eastern United States. Up to 65% of lakes within sensitive areas receive acid deposition that exceeds critical loads. ??? Mercury contamination adversely affects fish in many inland and coastal waters. Fish consumption advisories for mercury exist in all 50 states and on many tribal lands. High concentrations of mercury in wildlife are also widespread and have multiple adverse effects. ??? Air quality programs, such as those stemming from the 1990 Clean Air Act Amendments, have helped decrease air pollution even as population and energy demand have increased. Yet, they do not adequately protect ecosystems from long-term damage. Moreover they do not address ammonia emissions. ??? A stronger ecosystem basis for air pollutant policies could be established through adoption of science-based thresholds. Existing monitoring programs track vital information needed to measure the response to policies, and could be expanded to include appropriate chemical and biological indicators for terrestrial and aquatic ecosystems and establishment of a national ecosystem monitoring network for mercury. The development and use of air pollution thresholds for ecosystem protection and management is increasing in the United States, yet threshold approaches remain underutilized. Ecological thresholds for air pollution, such as critical loads for nitrogen and sulfur deposition, are not currently included in the formal regulatory process for emissions controls in the United States, although they are now considered in local management decisions by the National Park Service and U.S. Forest Service. Ecological thresholds offer a scientifically sound approach to protecting and restoring U.S. ecosystems and an important tool for natural resource management and policy. ?? The Ecological Society of America.

Issues in Ecology↗
USGS2018

A critical time for mercury science to inform global policy

Mercury is a global pollutant released into the biosphere by varied human activities including coal combustion, mining, artisanal gold mining, cement production, and chemical production. Once released to air, land and water, the addition of carbon atoms to mercury by bacteria results in the production of methylmercury, the toxic form that bioaccumulates in aquatic and terrestrial food chains resulting in elevated exposure to humans and wildlife. Global recognition of the mercury contamination problem has resulted in the Minamata Convention on Mercury, which came into force in 2017. The treaty aims to protect human health and the environment from human-generated releases of mercury curtailing its movement and transformations in the biosphere. Coincident with the treaty’s coming into force, the 13th International Conference of Mercury as a Global Pollutant (ICMGP-13) was held in Providence, Rhode Island USA. At ICMGP-13, cutting edge research was summarized and presented to address questions relating to global and regional sources and cycling of mercury, how that mercury is methylated, the effects of mercury exposure on humans and wildlife, and the science needed for successful implementation of the Minamata Convention. Human activities have the potential to enhance mercury methylation by remobilizing previously released mercury, and increasing methylation efficiency. This synthesis concluded that many of the most important factors influencing the fate and effects of mercury and its more toxic form, methylmercury, stem from environmental changes that are much broader in scope than mercury releases alone. Alterations of mercury cycling, methylmercury bioavailability and trophic transfer due to climate and land use changes remain critical uncertainties in effective implementation of the Minamata Convention. In the face of these uncertainties, important policy and management actions are needed over the short-term to support the control of mercury releases to land, water and air. These include adequate monitoring and communication on risk from exposure to various forms of inorganic mercury as well as methylmercury from fish and rice consumption. Successful management of global and local mercury pollution will require integration of mercury research and policy in a changing world.

Environmental Science & Technology↗
USGS2024

Interdisciplinary science approach for harmful algal blooms (HABs) and algal toxins—A strategic science vision for the U.S. Geological Survey

Executive Summary Algal blooms in water, soils, dusts, and the environment have captured national attention because of concerns associated with exposure to algal toxins for humans and animals. Algal blooms naturally occur in all surface-water types and are important primary producers for aquatic ecosystems. However, excessive algae growth can be associated with many harmful effects ranging from aesthetic to toxicity concerns, so this excessive growth is commonly called a harmful algal bloom (HAB). Ecological imbalances that can lead to excessive algal growth, such as increased nutrient availability to waterbodies from natural and anthropogenic sources, are well documented in scientific literature. On the other hand, fundamental scientific understandings of environmental causes and controls leading to algal toxin production, environmental exposures, and adverse health outcomes for humans and animals could benefit from more attention by U.S. Geological Survey (USGS) scientists. Understanding when, why, and how the toxin is produced by individual algal cells or communities and why the toxin is released to the surrounding waterbody requires fundamental research to determine a toxin’s role, whether it provides competitive advantage or if other potential reasons exist for toxin production and release, such as secretions from otherwise benign biological processes. This research will require groundbreaking scientific discovery about underlying biologic and abiotic (non-living) processes commonly complicated by local variation in land use, microbial species composition, and ecosystem structure of the surrounding watershed. Although underlying processes by which HABs form may be similar from one waterbody to another, individual waterbodies may be controlled by local factors for HAB development and toxin production that are unique to the watershed. Consequently, many fundamental science gaps exist that prevent informed mitigation and prevention of toxic HAB events. There are also gaps in understanding local conditions that control algal growth unique to specific watersheds. Addressing these science gaps is needed to inform evidence-based decisions that protect human and animal health and that reduce recreational and socioeconomic losses.

Circular↗
USGS2025

A comprehensive assessment of membrane bioreactor contaminant removal efficacy through analytical chemistry, fish exposures, and microbiome characterization

Treated municipal wastewater effluent is an important pathway for Contaminants of Emerging Concern (CEC) to enter aquatic ecosystems. As the aging wastewater infrastructure in many industrialized countries requires upgrades or replacement, assessing new treatment technologies in the context of CEC effects may provide additional support for science-based resource management. Here, we used three lines of evidence, analytical chemistry, fish exposure experiments, and fish and water microbiome analysis, to assess the effectiveness of membrane bioreactor treatment (MBR) to replace traditional activated sludge treatment. To do this, we sampled a municipal wastewater treatment plant with a split wastewater stream, a portion of which was treated with an MBR and another via an oxidation ditch (OXI). The OXI and MBR treatments substantially reduced most measured CECs compared to the primary effluent (PRI). Only pesticides and some pharmaceuticals were recalcitrant to both secondary treatment methods. While ammonia toxicity of PRI prevented its inclusion in fish exposure experiments, exposure of fish with waters from the OXI or MBR treated wastewater produced only subtle biological differences with no adverse apical outcomes. These findings were consistent with low chemically derived exposure: activity ratios for OXI and MBR. Microbiome analysis of fish and wastewater highlighted the significant reduction of microbial abundance and diversity in the MBR treatment compared to all other treatments. The comparable removal efficacy of CECs in MBR makes it an attractive alternative to traditional OXI, especially when MBR may eliminate the need for tertiary treatment for wastewater disinfection.

Environmental Toxicology and Chemistry↗
USGS2006

Helping solve Georgia's water problems - the USGS Cooperative Water Program

The U.S. Geological Survey (USGS) addresses a wide variety of water issues in the State of Georgia through the Cooperative Water Program (CWP). As the primary Federal science agency for water-resource information, the USGS monitors the quantity and quality of water in the Nation's rivers and aquifers, assesses the sources and fate of contaminants in aquatic systems, collects and analyzes data on aquatic ecosystems, develops tools to improve the application of hydrologic information, and ensures that its information and tools are available to all potential users. This broad, diverse mission cannot be accomplished effectively without the contributions of the CWP.

Georgia↗
USGS1992

Water, Energy, and Biogeochemical Budgets (WEBB) program: Data availability and research at the Northern Temperate Lakes site in north-central Wisconsin

More than three thousand kettle lakes, widely dispersed within a mixed temperate forest ecosystem, are predominant features of the Northern Highland area of north-central Wisconsin. A hydrological and biogeochemical investigation of seven of these lakes and their watershed area is currently in progress as part of the Water, Energy, and Biogeochemical Budgets (WEBB) program of the U.S. Geological Survey. The objectives of the overall WEBB program are to: (1) improve understanding of processes controlling water, energy, and biogeochemical fluxes in freshwater systems, the interactions among those processes, and their relations to climatic variables; and (2) improve the capability to predict freshwater, energy, and biogeochemical budgets over a range of spatial and temporal scales. The focus of the WEBB project in Wisconsin is hydrologic research in the Northern Temperate Lakes (NTL) area of the state. Based on the premise that an understanding of hydrologic and biogeochemical cycles in the watershed is predicated on a thorough understanding of the individual components that control the water flow, the project involves a detailed study of the hydrologic budget, including the roles of rainfall, streamflow, ground water, and flow in the unsaturated zone. It also involves investigation of ground-water/ surface-water interactions. The objectives of the Northern Temperate Lakes WEBB project are to: (1) describe processes controlling water and solute fluxes in the NTL watersheds; (2) examine interactions among those processes and their relations to climatic variables; and (3) improve the capability to predict changes in water and solute fluxes for a range of spatial and temporal scales. A variety of procedures will be used to address the objectives of the project including: installation of piezometers, lysimeters, stream-gaging sites, precipitation collectors, climate-monitoring instruments; analysis of transport of nutrients and other solutes through the system; analysis of changes in isotopic composition of water; and temperature profiling. The implementation of these procedures is described in this report. The NTL-WEBB study area includes seven lakes that are also the site of a Long-Term Ecological Research (LTER) project, sponsored by the National Science Foundation. This project incorporates diverse research investigations conducted by faculty and research associates of the University of Wisconsin-Madison. The research orientation of NTL-LTER is principally toward aquatic ecology and geochemistry of the lakes. The WEBB research plan, with its emphasis on hydrologic processes in the lake watersheds, is designed to complement and enhance the LTER work.

Wisconsin↗
USGS1997

The effects of pollutants on wildlife

In this chapter, selected sources of information which address the effects of pollutants on wildlife are reviewed. Although naturally occurring plant and animal toxins also affect wildlife, the focus of this review is xenobiotic toxicants. Xenobiotic substances are chemicals introduced into the environment in the form of pesticides, heavy metals, polychlorinated biphenyls (PCBs), and other by-products of human activities. The science of examining the effects of these substances on animal and plant life is multi-disciplinary in nature and contributors to the literature in this field include toxicologists, wildlife and aquatic ecologists, chemists and those in the veterinary and medical professions.

Book chapter↗
USGS2021

Riverscape approaches in practice: Perspectives and applications

Landscape perspectives in riverine ecology have been undertaken increasingly in the last 30 years, leading aquatic ecologists to develop a diverse set of approaches for conceptualizing, mapping and understanding ‘riverscapes’. Spatiotemporally explicit perspectives of rivers and their biota nested within the socio-ecological landscape now provide guiding principles and approaches in inland fisheries and watershed management. During the last two decades, scientific literature on riverscapes has increased rapidly, indicating that the term and associated approaches are serving an important purpose in freshwater science and management. We trace the origins and theoretical foundations of riverscape perspectives and approaches and examine trends in the published literature to assess the state of the science and demonstrate how they are being applied to address recent challenges in the management of riverine ecosystems. We focus on approaches for studying and visualizing rivers and streams with remote sensing, modelling and sampling designs that enable pattern detection as seen from above (e.g. river channel, floodplain, and riparian areas) but also into the water itself (e.g. aquatic organisms and the aqueous environment). Key concepts from landscape ecology that are central to riverscape approaches are heterogeneity, scale (resolution, extent and scope) and connectivity (structural and functional), which underpin spatial and temporal aspects of study design, data collection and analysis. Mapping of physical and biological characteristics of rivers and floodplains with high-resolution, spatially intensive techniques improves understanding of the causes and ecological consequences of spatial patterns at multiple scales. This information is crucial for managing river ecosystems, especially for the successful implementation of conservation, restoration and monitoring programs. Recent advances in remote sensing, field-sampling approaches and geospatial technology are making it increasingly feasible to collect high-resolution data over larger scales in space and time. We highlight challenges and opportunities and discuss future avenues of research with emerging tools that can potentially help to overcome obstacles to collecting, analysing and displaying these data. This synthesis is intended to help researchers and resource managers understand and apply these concepts and approaches to address real-world problems in freshwater management.

Biological Reviews↗
USGS2022

The silence of the clams: Forestry registered pesticides as multiple stressors on soft-shell clams

Contaminants are ubiquitous in the environment, often reaching aquatic systems. Combinations of forestry use pesticides have been detected in both water and aquatic organism tissue samples in coastal systems. Yet, most toxicological studies focus on the effects of these pesticides individually, at high doses, and over acute time periods, which, while key for establishing toxicity and safe limits, are rarely environmentally realistic. We examined chronic (90 days) exposure by the soft-shell clam, Mya arenaria , to environmentally relevant concentrations of four pesticides registered for use in forestry (atrazine, 5 μg/L; hexazinone, 0.3 μg/L; indaziflam, 5 μg/L; and bifenthrin, 1.5 μg/g organic carbon (OC)). Pesticides were tested individually and in combination, except bifenthrin, which was tested only in combination with the other three. We measured shell growth and condition index every 30 days, as well as feeding rates, mortality, and chemical concentrations in tissue from a subset of clams at the end of the experiment to measure contaminant uptake. Indaziflam caused a high mortality rate (max. 36%), followed by atrazine (max. 27%), both individually as well as in combination with other pesticides. Additionally, indaziflam concentrations in tissue (61.70–152.56 ng/g) were higher than those of atrazine (26.48–48.56 ng/g), despite equal dosing concentrations, indicating higher tissue accumulation. Furthermore, clams exposed to indaziflam and hexazinone experienced reduced condition index and clearance rates individually and in combination with other compounds; however, the two combined did not result in significant mortality. These two compounds, even at environmentally relevant concentrations, affected a non-target organism and, in the case of the herbicide indaziflam, accumulated in clam tissue and appeared more toxic than other tested pesticides. These findings underscore the need for more comprehensive studies combining multiple compounds at relevant concentrations to understand their impacts on aquatic ecosystems.

Science of the Total Environment↗