Biological and chemical contaminants enter aquatic ecosystems from both land and the atmosphere. Biological contaminants include viruses, bacteria, and parasites that infect humans, wildlife, or livestock. These enter our waterways through untreated sewage or wastewater, or via run-off from forests, agricultural fields, concentrated animal growth operations on land, or intensive aquaculture operations. Chemical contaminants also enter via these routes and occur in a wide variety of forms including organic nutrients, pesticides, herbicides, industrial products (e.g., PFAS and 6ppd- quinone), personal care products, pharmaceuticals, microplastics, and heavy metals. Many chemicals, especially PFAS, 6ppd-quinone, and microplastics are considered “contaminants of emerging concern” due to their longevity and potential for biomagnification in food webs. Inputs of many contaminants are poorly regulated, so concentrations are steadily increasing in aquatic ecosystems. Contaminants in surface waters may have direct effects on human health but may also profoundly influence aquatic ecosystems through indirect impacts on aquatic biota, resulting in poor water quality. The central focus of this session will be oral presentations on the quantification of environmental concentrations of these compounds in aquatic ecosystems, information on the real and potential impacts on biota (aquatic and human), characterizing biomarkers to demarcate exposure and adverse effects, new detection technologies, and strategies for mitigating contaminant impacts within these systems.
Lead Organizer: James Pinckney, University of South Carolina (pinckney@sc.edu)
Co-organizers:
David Hala, Texas A&M - Galveston (halad@tamug.edu)
Antonietta Quigg, Texas A&M - Galveston (quigga@tamug.edu)
Karl Kaiser, Texas A&M University - Galveston (kaiserk@tamug.edu)
Catherine Schlenker, University of South Carolina (schlenkc@email.sc.edu)
Presentations
09:00 AM
WATER QUALITY STATUS OF LOWER RIVER NIGER, AGENEBODE, NIGERIA (9758)
Primary Presenter: Adeniyi OSAIMIANMIONMWAN, Ajayi Crowther University Oyo. Nigeria (osasadeniyi@gmail.com)
Freshwater is often exposed to pollution, unhealthy environment due to rapid industrialization and population resulting in human afflictions and disease transmission, thus the need to study the water quality status of Lower River Niger, Agenebode. This paper reports findings from a study which evaluated the spatio-temporal variations in the physico-chemical parameters of the study area which is a vital resource for fishery and domestic uses for communities of over two-hundred thousand. Unfortunately, it’s fast degrading due to various anthropogenic activities, hence, the aim of this study is to investigate some physical and chemical parameters of Lower River Niger at Agenebode. Lower River Niger (LRN) was stratified downstream (DNS), midstream (MDS) and upstream (UPS) zones based on hydrological features and two sampling points each were randomly selected. Water samples were collected bi-monthly over two wet and dry seasons and analyzed for Dissolved-Oxygen (DO, mg/l), Chemical-Oxygen-Demand (COD mg/l), Total Suspended Solids (TSS mg/l), Alkalinity(mg/l), Phosphate(mg/l), conductivity(S/cm), Biochemical-Oxygen-Demand (BOD,mg/l), and temperature (0C) following standard methods. Highest (84.46±24.95) and lowest (75.45±24.23 mg/l) alkalinity was recorded for MDS and DNS respectively. Temperature and DO ranged from 27.52±1.48oC (DNS) to 28.32±1.56oC (MDS) and 4.27±0.42 (UPS) to 6.06±10 mg/l (DNS) respectively, TSS varied between 51.68±8.81mg/1 to 84±19.8mg/1, with maximum value in UPS and MDS. The seasonal variation showed that mean DO values, COD, transparency, temperature, conductivity, ammonia, phosphate, chloride, TDS, TSS, calcium, magnesium, sulphate, and depth vary significantly. Conductivity were 60.28±6.1 and 58.67±6.52 mg/l, phosphate (3.89±1.63;0.52±0.09) mg/l, temperature (28.20±2.34; 25.52±1.74) oC and DO (5.25±0.56; 5.5±0.61) mg/l in dry and wet seasons respectively. The mean values for BOD (68.52±61.21mg/l), temperature (27.52±1.48)oC, conductivity (59.55±25.19)mg/l, alkalinity (79.03±22.61) mg/l and ions were within desirable limits for aquatic life. However, TSS 101.49 ±105.27, Transparency 49.88±12.46, Sulphate 5.30±4.40 and COD 84.03±25.37 (mg/l) were above the recommended level for aquatic life. These findings are indicative of warning signs for pollution which impact not only aquatic organisms but also drinking water. Crucial restorative steps are needed therefore to reduce direct discharges of agricultural and anthropogenic effluents into LRN
09:15 AM
DETECTION AND SOURCE TRACKING OF FECAL POLLUTION IN ALABAMA RIVERS (9712)
Primary Presenter: Julie Olson, University of Alabama (jolson@ua.edu)
Alabama has an amazing network of streams and rivers that provide opportunities for recreational activities, including swimming, boating, and fishing, as well drinking water to more than one-fourth of the state’s population. However, these aquatic environments also receive fecal pollution from unprocessed human wastewater (e.g., failing septic systems or sewage overflows following large storms), manure from concentrated animal farming operations (both cattle and chickens), and wild animals (birds, fish, deer, feral hogs, etc.). To better understand the extent and sources of fecal pollution, river water samples were collected monthly for two years at fifteen locations (ten constant and five variable) on each of three rivers by their associated Riverkeeper organizations. After DNA was extracted from replicate subsample filters, droplet digital PCR (ddPCR) was performed to determine the presence and origin of Bacteroides, a gut-obligate, anaerobic bacterial genus. By obtaining variable location samples upstream of fecally-impacted constant sampling sites and employing a multiplex ddPCR assay to identify various sources of Bacteroides, specific point and non-point sources of fecal pollution have been identified. Not surprisingly, precipitation appears to impact the movement of fecal material into rivers, both via enhanced overland flow and by creating episodic sewage overflow events. Quantitative microbial risk assessments are underway to better determine the human health risks associated with exposure to fecally-polluted river waters, particularly from human sources.
09:30 AM
MERCURY CONCENTRATIONS CORRELATE WITH PARASITE PRESENCE IN EASTERN OYSTERS IN THE LONG ISLAND SOUND (8998)
Primary Presenter: Anika Agrawal, University of Connecticut (anika.agrawal@uconn.edu)
Contaminants and parasites are ubiquitous in aquatic environments and their interactions can have detrimental effects on host physiological and ecological responses. Yet, few studies have investigated the combined influence of chemical stress and parasite infections on bivalves. We studied the relationships between mercury (Hg) and methylmercury (MeHg) and macroparasite infections of pea crabs (Zaops ostreum) on Eastern oyster (Crassotrea virginica). Between 2022-2023, pea crabs (n=95) were opportunistically collected during monthly sampling of oysters (n=674) deployed at four coastal sites in the Long Island Sound (CT, USA). Hg concentrations in oysters with pea crabs (least-squares mean ± SE: 28.8 ± 1.07 ng g-1 ww) were 13% higher than in oysters without pea crabs (25.4 ± 1.08 ng g-1 ww), with no observed difference in MeHg concentrations nor %MeHg. We did not observe significant relationships between pea crab and oyster tissue concentrations of Hg, MeHg, or %MeHg. Pea crab infection and oyster tissue Hg and MeHg concentrations were independently associated with reduced oyster condition index, suggesting an additive but not synergistic influence of these two stressors on oyster health. These results motivate additional research into the dynamics of Hg bioaccumulation in oyster-pea crab systems and their implications for the health of oysters and their consumers.
09:45 AM
Leaching of Tire Wear Particles Additives Under Controlled Physicochemical Conditions (9563)
Primary Presenter: Nigel Lascelles, Texas A&M University - Corpus Christi/NOAA NOS NCCOS (nigellascelles@yahoo.com)
Tire particles, generated from everyday road use, are a significant source of non-exhaust emissions. As data increasingly reveals their widespread environmental presence, it is crucial to understand the pollutant loads inherited in these particles and those sorbed onto them. Tire wear consists of various components, including additive chemicals, aromatic oils, synthetic rubbers, and natural rubbers. Among these, 6PPD, 6PPD-quinone and Hexamethoxymethylmelamine (HMMM) are of particular concern because of its acute and chronic toxicity effects on aquatic organisms. Several precursor and transformation products of these compounds has been detected in waters bodies, particularly following road runoff after rain events, suggesting their presence in aquatic systems. This study investigates the leaching kinetics of tire wear particles and the associated chemical additives under controlled conditions. Using LC-Orbitrap Mass Spectrometry, we perform high-resolution and accurate mass measurements to enhance molecular identification and quantification, employing both targeted and untargeted approaches. Quadruplicates tire particle samples are incubated in Milli-Q water, artificial seawater and sterilized water from Lavaca River for one month. Following the incubation, the sample were extracted through solid-phase extraction, and analyzed for targeted tire additives and a untargeted chemical profile. Although the research is ongoing, our preliminary data will guide a more comprehensive study aimed at understanding the role of environmental factors in leaching of additives from tire wear particles.
10:00 AM
PFAS Bioaccumulation and Biomagnification in Middle Tennessee Freshwater Food Webs (9694)
Primary Presenter: Peter Blum, Tennessee Technological University (pwblum@gmail.com)
PFAS Bioaccumulation and Biomagnification in Middle Tennessee Freshwater Food Webs Per- and polyfluorinated alkyl substances (PFAS) are a diverse group of human-generated molecules that consist of a non-polar fluorinated carbon chain and a polar head. Due to their beneficial properties, they are used in many personal, industrial, and military applications. However, PFAS compounds are associated with endocrine disruption, some cancers, and other adverse health outcomes. Military installations have experienced PFAS contamination through activities, including using aqueous film-forming foams for fire control and regular firefighting training exercises using PFOS and PFOA. Freshwater insects developing in PFAS-contaminated streams can bioaccumulate these compounds as juveniles and transport PFAS to terrestrial consumers, including spiders, bats, and birds. We examined the potential for PFAS to move across the aquatic/terrestrial boundary through adult emergent aquatic insects to riparian predators at a military installation with a history of PFAS contamination. We found that PFAS compounds concentrate in adult insects, and biomagnification factors for organisms were both site and species-specific. Also we found that Tetragnatha spiders can be useful bioindicators for PFAS contamination in freshwaters. Understanding which PFAS compounds biomagnify and what routes they move through food webs can help inform mitigation efforts.
SS16A - Emerging Chemical and Biological Contaminants in Aquatic Ecosystems
Description
Time: 9:00 AM
Date: 30/3/2025
Room: W201CD