Human activities, including urbanization, agriculture, and industry, coupled with a changing climate, exert significant pressure on freshwater ecosystem functions, driving alterations in external inputs that subsequently affect internal recycling mechanisms. External inputs and internal recycling mechanisms encompass and influence a wide range of water quality parameters, including biological, chemical, and physical contaminants, all of which have the capacity to substantially affect the health and stability of freshwater systems. Increased anthropogenic inputs coupled with pressure on freshwater resources have led to alterations in freshwater ecosystems such as eutrophication and subsequent harmful cyanobacterial blooms. In addition, climate change models predict increased occurrence of extreme events (flooding, extended droughts), which may further magnify the seasonal and multiannual disruption of ecosystem functions. To protect water resources, it is crucial for managers and decision-makers to set realistic targets for sustainable water quality management. Consequently, there is a pressing need for the development of comprehensive indicators capable of encapsulating the intricate interplay between anthropogenic inputs and the escalating impact of climate-related events.

The nature of input patterns in freshwater ecosystems vary based on factors such as temperature and trophic regimes. Responses to these alterations diverge among different freshwater systems, such as streams, impoundments, and natural lakes. Naturally, methods for monitoring and assessing water quality within these systems will also vary. Bioindicators, gray water footprint (GWF), discrete water column sampling and subsequent laboratory techniques such as colorimetry, stable isotopes and other physico-chemical tests have been used qualitatively and quantitatively to understand the nature of external inputs. Recent advancements in Unmanned Aerial Vehicles (UAVs), Autonomous Surface Vehicles (ASVs), and Unmanned Underwater Vehicles (UUVs) present promising prospects for large-scale monitoring of freshwater systems that otherwise lack robust spatial and temporal data.

This session aims to invite talks from academic and nonacademic researchers working with techniques like stable isotopes, satellite data, and autonomous systems to quantify the influence of anthropogenic inputs and climate change using water quality indicators in freshwaters.

Lead Organizer: Archana Venkatachari, University South Carolina (avenkatachari@seoe.sc.edu)

Co-organizers:

Quin Shingai, Dartmouth College (quin.k.shingai.gr@dartmouth.edu)

Panditha Gunawardana, Trent University (sasindugunawardana@trentu.ca)

Annie Bourbonnais, University of South Carolina (abourbonnais@seoe.sc.edu)

Kathryn Cottingham, Dartmouth College (Kathryn.L.Cottingham@dartmouth.edu)

Presentations

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05:30 PM

WATER QUALITY ASSESSMENT OF FISH FARMS AND IMPLICATIONS OF WASTE WATER IN LAGOS LAGOON (7681)

Primary Presenter: Nkechi Achilike, NIGERIAN INSTITUTE FOR OCEANOGRAPHY AND MARINE RESEARCH, VICTORIA ISLAND, LAGOS NIGERIA (nkechi780@gmail.com)

Discharge of effluents from aquaculture practice has been on increase in coastal areas such as Lagos State, Southwest Nigeria, which could lead to eutrophication and destruction of natural ecosystem in the receiving water body. Variations of water quality in fish farms in three agricultural zones in Lagos State were evaluated using multivariate statistical technique such as cluster analysis (CA) to analyze the temporal variations of water quality during fish production. Water quality data were generated from 8 fish farms (4 earthen ponds and 4 concrete tanks) at 2 production cycles. The water samples were monitored and analyzed for 9 physico-chemical parameters such as dissolved oxygen, pH, water temperature, total ammonia, nitrite, nitrate, alkalinity, hardness and transparency. Results showed a significant difference (p<0.05) in the investigated parameters between the fish farms and control farms indicating poor management practices. Cluster analysis revealed two groups in 4 earthen pond fish farms and two groups in 4 concrete tank fish farms based on similarities of water quality. This study recommended waste water treatment plants and integrated fish farming in farms along coastal areas.   Keywords: Effluent, Fish farm, physicochemical parameters, Water quality

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05:30 PM

LONG-TERM MONITORING OF ENVIROMENTAL CHANGES USING ZOOPLANKTON (8168)

Primary Presenter: Chuck Williams, University of Wyoming (cwilliamsargyle@gmail.com)

Freshwater lake ecosystems provide necessary services to humans and animals such as drinking water, irrigation, recreational opportunities, and habitat. However, human activities are greatly degrading aquatic ecosystems and monitoring programs are needed to identify and assess long-term changes. Jackson Lake, found in Grand Teton National Park, has been largely overlooked for long term lake monitoring efforts despite its unique trophic status, minimal anthropogenic alterations, and value to the community. Zooplankton have proven to be effective bio-indicators because of their intermediary position in the food web and ability to rapidly respond to environmental change. In this study, we evaluated changes in zooplankton population dynamics and characteristics at several sites across Jackson Lake to determine whether they are linked to water pollution, invasive species, and climate change. In the first year of zooplankton monitoring samples, we observed spatial and temporal heterogeneity of zooplankton populations within Jackson Lake, but limited historical data provides minimal context for long-term change. Therefore, we also discuss plans for long-term monitoring of zooplankton to see how freshwater lake ecosystems, such as Jackson Lake, will respond to anthropogenic disturbances in the future. 

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05:30 PM

Daphnia stress response to environmental concentrations of chloramphenicol (8222)

Primary Presenter: Adrian Gorecki, Warsaw University of Life Sciences (SGGW) (adrian_gorecki@sggw.edu.pl)

Commonly used medicines, when discarded or improperly disposed of, are known to contaminate freshwater ecosystems. Pharmaceuticals can be toxic, mutagenic, and can modify freshwater organisms, even at low concentrations if one considers their permanent presence in the environment. The aim of this study was to evaluate the impact of chloramphenicol (CAP) contamination in freshwater on the model organism Daphnia magna. Specific life history parameters, transcriptome, proteome, and host-associated microbiome of four D. magna clones were analysed during a three-generation exposure to CAP at environmental concentrations (32 ng L^-1). In the first generation, no statistically significant CAP effect at the individual level was detected. After three-generations, exposed animals were smaller at first reproduction and on average producing less offspring. Daphnia’s response to CAP presence indicates the high stress that the tested organisms are under, e.g. male production, upregulation of ubiquitin-conjugating enzyme E2 and calcium-binding protein, downregulation of glutathione transferase. Microbiome analysis showed a significant difference in the community diversity between the control and the chloramphenicol-treated samples. The ecotoxicogenomic approach together with long exposure in the laboratory imitating conditions in a polluted environment allows us to obtain a more complete picture of the CAP impact on Daphnia. This work was supported by the National Science Centre, Poland UMO-2021/03/Y/NZ9/00141 under the framework of JPIAMR-ACTION GA no 963864.

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05:30 PM

Capturing tributary input dynamics in an oligotrophic lake using an autonomous surface vehicle (8058)

Primary Presenter: Quin Shingai, Dartmouth College (quin.k.shingai.gr@dartmouth.edu)

Tributary inputs alter physical and chemical lake characteristics through acting as a major source of external loading. These inputs vary temporally due to weather and seasonality, and spatially due to surrounding land use. The temporal and spatial constraints of traditional limnological point sampling methods make it difficult to capture fine-scale patterns in tributary input dynamics. However, advancements in autonomous surface vehicle (ASV) technology facilitate spatial mapping of plume boundaries in relation to tributary inflows, increasing our capacity to capture and evaluate patterns in tributary inputs. Using an ASV, Catabot, we captured tributary plume dynamics across summers 2021, 2022, and 2023 in the upper arms of oligotrophic Lake Sunapee (New Hampshire, USA). Surface surveys of water quality parameters collected during ASV deployments throughout each summer allowed us to quantify the distance and magnitude of tributary inputs, in relation to precipitation events and drought. We observed spatial gradients in specific conductance with higher concentrations located in proximity to tributary inflows; steeper gradients during mid-to-late summer co-occurred with periods of heightened precipitation. Specific conductance was highest in 2023, the wettest summer, and lowest in 2021, the dryest summer. Preliminary attempts to quantify the reach of tributary inputs, the distance to which the tributary plume extends into the lake, indicate that increased precipitation may have a larger influence on reach than prior drought occurrence.

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