In most watersheds, ecosystem changes are responses to complex multiple pressures, including anthropogenic and natural environmental factors and their joint effects/interactions. Managing and monitoring aquatic systems under this scenario remains a complex task for researchers, managers and policymakers. Despite considerable growth in understanding the consequences of multiple environmental stressors on aquatic ecosystem structure and function in the last decade, significant knowledge gaps and challenges remain in developing approaches to detect, quantify and manage stressor interactions in the real world. As the rate of landscape disturbance and climate change continues to increase globally, it is urgent to develop new integrated methods to diagnose multiple stressors and assess ecological indicators' responses to them. Understanding these effects in terms of changes in the ecosystem’s diversity and function is especially important, as well as developing effective management actions, as water stress is a worrying issue internationally. Aquatic monitoring efforts are used worldwide to gather substantial amounts of data on environmental change at a variety of temporal and spatial scales. These data can have multiple sources (i.e., remote sensing, in-situ sampling, genomic, Traditional Knowledge from local and Indigenous communities, high-frequency monitoring equipment, citizen science, etc.). However, their utilization in a coordinated manner to assess environmental change has been limited. It is now essential to determine how monitoring and evaluation programs incorporate measures to understand multiple stressors' effects. To move forward, it is crucial to identify key physical-chemical drivers (i.e., hydrology, water quality, climate, etc.) which directly and indirectly affect biological/ecological receptors (i.e., from cells to ecosystems), as well as the likelihood of stressor exposure, recovery potential/resilience, or vulnerability of the endpoints. Designing the best path forward for observing aquatic ecosystems requires building robust monitoring programs that allow us to address the connection between all dimensions involved: physical, biological, and social. This session aims to bring together researchers and practitioners from a range of geographic regions and programs to share knowledge and experiences on the effectiveness and challenges associated with implementing monitoring programs addressing multiple stressor impacts, including policy and decision-making hurdles they faced. A focus will be placed on solutions and examples of successful implementation and emerging approaches/technologies for monitoring systems. Discussions around the importance of a variety of experimental and in-situ studies and monitoring, with a specific focus on the critical step of translating results and outcomes to monitoring design, adaptive monitoring and policy, are encouraged. We welcome submissions across all aquatic environments (lakes, oceans, deltas, etc.) and geographical regions. The outcomes of this session will help inform ongoing and future effective implementations of monitoring and environmental change programs and to address contemporary and future aquatic environmental issues at an ecosystem/watershed scale.
Lead Organizer: David Barrett, University of Calgary (david.barrett@ucalgary.ca)
Co-organizers:
Ana Carolina Sinigali Alves Lima, University of Calgary (anacarolina.sinigali@ucalgary.ca)
Frederick Wrona, University of Calgary (frederickjohn.wrona@ucalgary.ca)
Presentations
06:30 PM
Enhancing the Laurentian Great Lakes Biology Monitoring Program: the latest in diatom taxonomy (4921)
Primary Presenter: Elizabeth Alexson, Natural Resources Research Institute, University of Minnesota Duluth (alexs005@d.umn.edu)
Diatoms make up a significant portion of the phytoplankton biovolume in the Laurentian Great Lakes and are powerful indicators of many stressors such as nutrient pollution and climate change. Despite their ecological significance, our understanding of their taxonomy and diversity is still evolving. Recently, we named five new species of very common diatoms from the genera Fragilaria and Pantocsekiella, and we are now (re)considering species from the genus Stephanodiscus. Stephanodiscus spp. are common in the pelagic region of all five great lakes and are dominant in the spring assemblages of the more productive lakes Erie and Ontario. Several cosmopolitan species are excellent ecological indicators; for example, S. parvus and S. binderanus are often considered indicators of eutrophication. We use high-resolution microscopy to investigate the most commonly encountered species of Stephanodiscus. The results from morphometric analyses and ecological assessments of these taxa will aid in the identification and documentation of these species. By bettering our understanding of their taxonomy and morphology, we can improve our detection of these critical species and the ecological shifts that determine their presence. These early warnings are especially important in the Laurentian Great Lakes, which are facing threats from nutrient loading, anthropogenic warming, and harmful algal blooms.
06:30 PM
Places and moments with abundant submerged aquatic vegetation (SAV): new tools for high frequency monitoring at broad spatial scales (5594)
Primary Presenter: Morgan Botrel, Université de Montréal, Groupe de recherche interuniversitaire en limnologie (GRIL) (morgan.botrel@umontreal.ca)
Submerged aquatic vegetation (SAV) are essential components of inland water ecosystems and provides many ecosystem services, such as supplying food and habitat for fauna and promoting a clear water state. These ecosystem services are threatened by the rapid changes in SAV quantities associated with various drivers, where the predominant decline in recent decades is due to eutrophication. However, this information comes from biased time series primarily located in temperate zones, measured through single recurrent annual inventories. Therefore, our understanding of both SAV ecology and their response to human activities is hampered by the lack of observations in the many lake-rich regions of the world and the limited description of the timing in SAV seasonal development. To improve knowledge on SAV geographic distribution and temporal evolution, we present an overview of methodological developments that we have conducted in recent years. We first show an intercalibration of three methods, quadrat, rake and echosounding, to facilitate the monitoring of SAV biomass at large spatial and temporal scale. We then discuss the use of the slope of water surface elevation as an indicator of biomass and how it allowed for the detection of detailed seasonal growth and phenological changes. We finally present a novel model to predict lake bathymetry from the surrounding topography, for a better estimate of littoral area at broad scales. In combination with information on light availability to SAV, the model will allow mapping and estimating change in potential SAV colonization area.
06:30 PM
Quantifying Stability and Resilience in Estuaries and Lakes Using High Frequency Data (5729)
Primary Presenter: MLP Michael L. Pace, University of Virginia (mlp5fy@virginia.edu)
High frequency data are increasingly available with potential to assess critical properties of aquatic ecosystems under threat from global change. Here, we review examples of quantifying stability and resilience using 1) long-term monitoring data and 2) experiments where we collected in situ high frequency data. In the first case we quantified the recovery of estuaries from hurricanes to assess stability. In the second case we quantified resilience using manipulations of lakes where thresholds were approached and crossed. For estuaries, we used long-term, high frequency measures of salinity and dissolved oxygen from the U.S. National Estuarine Research Reserve measuring disturbance and recovery in 19 estuaries impacted by hurricanes. Estuarine salinity and dissolved oxygen recovered from hurricane disturbances within 1 to 10 days. Some disturbances are longer (up to 100 days) but estuarine salinity and dissolved oxygen are typically in response to hurricanes. For lakes, we measured phytoplankton pigments and processes (dissolved oxygen and pH change) at high frequency during nutrient enrichment manipulations. Dynamic linear models provided reliable measures of loss of resilience with increases in phytoplankton from low to high biomass. Repeated transitions of phytoplankton biomass between low and high states enabled measurement of exit time – the time an ecosystem remains in a state. Our lake manipulations quantified resilience of lakes to nutrient enrichment and indicate possibilities for early warning and for comparisons among ecosystems. High frequency data that yield long-term references and frame disturbances provide opportunities to measure ecosystem stability and resilience.
06:30 PM
Long-term changes in the ichthyofaunal composition in a temperate estuarine ecosystem – developments in the Elbe estuary over the past 40 years (5784)
Primary Presenter: Jesse Theilen, University of Hamburg (jesse.theilen@uni-hamburg.de)
The Elbe estuary is subject to constantly changing abiotic factors such as salinity, water temperature, oxygen content, turbidity and river runoff. In estuarine food webs, keystone fish species are considered suitable indicators for the assessment of ecosystem quality. With climate change and other human impacts, such as channel management, wastewater sewage and nutrient inputs, the Elbe estuary has faced several anthropogenic stressors in the past and present. Within the past four decades, severe alterations of the ecosystem occurred. With regard to changing abiotic factors, the aim of this study is to check whether these influences have led to significant changes in the fish fauna of the Elbe estuary. Data from research catches with stow net vessels over four time periods (I: 1984-1986, II: 1994-1995, III: 2009-2010 and IV: 2021-2022) were standardized. The composition of the fish fauna at five main channel stations along the salinity gradient of the Elbe estuary was compared during all four seasons. The highest total fish biomasses per haul were recorded in periods II and III (75.36 and 119.46 kg/Mio m3, respectively), whereas biomasses were much lower in periods I and IV (39.09 and 16 kg/Mio m3, respectively). These changes are mainly related to changes in abundance and biomass of O. eperlanus, the most important fish species in the Elbe estuary. Between periods III and IV the abundance of A. fallax, P. flesus, G. cernua and other species declined, while abundance of two marine estuarine opportunists (C. harengus and M. merlangus) increased.
06:30 PM
Quantifying algal blooms with high frequency data and a disturbance-recovery algorithm (6024)
Primary Presenter: Dat Ha, University of Virginia (dh3dv@virginia.edu)
Algal blooms are disturbances to aquatic ecosystems that can impact water quality and ecosystem services. It is often difficult to detect algal bloom disturbance magnitudes and recovery times, making it challenging to compare disturbances within and among aquatic systems. Using high frequency phycocyanin and chlorophyll-a data and a disturbance-recovery algorithm, we quantified the magnitude and duration of algal bloom disturbances. We first applied the algorithm to nutrient enriched experimental lakes with detailed algal data. Next, we applied the algorithm to non-experimental lakes with long pigment sensor time series. The algorithm accurately detected algal bloom onsets, magnitudes, and recoveries in the experimental lakes, facilitating within and cross-system comparisons. In non-experimental lakes, we identified the most severe/intense disturbances and those that occurred at unusual times. Recovery time and peak disturbance magnitude differed among non-experimental lakes. Lakes with phycocyanin and chlorophyll-a time series rarely had concurrent disturbances in both variables. Algal bloom disturbances and recoveries can be accurately detected with appropriate reference data, but the problem is more difficult in non-experimental lakes due to the complexities of reference data selection, missing values, and pigment sensor errors. Overall the approach shows promise in quantifying algal bloom dynamics where long-term high frequency data are available.
06:30 PM
BIG DATA FOR MARINE PROTECTED AREAS FISHERIES MONITORING (6421)
Primary Presenter: Joan Sala-Coromina, Institut de Ciències del Mar (ICM-CSIC) / Institut Català de Recerca per a la Governança del Mar (ICATMAR) (jsala@icm.csic.es)
Marine protected areas (MPA) have been established both for biodiversity conservation and under a fisheries management framework. Targeting fisheries sustainability, one of the main expected effects of MPAs is spillover effect. That is, the exportation of commercial species biomass outside the protected areas as a consequence of its increased abundance inside the fishing bans boundaries.The European regulation of Western Mediterranean Multiannual Plan for demersal stock management (2019) stated MPAs should be established for fisheries sustainability. In the Spanish Mediterranean coast, trawling fisheries were banned in a total of 41 new marine protected areas (MPAs), 21 of which are permanent (973 km2) and 16 temporary (6013 km2). After the establishment of MPAs, it remains crucial to correctly reinforce and monitor them to allow an adaptative fisheries management approach based on sound scientific advice. In this work, we present a methodology that combines trawling Vessel Monitoring System data and commercial fishing landings datasets to evaluate spillover effects after the protection of an MPA. After testing the methodology in three MPAs closed for 10 and 5 years there were evidences of spillover effects for some of the most important commercial species. These results validate the methodology used and will allow to expand the data analysis to all the Spanish Mediterranean trawling fleets and closed areas. It is an example of how digital technologies allow marine non-invasive monitoring to work towards the sustainability of marine resources.
06:30 PM
A FISHERIES MONITORING PROGRAM FOR BETTER BOTTOM TRAWLING MANAGEMENT PRACTICES IN THE NW MEDITERRANEAN SEA (6443)
Primary Presenter: Marta Carreton, Institut Català de Recerca per a la Governança del Mar (ICATMAR) (martacarreton@gencat.cat)
The long-time fishery tradition of the Mediterranean Sea has led to an overexploitation of the main fishing resources. To overturn this trend, the European Union Data Collection Framework (DCF) established that the member states had to collect, manage and annually report biological, environmental and socioeconomic fisheries data to use for scientific advice in management actions (EU 2017/1004). Since 2019, the Catalan Institute of Research for the Governance of the Sea (ICATMAR) has designed and implemented a continuous fisheries monitoring program that concerns the commercial fishing fleet along the Catalan coast (NW Mediterranean Sea) in order to potentially address spatial management at a fine scale, complementing the management strategies in place in the Geographical Subarea 6 (GSA 6: Spanish Mediterranean coast). This study is aimed at testing how the data obtained in the bottom-trawling-based monitoring program reliably represent the spatial variability of the fleet activity and are comparable over time. The data show variability over the northern, central and southern sampling zones and a clear differentiation of the catch composition by sampling depth ranges, while remaining comparable over 2019-2021. Despite the short span of our dataset, it is already being used, along with data obtained through fisheries-independent surveys, daily landings, and fleet geolocation data, to inform fisheries management decisions processes both at a local and national levels, with the aim to be of use at a European scale in the future.
SS023P From Cells to Satellites: Current and Future Directions of Detecting Environmental Change in Aquatic Ecosystems
Description
Time: 6:30 PM
Date: 6/6/2023
Room: Mezzanine