The ASLO journal editors convene this invitation-only special session to recognize authors who published highly cited or highly downloaded articles in 2022-2023 in one of the ASLO family of journals: Limnology and Oceanography, Limnology and Oceanography: Methods, Limnology and Oceanography: Letters, and Limnology and Oceanography: Bulletin. Authors publish their finest work in ASLO journals, making them a success. We therefore greatly appreciate authors’ contributions to our science and the ASLO community. This session is an opportunity to celebrate authors and their work, highlighting some of the most influential research advances and trends in recent years. We invite the lead author (or any co-author) to present updates to the selected article, describe their evolving research directions, or present a review of the state of the art in their field. Author Spotlight presentations showcase both the breadth of the aquatic sciences and cutting-edge research currently underway. Articles are selected based on their average monthly rate of downloads and/or citations, both of which serve as indicators of reader interest.
Lead Organizer: Erin Peck, University of Rhode Island, Graduate School of Oceanography (erin.peck@uri.edu)
Co-organizers:
James Cloern, ASLO, Limnology & Oceanography Letters (loletters-eic@aslo.org)
Laura Falkenberg, ASLO, Limnology & Oceanography Bulletin (lobulletin-editor@aslo.org)
K. David Hambright, ASLO, Limnology & Oceanography (dhambright@aslo.org)
Krista Longnecker, ASLO, Limnology & Oceanography: Methods (lom-editor@aslo.org)
Presentations
09:00 AM
The Silent Mental Health and Well-Being Crisis of Early Career Researchers in Aquatic Sciences (8751)
Primary Presenter: Heili Lowman, Duke University (heili.lowman@duke.edu)
A severe mental health and well-being crisis lurks in academia and early career researchers face a particularly daunting set of challenges. Early career scientists may face short-term and uncertain pay, anticipated relocation for work, and high productivity expectations. They also often experience significant feelings of imposter syndrome, isolation, disenchantment, and anxiety. Here, we present an article written for the Limnology and Oceanography Bulletin that discusses and highlights the challenges particular to this career stage in the aquatic sciences. In addition, we mark the 2-year anniversary of the successful “Voices for Well-being in Aquatic Sciences” quarterly seminar series and reflect on the topics presented to date. The topics we have covered, both in-person and online, include battling imposter syndrome, navigating uncertainty in research, banishing burnout, misconceptions about procrastination, maintaining positive well-being during periods of change, and academic mental health. We have organized eight webinars (two in-person, six online), and we have more planned for the 2025 calendar year, both at this conference as well as online. The ASLO Early Career Committee is committed to providing means of open dialogue and community support for researchers at all career stages.
09:15 AM
SOME THOUGHTS ON “UPON COMPARING ONESELF TO OTHERS” (9013)
Primary Presenter: Paul del Giorgio, Univ. du Quebec a Montreal (del_giorgio.paul@uqam.ca)
Like many of us, I keep a number of unfinished drafts in my computer, not all scientific, some lighter than others, of things that interest, worry, anguish, puzzle or amuse me. Among these was a brief text on comparison and competition in academia and research, and some negative aspects related to this. Events around me decided me to finish this one up. It was with much hesitation that I submitted it to Limnology and Oceanography Bulletin, I have not published many non-research texts, and I felt very unsure as to whether this was appropriate for the Bulletin and even relevant for our readership in general. I was fortunate that the Editorial Board were very encouraging, and helpful in their comments and suggestions, and a revised version of the short opinion paper was eventually published. This text did not provide any profound or novel insight, there was no epiphany, no grand message or smart answers of any kind. It was just a candid and quite personal reflection on common yet often unspoken issues that many of us face. I was very surprised (and touched) by the amount of positive feedback I received after the paper came out, and grateful for the invitation to present in this session, and I have wondered why this simple, unassuming text elicited such response. Here I would like to reflect (with the audience) upon how sharing one’s own experiences and feelings, while entraining risks and challenges, may help discuss and address certain issues by tapping upon our common humanity, and by helping overcome the multitude of barriers that often separate us and muffle exchange.
09:30 AM
Carbon loss from rivers following terrestrial enhanced rock weathering (8854)
Primary Presenter: Shuang Zhang, Texas A&M University (shuang-zhang@tamu.edu)
Enhanced Rock Weathering (ERW) is emerging as a promising Carbon Dioxide Removal (CDR) strategy, offering a path to lower atmospheric CO₂ concentrations while providing benefits such as soil pH improvement and nutrient release. However, the impacts of ERW on river carbonate chemistry and the potential loss of initially captured CO₂ during river transport to the coastal ocean remain poorly understood. This limitation challenges ERW’s viability as a carbon mitigation strategy. This study seeks to address this gap through an integrated approach using machine learning and numerical modeling, specifically focusing on North American river systems. Central to our methodology is the development of a dynamic river network model designed to simulate changes in river chemistry and carbon degassing following ERW. Our findings reveal relatively low carbon loss across most river segments within a two-year timeframe, but also highlight significant seasonal and spatial variations, informing a strategic framework for improving ERW implementation.
09:45 AM
Extent, patterns, and drivers of hypoxia in the world's streams and rivers (8708)
Primary Presenter: Alice Carter, University of Montana (alice.carter@flbs.umt.edu)
Hypoxia in coastal waters and lakes is widely recognized as a detrimental environmental issue, yet we lack a comparable understanding of hypoxia in rivers. We investigated controls on hypoxia using 118 million paired observations of dissolved oxygen (DO) concentration and water temperature in over 125,000 locations in rivers from 93 countries. We found hypoxia (DO < 2 mg L−1) in 12.6% of all river sites across 53 countries, but no consistent trend in prevalence since 1950. High-frequency data reveal a 3-h median duration of hypoxic events which are most likely to initiate at night. River attributes were better predictors of riverine hypoxia occurrence than watershed land cover, topography, and climate characteristics. Hypoxia was more likely to occur in warmer, smaller, and lower-gradient rivers, particularly those draining urban or wetland land cover. Our findings suggest that riverine hypoxia and the resulting impacts on ecosystems may be more pervasive than previously assumed.
10:00 AM
Stream respiration exceeds CO2 evasion in a low-energy, oligotrophic tropical stream (9450)
Primary Presenter: Vanessa Solano, UQAM (solano.vanessa@uqam.ca)
Carbon dioxide (CO2) can be either imported to streams through groundwater and subsurface inputs of soil-respired CO2 or produced internally through stream metabolism. The contribution of each source to the CO2 evasion flux from streams is not well quantified, especially in the tropics, an underrepresented region in carbon (C) cycling studies. We used high-frequency measurements of dissolved O2 and CO2 concentrations to estimate the potential contribution of stream metabolism to the CO2 evasion flux in a tropical lowland headwater stream. We found that the stream was heterotrophic all year round, with net ecosystem productivity (NEP) values ranging from 0.84 to 4.06 g C m−2 d−1 (median 1.29 g C m−2 d−1; here we expressed gross primary productivity (GPP) as a negative flux and ecosystem respiration (ER) as a positive flux). Positive NEP values were the result of a relatively low and stable GPP through the seasons, compared to a higher and more variable ER favored by the high temperatures and organic matter availability, particularly during the wet season. The CO2 evasion flux was relatively low due to low turbulence (median: 1.09 g C m−2 d−1). As a result, daily NEP rates exceeded the CO2 evasion flux with a potential contribution of 129% (median; 120–175% interquartile range), despite the strong seasonal changes in flow regime and landscape connectivity. The CO2 excess was likely transported downstream, where it was ultimately emitted to the atmosphere. Our results highlight the overwhelming importance of ER to the C cycle of low-energy, oligotrophic tropical streams.
10:15 AM
Effects of filtration timing and pore size on measured nutrient concentrations in environmental water samples (8711)
Primary Presenter: Mark McCarthy, Estonian University of Life Sciences (mark.mccarthy@emu.ee)
Nutrient monitoring is important for informing management decisions to mitigate eutrophication in aquatic systems. Many nutrient monitoring programs use filter pore sizes that allow microorganisms to pass into samples and/or wait extended times between sample collection and filtration/preservation, allowing microbial processes to alter nutrient concentrations. Here, 34 sites were sampled to determine how filter pore size and filtration timing affected measured ammonium (NH4+) and orthophosphate (ortho-P) concentrations. Three filter pore sizes (0.22, 0.45, and 0.70 μm) were used to filter water immediately upon collection and after 5 and 22 h in a bottle. NH4+ and ortho-P concentrations varied relative to “baseline” measurements (i.e., 0.22 μm, field-filtered samples), both over time and with different filter pore sizes, and showed no predictable direction of change based on ambient nutrient concentration or trophic status. As expected, larger relative changes occurred with lower ambient concentrations; however, for the entire dataset, samples with > 1 μmol L-1 ortho-P and > 3 μmol L-1 NH4+ were lower by 11 and 33%, respectively, which would result in reported nutrient concentrations that were not representative of in situ conditions. Whole-water samples filtered after 22 h varied up to 3070% for NH4+ and 480% for ortho-P from baseline concentrations. Filtering water samples with a 0.22 μm filter (or 0.45 μm, at worst), immediately upon collection, should be adopted as standard practice to ensure that reported nutrient concentrations represent the most accurate measurement possible. Inconsistent and/or insufficient sampling and sample handling procedures can lead to poorly calibrated models and misinformed management and legislative decisions.
SPOTA - Author Spotlight: Recent high-impact publications from the ASLO journals
Description
Time: 9:00 AM
Date: 28/3/2025
Room: W207AB