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
02:30 PM
Interactive effects of nitrogen and phosphorus on growth and stoichiometry of lake phytoplankton (8807)
Primary Presenter: Paul Frost, Trent University (paulfrost@trentu.ca)
While universal responses to nutrient enrichment is often assumed, the effect size of phytoplankton responses to an increased supply of one nutrient can vary with the availability of the other. Here, we used two complementary two-way factorial experiments to determine how responses of lake phytoplankton to increased N and P supply vary with increasing concentrations of the other nutrient. We manipulated dissolved N and P concentrations in a four-day bioassay conducted with lake phytoplankton and measured chlorophyll-a and carbon (C) specific growth rates, phytoplankton size-classes, chlorophyll-specific N and P removal, and seston C:N:P ratios. These data were used to assess the presence and type of interactive effects between N and P on phytoplankton responses. For most response variables, the effects of increased N supply depended on the background concentration of P and vice versa. The specific nature of effects differed among response variables and depended on the N and P concentrations during the bioassay. Generally, increases of N or P alone elicited few and weaker effects than increased supplies of one element in combination with the other. Overall, our results show that phytoplankton responses to increases in N or P supply are context dependent and likely reflect multiple processes involved in phytoplankton nutrient uptake and use. These results also show that phytoplankton responses to N and P supply ratios can depend on the supply rates of the nutrients, which complicates understanding how single nutrient enrichment affects primary producers in pelagic ecosystems.
02:45 PM
THE INTERACTIVE EFFECTS OF TEMPERATURE AND NUTRIENTS ON A SPRING PHYTOPLANKTON COMMUNITY (8822)
Primary Presenter: Stephanie Anderson, University of Rhode Island (sianderson@uri.edu)
A complex interplay of environmental variables impacts phytoplankton community composition and physiology. Temperature and nutrient availability are two principal factors driving phytoplankton growth and composition, but are often investigated independently and on individual species in the laboratory. To assess the individual and interactive effects of temperature and nutrient concentration on phytoplankton community composition and physiology, we altered both the thermal and nutrient conditions of a cold-adapted spring phytoplankton community in Narragansett Bay, Rhode Island, when surface temperature was 2.6°C and chlorophyll > 9 μg L−1. Water was incubated in triplicate at −0.5°C, 2.6°C, and 6°C for 10 d. At each temperature, treatments included both nutrient amendments (N, P, Si addition) and controls (no macronutrients added). The interactive effects of temperature and resource availability altered phytoplankton growth and community structure. Nutrient amendments resulted in species sorting and communities dominated by larger species. Under replete nutrients, warming tripled phytoplankton growth rates, but under in situ nutrient conditions, increased temperature acted antagonistically, reducing growth rates by as much as 33%, suggesting communities became nutrient limited. The temperature–nutrient interplay shifted the relative proportions of each species within the phytoplankton community, resulting in more silica rich cells at decreasing temperatures, irrespective of nutrients, and C : N that varied based on resource availability, with nutrient limitation inducing a 47% increase in C : N at increasing temperatures. Our results illustrate how the temperature–nutrient interplay can alter phytoplankton community dynamics, with changes in temperature amplifying or exacerbating the nutrient effect with implications for higher trophic levels and carbon flux.
03:00 PM
BLOOMS ALSO LIKE IT COLD (8890)
Primary Presenter: Kaitlin Reinl, Lake Superior National Estuarine Research Reserve (kreinl@wisc.edu)
Cyanobacterial blooms have substantial direct and indirect negative impacts on freshwater ecosystems including releasing toxins, blocking light needed by other organisms, and depleting oxygen. There is growing concern over the potential for climate change to promote cyanobacterial blooms, as the positive effects of increasing lake surface temperature on cyanobacterial growth are well documented in the literature; however, there is increasing evidence that cyanobacterial blooms are also being initiated and persisting in relatively cold-water temperatures (< 15°C), including ice-covered conditions. In this work, we provide evidence of freshwater cold-water cyanobacterial blooms, review abiotic drivers and physiological adaptations leading to these blooms, offer a typology of these lesser-studied cold-water cyanobacterial blooms, and discuss their occurrence under changing climate conditions.
03:15 PM
From webs, loops, shunts, and pumps to microbial multitasking: Evolving concepts of marine microbial ecology and implications for a future ocean (8716)
Primary Presenter: Patricia Glibert, UMCES Horn Point Lab (glibert@umces.edu)
Emerging knowledge of mixoplankton—ubiquitous microbes that employ phototrophy and phagotrophy synergistically in one cell—reshapes our knowledge of the flow of materials and energy, with wide-reaching impacts on marine productivity, biodiversity, and sustainability. Conceptual models of microbial interactions have evolved from food-chains, where carbon-fixing phytoplankton are conceived as being grazed solely by zooplankton that, in turn, support fisheries and higher trophic levels, to microbial webs, loops, and shunts, as knowledge about abundance, activity, and roles of marine microbial organisms—as well as the complexity of their interactions—has increased. In a future world, plankton that depend on a single strategy for acquiring nutrition (photo-autotrophy or phago-heterotrophy) may be disadvantaged with increasing temperatures and ocean acidification impacting vital rates, thermal stratification decreasing water column nutrient exchange, and anthropogenic pollution shifting amounts, forms, and proportions of nutrients. These conditions can lead to stoichiometric imbalances that may promote mixoplanktonic species with an increasing likelihood of harmful blooms. Such changes in plankton species composition alters the interconnectivity of oceanic microbes with direct consequences on biogeochemical cycling, trophic dynamics, and ecosystem services. Here, the implications of the mixoplankton paradigm relative to traditional concepts of microbial oceanography in a globally changing, anthropogenically-impacted world are explored.
03:30 PM
THE OCEAN’S LABILE DOC SUPPLY CHAIN (8720)
Primary Presenter: Mary Ann Moran, University of Georgia (mmoran@uga.edu)
Microbes of the surface ocean release, consume, and exchange labile metabolites at time scales of minutes to days. The details of this important step in the global carbon cycle remain poorly resolved, largely due to the methodological challenges of studying a diverse pool of metabolites that are produced and consumed nearly simultaneously. In this perspective, a new compilation of published data builds on previous studies to obtain an updated estimate of the fraction of marine net primary production that passes through the labile dissolved organic carbon (DOC) pool. In agreement with previous studies, our data mining and modeling approaches hypothesize that about half of ocean net primary production is processed through the labile DOC pool. The fractional contributions from three major sources are estimated at 0.4 for living phytoplankton, 0.4 for dead and dying phytoplankton, and 0.2 for heterotrophic microbes and mesoplankton.
SPOTB - Author Spotlight: Recent high-impact publications from the ASLO journals
Description
Time: 2:30 PM
Date: 28/3/2025
Room: W207AB