Trophic state resilience to hurricane disturbance of Lake Yojoa, Honduras

Fadum, Jemma; Waters, Matthew N.; Hall, Edward K.

doi:10.1038/s41598-023-32712-3

Cited by 5 publications

(5 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our study highlights the putative contributions of mineralization and DNRA to the hypolimnetic NH 4 + pool of a large tropical lake. We acknowledge that multiple other pathways may play an important role in the accumulation of hypolimnetic reactive N (e.g., sediment-derived NH 4 + flux [ 22 ], mineralization of fish waste, or interactive effects of Lake Yojoa’s virome on N cycling [ 41 , 42 ]). However, DNRA (because of its competition with denitrification) remains a critical pathway for assessing annual N dynamics, particularly in systems, like Lake Yojoa, that experience seasonal N limitation ( 17 ).…”

Section: Discussionmentioning

confidence: 99%

“…Stations were chosen to be approximately equidistant from each other to capture the potential spatial heterogeneity of the pelagic zone of Lake Yojoa. Methods for sample collection, preservation, transportation, and analysis as well as thermophysical profile measurements are available in previously published works on Lake Yojoa ( 17 , 22 ).…”

Section: Methodsmentioning

confidence: 99%

“…Although we only compared two sampling dates, the contrast between June 2021, when stratification was fully developed, juxtaposed against January 2022, when the water column was fully mixed, is representative of the geochemical conditions of the two phases of stratification that Lake Yojoa experiences. No disruption to stratification was identified prior to June sampling ( 22 ). Thus, the samples taken in June and January are likely representative of the stratified and mixed water column seasons, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…Samples for metagenomics were taken during both sampling events (June 2021 and January 2022) from each location (North, Central, and South) and each depth (1 and 16 m) and extracted for DNA ( n = 12 metagenomes). To maximize genome recovery and build a robust MAG database for metatranscriptome mapping, we performed additional metagenomic sequencing ( n = 15 metagenomes) on samples collected during 2019 and 2020 sampling campaigns ( 17 , 22 ). Samples for RNA were paired with the June 2021 and January 2022 metagenomic sampling and collected from the same locations and depths in triplicate ( n = 36 metatranscriptomes).…”

Section: Methodsmentioning

confidence: 99%

“…The watershed has persistently warm temperatures (annual average air temperatures above 20°C) and receives approximately 2 m of annual precipitation with the warmest months typically corresponding with the monsoon season (June to October). Primary productivity during the mixed water column phase is largely driven by hypolimnetic nutrients which are released to the epilimnion following water column mixing, typically in November ( 17 , 22 ).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Dominant nitrogen metabolisms of a warm, seasonally anoxic freshwater ecosystem revealed using genome resolved metatranscriptomics

Fadum,

Borton,

Daly

et al. 2024

mSystems

Self Cite

View full text Add to dashboard Cite

Nitrogen (N) availability is one of the principal drivers of primary productivity across aquatic ecosystems. However, the microbial communities and emergent metabolisms that govern N cycling in tropical lakes are both distinct from and poorly understood relative to those found in temperate lakes. This latitudinal difference is largely due to the warm (>20°C) temperatures of tropical lake anoxic hypolimnions (deepest portion of a stratified water column), which result in unique anaerobic metabolisms operating without the temperature constraints found in lakes at temperate latitudes. As such, tropical hypolimnions provide a platform for exploring microbial membership and functional diversity. To better understand N metabolism in warm anoxic waters, we combined measurements of geochemistry and water column thermophysical structure with genome-resolved metatranscriptomic analyses of the water column microbiome in Lake Yojoa, Honduras. We sampled above and below the oxycline in June 2021, when the water column was stratified, and again at the same depths and locations in January 2022, when the water column was mixed. We identified 335 different lineages and significantly different microbiome membership between seasons and, when stratified, between depths. Notably, nrfA (indicative of dissimilatory nitrate reduction to ammonium) was upregulated relative to other N metabolism genes in the June hypolimnion. This work highlights the taxonomic and functional diversity of microbial communities in warm and anoxic inland waters, providing insight into the contemporary microbial ecology of tropical ecosystems as well as inland waters at higher latitudes as water columns continue to warm in the face of global change. IMPORTANCE In aquatic ecosystems where primary productivity is limited by nitrogen (N), whether continuously, seasonally, or in concert with additional nutrient limitations, increased inorganic N availability can reshape ecosystem structure and function, potentially resulting in eutrophication and even harmful algal blooms. Whereas microbial metabolic processes such as mineralization and dissimilatory nitrate reduction to ammonium increase inorganic N availability, denitrification removes bioavailable N from the ecosystem. Therefore, understanding these key microbial mechanisms is critical to the sustainable management and environmental stewardship of inland freshwater resources. This study identifies and characterizes these crucial metabolisms in a warm, seasonally anoxic ecosystem. Results are contextualized by an ecological understanding of the study system derived from a multi-year continuous monitoring effort. This unique data set is the first of its kind in this largely understudied ecosystem (tropical lakes) and also provides insight into microbiome function and associated taxa in warm, anoxic freshwaters.

show abstract