18S rRNA amplicon sequence data (V1–V3) of the Bronx river estuary, New York

Characterising and monitoring biological diversity to foster sustainable ecosystems is highly recommended as urban centres rapidly expand. However, much of New York City’s biodiversity remains undescribed, including in the historically degraded, but recovering Bronx River Estuary. In a pilot study to identify organisms and characterise biodiversity patterns there, 18S rRNA gene amplicons (V1–V3 region), obtained from river sediments and surface waters of Hunts Point Riverside and Soundview Parks, were sequenced. Across 48 environmental samples collected over three seasons in 2015 and 2016, following quality control and contaminant removal, 2,763 Amplicon Sequence Variants (ASVs) were identified from 1,918,463 sequences. Rarefaction analysis showed sufficient sampling depth, and community composition varied over time and by substrate at the study sites over the sampling period. Protists, plants, fungi and animals, including organisms of management concern, such as Eastern oysters (Crassostrea virginica), wildlife pathogens and groups related to Harmful Algal Blooms, were detected. The most common taxa identified in river sediments were annelid worms, nematodes and diatoms. In the water column, the most commonly observed organisms were diatoms, algae of the phylum Cryptophyceae, ciliates and dinoflagellates. The presented dataset demonstrates the reach of 18S rRNA metabarcoding for characterising biodiversity in an urban estuary.

Divergent epigenetic profiles from two differentially impacted wild populations of estuarine cordgrass (Sporobolus alterniflorus)

The effects of urbanization on watershed ecosystems present critical challenges to modern survival. Organisms in urbanized areas experience high rates of evolutionary change, but genetic adaptation alone cannot mitigate the rapid and severe effects of urbanization on biodiversity. Highly resilient, foundation species are key to maintaining an ecosystem’s integrity in the face of urban stressors. However, the rapid collapse and disappearance of watershed ecosystems calls into question the extent to which we can rely on such species for their services. Our research investigates the molecular mechanisms by which the foundation ecosystems provider, Sporobolus alterniflorus, adapts to life in an urbanized environment. To elucidate these mechanisms, we quantified changes in global DNA methylation (% 5-mC) as a result of acute heat stress. Specimens from two differentially impacted populations across an urban to suburban geographical transect formed the basis of this study. These two populations of Sporobolus alterniflora exhibit inverse global DNA methylation patterns when exposed to the same acute heat stress. Our findings suggest that epigenetic mechanisms, such as DNA methylation, control rapid and transient adaptation, in the form of differential stress responses, to distinct environment challenges.Highlights for manuscript submission▪estuarine grasses native to the Bronx River, NY face stresses associated with low dissolved oxygen and urbanization▪differentially impacted populations of estuarine grasses exhibit inverse global DNA methylation profiles in response to acute heat stress▪DNA methylation may represent a mechanism by which plants transiently respond to environmental stressors, and this may represent a form of rapid adaptive evolution▪stress priming by transgenerational epigenetic modification may enhance fitness in grasses native to the heavily impacted Bronx River estuary

16S rRNA Amplicon Sequencing of Urban Prokaryotic Communities in the South Bronx River Estuary

ABSTRACT Biodiversity monitoring is an essential component of restoration efforts. We sequenced 16S rRNA gene amplicons from sediments and waters of Hunts Point Riverside Park and Soundview Park, located in a historically degraded but recovering urban estuary in New York. In total, 508,352 unique amplicon sequence variants were recovered, and Proteobacteria was the dominant phylum.