Phytoplankton assemblage responses to nitrogen following COVID-19 stay-in-place orders in western Long Island Sound (New York/Connecticut).

Maximillian Brown, Mariapaola Ambrosone, Kyle J Turner, Georgie E Humphries, Maria Tzortziou, Sílvia Anglès, Caterina Panzeca, Dianne I Greenfield

Journal: Marine environmental research 2024;196():106371

PMID: 38309244

Full Text on Elsevier Science View on PubMed

Abstract

This study evaluated water quality, nitrogen (N), and phytoplankton assemblage linkages along the western Long Island Sound (USA) shoreline (Nov. 2020-Dec. 2021) following COVID-19 stay-in-place (SIP) orders through monthly surveys and N-addition bioassays. Ammonia-N (AmN; NH+NH) negatively correlated with total chlorophyll-a (chl-a) at all sites; this was significant at Alley Creek, adjacent to urban wastewater inputs, and at Calf Pasture, by the Norwalk River (Spearman rank correlation, p < 0.01 and 0.02). Diatoms were abundant throughout the study, though dinoflagellates (Heterocapsa, Prorocentrum), euglenoids/cryptophytes, and both nano- and picoplankton biomass increased during summer. In field and experimental assessments, high nitrite + nitrate (N + N) and low AmN increased diatom abundances while AmN was positively linked to cryptophyte concentrations. Likely N + N decreases with presumably minimal changes in AmN and organic N during COVID-19 SIP resulted in phytoplankton assemblage shifts (decreased diatoms, increased euglenoids/cryptophytes), highlighting the ecological impacts of N-form delivered by wastewater to urban estuaries.

Address: School of Earth and Environmental Sciences, Queens College, City University of New York, Flushing, NY, 11367, USA; Advanced Science Research Center at the Graduate Center, City University of New York, New York, NY, 10031, USA.; Advanced Science Research Center at the Graduate Center, City University of New York, New York, NY, 10031, USA.; Earth and Atmospheric Science, Center for Discovery and Innovation, The City College of New York, City University of New York, New York, NY, 10031, USA.; State University of New York Maritime College, Bronx, NY, 10465, USA.; School of Earth and Environmental Sciences, Queens College, City University of New York, Flushing, NY, 11367, USA; Advanced Science Research Center at the Graduate Center, City University of New York, New York, NY, 10031, USA. Electronic address: [email protected].

DOI: 10.1016/j.marenvres.2024.106371