Synergistic effects of seasonal deoxygenation and temperature truncate copepod vertical migration and distribution

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 575:57-68 (2017) - DOI: https://doi.org/10.3354/meps12205 Synergistic effects of seasonal deoxygenation and temperature truncate copepod vertical migration and distribution James J. Pierson*, Wen-Cheng L. Slater, David Elliott, Michael R. Roman Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, MD 21613, USA *Corresponding author: jpierson@umces.edu ABSTRACT: The vertical distribution of copepods in coastal and estuarine systems is altered by the concentration of dissolved oxygen in the water column. We studied the combined effects of temperature and dissolved oxygen on vertical distribution and migration behavior of the copepod Acartia tonsa in the Chesapeake Bay throughout the period of seasonal deoxygenation in 2010 and 2011. Vertically stratified net tows and hydrographic casts were conducted at 2 stations over diel cycles in spring, summer, and autumn. The partial pressure of dissolved oxygen ( pO2) was used as a metric for the condition of copepod habitat during each cruise instead of oxygen concentration, because partial pressure incorporates the temperature dependence of dissolved oxygen solubility, making it a more useful indication of available oxygen supply than concentration. Habitat conditions were described as having pO2 above limiting conditions, below the maximum respiratory demand but above potentially lethal conditions, or below the minimum basal respiratory demand. In general, adult males were found deeper in the water than females in most oxygen conditions. Regression tree analysis supported these findings and showed that pO2 was a key predictor of the fraction of copepodites, adult females, and adult males above the pycnocline, and for copepodites and adult females below the pycnocline. Temperature was a strong predictor of the fraction of adult males below the pycnocline, with a smaller fraction found there at higher temperatures. These findings suggest sex-specific responses to deoxygenation, potentially as a result of different oxygen demands or behavior. KEY WORDS: Copepod · Hypoxia · Diel vertical migration · Vertical distribution · Acartia tonsa · Chesapeake Bay · Estuarine Full text in pdf format Supplementary material PreviousNextCite this article as: Pierson JJ, Slater WCL, Elliott D, Roman MR (2017) Synergistic effects of seasonal deoxygenation and temperature truncate copepod vertical migration and distribution. Mar Ecol Prog Ser 575:57-68. https://doi.org/10.3354/meps12205 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 575. Online publication date: July 20, 2017 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2017 Inter-Research.