Next Article in Journal
Acknowledgement to Reviewers of Diversity in 2019
Next Article in Special Issue
Historical Shifts in Benthic Infaunal Diversity in the Northern Gulf of Mexico since the Appearance of Seasonally Severe Hypoxia
Previous Article in Journal
Beyond Endocasts: Using Predicted Brain-Structure Volumes of Extinct Birds to Assess Neuroanatomical and Behavioral Inferences
Previous Article in Special Issue
Negative Effects of Diurnal Changes in Acidification and Hypoxia on Early-Life Stage Estuarine Fishes
Open AccessArticle

Fewer Copepods, Fewer Anchovies, and More Jellyfish: How Does Hypoxia Impact the Chesapeake Bay Zooplankton Community?

1
Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, MD 21613, USA
2
Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT 06511, USA
3
Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, MD 20688, USA
4
AKRF, Inc., Hanover, MD 21076, USA
*
Author to whom correspondence should be addressed.
Diversity 2020, 12(1), 35; https://doi.org/10.3390/d12010035
Received: 1 December 2019 / Revised: 7 January 2020 / Accepted: 11 January 2020 / Published: 17 January 2020
(This article belongs to the Special Issue The Effects of Hypoxia on Marine Food Webs and Ecosystems)
To understand dissolved oxygen deficiency in Chesapeake Bay and its direct impact on zooplankton and planktivorous fish communities, six research cruises were conducted at two sites in the Chesapeake Bay from spring to autumn in 2010 and 2011. Temperature, salinity, and dissolved oxygen were measured from hourly conductivity, temperature, and depth (CTD) casts, and crustacean zooplankton, planktivorous fish and gelatinous zooplankton were collected with nets and trawls. CTD data were grouped into three temperature groups and two dissolved oxygen-level subgroups using principal component analysis (PCA). Species concentrations and copepod nonpredatory mortalities were compared between oxygenated conditions within each temperature group. Under hypoxic conditions, there usually were significantly fewer copepods Acartia tonsa and bay anchovies Anchoa mitchilli, but more bay nettles Chyrsaora chesapeakei and lobate ctenophores Mnemiopsis leidyi. Neutral red staining of copepod samples confirmed that copepod nonpredatory mortalities were higher under hypoxic conditions than under normoxia, indicating that the sudden decline in copepod concentration in summer was directly associated with hypoxia. Because comparisons were made within each temperature group, the effects of temperature were isolated, and hypoxia was clearly shown to have contributed to copepod decreases, planktivorous fish decreases, and gelatinous zooplankton increases. This research quantified the direct effects of hypoxia and explained the interactions between seasonality and hypoxia on the zooplankton population. View Full-Text
Keywords: oxygen deficiency; planktivorous fish; gelatinous zooplankton; crustacean zooplankton; estuary; water quality; ecosystem oxygen deficiency; planktivorous fish; gelatinous zooplankton; crustacean zooplankton; estuary; water quality; ecosystem
Show Figures

Figure 1

MDPI and ACS Style

L. Slater, W.; Pierson, J.J.; Decker, M.B.; Houde, E.D.; Lozano, C.; Seuberling, J. Fewer Copepods, Fewer Anchovies, and More Jellyfish: How Does Hypoxia Impact the Chesapeake Bay Zooplankton Community? Diversity 2020, 12, 35.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop