Home > Explore Data & Reports > Detecting copepod grazing on low-concentration populations of Alexandrium fundyense using PCR

Citation:

Haley, S.T., A.R. Juhl, B.A. Keafer, D.M. Anderson, and S.T. Dyhrman. 2011. Detecting copepod grazing on low-concentration populations of Alexandrium fundyense using PCR. Journal of Plankton Research, 33(6):927-936. https://doi.org/10.1093/plankt/fbq151

Data/Report Type:

Sponsored Research

Description

Zooplankton grazing is often a significant loss term for phytoplankton populations, including harmful algae, impacting the development and decline of blooms. However, detecting and quantifying predation on phytoplankton is often challenging, particularly during early bloom stages when phytoplankton cell concentrations are low. In this study, we used polymerase chain reaction (PCR) to detect ingestion of toxic dinoflagellates of the Alexandrium tamarense species complex by two copepods, Acartia hudsonica (laboratory population) and Calanus finmarchicus (field population). Recent ingestion of Alexandrium fundyense cells was indicated by positive amplification of an LSU rDNA fragment specific to A. fundyense from whole copepod extracts. In laboratory experiments, A. fundyense DNA was detectable for 2–4 h post-ingestion in A. hudsonica fed A. fundyense, but not detected in animals fed other phytoplankton, or starved. In field samples, ingestion of A. fundyense by C. finmarchicus was confirmed by PCR, including at four stations where the A. fundyense concentration was ?14 cells L?1. At these low prey concentrations, ingestion rates on A. fundyense may have been as low as 1 cell copepod?1 day?1. Nevertheless, simulations of A. fundyense population growth suggest that a few predators L?1 have the potential to curb the early development of a slow-growing bloom, even if ingestion rates are extremely low. Low predation rates can still have a large impact when prey populations are small.

Note to readers with disabilities: Some scientific publications linked from this website may not conform to Section 508 accessibility standards due to the complexity of the information being presented. If you need assistance accessing this electronic content, please contact the lead/corresponding author, Primary Contact, or nccos.webcontent@noaa.gov.

Explore Similar Data/Reports
NCCOS-with-tag-to-side-bld

NCCOS delivers ecosystem science solutions for stewardship of the nation’s ocean and coastal resources, in direct support of NOS priorities, offices, and customers, and to sustain thriving coastal communities and economies.

National Centers for Coastal Ocean Science
1305 East West Highway, Rm 8110
Silver Spring, MD 20910
Phone: (240) 533-0300 / Fax: (301) 713-4353
Email: nccos.webcontent@noaa.gov

    Sign Up for Our Quarterly Newsletter