It's like night and day: Diel net-effects on Cercopagidae densities in the Laurentian Great Lakes

Journal of Great Lakes Research
By: , and 

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Abstract

In the Laurentian Great Lakes, zooplankters are often sampled using standard ≤153 μm mesh nets without regard to the time of day they are collected. We sampled Cercopagidae during 2013–2014 in northern Lake Huron during day, dusk, and night using two different nets (a 0.5 m wide 153 μm mesh “standard” net and a 0.75 m wide 285 μm mesh “Bythotrephes” net) to determine if there were any differences in their sampled densities. Bythotrephes densities with the standard net were approximately 2.07-fold greater when captured at night than during the day. No time of day bias occurred with the Bythotrephes net. Nighttime Bythotrephes densities did not differ between the two net types. Cercopagis densities did not vary with net type or the time of day in this study, but future work should revisit this result given our low sample size and the low occurrence of Cercopagis in Lake Huron. To reduce bias and calculate accurate density estimates, Cercopagidae should be sampled at night if using a standard net or any time of day with the Bythotrephes net. Given the large impact of invasive predatory cladocerans Bythotrephes longimanus and Cercopagis pengoi on food webs since their invasion in the Laurentian Great Lakes in the 1980s, proper estimation of their densities is essential.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title It's like night and day: Diel net-effects on Cercopagidae densities in the Laurentian Great Lakes
Series title Journal of Great Lakes Research
DOI 10.1016/j.jglr.2016.12.001
Volume 43
Issue 2
Year Published 2017
Language English
Publisher Elsevier
Contributing office(s) Great Lakes Science Center
Description 5 p.
First page 394
Last page 398