Inter-Research > MEPS > v703 > p1-16  
Marine Ecology Progress Series

via Mailchimp

MEPS 703:1-16 (2023)  -  DOI:

Estimating North Atlantic right whale prey based on Calanus finmarchicus thresholds

Camille H. Ross1,2,*, Jeffrey A. Runge2, Jason J. Roberts3, Damian C. Brady2, Benjamin Tupper1, Nicholas R. Record1

1Tandy Center for Ocean Forecasting, Bigelow Laboratory for Ocean Sciences, East Boothbay, ME 04544, USA
2Darling Marine Center, University of Maine, School of Marine Sciences, Walpole, ME 04573, USA
3Marine Geospatial Ecology Laboratory, Duke University, Durham, NC 27708, USA
*Corresponding author:

ABSTRACT: The planktonic copepod Calanus finmarchicus is a fundamental prey resource for the critically endangered North Atlantic right whale Eubalaena glacialis. Incorporation of prey information into E. glacialis decision support tools could improve management. Zooplankton time series are usually analyzed with respect to abundance, but predators such as E. glacialis forage based on whether prey aggregations exceed energetic thresholds. In order to better understand the distribution and dynamics of the high-abundance end of C. finmarchicus on the northeastern US continental shelf, where E. glacialis feed, we modeled the environmental conditions associated with C. finmarchicus densities that exceed nominal feeding thresholds. Threshold values were chosen based on a review of E. glacialis feeding behavior throughout the domain. Following model selection procedures, we used a random forest model with bathymetry, bottom temperature, bottom salinity, day of year, sea surface temperature, sea surface temperature gradient, bathymetric slope, time-integrated chlorophyll, current velocity gradient, and wind covariates. Model performance was highest with thresholds that matched reported E. glacialis feeding thresholds equivalent to 10000 copepods m-2. The high-density aggregations of C. finmarchicus had some different covariate responses compared to previous statistical abundance models, such as a warmer temperature range at both the surface and at depth, as well as a much higher degree of spatial variability. The output data layers of the model are designed to link with E. glacialis models used in US governmental decision support tools. Including this type of foraging information in decision support tools is a step forward in managing this critically endangered species.

KEY WORDS: Calanus finmarchicus · Eubalaena glacialis · Habitat modeling · Prey density

Full text in pdf format
Information about this Feature Article
Cite this article as: Ross CH, Runge JA, Roberts JJ, Brady DC, Tupper B, Record NR (2023) Estimating North Atlantic right whale prey based on Calanus finmarchicus thresholds. Mar Ecol Prog Ser 703:1-16.

Export citation
Share:    Facebook - - linkedIn

Next article