ZOOPLANKTON COMMUNITY COMPOSITION IN WAQUOIT BAY, A SHALLOW, TEMPERATE ESTUARY

We sought to characterize the zooplankton community within Waquoit Bay, a shallow, tidally-mixed estuary on the south shore of Cape Cod, Massachusetts. As a National Estuarine Research Reserve, Waquoit Bay has been the site of diverse research studies and a long-term water quality monitoring program that is supported by volunteers. Despite the wealth of information about the Bay, the mesozooplankton community is not routinely monitored. We collected mesozooplankton via net tows from four stations within the Bay at four monthly intervals between March and July 2025. Over this time the temperature ranged from 6.6-26 C, and salinity ranged from 28-31 ppt. Samples were preserved in formalin and imaged using a FlowCam Macro. Debris and particles <350 um were filtered using Visual Spreadsheet software, and zooplankton images are being classified within EcoTaxa. Consistent with previous observations, the community was dominated by calanoid copepods, including Acartia spp, Eurytemora affinis, and Centropages hamatus. Zooplankton abundance was highest in March and decreased over the summer. Qualitatively, the decrease in zooplankton abundance coincided with increases in gelatinous zooplankton, suggesting top-down control. Analysis is ongoing to quantify calorimetric content of zooplankton samples and assess zooplankton community composition in the context of nutrient and chlorophyll measurements. Semi-automated image analysis provides a relatively rapid means of zooplankton community assessment and could facilitate sustained monitoring of this coastal ecosystem.  *This research was developed with funding from the Defense Advanced Research Projects Agency (DARPA). The views, opinions and/or findings expressed are those of the author and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government.

Presentation Preference: Poster

Primary Presenter: Sierra Brown, Woods Hole Oceanographic Institution (brown_sierra@outlook.com)

Authors:

Sierra Brown, Woods Hole Oceanographic Institution  (brown_sierra@outlook.com)

Philip Alatalo, Woods Hole Oceanographic Institution  (palatalo@whoi.edu)

Theophilos Collins, Waquoit Bay National Estuarine Research Reserve  (theophilos.j.collins@mass.gov)

Megan Tyrrell, Waquoit Bay National Estuarine Research Reserve  (megan.tyrrell@mass.gov)

Adewale Aromolaran, Woods Hole Oceanographic Institution  (aromolaran.adewale@whoi.edu)

Amy Apprill, Woods Hole Oceanographic Institution  (aaprill@whoi.edu)

Ann Tarrant, Woods Hole Oceanographic Institution  (atarrant@whoi.edu)