Date of Award


Document Type

Open Access Thesis

Degree Name

Master of Science (MS)



First Advisor

Karen Wilson

Second Advisor

Chris Maher,

Third Advisor

Theresa Theodose


As human-made dams are removed and fish passage at dams is improved in

support of restoration efforts, anadromous alewives (Alosa pseudoharengus) gain

access to historic spawning grounds. As they migrate to spawn, adult alewives import

marine derived nutrients to lakes and impoundments. Young of year alewives (juveniles)

export nutrients as they emigrate to the sea. These nutrients support primary

production and are incorporated into freshwater food webs. However, many lakes in

New England are mesotrophic or eutrophic. Additional nutrients, specifically

phosphorus (P), may exacerbate water quality issues. To examine these issues, I

compared outputs ofan alewife nutrient and population model to background lake P

data from seven lakes in New England. My objective was to provide a nutrient analysis

as an example for stakeholders, communities and organizations considering dam

removal or improved fish passage and the restoration of alewife populations. Results

demonstrated that alewives' impact on P levels was minimal under most scenarios. In

2017, alewives contributed less than 5% of mean epilimnetic Pin four of seven lakes

studied (China Lake, Highland Lake, Tagus Pond, and Pawtuckaway Lake). Alewives

contributed more Pin Warwick and Webber Ponds, which translated to 3.6-11.19% of

mean summer epilimnetic total phosphorus (TP) in Warwick Pond and 8.67 - 23.86% in

Webber Pond. In Carr Pond, however, alewives contributed 11.43 -93.67% of summer

epilimnetic TP, which is potentially a large portion of the in-lake P budget. Alewife P

import increased as adult escapement increased, and eventually adult import

outweighed juvenile export, relative to lake size. Although the scale of P contributed by

alewife was not extensive in the majority of the study lakes, it could be instructive to

include alewife derived Pas part of the flux of nutrients in management documents

such as total maximum daily load (TMDL) reports.

Included in

Biology Commons



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