Comparing Juvenile River Herring Growth in Two Coastal Massachusetts Lakes

Presenter

Grace Natiele Davis

Campus

UMass Amherst

Sponsor

Ayodele C. O'Uhuru, Department of Environmental Conservation, UMass Amherst

Schedule

Session 1, 10:30 AM - 11:15 AM [Schedule by Time][Poster Grid for Time/Location]

Location

Poster Board A27, Campus Center Auditorium, Row 2 (A21-A40) [Poster Location Map]

Abstract

Alewife (Alosa pseudoharengus) and Blueback Herring (A. aestivalis) are anadromous fish species that spawn in freshwater where juveniles grow for ~3–6 months before emigrating to the ocean where they reside until reaching adulthood. Collectively referred to as river herring, their populations have declined drastically over the past centuries due to overfishing, habitat loss from damming, and pollution. Previous research suggests that juvenile river herring population densities in freshwater lakes significantly affect their growth and survival, but limited information exists regarding intra-annual variation in growth that occurs among early and late hatching juvenile river herring cohorts in freshwater lakes with different species compositions and population densities. We compared juvenile river herring growth rates among the months of June, July, and August 2022 in two freshwater lakes in coastal Massachusetts (USA). We deployed nighttime pelagic purse seines to sample juvenile river herring in Chebacco Lake (low-density, Alewife-only) and Upper Mystic Lake (high density, Alewife and Blueback Herring). Juvenile river herring were enumerated in the field and a subset from each sample date were retained for age and growth analysis using sagittal otoliths. We predict that growth rates will be greatest earlier in season and trend down in the high density, mixed species system (Upper Mystic Lake) due to competition for prey. We also predict that monthly growth rates will remain constant in the low density, Alewife-only system (Chebacco Lake). Results from this research will be used to inform management strategies that maximize juvenile river herring growth and survival in freshwater nursery habitats.

Keywords

Fish, Lentic, Life History, Population, Connectivity

Research Area

Environmental Science and Sustainability

SIMILAR ABSTRACTS (BY KEYWORD)