Energy Content Determination of Atlantic Forage Species Menidia menidia and Fundulus majalis through Proximate Composition Analysis

Tuesday, February 24, 2026 at 1:00pm to 2:00pm

Advisor: Dr. Robert Drew

Committee Members: Dr. Kenneth Oliveira, Dr. Tara Rajaniemi and Dr. Robert Drew

Abstract:

Energy density data can give a comprehensive view of a species’ condition as well as their predators. Energy moves through an ecosystem and is constantly changing. It fluctuates due to metabolic processes, but also external factors, such as seasonality and location. Estimating energy density for a species is possible when it is plotted against percent dry weight; however, in fishes, energy data is still not widely studied, especially for small forage fish that are not a part of the larger ecosystem surveys. This study estimates the energy density of two small forage fishes, Menidia menidia and Fundulus majalis, and presents the relationship of energy density against percent dry weights over a one-year period before an interspecies comparison. Samples were collected from locations along the southeast coast of Massachusetts from 2023-2024. Proximate composition analysis was completed on each specimen to achieve energy density (kJ/g). The percent dry weight and energy density relationship was developed along with a month-by-month distribution of energy for each species. The plotted energy density-percent dry weight curves were confirmed to be reliable predictors of energy density for each species. Seasonal trends were consistent with breeding periods but wavered in locational symmetry. Standard relationships can be used to estimate the energy density of an individual of their respective species as well as when their energetic contents peak. This shows when it would be advantageous for predators to choose these species as prey items or when it may be better to choose another option. This has important implications for ecosystem-based management, as declines in prey quality could provide insight into predator condition and further management strategies.

SENG Bldg. Room#105
Robert Drew
(508) 999-8905
rdrew@umassd.edu