DFO PhD Dissertation Defense -"Environmental Effects on Population Dynamics of New England Yellowtail Flounder" by Jessica Kittel on April 7th
Department of Fisheries Oceanography
"Environmental Effects on Population Dynamics of New England Yellowtail Flounder"
By: Jessica Kittel
Advisor
Steven X. Cadrin
Committee Members
Kevin Stokesbury (UMass Dartmouth), Gavin Fay (UMass Dartmouth), Lisa Kerr (U Maine), Alex Hansell (NEFSC)
Tuesday April 7th, 2025
2 PM
SMAST East 101-103
836 S. Rodney French Blvd, New Bedford
and via Zoom
Abstract:
Yellowtail flounder, Limanda ferruginea (a.k.a., Pleuronectes ferruginea, Myzopsetta ferruginea), inhabit the continental shelf of the northwest Atlantic and historically supported target fisheries off New England. However, the Georges Bank and Southern New England/ Mid-Atlantic stocks have declined in recent decades and have not recovered despite severely restricted fisheries, suggesting that productivity may be negatively affected by climate change. Ocean waters off New England are warming four times faster than the global average, and decreased yellowtail flounder productivity has been associated with ocean warming in the region. US stock assessments of yellowtail flounder have exhibited retrospective patterns, in which contemporary estimates of abundance decrease when a new year of data is added, presenting a major source of uncertainty for determining stock status and informing rebuilding plans. Retrospective patterns may result from model assumptions that do not account for environmental effects on population or fishery dynamics. In the face of climate change, there is increasing exploration of climate impacts on stock dynamics in the context of stock assessments. However, incorrectly integrating climate information can contribute to model misspecification. Thus, it is important to identify significant relationships and understand mechanisms before including them in assessments. Process error refers to the variability in population dynamics due to natural fluctuations (such as environmental effects) not captured by the model. State space models explicitly model this uncertainty, potentially improving the accuracy of assessments and supporting more adaptive, sustainable fisheries management. I led a review of the available information on environmental drivers that may be impacting US stocks of yellowtail flounder from literature and harvesters’ ecological knowledge, tested relationships between environmental indices and components of productivity (i.e., recruitment, growth, maturity, survival), and helped developed stock assessment models that account for environmental effects.......For entire abstract, email contact below to receive.
Join Zoom Meeting
https://umassd.zoom.us/j/94884382648
Note: Meeting passcode required, email contact below to receive
To request the Zoom passcode, the full abstract, or for any other questions, please email Callie Rumbut
SMAST East 101-103 and Zoom
Callie Rumbut
c.rumbut@umassd.edu