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Full-Text Articles in Ecology and Evolutionary Biology

Timing Is Everything: Climate Change Implications For Phenological Events And Reproductive Success In River Herring, Meghna N. Marjadi Aug 2023

Timing Is Everything: Climate Change Implications For Phenological Events And Reproductive Success In River Herring, Meghna N. Marjadi

Doctoral Dissertations

Anadromous river herring (alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis)) make annual spring spawning migrations from the ocean to freshwater, where juveniles reside before emigrating to the ocean. Climate change may alter environmental and biological cues that prompt both adult migration and juvenile emigration, with implications for adult spawning success and offspring survival for these imperiled species. Shifts in adult migration have been observed in some rivers, while impacts on reproductive success and juvenile survival remain unknown. Cues for juvenile emigration are poorly understood as they have been explored at limited spatial and temporal scales. …


Thermal Ecophysiology Of Juvenile Anadromous River Herring, Lian W. Guo Feb 2022

Thermal Ecophysiology Of Juvenile Anadromous River Herring, Lian W. Guo

Doctoral Dissertations

Temperature controls the rate of all biochemical processes, and thus can significantly influence the physiology and ecology of all living organisms on earth. Understanding how temperature influences fitness can therefore provide insight into mechanisms affecting population size, dynamics, and geographic distributions, especially in the context of climate change. Early life stages of fishes experience significant selective pressure to grow large and accumulate energy reserves in order to avoid predation and starvation. Increasing temperatures will increase routine metabolic rates, which may result in less energy being available for growth and energy storage. In this thesis, I examine the effects of temperature, …


Don't Delay: The Effects Of Tide Gates And Road-Stream Crossing Culverts On River Herring (Alosa Spp.) Spawning Migrations, Derrick J. Alcott Dec 2020

Don't Delay: The Effects Of Tide Gates And Road-Stream Crossing Culverts On River Herring (Alosa Spp.) Spawning Migrations, Derrick J. Alcott

Doctoral Dissertations

River herring (Alosa spp.) are anadromous fish that spawn in freshwater rivers and lakes in North America from Florida to Nova Scotia, CA. They have been listed as a species of conservation concern due to dramatic stock declines observed in the 1970’s. Stocks have failed to show significant signs of recovery despite over a decade of harvest restrictions throughout their range. Bycatch in commercial fisheries and reduced access to spawning habitat due to anthropogenic barriers to migration, such as dams and tide gates, have been identified as major causes of the decline in herring populations. Physical barriers to …


River Herring Conservation In Freshwater: Investigating Fish Reproductive Success And The Educational Value Of Citizen Monitoring Programs, Meghna Marjadi Nov 2016

River Herring Conservation In Freshwater: Investigating Fish Reproductive Success And The Educational Value Of Citizen Monitoring Programs, Meghna Marjadi

Masters Theses

Over the last century anadromous alewife (Alosa psuedoharengus) and blueback herring (Alosa aestivalis), collectively called river herring, suffered drastic declines throughout their range from Newfoundland (Canada) to North Carolina (USA). A 2011 petition to include river herring in the Endangered Species Act (ESA) was rejected, partly due to inadequate information towards identifying coast-wide population status. Additionally, knowledge gaps were identified with basic ecology of the river herring life cycle in freshwater, including species reproductive strategies. In Chapter 2, I investigated how body size, spawning arrival time, and sex influence river herring reproductive success. I collaborated with …