Effects of temperature and energy use on fish passage and spawning success of American shad
Dates
Start Date
2015-01-10
End Date
2018-01-09
Summary
American Shad (Alosa sapidissima) are the most numerous and economically important anadromous species on the east coast of the United States. Yet in many river systems their populations have experienced declines, primarily due to the impacts of dams and habitat loss (Limburg and Waldman 2009). Although fish passage facilities have been constructed to mitigate the impacts of dams, many of these have not provided adequate passage success for self-sustaining populations or populations at levels that meet management goals. The negative impacts of fish passage facilities may be exacerbated by high temperature late in the migratory period (Castro-Santos and Letcher 2010), a phenomenon that is likely to become worse with higher freshwater [...]
Summary
American Shad (Alosa sapidissima) are the most numerous and economically important anadromous species on the east coast of the United States. Yet in many river systems their populations have experienced declines, primarily due to the impacts of dams and habitat loss (Limburg and Waldman 2009). Although fish passage facilities have been constructed to mitigate the impacts of dams, many of these have not provided adequate passage success for self-sustaining populations or populations at levels that meet management goals. The negative impacts of fish passage facilities may be exacerbated by high temperature late in the migratory period (Castro-Santos and Letcher 2010), a phenomenon that is likely to become worse with higher freshwater temperatures associated with climate change. Migratory delays associated with low rates of dam passage appear to substantially aggravate this effect. Previous research has established that energetic considerations are a critical component of adult American shad migration, spawning success and itero/semelparity (Glebe and Leggett 1981;Leonard and McCormick 1999a).
Modelling studies have found that energetics is an important issue for understanding the influence of temperature on migration, spawning success and iteroparity in American shad (Castro-Santos and Letcher 2010). Key components of these models have relied on information from other species because the influence of temperature on maximum sustained swimming capacity, burst swimming capacity and oxygen demand of American shad are currently unknown, leading to great uncertainty in model predictions. We will use a combination of field and laboratory approaches to understand the influence of temperature on migration and spawning success of American shad. This information will be used to provide a robust scientific basis for fish passage performance criteria for current and pending hydro power passage recommendations by the Service and for restoration planning, management, and evaluation.
Objectives:
The overall goal of the project is to determine the impacts of temperature, energy use, and efficiency of fish passage facilities on the spawning success of American shad. To achieve this goal we have developed the following specific objectives:
How do thermal conditions experienced during migration affect energy use and swimming capacity?
How does the total energy used by migrating shad affect migration and spawning success?
Are there energetic differences between early and late run fish and between sexes that affect migration and spawning success?
These data and analyses can be used to quantify effects of dam-induced delays, cumulative effects of dams and the effects of climate change on American shad migration, spawning success and population sustainability.
