Geology topics

Shannon Michael Bayse

Publications and source records attributed to Shannon Michael Bayse.

3 recordsLinked to original sources

USGS2020

How lipid content and temperature affect American shad (Alosa sapidissima) attempt rate and sprint swimming: Implications for overcoming migration barriers

How seasonal effects such as temperature increases and reduced lipid content affect the ability of anadromous fishes to traverse high-velocity barriers and sprint swimming is poorly understood. We evaluated American shad ( Alosa sapidissima ) swimming performance in a flume against high flow velocities (2.5–3.7 m·s −1 ) during the upstream migration period (April–May; temperatures 11.1–21.4 °C) to determine how their willingness to enter a velocity barrier (attempt rate) and their swimming endurance changed during migration. American shad did not make attempts at low temperatures, and attempt rate gradually increased throughout the migration as temperatures warmed. American shad displayed two distinct, nonsustained swimming modes (prolonged and sprint swimming), and endurance was different between sexes. At warmer temperatures, females swam at prolonged speeds more often and longer females displayed a lower endurance. Males primarily swam at sprint speeds and were affected by swimming speed, fork length, and lipid content. Our results indicate that American shad motivation and swimming endurance change over the course of the migration as conditions change, potentially limiting their ability to pass barriers.

Canadian Journal of Fisheries and Aquatic Sciences↗

USGS2019

Upper thermal tolerance and heat shock protein response of juvenile American shad (Alosa sapidissima)

Juvenile American shad ( Alosa sapidissima ) experience a wide range of temperatures in rivers before migrating to the ocean. Temperatures in these freshwater environments can vary greatly spatially, seasonally, year-to-year, and can be impacted by anthropogenic factors such as power plant discharge or climate change. Currently, there is uncertainty concerning juvenile American shad thermal tolerance due to a lack of a well-controlled study. Here, we report results of laboratory experiments to establish the upper thermal tolerance and heat shock protein response of juvenile American shad exposed to gradually increasing temperatures. Upper thermal tolerance was determined to be 35 °C (median; range = 34–36 °C) when fish were acclimated to 25 °C and temperatures were raised 1 °C day −1 . Heat shock protein response was indicated by changes in branchial mRNA abundance of the inducible heat shock protein 90 alpha ( hsp90α ), which was significantly elevated (more than 5-fold increase) at 30 °C, and highest in fish that had reached their upper thermal maximum between 34 and 36 °C. Our findings indicate a higher upper thermal tolerance than previously reported for juvenile American shad, and an onset temperature of hsp90α induction at 30 °C, a temperature juvenile American shad commonly experience during summer months.

Estuaries and Coasts↗

USGS2018

Proximate composition, lipid utilization and validation of a non‐lethal method to determine lipid content in migrating American shad Alosa sapidissima

Lipid content forms the most important energy reserve in anadromous fish and can limit survival, migration and reproductive success. A fat meter was evaluated and compared with a traditional extractive method of measuring available lipid for migrating American shad Alosa sapidissima in the Connecticut River, U.S.A. The fat meter gives rapid (<10 s) and non‐lethal lipid measurements, whereas traditional methods require lethal sampling that is both time consuming and expensive. The fat‐meter readings had a strong relationship to traditional lipid extractions for 60 fish, 30 whole body ( R 2 = 0·72) and 30 fillet only ( R 2 = 0·81). Additional validation showed that fat‐meter readings captured the gradual decrease of lipid in individual fish over time, were not affected by removal of gonads or scales and were stable for fish exposed to water or air for 24 h after death. These experiments indicate that the fat meter can be used as a reliable tool for future A. sapidissima energetic studies, allowing for larger sample sizes and non‐lethal sampling.

Connecticut, Massachusetts, Vermont↗