Geology topics

M.M. Bailey

Publications and source records attributed to M.M. Bailey.

3 recordsLinked to original sources

USGS2014

Survival of Atlantic salmon Salmo salar smolts through a hydropower complex

This study evaluated Atlantic salmon Salmo salar smolt survival through the lower Penobscot River, Maine, U.S.A., and characterized relative differences in proportional use and survival through the main-stem of the river and an alternative migration route, the Stillwater Branch. The work was conducted prior to removal of two main-stem dams and operational changes in hydropower facilities in the Stillwater Branch. Survival and proportional use of migration routes in the lower Penobscot were estimated from multistate (MS) models based on 6 years of acoustic telemetry data from 1669 smolts and 2 years of radio-telemetry data from 190 fish. A small proportion (0·12, 95% c.i. = 0·06–0·25) of smolts used the Stillwater Branch, and mean survival through the two operational dams in this part of the river was relatively high (1·00 and 0·97). Survival at Milford Dam, the dam that will remain in the main-stem of the Penobscot River, was relatively low (0·91), whereas survival through two dams that were removed was relatively high (0·99 and 0·98). Smolt survival could decrease in the Stillwater Branch with the addition of two new powerhouses while continuing to meet fish passage standards. The effects of removing two dams in the main-stem are expected to be negligible for smolt survival based on high survival observed from 2005 to 2012 at those locations. Survival through Milford Dam was been well below current regulatory standards, and thus improvement of passage at this location offers the best opportunity for improving overall smolt survival in the lower river.

Maine↗

USGS2009

Atlantic salmon (Salmo salar) smolt production: the relative importance of survival and body growth

The complex life history of Atlantic salmon (Salmo salar) coupled with interacting abiotic and biotic factors leads to extreme demographic variability across the species' range. Our goal was to evaluate the relative importance of survival and body growth in determining smolt production across space and time. We used passive integrated transponder tags and capture-mark-recapture analyses to estimate survival, emigration, and growth for six cohorts of presmolt Atlantic salmon in two streams (three cohorts per stream) in New England, USA. We observed remarkable among-cohort consistency in mean monthly survival during a 17-month period from age-0+ autumn to age-2+ spring yet high variability in monthly survival over shorter time intervals (seasons). Despite this latter variability, survival did not translate into amongcohort differences in proportions of age-2+ versus age-3+ smolts. Alternatively, the high variability across seasons and cohorts in mean individual growth rate did lead to differences in within-cohort proportions of age-2+ versus age-3+ smolts (regardless of stream). We conclude that in our two small study streams, variability in growth and size impacted smolt age and, ultimately, smolt production. Density-dependent effects on growth at the scale of the entire study site represent a possible mechanism underlying our observations.

Canadian Journal of Fisheries and Aquatic Sciences↗

USGS2004

Movement and population size of American shad near a low-head lock and dam

We investigated the population size and the proportion of the population of American shad Alosa sapidissima that passed through the New Savannah Bluff Lock and Dam, a low-head lock and dam on the Savannah River in South Carolina and Georgia. We fitted 110 American shad with radio transmitters in 2001 and 2002. All but two fish moved downstream after transmitter implantation. In 2001, a smaller proportion of American shad implanted with radio transmitters earlier in the season returned to the dam than fish released later. Of the fish that returned to the dam, over 50% in 2001 and 9% in 2002 passed through the lock and continued migrating upstream. In both years, the modal daily movement distance was less than 1 km. Movements greater than 5 km/d were generally associated with fish rapidly returning upstream after their initial downstream movement. Continuous diel monitoring indicated that movements greater than 0.1 km/h were more frequent at night than during the day. In both years, American shad were not uniformly distributed over the study area but were predominantly grouped just below the dam and in a relatively large pool approximately 6 km below the dam. We estimated the population size of American shad that reached the New Savannah Bluff Lock and Dam at 157,685 in 2001 and 217,077 in 2002.

Transactions of the American Fisheries Society↗