Striped Bass (Morone saxatilis) Year Class Strength in Relation to River Flow in the Sacramento-San Joaquin Estuary, California

1977 ◽  
Vol 106 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Donald E. Stevens
Keyword(s):  
Striped Bass ◽  
River Flow ◽  
Morone Saxatilis ◽  
Class Strength

Winter mortality of young-of-the-year Hudson River striped bass (Morone saxatilis): size-dependent patterns and effects on recruitment

1998 ◽  
Vol 55 (5) ◽  
pp. 1122-1130 ◽  
Author(s):  
Thomas P Hurst ◽  
David O Conover
Keyword(s):  
Striped Bass ◽  
Morone Saxatilis ◽  
Hudson River ◽  
Progressive Increase ◽  
Winter Mortality ◽  
Ambient Conditions ◽  
Catch Per Unit Effort ◽  
Size Dependent ◽  
Class Strength ◽  
Young Of The Year

Winter mortality plays a significant role in the dynamics of some temperate fish populations and has been shown to be size-dependent for some species, but not for others. Our objective was to determine how winter mortality affects the recruitment dynamics of Hudson River striped bass (Morone saxatilis). We used catch-per-unit-effort data from three separate surveys targeting young-of-the-year (YOY), overwintering, and age 1 striped bass. Age 1 abundance was negatively correlated with the severity of winter. In contrast, the abundance of age 0 fish was not correlated with age 1 abundance, suggesting that winter mortality greatly modifies year-class strength. A progressive increase in the mean length of YOY fish, coupled with a decrease in the coefficient of variation in length, occurred during some winters. Laboratory experiments showed that growth in length requires temperatures in excess of 10°C; hence, these changes likely result from selective mortality of smaller fish. Direct evidence of size-dependent mortality was obtained from a laboratory experiment that exposed fish to ambient conditions throughout the winter. Accounting for interannual differences in the severity and size dependency of winter mortality may improve our ability to evaluate striped bass year-class strength in the Hudson River.

Density-dependent regulation of year-class strength in age-0 juvenile striped bass (Morone saxatilis)

2012 ◽  
Vol 69 (3) ◽  
pp. 430-446 ◽  
Author(s):  
E.J. Martino ◽  
E.D. Houde
Keyword(s):  
Chesapeake Bay ◽  
Striped Bass ◽  
Morone Saxatilis ◽  
Winter Temperature ◽  
Density Dependent ◽  
Early Juvenile Stage ◽  
Class Strength ◽  
Dependent Growth ◽  
Overwinter Mortality ◽  
Density Dependent Regulation

Abundance of age-0 striped bass ( Morone saxatilis ) exhibits 50-fold variability in Chesapeake Bay. Processes that act to reduce and thus regulate this variability were investigated. The potential for density-dependent regulation of growth and mortality in the early juvenile stage and its causes were investigated. Data from multiple seine and trawl surveys in upper Chesapeake Bay and tributaries were analyzed to construct growth and mortality indices having a high degree of spatial and temporal resolution. Age-0 mean lengths in September were inversely related to density, ranging from 67.8 mm in 1994, when mean density was 0.036·m–2, to 104.5 mm in 1992, when mean density was 0.003·m–2. Except for the Potomac River, evidence for density-dependent growth was consistent across subpopulations. Bioenergetics modeling indicated that prey consumption was limiting except in low-abundance years. Mortality increased with respect to abundance and also was density-dependent. The significant interaction between age-0 juvenile length in September and subsequent winter temperature on mortality indicated that density-dependent growth leads to size-selective overwinter mortality. A statistical model including age-0 abundances, age-0 lengths, and winter temperature explained a substantial fraction of variability and the mechanisms for regulation of striped bass recruitment.

Emamectin benzoate is a safe and effective anthelmintic against coelomic nematode Philometra rubra in striped bass Morone saxatilis

2020 ◽  
Vol 142 ◽  
pp. 47-53
Author(s):  
K Béland ◽  
G Séguin ◽  
S Lair
Keyword(s):  
Mortality Rate ◽  
Striped Bass ◽  
High Mortality ◽  
Morone Saxatilis ◽  
Treatment Results ◽  
Emamectin Benzoate ◽  
Once Daily ◽  
Fish Hatchery ◽  
Parasitic Burden

An unusually high mortality rate due to verminous (Philometra rubra) coelomitis was documented in wild-hatched striped bass Morone saxatilis raised in a fish hatchery as part of a stock restoration program. To decrease the parasitic burden and therefore potentially minimize mortality, the effectiveness of 2 different anthelmintics was evaluated. Two trials were conducted on wild-collected fingerlings naturally infected by P. rubra. In 2006, 144 yearling fish were randomly assigned to 4 experimental groups: (1) levamisole (Levasol®) at 2 mg l-1 via immersion for 8 h once weekly for 3 wk; (2) levamisole at a dose of 2.5 mg kg-1 biomass via feed once daily for 7 d; (3) emamectin benzoate (Slice®) at a dose of 0.05 mg kg-1 biomass via feed once daily for 7 d; and (4) control. Emamectin successfully eliminated live nematodes in 84.9% of the fish, whereas the administration of levamisole, either via immersion or feed, was not successful in significantly reducing the number of live P. rubra. In 2007, the administration of the same dosage of emamectin to approximately 1000 naturally infected yearling striped bass was associated with a 100% mortality rate of P. rubra in the 30 fish randomly examined 5 wk after the beginning of the treatment. Results of these trials indicate that, at the dosage used, the administration of emamectin at the end of the summer is safe for striped bass yearlings and considerably reduces the prevalence and intensity of the infection by this parasite.

Feeding ecology of early life stages of striped bass (Morone saxatilis) along an estuarine salinity-turbidity gradient, St. Lawrence Estuary, Canada

2019 ◽  
Vol 41 (4) ◽  
pp. 507-520 ◽  
Author(s):  
L Vanalderweireldt ◽  
P Sirois ◽  
M Mingelbier ◽  
G Winkler
Keyword(s):  
Striped Bass ◽  
Feeding Ecology ◽  
Early Life ◽  
Morone Saxatilis ◽  
Early Summer ◽  
Gut Contents ◽  
Life Stages ◽  
Early Life Stages ◽  
Lawrence Estuary ◽  
Feeding Niche

Abstract After being extirpated from the St. Lawrence River in the 1960s, striped bass (Morone saxatilis) were reintroduced to the estuary in 2002 and by 2008, they were naturally reproducing. To document the habitat use and feeding ecology of this reintroduced population, we examined the gut contents of 333 larvae and juveniles. Samples were collected in four estuarine habitats in 2014: the upstream freshwater section (UP), the oligohaline (O-ETM) and the mesohaline (M-ETM) estuarine turbidity maximum zones, and the downstream polyhaline section (DOWN). In June, pelagic larvae developed in the UP and the O-ETM, feeding mainly on copepods such as Eurytemora affinis. The O-ETM exhibited better suitable feeding conditions compared to the UP, likely due to the presence of Bosmina sp. as a primary prey. After July, striped bass shifted to larger prey items, consuming mainly dipteran pupa in upstream littoral habitats and gammarids and mysids in downstream habitats. In the early summer, the UP provided a high-quality nursery habitat and as the season progressed, the smallest juveniles dispersed downstream and improved their feeding success by exploiting a new feeding niche. This observation suggests that being distributed throughout the estuary may increase the potential survival of striped bass early life stages.

Sign in / Sign up

Export Citation Format

Share Document