scholarly journals Evaluating the Role of Boat Electrofishing in Fish Monitoring of the Sacramento–San Joaquin Delta

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Ryan McKenzie ◽  
Brian Mahardja
Keyword(s):  
San Francisco ◽  
Fish Species ◽  
Life Stages ◽  
Detection Rates ◽  
Resource Managers ◽  
Fish Catch ◽  
Current Sampling ◽  
Fish Monitoring

The San Francisco Estuary is an incredibly diverse ecosystem with a mosaic of aquatic habitats inhabited by a number of economically, culturally, and ecologically important fish species. To monitor the temporal and spatial trends of this rich fish community, long-term fish monitoring programs within the estuary use a variety of gear types to capture fish species across life stages and habitats. However, concerns have been raised that current sampling gears may fail to detect certain species—or life stages—that inhabit areas that are not accessible by current gear types (e.g., riprap banks, shallow vegetated areas). Boat electrofishing is one sampling method that has been proposed to supplement current long-term fish monitoring in the upper estuary. In this study, we used fish catch data from past boat electrofishing studies, a long-term beach seine survey, and a couple of long-running trawl surveys to compare the relative probability of detecting various fishes across these sampling gears. Overall, we found that boat electrofishing led to notable improvements in the detection rates for many native and non-native fishes we examined. Boat electrofishing gear was better at detecting the majority of species in the spring (20 out of 38 species, 53%) and fall-winter (24 out of 34 species, 70%) sampling periods. Based on these findings, we recommend that resource managers consider the implementation of a long-term boat electrofishing survey to help them in their long-term conservation planning for fishes within the upper estuary.

scholarly journals Evaluating the Role of Boat Electrofishing in Fish Monitoring of the Sacramento–San Joaquin Delta

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Ryan McKenzie ◽  
Brian Mahardja
Keyword(s):  
San Francisco ◽  
Fish Species ◽  
Life Stages ◽  
Detection Rates ◽  
Resource Managers ◽  
Fish Catch ◽  
Current Sampling ◽  
Fish Monitoring

The San Francisco Estuary is an incredibly diverse ecosystem with a mosaic of aquatic habitats inhabited by a number of economically, culturally, and ecologically important fish species. To monitor the temporal and spatial trends of this rich fish community, long-term fish monitoring programs within the estuary use a variety of gear types to capture fish species across life stages and habitats. However, concerns have been raised that current sampling gears may fail to detect certain species—or life stages—that inhabit areas that are not accessible by current gear types (e.g., riprap banks, shallow vegetated areas). Boat electrofishing is one sampling method that has been proposed to supplement current long-term fish monitoring in the upper estuary. In this study, we used fish catch data from past boat electrofishing studies, a long-term beach seine survey, and a couple of long-running trawl surveys to compare the relative probability of detecting various fishes across these sampling gears. Overall, we found that boat electrofishing led to notable improvements in the detection rates for many native and non-native fishes we examined. Boat electrofishing gear was better at detecting the majority of species in the spring (20 out of 38 species, 53%) and fall-winter (24 out of 34 species, 70%) sampling periods. Based on these findings, we recommend that resource managers consider the implementation of a long-term boat electrofishing survey to help them in their long-term conservation planning for fishes within the upper estuary.

scholarly journals Novel Astroviruses in Insectivorous Bats

2008 ◽  
Vol 82 (18) ◽  
pp. 9107-9114 ◽  
Author(s):  
D. K. W. Chu ◽  
L. L. M. Poon ◽  
Y. Guan ◽  
J. S. M. Peiris
Keyword(s):  
Virus Detection ◽  
High Genetic Diversity ◽  
Insectivorous Bats ◽  
Detection Rates ◽  
Human Astroviruses ◽  
Wide Range ◽  
The Family ◽  
Apparently Healthy

ABSTRACT Bats are increasingly recognized to harbor a wide range of viruses, and in most instances these viruses appear to establish long-term persistence in these animals. They are the reservoir of a number of human zoonotic diseases including Nipah, Ebola, and severe acute respiratory syndrome. We report the identification of novel groups of astroviruses in apparently healthy insectivorous bats found in Hong Kong, in particular, bats belonging to the genera Miniopterus and Myotis. Astroviruses are important causes of diarrhea in many animal species, including humans. Many of the bat astroviruses form distinct phylogenetic clusters in the genus Mamastrovirus within the family Astroviridae. Virus detection rates of 36% to 100% and 50% to 70% were found in Miniopterus magnater and Miniopterus pusillus bats, respectively, captured within a single bat habitat during four consecutive visits spanning 1 year. There was high genetic diversity of viruses in bats found within this single habitat. Some bat astroviruses may be phylogenetically related to human astroviruses, and further studies with a wider range of bat species in different geographic locations are warranted. These findings are likely to provide new insights into the ecology and evolution of astroviruses and reinforce the role of bats as a reservoir of viruses with potential to pose a zoonotic threat to human health.

scholarly journals Fish Misidentification and Potential Implications to Monitoring Within the San Francisco Estuary, California

2018 ◽  
Vol 9 (2) ◽  
pp. 467-485
Author(s):  
Joseph E. Kirsch ◽  
Julie L. Day ◽  
James T. Peterson ◽  
David K. Fullerton
Keyword(s):  
San Francisco ◽  
Fish Species ◽  
False Positive ◽  
Juvenile Fish ◽  
Monitoring Program ◽  
San Francisco Estuary ◽  
Full Time ◽  
Monitoring Programs ◽  
Observer Experience ◽  
Fish Monitoring

Abstract Fish monitoring programs often rely on the collection, species identification, and counting of individual fish over time to inform natural resource management decisions. Thus, the utility of the data used to inform these decisions can be negatively affected by species misidentification. Fish species misidentification bias can be minimized by confirming identification using genetic techniques, training observers, or adjusting monitoring data using estimates of incomplete detection and false-positive misidentification. Despite the existence of well-established fish identification training and quality control programs, there is considerable uncertainty about fish species false-positive misidentification rates and the effectiveness of fish identification training programs within the San Francisco Estuary. We evaluated the misidentification of fish species among Delta Juvenile Fish Monitoring Program observers by conducting five fish identification exams under controlled conditions at the Lodi Fish and Wildlife Office in Lodi, California, between 2012 and 2014. To assess the variability in false-positive misidentification, we fitted data to species and observer characteristics using hierarchical logistic regression. We found that fish species misidentification was fairly common, averaging 17% among 155 test specimens and 32 observers. False-positive misidentification varied considerably among species and was negatively related to fish size, the abundance of the species within monitoring samples, and observer experience. In addition, observers who were not formally trained or used as full-time observers were, on average, 6.0 times more likely to falsely identify a species. However, false-positive misidentification rates among observers and specimens still varied considerably after controlling for observer experience and training, and species and size, respectively. Our results could be used to improve fish identification training and testing, increase the accuracy of fish occupancy or abundance estimation, and justify the allocation of resources to continually use and formally train full-time observers within long-term monitoring programs operating in the system.

scholarly journals COVID-19-Associated Deaths in San Francisco: the Important Role of Dementia and Atypical Presentations in Long-term Care Facilities

2020 ◽  
Vol 35 (11) ◽  
pp. 3413-3415 ◽  
Author(s):  
Janice K. Louie ◽  
Hyman M. Scott ◽  
Wendy Lu ◽  
Anna Chodos ◽  
Amie DuBois ◽  
...  
Keyword(s):  
San Francisco ◽  
Long Term Care ◽  
Term Care ◽  
Care Facilities ◽  
Atypical Presentations

The Role of the Neighbourhood in Rehabilitation of an Urban Aquatic Ecosystem

1997 ◽  
Vol 32 (2) ◽  
pp. 245-256 ◽  
Author(s):  
K.W. Dance
Keyword(s):  
Fish Species ◽  
Exotic Fish ◽  
Positive Role ◽  
Management Intervention ◽  
Rehabilitation Plan ◽  
Management Interventions ◽  
Periodic Monitoring ◽  
Exotic Fish Species

Abstract For the first 10 to 15 years following rehabilitation, the original goals at West Heights Pond, Kitchener, were attained. Monitoring over a 16-year period revealed that if ecosystem health and aesthetics goals are to be sustained in the future, management intervention is required. Required management includes on-going control of aggressive wetland plant pests; efforts to discourage waterfowl feeding so that numbers decline and water quality improves; and potential future control of exotic fish species goldfish and carp. The study has concluded that (1) periodic monitoring over the long term is required to determine whether rehabilitation plan goals are being met and to identify the nature of required management interventions; (2) human neighbours are a critical species in the ecosystem management process since they can be the agents of significant positive and negative actions which affect attainment of rehabilitation plan goals; and (3) the lead agency in rehabilitation implementation should ensure that a long-term dialogue with site neighbours capitalizes on the positive role neighbours can play and avoids negative actions such as feeding waterfowl, trampling banks and vegetation, and introducing exotic fish species.

Multidecadal trends for three declining fish species: habitat patterns and mechanisms in the San Francisco Estuary, California, USA

2007 ◽  
Vol 64 (4) ◽  
pp. 723-734 ◽  
Author(s):  
Frederick Feyrer ◽  
Matthew L Nobriga ◽  
Ted R Sommer
Keyword(s):  
Water Quality ◽  
San Francisco ◽  
Striped Bass ◽  
Fish Species ◽  
Habitat Suitability ◽  
Specific Conductance ◽  
San Francisco Estuary ◽  
Delta Smelt ◽  
Threadfin Shad

We examined a 36-year record of concurrent midwater trawl and water quality sampling conducted during fall to evaluate habitat trends for three declining fish species in the San Francisco Estuary, California, USA: delta smelt (Hypomesus transpacificus), striped bass (Morone saxatilis), and threadfin shad (Dorosoma petenense). Generalized additive modeling revealed that Secchi depth and specific conductance were important predictors of occurrence for delta smelt and striped bass, while specific conductance and water temperature were important for threadfin shad. Habitat suitability derived from model predictions exhibited significant long-term declines for each species; the southeastern and western regions of the estuary exhibited the most dramatic changes. Declines in habitat suitability were associated with anthropogenic modifications to the ecosystem. For delta smelt, an imperiled annual species endemic to the estuary, the combined effects of fall stock abundance and water quality predicted recruit abundance during recent years of chronically low food supply. Our results are consistent with existing evidence of a long-term decline in carrying capacity for delta smelt and striped bass and demonstrate the utility of long-term data sets for evaluating relationships between fish and their habitat.

scholarly journals Understanding imperfect detection in a San Francisco Estuary long-term larval and juvenile fish monitoring programme

2017 ◽  
Vol 24 (6) ◽  
pp. 488-503 ◽  
Author(s):  
B. Mahardja ◽  
M. J. Young ◽  
B. Schreier ◽  
T. Sommer
Keyword(s):  
San Francisco ◽  
Juvenile Fish ◽  
San Francisco Estuary ◽  
Monitoring Programme ◽  
Imperfect Detection ◽  
Fish Monitoring

Abusive head trauma (AHT) outcome at long-term follow-up and the role of elective neurosurgical approach: A report of 22 cases

2013 ◽  
Author(s):  
Francesca Menegazzo ◽  
Melissa Rosa Rizzotto ◽  
Martina Bua ◽  
Luisa Pinello ◽  
Elisabetta Tono ◽  
...  
Keyword(s):  
Head Trauma ◽  
Abusive Head Trauma ◽  
Long Term Follow Up
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