Download or read book Niche Partitioning by Green Sturgeon Acipenser Medirostris and White Sturgeon A Transmontanus in the San Francisco Estuary and Sacramento River written by Emily Anne Miller and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Niche partitioning allows two similar species to coexist through differential use of resources. Green Sturgeon (Acipenser medirostris) and White Sturgeon (A. transmontanus) are two closely related species that inhabit the San Francisco Estuary and Sacramento River. To examine evidence of niche partitioning, I used acoustic telemetry to describe their movements in the watershed and stable isotope analysis to compare their dietary sources. The effect of acoustic tagging had been studied in White Sturgeon, but it had not been studied in Green Sturgeon. Despite some similarities in morphology and life history the two species have distinct differences. For this reason, one species cannot serve as a proxy for the other. For my dissertation, first I studied the effect of acoustic tagging on Green Sturgeon growth, incision healing, and swimming performance in the laboratory. The results demonstrated no detrimental effect of tagging on the Green Sturgeon so critical telemetry studies are justified when using recommended tagging practices. There were cases of inflammation around undissolved sutures so practices that reduce the number of sutures and the use of suture material that dissolves rapidly is advisable. Using these results, I could interpret my telemetry data as representative of untagged individuals. I tagged 41 Green Sturgeon and 160 White Sturgeon ranging from large juveniles to adults. I found that Green and White Sturgeon adults differed the timing of their migratory movements at every reach of the watershed. They also differed in their route selection through the Sacramento-San Joaquin Delta. White Sturgeon were more likely to use northern sloughs and Green Sturgeon were more likely to use the mainstem of the Sacramento River. White Sturgeon also spent more time in the Delta prior to entering the Sacramento River and appears to be over-wintering behavior. Green Sturgeon spent significantly longer time in the spawning reaches than White Sturgeon, with some individuals staying nearly a year. Green Sturgeon juveniles and subadults were distributed lower in the system (more marine) relative to White Sturgeon juveniles and subadults. Juveniles and subadults of both species moved between the San Francisco Bay and Delta throughout the year. Finally, to compare differences in dietary sources, I collected whole blood and plasma samples from 26 Green Sturgeon and 35 White Sturgeon of various body sizes. Green Sturgeon had more marine d13C signatures than White Sturgeon. Larger sturgeon of each species had more marine d13C signatures than smaller sturgeon. Green and White Sturgeon did not have different d15N signatures for whole blood indicating that they fed at the same trophic level, but d15N values were lower for White Sturgeon than Green Sturgeon in plasma samples. This difference suggests White Sturgeon were feeding at a lower trophic level more recently, though not over a longer time scale. Length did not affect d15N signatures of either species. There is evidence of niche partitioning by Green and White Sturgeon spatially, temporally, and in the dietary sources.
Download or read book Early Life History Comparison of the Green Sturgeon Acipenser Medirostris and White Sturgeon Acipenser Transmontanus of the Sacramento San Joaquin River Delta California written by Johnson C. S. Wang and published by . This book was released on 2006 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Migration of Green Sturgeon Acipenser Medirostris in the Sacramento River written by Joseph Chapler Heublein and published by . This book was released on 2007 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flow vector Kinesis in the Daily Movements of an Anadromous Fish written by John Thomas Kelly (III.) and published by . This book was released on 2006 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Population Dynamics and Management for White Sturgeon in the Sacramento San Joaquin River Basin California written by Shannon E. Blackburn and published by . This book was released on 2018 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent surveys suggest that the population of White Sturgeon Acipenser transmontanus in the Sacramento-San Joaquin River basin (SSJ) is declining. Probable reasons for the decline include overharvest and habitat degradation, compounded by poor recruitment during recent droughts. Despite the importance and status of White Sturgeon, knowledge of their population dynamics in the SSJ remains incomplete and additional information is warranted to develop an effective management and conservation plan. The purpose of this research was to establish baseline demographics for White Sturgeon in the SSJ and evaluate possible influences of water management characteristics (i.e., discharge, temperature) on growth. Information from this thesis will provide insight on the population-level responses under different management scenarios. Overall, White Sturgeon in the SSJ experienced higher rates of mortality and growth than other populations. Additionally, growth has increased since the 1980s. Thermal and hydrological variables had little influence on growth of juvenile White Sturgeon, suggesting that annual growth may be affected by other abiotic and biotic factors. Model projections, in conjunction with demographic information, indicated that White Sturgeon in the SSJ are likely exploited to an excessive degree. Under current conditions, the population will continue to decrease. Low levels of exploitation (i.e.,
Download or read book Green Sturgeon Acipenser Medirostris Status Review Update written by Green Sturgeon Biological Review Team (U.S.) and published by . This book was released on 2005 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Status Review for North American Green Sturgeon Acipenser Medirostris written by Peter Burton Adams and published by . This book was released on 2002 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In 2001, the National Marine Fisheries Service (NMFS) received a petition requesting Endangered Species Act (ESA) listing of North American green sturgeon (Acipenser medirostris) as a threatened or endangered species. In response to this petition, NMFS announced that it would initiate an ESA status review. The ESA allows the listing of ADistinct Population Segments© (DPSs) of vertebrates as well as named species and subspecies. The combined U. S. Fish and Wildlife Service and NMFS policy on recognition of DPSs outlines two tests to identify separate units: discreteness and significance. A DPS may be considered discrete if it is markedly separate from other populations of the same taxon as a consequence of physical, physiological, ecological, or behavioral factors or if it is delimited by international governmental boundaries. The significance of the population will be decided on the basis of considerations including, but not limited to its persistence, evidence that loss of the DPS would result in a significant gap in spatial structure, evidence of the DPS representing the only surviving natural occurrence of a taxon, or evidence that the DPS differs markedly in its genetic characteristics. Once a DPS has been identified, a risk assessment is preformed to determine whether a listing is warranted for that unit"--Executive Summary.
Download or read book Observations on the Systematics of Juveniles White Sturgeon and Green Sturgeon written by Max R. Schreiber and published by . This book was released on 1960 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Migratory Fishes of South America written by Joachim Carolsfeld and published by IDRC. This book was released on 2003 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Observations on the Systematics of Juvenile White Sturgeon and Green Sturgeon written by Max R. Schreiber and published by . This book was released on 1960 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Substrate Composition on Foraging Behavior and Growth Rate of Larval Green Sturgeon Acipenser Medirostris written by Rosalee Mai Nguyen and published by . This book was released on 2006 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Non lethal Tissue Sampling of Middle Fraser River White Sturgeon Acipenser Transmontanus written by Kim Keogh and published by . This book was released on 2017 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sturgeons and Paddlefish of North America written by G.T.O LeBreton and published by Springer Science & Business Media. This book was released on 2006-01-20 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern North American sturgeons and paddlefish are the result of 100 million years of evolution. Once an integral part of aboriginal culture, their numbers were decimated by overfishing and habitat destruction during the past two centuries. This book details the extensive science aimed at helping these remarkable species recover from the brink of extinction, and describes the historical, biological, and ecological importance of North American sturgeon and paddlefish. The text is enhanced by photographs and detailed line drawings. This comprehensive volume will be an invaluable resource for researchers, educators, and consultants, in academic and government settings, who work to further scientific understanding of these fishes. No other single compilation has documented current information in such detail.
Download or read book The Histology of Fishes written by Krzysztof Formicki and published by CRC Press. This book was released on 2019-10-08 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is a multi-authored book of 18 chapters comprising the state of the art work of all relevant topics on modern fish histology from 28 authors from ten countries. The topics include Introduction to Histological Techniques, Integument, Fish Skeletal Tissues, Muscular System, Structure and Function of Electric Organs, Digestive System, Glands of the Digestive Tract, Swim Bladder, Kidney, Ovaries and Eggs, Egg Envelopes, Testis Structure, Spermatogenesis, and Spermatozoa in Teleost Fishes, Cardiovascular System and Blood, Immune System of Fish, Gills: Respiration and Ionic-Osmoregulation, Sensory Organs, Morphology and Ecomorphology of the Fish Brain, and Endocrine System. Structural and functional aspects are treated and in a comparative way fish diversity at various taxonomic levels is integrated.
Download or read book White Sturgeon Acipenser Transmontanus written by Keith R. Garner and published by . This book was released on 2006 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: "White sturgeon (Acipenser transmontanus) are native to the upper Columbia River. Population demographics during the past 30 years have documented a shift to larger, older fish which indicates little or no recruitment of juveniles into the aging adult population. Predation is one possible explanation for the lack in recruitment of age-0 white sturgeon. Laboratory experiments revealed that several species (walleye, northern pikeminnow, channel catfish, prickly sculpin, burbot) will prey on young-of-the-year (age-0) white sturgeon; but there are few reports that document predation of juvenile white sturgeon in the wild. I conducted four experiments to determine why more white sturgeon are not seen in predator diets: 1) How vulnerable are juvenile white sturgeon to predation? 2) Are white sturgeon digested faster than other fish? 3) How long do white sturgeon remains persist in the gut of predators? 4) What parts of a white sturgeon are most easily distinguishable in the gut of a predator. To answer my first question, I examined the vulnerability of juvenile white sturgeon to predation by walleye and burbot (Lota Iota), two of the most abundant predators in Lake Roosevelt. I placed age-0 white sturgeon (TL = 24 ± 4 mm), yearling (age-1) white sturgeon (TL = 173 ± 24 mm), rainbow trout and kokanee together in tanks with walleye and in other tanks with burbot. Walleye ate the following percentages of prey: 65% rainbow trout, 75% kokanee, and 100% age-0 white sturgeon in study one, and 55% kokanee, 55% rainbow trout, 0% age-1 white sturgeon, and in 35% no fish for study two. Burbot ate the following percentages of prey: 100% kokanee, 100% rainbow trout, and 100% age-0 white sturgeon in study one, and 100% kokanee, 92% rainbow trout, and 0% age-1 white sturgeon in study two. The results of this laboratory study supported the hypothesis that predation may limit recruitment of age-0 white sturgeon, but field validation is needed to confirm it. To answer the second question, I tested the hypothesis that the cartilaginous endoskeleton of the white sturgeon may be digested quicker than bony fish endoskeletons resulting in few predation observations. To test this hypothesis, white sturgeon and kokanee (Oncorhynchus nerka) of comparable size were force fed to walleye (Sander vitreus) and the rate at which the prey was evacuated from the gut was measured at 12 ± 1 °C and 19 ± 1°C for three and eight hours. Wet and dry weights were taken and compared using t-tests. After eight hours, walleye held at 12.0 ± 1 °C and 19.0 ± 1°C evacuated white sturgeon (wet weight) at a rate 3.0 times faster than the kokanee at 12°C (t = 14.02, P
Download or read book Review of Potential Critical Habitats for White Sturgeon Acipenser Transmontanus in the Fraser River Estuary written by Colin D. Levings and published by . This book was released on 2003 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Ecology of Marine Fishes written by Dr. Larry G. Allen and published by Univ of California Press. This book was released on 2006-02-15 with total page 1353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine fishes have been intensively studied, and some of the fundamental ideas in the science of marine ecology have emerged from the body of knowledge derived from this diverse group of organisms. This unique, authoritative, and accessible reference, compiled by 35 luminary ecologists, evolutionary biologists, and ichthyologists, provides a synthesis and interpretation of the large, often daunting, body of information on the ecology of marine fishes. The focus is on the fauna of the eastern Pacific, especially the fishes of the California coast, a group among the most diverse and best studied of all marine ecosystems. A generously illustrated and comprehensive source of information, this volume will also be an important launching pad for future research and will shed new light on the study of marine fish ecology worldwide. The contributors touch on many fields in biology, including physiology, development, genetics, behavior, ecology, and evolution. The book includes sections on the history of research, both published and unpublished data, sections on collecting techniques, and references to important earlier studies.
