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Upstream Migration (upstream + migration)
Selected AbstractsUpstream migration of Atlantic salmon at a power station on the River Nidelva, Southern NorwayFISHERIES MANAGEMENT & ECOLOGY, Issue 3 2003E. B. Thorstad Abstract The upstream migration of 17 radio-tagged adult Atlantic salmon, Salmo salar L., past hydroelectric developments on the River Nidelva, Southern Norway, was examined. Salmon migrated quickly from the site of release in the lower part of the river up to the tunnel outlet of Rygene power station, but were substantially delayed at the outlet. The salmon stayed in the outlet area for 0,71 days (median = 20), and mainly took up a position inside the dark power station tunnel. Water discharge in the tunnel was 57,176 m3 s,1, while residual flow in the river between the outlet and the dam 2.5 km further upstream was 3 m3 s,1. Ten salmon passed the outlet and entered the residual flow stretch, but none passed the dam. Six of the 10 salmon returned to the tunnel outlet. No major migration barriers were identified in the residual flow stretch, suggesting lack of motivation among the salmon to migrate due to either low water discharge compared with the main river, or several minor migration barriers along the river stretch. [source] Predator,prey interactions in river networks: comparing shrimp spatial refugia in two drainage basinsFRESHWATER BIOLOGY, Issue 3 2009ALAN P. COVICH Summary 1.,Analysis of drainage networks provides a framework to evaluate the densities and distributions of prey species relative to locations of their predators. Upstream migration by diadromous shrimp (Atya lanipes and Xiphocaris elongata) during their life cycle provides access to headwater refugia from fish predation, which is intense in estuaries and coastal rivers. 2.,We postulate that geomorphic barriers (such as large, steep waterfalls >3.5 m in height), can directly limit the distribution of predatory fishes and, indirectly, affect the densities of their prey (freshwater shrimps) in headwater streams. 3.,We compared densities of shrimp in pools above and below waterfalls, in four headwater tributaries in two river basins of the Luquillo Mountains of northeastern Puerto Rico. We measured shrimp densities twice a year over 8 years (1998,2005) in Prieta, Toronja, Bisley 3 and Bisley 5 streams, which differ in drainage network positions relative to steep waterfalls in Río Espíritu Santo and Río Mameyes. 4.,Predatory fishes are absent in the Prieta and Toronja pools and present in Bisely 3 and in lower Bisley 5 pools. Atya lanipes and X. elongata rarely occur in the Bisley streams where predatory fishes are present but these shrimps are abundant in Prieta and Toronja, streams lacking predatory fishes. 5.,The mean carapace length of X. elongata is longer in pools where fish are present (Bisley 3 and lower Bisley 5) than in pools lacking fish (Prieta, Toronja, Upper Bisley 5). The increased body size is primarily due to significantly longer rostrums of individuals in stream reaches with fish (below waterfall barriers) than in those reaches lacking fish (above waterfall barriers). Rostrum length may be an adaptation to avoid predation by visually feeding fishes. 6.,Atya lanipes and X. elongata distributions and densities were predicted primarily by drainage network position relative to the presence or absence of predatory fishes. High, steep waterfalls effectively impeded fish from moving upstream and created a spatial refuge. Xiphocaris elongata may rely on size refugia (longer rostrum) to minimize predation where spatial refugia are lacking. [source] Elevation of gene expression for salmon gonadotropin-releasing hormone in discrete brain loci of prespawning chum salmon during upstream migrationDEVELOPMENTAL NEUROBIOLOGY, Issue 2 2005Takeshi Onuma Abstract Our previous studies suggested that salmon gonadotropin-releasing hormone (sGnRH) neurons regulate both final maturation and migratory behavior in homing salmonids. Activation of sGnRH neurons can occur during upstream migration. We therefore examined expression of genes encoding the precursors of sGnRH, sGnRH-I, and sGnRH-II, in discrete forebrain loci of prespawning chum salmon, Oncorhynchus keta. Fish were captured from 1997 through 1999 along their homing pathway: coastal areas, a midway of the river, 4 km downstream of the natal hatchery, and the hatchery. Amounts of sGnRH mRNAs in fresh frozen sections including the olfactory bulb (OB), terminal nerve (TN), ventral telencephalon (VT), nucleus preopticus parvocellularis anterioris (PPa), and nucleus preopticus magnocellularis (PM) were determined by quantitative real-time polymerase chain reactions. The amounts of sGnRH-II mRNA were higher than those of sGnRH-I mRNA, while they showed similar changes during upstream migration. In the OB and TN, the amounts of sGnRH mRNAs elevated from the coast to the natal hatchery. In the VT and PPa, they elevated along with the progress of final maturation. Such elevation was also observed in the rostroventral, middle, and dorsocaudal parts of the PM. The amounts of gonadotropin II, and somatolactin mRNAs in the pituitary also increased consistently with the elevation of gene expression for sGnRH. These results, in combination with lines of previous evidence, indicate that sGnRH neurons are activated in almost all the forebrain loci during the last phases of spawning migration, resulting in coordination of final gonadal maturation and migratory behavior to the spawning ground. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005 [source] Relationships between water temperatures and upstream migration, cold water refuge use, and spawning of adult bull trout from the Lostine River, Oregon, USAECOLOGY OF FRESHWATER FISH, Issue 1 2010P. J. Howell Howell PJ, Dunham JB, Sankovich PM. Relationships between water temperatures and upstream migration, cold water refuge use, and spawning of adult bull trout from the Lostine River, Oregon, USA. Ecology of Freshwater Fish 2010: 19: 96,106. This article is a US Government work and is in the public domain in the USA Abstract,,, Understanding thermal habitat use by migratory fish has been limited by difficulties in matching fish locations with water temperatures. To describe spatial and temporal patterns of thermal habitat use by migratory adult bull trout, Salvelinus confluentus, that spawn in the Lostine River, Oregon, we employed a combination of archival temperature tags, radio tags, and thermographs. We also compared temperatures of the tagged fish to ambient water temperatures to determine if the fish were using thermal refuges. The timing and temperatures at which fish moved upstream from overwintering areas to spawning locations varied considerably among individuals. The annual maximum 7-day average daily maximum (7DADM) temperatures of tagged fish were 16,18 °C and potentially as high as 21 °C. Maximum 7DADM ambient water temperatures within the range of tagged fish during summer were 18,25 °C. However, there was no evidence of the tagged fish using localized cold water refuges. Tagged fish appeared to spawn at 7DADM temperatures of 7,14 °C. Maximum 7DADM temperatures of tagged fish and ambient temperatures at the onset of the spawning period in late August were 11,18 °C. Water temperatures in most of the upper Lostine River used for spawning and rearing appear to be largely natural since there has been little development, whereas downstream reaches used by migratory bull trout are heavily diverted for irrigation. Although the population effects of these temperatures are unknown, summer temperatures and the higher temperatures observed for spawning fish appear to be at or above the upper range of suitability reported for the species. [source] Gillnet fishing drives lake-migrating brown trout to near extinction in the Lake Päijänne region, FinlandFISHERIES MANAGEMENT & ECOLOGY, Issue 2 2010J. SYRJÄNEN Abstract, Wild stocks of brown trout, Salmo trutta L., collapsed in Finnish inland waters during the 20th Century because dams prevented upstream migration, and low water quality and stream dredging weakened reproduction. The demise in migratory stocks was coupled with overfishing, mainly by gillnetting on lakes. Consequently, the migratory spawning stocks have diminished to negligible levels. The remaining stocks exhibit restricted immigration and emigration, are supplemented by continuous stocking, and their natural genetic diversity is affected by human activities. In recent years, various recovery actions have been implemented including stream channel restorations, fish passage facilities constructed and stocking of eggs and smolts. Gillnetting has also been regulated by banning certain mesh sizes, and catch-and-release of wild trout is spreading amongst sport fishers. However, these measures seem to be inadequate and almost no recovery of migratory populations has been reported. The problem of by-catch in intensive gillnetting continues to threaten stocks and creates disputes between stakeholders. [source] Population genetic studies of hilsa shad, Tenualosa ilisha (Hamilton), in Bangladesh waters: evidence for the existence of separate gene poolsFISHERIES MANAGEMENT & ECOLOGY, Issue 5 2000M. Rahman Hilsa shad, Tenualosa ilisha (Hamilton), in Bangladesh is found in inland rivers, estuaries and the marine environment, throughout the year, but the peak catch period is during upstream migration. Tissue (white muscle, liver, brain) samples (total 640 specimens) were collected from three different localities, representing marine, brackish and fresh water, during the monsoon in the summer of the years 1993,1996 to identify genetic markers and study the population structure of this species. The samples were analysed by starch gel electrophoresis and isoelectric focusing, and stained for 15 enzymes and general muscle proteins. Only phosphoglucomutase, aspartate amino transferase, esterase and unidentified muscle proteins were found to be polymorphic. The allele frequencies for the samples collected in the marine environment deviated from corresponding samples from freshwater and estuarine localities, indicating that hilsa shad in Bangladesh waters comprise more than one gene pool. [source] Hydrological disturbance benefits a native fish at the expense of an exotic fishJOURNAL OF APPLIED ECOLOGY, Issue 5 2006F. LEPRIEUR Summary 1Some native fish in New Zealand do not coexist with introduced salmonids. Previous studies of disjunct distributions of exotic brown trout Salmo trutta and native galaxiids demonstrated native extirpation except where major waterfalls prevented upstream migration of trout. In the Manuherikia River system, we predicted that water abstraction might be a further factor controlling the spatial distribution of both the invader and a native fish. 2We applied multiple discriminant function analyses to test for differences in environmental conditions (catchment and instream scales) at sites with roundhead galaxias Galaxias anomalus and brown trout in sympatry and allopatry. We then used a supervised artificial neural network (ANN) to predict the presence,absence of G. anomalus and brown trout (135 sites). The quantification of contributions of environmental variables to ANN models allowed us to identify factors controlling their spatial distribution. 3Brown trout can reach most locations in the Manuherikia catchment, and often occur upstream of G. anomalus. Their largely disjunct distributions in this river are mediated by water abstraction for irrigation, together with pool habitat availability and valley slope. Trout are more susceptible than the native fish to stresses associated with low flows, and seem to be prevented from eliminating galaxiid populations from sites in low gradient streams where there is a high level of water abstraction. 4Synthesis and applications. In contrast to many reports in the literature, our results show that hydrological disturbance associated with human activities benefits a native fish at the expense of an exotic in the Manuherikia River, New Zealand. Water abstraction is also known to have negative impacts on native galaxiids, therefore we recommend restoring natural low flows to maintain sustainable habitats for native galaxiids, implementing artificial barriers in selected tributaries to limit trout predation on native fish, and removing trout upstream. [source] Annual dynamics variation of a landlocked Galaxias maculatus (Jenyns 1842) population in a Northern Patagonian river: occurrence of juvenile upstream migrationJOURNAL OF APPLIED ICHTHYOLOGY, Issue 2 2007J. P. Barriga Summary Galaxias maculatus, broadly distributed in the southern hemisphere, presents both diadromic and landlocked populations. The upstream migration of larvae and juveniles from the sea to freshwater habitats is a characteristic phenomenon of diadromous populations, but upstream migration has never been reported in those that are landlocked. The objective of this study was to establish the population dynamics of a peculiar riverine landlocked population that presents an upstream migration at the larvae,juvenile transition from the Piedra del Águila Reservoir to the Caleufú River (Argentina). A spawning season from September to November and the arrival of shoals of metamorphic larvae and juveniles from February to April to the adult habitat were coincidental with lacustrine landlocked populations, but not with diadromous populations. Growth rate and age at migration, 147 ± 22.6 days, were also similar to other landlocked and diadromous populations. The arrival of these shoals produced a 20-fold increase in fish density while the two cohorts of G. maculatus overlapped in time and space. No significant differences in morphology or vertebrae number were detected when riverine and reservoir adults were compared. The great life history plasticity of G. maculatus, shown to be even greater in our results, could be the key to explain the wide distribution of this species in the southern hemisphere. Likewise, discovering this juvenile potamodromous behaviour in a landlocked population will provide a new view for the analysis of the ways of this species' dispersion in continental waters. [source] Effect of origin, sex and sea age of Atlantic salmon on their recapture rate after river ascentJOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2006E. Jokikokko Summary The recapture rate of Atlantic salmon (Salmo salar L.) after river ascent was examined by the trapping and tagging of ascending spawners in the lower reaches of the Simojoki River, which flows into the northern Baltic Sea. In 1997 and 1998, altogether 825 Carlin-tagged salmon were released to continue their upstream migration. Of these, 800 could be sexed and categorized as reared (91%) or wild (9%) salmon. In 1997, most of the ascending salmon were multi-sea-winter (MSW) fish, whereas in 1998 almost all were one-sea-winter (1SW) male grilse due to the late trapping season. About 10% of all tagged fish were recaptured, two-thirds of which were caught in the river before their descent to the sea. There was no difference in the recapture rate between salmon of wild (8.5%) or reared (9.5%) origin, or between females (11.6%) and males (9.3%). Generalized linear models for data from 1997 showed that the recapture rate increased with length and age of females, but that the opposite was true for males. River fishing did not seem to remove proportionally more early ascending salmon than fish that ascended later. [source] Synchrony in the downstream migration of smolts and upstream migration of adult Atlantic salmon in the subarctic River UtsjokiJOURNAL OF FISH BIOLOGY, Issue 6 2007P. Orell Seasonal and diel migration timing of wild Atlantic salmon Salmo salar smolts and adults were investigated annually (2001,2004) in the subarctic River Utsjoki, a tributary of the large River Teno (70° N), using underwater video monitoring. Submerged video cameras provided information on the exact timing and intensity of both migrations in a natural river channel, without disturbing the fish. In contrast to the mainly nocturnal migration pattern described from temperate rivers, the River Utsjoki smolts and adults migrated throughout the day. Smolts migrated most intensively during hours of rising (0300,0900 hours) and high sun (0900,1500 hours), while adults favoured the period of low sun (2100,0300 hours). Smolt migrations started in June and lasted on average 42 days. Adults usually ascended the site 2,3 weeks before the first descending smolts were observed and the adult migrations extended to the end of August. Seasonal synchrony was observed between smolt and adult migrations in years of slowly warming water, whereas in a year of exceptionally warm early summer (2002), smolts migrated earlier than adults. Thus, water temperature seemed to be an important environmental factor triggering the smolt migration, while the migration of adults was probably more fixed to a certain season. Weak positive correlations between fish counts and water temperature were observed, indicating that increasing water temperature may have promoted both smolt and adult migrations. The influence of discharge was negligible, although increasing discharge late in the season may have activated the remaining individuals in both groups. [source] Factors affecting river entry of adult Atlantic salmon in a small riverJOURNAL OF FISH BIOLOGY, Issue 4 2007B. Jonsson In this study, effects of stock origin, fish size, water flow and temperature on time of river ascent of adult Atlantic salmon Salmo salar were tested. Brood stocks were collected in eight Norwegian rivers situated between 59 and 69° N. The fish were reared to smolts, individually tagged and released in the River Imsa, south-west Norway (59° N). Adults from all stocks approached the Norwegian coast concurrently, but Atlantic salmon ,70 cm in natural tip length entered coastal water slightly earlier during summer than smaller fish. Atlantic salmon <70 cm, however, ascended the river significantly earlier and at lower water flow and higher water temperature than larger fish. Although largest in size, the fish from the northern populations (62,69° N) ascended the River Imsa almost 1 month earlier than those from the south (59,60° N). They seemed less restricted by the environmental factors than the fish originating from the more southern rivers. There was no apparent trend among years in time of river ascent. Maximum ascent per day occurred at water discharges between 12·5 and 15 m3 s,1 and at water temperatures between 10 and 12·5° C. There was a significant positive correlation between water flow and river ascent during the first part of the upstream run from July to September with best correlation for September, when multiple regression analysis indicated that water temperature had an additional positive effect. Stock origin, fish size and water discharge were important variables influencing the upstream migration of Atlantic salmon in small rivers. [source] Biology and ecology of amphidromous Gobiidae of the Indo-Pacific and the Caribbean regionsJOURNAL OF FISH BIOLOGY, Issue 4 2003P. Keith In the Indo-Pacific and the Caribbean regions, isolated rivers are host to amphidromous Gobiidae with a life cycle adapted to extreme climatic and hydrological seasonal variation. Although this is the most diverse family of freshwater fish, their biological cycle and the parameters and evolutionary processes that lead to such diversity are poorly understood. This paper reports on the current knowledge on reproduction (nidification, spawning, larval life and sexuality), recruitment into the rivers, upstream migration and distribution in the rivers. Management and restoration strategies to preserve amphidromous gobies, often endemic and bordering on extinction, require the development of research to have a better understanding of their life cycle. [source] Relationships between metabolic rate, muscle electromyograms and swim performance of adult chinook salmonJOURNAL OF FISH BIOLOGY, Issue 4 2003D. R. Geist Oxygen consumption rates of adult spring chinook salmon Oncorhynchus tshawytscha increased with swim speed and, depending on temperature and fish mass, ranged from 609 mg O2 h,1 at 30 cm s,1 (c. 0·5 BL s,1) to 3347 mg O2 h,1 at 170 cm s,1 (c. 2·3 BL s,1). Corrected for fish mass, these values ranged from 122 to 670 mg O2 kg,1 h,1, and were similar to other Oncorhynchus species. At all temperatures (8, 12·5 and 17° C), maximum oxygen consumption values levelled off and slightly declined with increasing swim speed >170 cm s,1, and a third-order polynomial regression model fitted the data best. The upper critical swim speed (Ucrit) of fish tested at two laboratories averaged 155 cm s,1 (2·1 BL s,1), but Ucrit of fish tested at the Pacific Northwest National Laboratory were significantly higher (mean 165 cm s,1) than those from fish tested at the Columbia River Research Laboratory (mean 140 cm s,1). Swim trials using fish that had electromyogram (EMG) transmitters implanted in them suggested that at a swim speed of c. 135 cm s,1, red muscle EMG pulse rates slowed and white muscle EMG pulse rates increased. Although there was significant variation between individual fish, this swim speed was c. 80% of the Ucrit for the fish used in the EMG trials (mean Ucrit 168·2 cm s,1). Bioenergetic modelling of the upstream migration of adult chinook salmon should consider incorporating an anaerobic fraction of the energy budget when swim speeds are ,80% of the Ucrit. [source] | |||||||||||||