Movements and habitat use by pikeperch (Stizostedion lucioperca (L.)) in a hydropeaking reservoir     

T. Vehanen  M. Lahti 《Ecology of Freshwater Fish》2003,12(3):203-215

Abstract –  We used radio telemetry to measure the habitat use and movements of 20 tagged pikeperch (44–59 cm) in the hydropeaking Pyhäkoski Reservoir, Finland, during June 1999–2000. The hydrological conditions in the 8-km-long reservoir were measured and then modeled over eight discharge rates between 30 and 700 m³ · s⁻¹. Pikeperch preferred relatively low water velocities and deep water depths especially during the winter. During the summer, pikeperch moved actively in different parts of the reservoir. No relationship was found between hydroelectric plant operations and distances moved by pikeperch during the summer. Movements peaked in autumn but decreased during the winter to a restricted area. After 1 year of monitoring, 4 out of 20 tagged pikeperch remained in the Pyhäkoski Reservoir, three had died when descending from hydroelectric dams, 10 had descended downstream to other reservoirs or sea, two were captured by local fishermen, and one fish's signal was lost for unknown reasons.  相似文献   

Analysis on the movement of bag-net in set-net by acoustictelemetry techniques     

BO-KYU  HWANG  HYEON-OK  SHIN 《Fisheries Science》2003,69(2):300-307

ABSTRACT:   A mooring-type underwater positioning system (UPS) to measurethe bag-net movements in a set-net by acoustic telemetry techniqueswith five transponders was reconstructed. The field experimentswere conducted in Jaran Bay, Kosung, Korea on 6 October 2000 (neaptide) and 28 November 2000 (spring tide). The average UPS fixingerrors of x -axis, y -axis and z -axis were less than0.6 m, 0.8 m and 1.2 m, respectively.The longitudinal movement range, the latitudinal range and the verticalrange of the bag-net at the neap tide were 3.2 m, 3.4 mand 2.1 m, respectively. At the spring tide, these rangeswere 7.8 m, 7.8 m and 5.0 m, respectively.It was confirmed that the UPS system could be used for measuringa part of the bag-net movement.  相似文献   

提高地面测报质量的方法     

施君 《北京农业》2012,(3):179-180

地面测报是气象业务工作的基础,而地面气象观测是气象观测工作的重要组成部分,也是每个气象台站的基本任务之一。做好测报工作是每一位观测员的职责。如何提高测报质量是气象工作的重要一环,也是观测员工作的宗旨。要想改变落后的测报面貌,必须首先从业务技术着手,同时辅之以职业道德修养和思想认识的提高。否则不能从根本上解决问题。  相似文献   

Satellite telemetry of Afrotropical ducks: methodological details and assessment of success rates     

《African Zoology》2013,48(2):425-434

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Winter movement activity patterns of anadromous Arctic charr in two Labrador lakes          下载免费PDF全文

Ingeborg M. Mulder  Corey J. Morris  J. Brian Dempson  Ian A. Fleming  Michael Power 《Ecology of Freshwater Fish》2018,27(3):785-797

Anadromous Arctic charr, Salvelinus alpinus, feed in the marine environment for several months during the summer and migrate back to fresh water in late summer to spawn and/or overwinter. While overwintering, anadromous Arctic charr are generally believed to reduce or cease feeding, and they are poorly described in their winter movement activity. This study used telemetry data collected from two locations to describe overwintering movement activity, including interindividual variation. Movement activity declined markedly during the ice‐covered period, suggesting opportunistic maintenance feeding was used as an energy conservation strategy. Fall and spring movement was correlated with daylight hours, and ice break‐up had a significant effect on the timing of outmigration. Movement activity was negatively correlated with body length, with smaller individuals being more active than larger fish. Although general activity patterns were evident, there were significant differences among individuals, particularly during spring immediately prior to lake departure. Lake size and individual differences in metabolic rate may account for some of this variation.  相似文献   

Movement behaviour of large female yellow European eel (Anguilla anguilla L.) in a freshwater polder area          下载免费PDF全文

Pieterjan Verhelst  Jan Reubens  Ine Pauwels  David Buysse  Bart Aelterman  Stijn Van Hoey  Peter Goethals  Tom Moens  Johan Coeck  Ans Mouton 《Ecology of Freshwater Fish》2018,27(1):471-480

Due to a recruitment decline of more than 90% in 30 years, the European eel (Anguilla anguilla L.) has been classified by IUCN as critically endangered. Although the species has been studied intensively to obtain knowledge to improve management, studies about the resident yellow stage are relatively scarce. In this study, 52 large female yellow eels were tagged with acoustic transmitters in a Belgian polder system and tracked by a network of 23 automatic listening stations. We studied both circadian and seasonal movement patterns and the effect of environmental variables on these patterns. Large female yellow eels were most active at night in late summer and early autumn. A generalised linear mixed model showed that their movement is only slightly influenced by environmental variables. Moreover, as yellow eels show high site fidelity (i.e., the majority was detected only in the habitat type of their catch‐release location), they do not encounter many human‐induced connectivity problems in polder systems, which makes these systems highly suitable as eel growth habitat. These results can contribute to an effective eel management regarding habitat protection and restoration.  相似文献   

Movement patterns of adult pike (Esox lucius L.) in a Belgian lowland river     

Ine S. Pauwels  Peter L.M. Goethals  Johan Coeck  Ans M. Mouton 《Ecology of Freshwater Fish》2014,23(3):373-382

Northern pike, Esox lucius, needs different habitats to survive and reproduce and thus depends on the availability and accessibility of these habitats. To efficiently manage pike, information is needed on its spatial and temporal patterns of migration. In this study, we investigated the occurrence of adult pike migration and which environmental variables influenced migration. From December 2010, we followed 15 pike for 1 year by use of radio telemetry in the River Yser, a typical lowland river characterised by anthropogenic impacts such as artificial embankments. Pike migrated most in February and March, which could indicate they frequented spawning habitat in this period. Four environmental variables significantly affected pike migration, ranging from the location where pike were observed (strongest effect), over water temperature and flow to diel water temperature change (weakest effect). The relation between migration and the location where pike were observed could demonstrate that pike preferred specific regions in the river. Increasing water temperature triggered migration for both sexes, and males started migrating at lower temperatures than females, which suggests that males start migrating earlier. This was the only substantial difference observed between male and female pike migration. The results suggest that migration was inhibited by high flow, as no migration was observed at high flow. River managers can use this information to efficiently manage their pike populations, for example, by removing or temporarily opening hydraulic structures like valves, weirs and sluices. This may facilitate access to suitable habitats at moments pike needs these habitats to fulfil its life cycle.  相似文献   

Evidence of cormorant‐induced mortality,disparate migration strategies and repeatable circadian rhythm in the endangered North Sea houting (Coregonus oxyrinchus): A telemetry study mapping the postspawning migration          下载免费PDF全文

Lasse Fast Jensen  Paul Rognon  Kim Aarestrup  Jesper Wøhlk Bøttcher  Cino Pertoldi  Søren Nøhr Thomsen  Morten Hertz  Jacob Winde  Jon C. Svendsen 《Ecology of Freshwater Fish》2018,27(3):672-685

Life history theory predicts a trade‐off between migration and residency where migration is favoured when it infers elevated fitness. Although migration to more favourable environments may offer higher growth rates, migrants often experience increased mortality due to predation. Here, we investigated mortality and migration behaviour of the North Sea houting (Coregonus oxyrinchus), an anadromous salmonid endemic to the Wadden Sea. We used acoustic telemetry to map the migration of the only remaining indigenous population by applying stationary hydrophones combined with manual tracking. Data suggested a total mortality of 26%, with 30% of the total mortality attributed to predation by great cormorants (Phalacrocorax carbo sinensis), highlighting that North Sea houting conservation could be jeopardised by increased cormorant predation. Risk of cormorant predation was size‐dependent, with smaller fish suffering higher risk of predation. The study found North Sea houting to exhibit disparate migration strategies and identified a lentic area in the estuary as an important habitat. Two newly established artificial lakes within the river system significantly reduced the migration speeds, possibly indicating constrained navigation through the lakes. The migration into the Wadden Sea correlated with temperature perhaps indicating osmoregulatory constraints of sea entry. Unlike many salmonid species, migration occurred both day and night. Moreover, fish exhibited repeatable individual differences in diel activity patterns, suggesting that individuals differ consistently in their migratory activity throughout the 24‐hr period. Our study provides novel information on salmonid migration, which is crucial for the development of science‐based conservation strategies.  相似文献   

Spawning movements of humpback whitefish in interior Alaska rivers     

Aaron W. Dupuis  Trent M. Sutton 《Ecology of Freshwater Fish》2014,23(3):295-304

This study was conducted to describe the spawning movements and identify spawning areas for humpback whitefish Coregonus pidschian in the Minto Flats–Chatanika River complex, Alaska, during 2008 and 2009. Radio transmitters were surgically implanted in humpback whitefish in 2008 (N = 60) and 2009 (N = 100), and fish positions were determined through a combination of boat and aerial surveys and fixed receiving stations. Two spawning areas were identified: one in the Chatanika River downstream of the Elliot Highway Bridge and the other in the Tanana River near Fairbanks. Humpback whitefish dispersed from the wetland complex of Minto Flats in June, moved upstream through late August, arrived at the spawning areas in early September and began moving downstream in early October. In 2009, spatially segregated movements were observed when approximately 40% of the radio‐tagged humpback whitefish moved to the Tanana River, suggesting that humpback whitefish in Minto Flats are comprised of mixed spawning stocks. These study results provide a complete account of humpback whitefish movements and their associated spawning habitats, which will allow for better‐informed management strategies.  相似文献   

Behaviour of endangered European eels in proximity to a dam during downstream migration: Novel insights using high accuracy 3D acoustic telemetry     

Thomas Trancart  Alexandre Carpentier  Anthony Acou  Valentin Danet  Sophie Elliott  Éric Feunteun 《Ecology of Freshwater Fish》2020,29(2):266-279

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