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Filipsson, K., Bergman, E., Österling, M., Erlandsson, A., Greenberg, L. & Watz, J. (2019). Effects of temperature and a piscivorous fish on diel winter behaviour of juvenile brown trout (Salmo trutta). Freshwater Biology, 64(1+), 1797-1805
Öppna denna publikation i ny flik eller fönster >>Effects of temperature and a piscivorous fish on diel winter behaviour of juvenile brown trout (Salmo trutta)
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2019 (Engelska)Ingår i: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 64, nr 1+, s. 1797-1805Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Low winter temperatures constrain predator-detection and escape capabilities, making poikilotherms vulnerable to predation. Investigations of temperature effects on predator-prey interactions can therefore be of special importance in light of ongoing climate change, where winter temperatures are predicted to increase substantially at northern latitudes. Behavioral responses of stream fishes to terrestrial predators in winter are well recognised, whereas responses to predatory fish have received little attention. Using stream flumes, we examined the anti-predator behaviour of one-summer-old brown trout (Salmo trutta) at 3 and 8 degrees C in the presence and absence of burbot (Lota lota) under night, dawn, and daylight conditions. Burbot was placed upstream of the trout, separated by net screens. Lower temperature and the presence of burbot reduced trout activity. Light increased trout shelter use, and trout sheltered more in the presence of burbot. An interaction between the presence of burbot and light conditions affected trout position in the flumes: at night and dawn, trout positioned themselves further downstream when burbot were present than when absent, whereas during the day, trout maintained the same position in the presence or absence of the predator. Our results suggest that piscivorous fish, in addition to terrestrial predators, shape the behaviour of prey fishes in streams during winter. We show how predator avoidance results in altered diel patterns of juvenile brown trout under winter conditions, and that temperature has additional effects on trout behaviour.

Nyckelord
anti-predator, burbot, climate change, light, predator avoidance
Nationell ämneskategori
Ekologi
Forskningsämne
Biologi
Identifikatorer
urn:nbn:se:kau:diva-74573 (URN)10.1111/fwb.13371 (DOI)000480404400001 ()
Tillgänglig från: 2019-08-29 Skapad: 2019-08-29 Senast uppdaterad: 2019-11-14Bibliografiskt granskad
Enefalk, Å., Huusko, A., Louhi, P. & Bergman, E. (2019). Fine stream wood decreases growth of juvenile brown trout (Salmo trutta). Environmental Biology of Fishes, 102(5), 759-770
Öppna denna publikation i ny flik eller fönster >>Fine stream wood decreases growth of juvenile brown trout (Salmo trutta)
2019 (Engelska)Ingår i: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 102, nr 5, s. 759-770Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

In this study, the growth rate, gut fullness, diet composition and spatial distribution of brown trout was compared between artificial channels with and without fine wood (FW). Access to FW resulted in significantly lower brown trout growth rates over the study period from late summer to early winter as water temperatures declined from 17 °C to 1 °C. Access to FW resulted in minor differences in occurrence of the most common taxa found in brown trout diets, except for chironomid larvae which were found in c. 60% of the brown trout guts from control treatments but in only 30% of the guts from FW treatments in early winter. Diet consisted primarily of case-bearing and free-living Trichoptera larvae, Asellus, chironomid and Ephemeroptera larvae. Brown trout gut fullness was not significantly affected by access to FW bundles. Brown trout aggregated among FW but were more evenly distributed in channels lacking it. Our results suggest that juvenile brown trout use FW as a shelter at a wide range of water temperatures, and that this behaviour may result in reduced growth rates during their first fall and the onset of their first winter. We also show that prey availability and the composition of brown trout diet changes from late summer to early winter and that FW has a small but significant effect on brown trout diet composition.

Ort, förlag, år, upplaga, sidor
Springer, 2019
Nyckelord
Fine woody debris, Structure, In-stream, Shelter, Predatory refuge
Nationell ämneskategori
Biologiska vetenskaper
Forskningsämne
Biologi
Identifikatorer
urn:nbn:se:kau:diva-45653 (URN)10.1007/s10641-019-00869-4 (DOI)000468519700008 ()
Anmärkning

Artikeln publicerad som manuskript i Enefalks doktorsavhandling Fine stream wood: effects on drift and brown trout (Salmo trutta) growth and behaviour.

Tillgänglig från: 2016-09-02 Skapad: 2016-09-02 Senast uppdaterad: 2019-06-12Bibliografiskt granskad
Hutchings, J. A. (2019). Life-history variability and conservation status of landlocked Atlantic salmon: an overview. Canadian Journal of Fisheries and Aquatic Sciences, 76(10), 1697-1708
Öppna denna publikation i ny flik eller fönster >>Life-history variability and conservation status of landlocked Atlantic salmon: an overview
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2019 (Engelska)Ingår i: Canadian Journal of Fisheries and Aquatic Sciences, ISSN 0706-652X, E-ISSN 1205-7533, Vol. 76, nr 10, s. 1697-1708Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Nonanadromous Atlantic salmon (Salmo salar) exhibit a combination of variation in life history, habitat, and species co-existence matched by few vertebrates. Distributed in eastern North America and northern Europe, habitat ranges from hundreds of metres of river to Europe’s largest lakes. As juveniles, those with access to a lake usually migrate to feed and grow prior to reproduction. Prey such as smelt (Osmerus mordax, Osmerus eperlanus) and vendace (Coregonus albula) facilitate large body size (50–85 cm at maturity) and persistence in high-diversity (>20 fish species) environments; small-bodied salmon (10–30 cm at maturity), relying on insects as prey, coexist with few (fewer than five) other fishes. At maturity, weight varies more than 400-fold (17 to 7200 g) among populations, fecundity more than 150-fold (33 to 5600), and longevity almost fivefold (3 to 14 years). Landlocked salmon are managed to support sustainable fishing, achieve conservation and restoration targets, and mitigate threats; successes are evident but multiple challenges persist. Extraordinary variability in life history coupled with extensive breadth of habitat and species co-existence render landlocked Atlantic salmon singularly impressive from a biodiversity perspective.

Ort, förlag, år, upplaga, sidor
Canadian Science Publishing, 2019
Nationell ämneskategori
Ekologi
Forskningsämne
Biologi
Identifikatorer
urn:nbn:se:kau:diva-74675 (URN)10.1139/cjfas-2018-0413 (DOI)000487999200002 ()
Tillgänglig från: 2019-09-06 Skapad: 2019-09-06 Senast uppdaterad: 2019-11-12Bibliografiskt granskad
Lafage, D., Bergman, E., Eckstein, R. L., Österling, M., Sadler, J. P. & Piccolo, J. (2019). Local and landscape drivers of aquatic-to-terrestrial subsidies in riparian ecosystems: A worldwide meta-analysis. Ecosphere, 10(4), 1-12, Article ID e02697.
Öppna denna publikation i ny flik eller fönster >>Local and landscape drivers of aquatic-to-terrestrial subsidies in riparian ecosystems: A worldwide meta-analysis
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2019 (Engelska)Ingår i: Ecosphere, ISSN 2150-8925, E-ISSN 2150-8925, Vol. 10, nr 4, s. 1-12, artikel-id e02697Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Cross-boundary fluxes of organisms and matter, termed “subsidies,” are now recognized to be reciprocal and of roughly equal importance for both aquatic and terrestrial systems, even if terrestrial input to aquatic ecosystems has received most attention. The magnitude of aquatic-to-terrestrial subsidies is well documented, but the drivers behind these subsidies and their utilization by terrestrial consumers are characteristically local-scale studies, limiting the inferences that can be drawn for broader geographic scales. We therefore built and analyzed a database of stable isotope data extracted from 21 studies worldwide, to identify both landscape-scale (catchment) and local-scale (100-m riparian zone) variables that may affect the diet of terrestrial predators in riparian ecosystems. Our meta-analysis revealed a greater magnitude of aquatic-to-terrestrial subsidies (>50%) than previously reported, albeit with large geographic and inter-annual variations. Moreover, we demonstrated a large effect of landscape-scale factors on aquatic-to-terrestrial subsidies, particularly anthropogenic land use and tree cover. Local human population was the only relevant factor at the local scale. We also found that studies on landscape-scale and anthropogenic land use effects on aquatic-to-terrestrial subsidies are strongly under-represented in the ecological literature, which limits the general inferences that can currently be drawn about landscape effects. We suggest that landscape-scale studies could improve our understanding of how land use and environmental change might influence future patterns of biodiversity and ecosystem function.

Ort, förlag, år, upplaga, sidor
John Wiley & Sons, 2019
Nyckelord
anthropogenic land use, aquatic subsidies, diet, human population, stable isotopes, terrestrial predators
Nationell ämneskategori
Ekologi Biologiska vetenskaper
Forskningsämne
Biologi
Identifikatorer
urn:nbn:se:kau:diva-72496 (URN)10.1002/ecs2.2697 (DOI)000472716600041 ()2-s2.0-85065024924 (Scopus ID)
Tillgänglig från: 2019-06-13 Skapad: 2019-06-13 Senast uppdaterad: 2019-11-28Bibliografiskt granskad
Gordon, T. A., Harding, H. R., Clever, F. K., Davidson, I. K., Davison, W., Montgomery, D. W., . . . Santos, E. M. (2018). Fishes in a changing world: learning from the past to promote sustainability of fish populations. Paper presented at 50th Anniversary Annual Symposium of the Fisheries-Society-of-the-British-Isles (FSBI) - Understanding Fish Populations, JUL 03-07, 2017, Univ Exeter, Exeter, ENGLAND. Journal of Fish Biology, 92(3), 804-827
Öppna denna publikation i ny flik eller fönster >>Fishes in a changing world: learning from the past to promote sustainability of fish populations
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2018 (Engelska)Ingår i: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 92, nr 3, s. 804-827Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Populations of fishes provide valuable services for billions of people, but face diverse and interacting threats that jeopardize their sustainability. Human population growth and intensifying resource use for food, water, energy and goods are compromising fish populations through a variety of mechanisms, including overfishing, habitat degradation and declines in water quality. The important challenges raised by these issues have been recognized and have led to considerable advances over past decades in managing and mitigating threats to fishes worldwide. In this review, we identify the major threats faced by fish populations alongside recent advances that are helping to address these issues. There are very significant efforts worldwide directed towards ensuring a sustainable future for the world's fishes and fisheries and those who rely on them. Although considerable challenges remain, by drawing attention to successful mitigation of threats to fish and fisheries we hope to provide the encouragement and direction that will allow these challenges to be overcome in the future.

Ort, förlag, år, upplaga, sidor
John Wiley & Sons, 2018
Nationell ämneskategori
Biologiska vetenskaper Annan samhällsvetenskap
Forskningsämne
Biologi
Identifikatorer
urn:nbn:se:kau:diva-66874 (URN)10.1111/jfb.13546 (DOI)000427477600016 ()29537086 (PubMedID)
Konferens
50th Anniversary Annual Symposium of the Fisheries-Society-of-the-British-Isles (FSBI) - Understanding Fish Populations, JUL 03-07, 2017, Univ Exeter, Exeter, ENGLAND
Tillgänglig från: 2018-03-29 Skapad: 2018-03-29 Senast uppdaterad: 2018-04-04Bibliografiskt granskad
Nyqvist, D., McCormick, S. D., Greenberg, L., Ardren, W. R., Bergman, E., Calles, O. & Castro-Santos, T. (2017). Downstream migration and multiple dam passage by Atlantic salmon smolts. North American Journal of Fisheries Management, 4(37), 816-828
Öppna denna publikation i ny flik eller fönster >>Downstream migration and multiple dam passage by Atlantic salmon smolts
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2017 (Engelska)Ingår i: North American Journal of Fisheries Management, ISSN 0275-5947, E-ISSN 1548-8675, Vol. 4, nr 37, s. 816-828Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

The purpose of this study was to investigate behavior and survival of radio-tagged wild and hatchery-reared landlocked Atlantic Salmon Salmo salar smolts as they migrated past three hydropower dams equipped with fish bypass solutions in the Winooski River, Vermont. Among hatchery-reared smolts, those released early were more likely to initiate migration and did so after less delay than those released late. Once migration was initiated, however, the late-released hatchery smolts migrated at greater speeds. Throughout the river system, hatchery-reared fish performed similarly to wild fish. Dam passage rates varied between the three dams and was highest at the dam where unusually high spill levels occurred throughout the study period. Of the 50 fish that did migrate downstream, only 10% managed to reach the lake. Migration success was low despite the presence of bypass solutions, underscoring the need for evaluations of remedial measures; simply constructing a fishway is not synonymous with providing fish passage.

Ort, förlag, år, upplaga, sidor
Taylor & Francis, 2017
Nyckelord
SALAR SMOLTS; CHINOOK SALMON; FISH PASSAGE; JUVENILE SALMONIDS; DELAYED MORTALITY; COLUMBIA RIVER; SNAKE RIVER; HYDROPOWER SYSTEM; TRUTTA SMOLTS; K+ ATPASE
Nationell ämneskategori
Ekologi
Forskningsämne
Biologi
Identifikatorer
urn:nbn:se:kau:diva-46900 (URN)10.1080/02755947.2017.1327900 (DOI)000407192600012 ()
Tillgänglig från: 2016-10-19 Skapad: 2016-10-19 Senast uppdaterad: 2018-09-10Bibliografiskt granskad
Nyqvist, D., Bergman, E., Calles, O. & Greenberg, L. (2017). Intake Approach and Dam Passage by Downstream-migrating Atlantic Salmon Kelts. Rivers Research and Applications: an international journal devoted to river research and management, 33(5), 697-706
Öppna denna publikation i ny flik eller fönster >>Intake Approach and Dam Passage by Downstream-migrating Atlantic Salmon Kelts
2017 (Engelska)Ingår i: Rivers Research and Applications: an international journal devoted to river research and management, ISSN 1535-1459, E-ISSN 1535-1467, Vol. 33, nr 5, s. 697-706Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Studying fish behaviour at hydropower dams is needed to facilitate the design and improvement of fish passage solutions, but few studies have focused on Atlantic salmon kelts. Here, we used radio telemetry (n = 40, size range = 50–81 cm) and acoustic sonar to study kelt movements in the forebay as well as their dam passage survival and subsequent migration success past multiple dams. We also compare radio telemetry and acoustic sonar observations of fish behaviour and used acoustic sonar to measure the depth distribution of fish approaching the turbine intake zone. Passage success at the dam was 41%, and mortality was largely associated with turbine passage (62%). The two fish that passed via the spill gates survived and continued their downstream migration. At the dam, all but one radio-tagged kelt approached the intake zone shortly after arrival to the forebay, and sonar data showed that approaching fish were predominantly surface oriented (72%, 88% and 96% of the observations were less than 1, 2 and 3 m deep, respectively). Turbine passage rate from the intake zone was higher at night than at day, indicating that the lack of visual cues may reduce the barrier effect of the 70-mm conventional trash rack. Turbine passage rate also increased with increasing hydropower generation. The percentage of observed upstream movements away from the intake zone compared with the total number of observations was considerably greater in the radio telemetry data (41%) than in the sonar data (4%). Only one fish survived passage of all eight hydropower dams to reach the lake. This low-passage survival underscores the need for remedial measures to increase the survival of migrating kelts, and the fish's surface orientation as well as their rapid approach to the intake rack should be taken into account when designing such measures.

Ort, förlag, år, upplaga, sidor
John Wiley & Sons, 2017
Nationell ämneskategori
Ekologi
Forskningsämne
Biologi
Identifikatorer
urn:nbn:se:kau:diva-46902 (URN)10.1002/rra.3133 (DOI)000402840900006 ()
Anmärkning

Was published as manuscript in D. Nyquists thesis and had then the title "Intake approach and dam passage by landlocked Atlantic salmon kelts at a hydropower dam"

Tillgänglig från: 2016-10-19 Skapad: 2016-10-19 Senast uppdaterad: 2018-09-10Bibliografiskt granskad
Nyqvist, D., Greenberg, L., Calles, O., Goerig, E., Bergman, E., Ardren, W. & Castro-Santos, T. (2017). Migratory delay leads to reduced passage success of Atlantic salmon smolts at a hydroelectric dam. Ecology of Freshwater Fish, 26(4), 707-718
Öppna denna publikation i ny flik eller fönster >>Migratory delay leads to reduced passage success of Atlantic salmon smolts at a hydroelectric dam
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2017 (Engelska)Ingår i: Ecology of Freshwater Fish, ISSN 0906-6691, E-ISSN 1600-0633, Vol. 26, nr 4, s. 707-718Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Passage of fish through hydropower dams is associated with mortality, delay, increased energy expenditure and migratory failure for migrating fish and the need for remedial measures for both upstream and downstream migration is widely recognised. A functional fish passage must ensure safe and timely passage routes that a substantial portion of migrating fish will use. Passage solutions must address not only the number or percentage of fish that successfully pass a barrier, but also the time it takes to pass. Here, we used radiotelemetry to study the functionality of a fish bypass for downstream-migrating wild-caught and hatchery-released Atlantic salmon smolts. We used time-to-event analysis to model the influence of fish characteristics and environmental variables on the rates of a series of events associated with dam passage. Among the modelled events were approach rate to the bypass entry zone, retention rates in both the forebay and the entry zone and passage rates. Despite repeated attempts, only 65% of the tagged fish present in the forebay passed the dam. Fish passed via the bypass (33%), via spill (18%) and via turbines (15%). Discharge was positively related to approach, passage and retention rates. We did not detect any differences between wild and hatchery fish. Even though individual fish visited the forebay and the entry zone on multiple occasions, most fish passed during the first exposures to these zones. This study underscores the importance of timeliness to passage success and the usefulness of time-to-event analysis for understanding factors governing passage performance.

Ort, förlag, år, upplaga, sidor
Wiley-Blackwell, 2017
Nyckelord
downstream passage, fish passage, landlocked salmon, Salmo salar, smolt migration, nedströmspassage, fiskpassage, smolt, lax
Nationell ämneskategori
Ekologi
Forskningsämne
Biologi
Identifikatorer
urn:nbn:se:kau:diva-46897 (URN)10.1111/eff.12318 (DOI)000409505000019 ()
Tillgänglig från: 2016-10-19 Skapad: 2016-10-19 Senast uppdaterad: 2018-09-10Bibliografiskt granskad
Enefalk, Å., Watz, J., Greenberg, L. & Bergman, E. (2017). Winter sheltering by juvenile brown trout (Salmo trutta): Effects of stream wood and an instream ecothermic predator. Freshwater Biology, 62(1), 111-118
Öppna denna publikation i ny flik eller fönster >>Winter sheltering by juvenile brown trout (Salmo trutta): Effects of stream wood and an instream ecothermic predator
2017 (Engelska)Ingår i: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 62, nr 1, s. 111-118Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

In boreal streams, juvenile salmonids spend substantial amounts of time sheltering in the streambed and in stream wood, presumably as a means of protection against the physical environment and from terrestrial endothermic predators. Relatively little is known about sheltering by salmonids in response to instream ectothermic predators.We tested the effects of burbot (Lota lota) on the winter sheltering behaviour of PIT-tagged 0+ brown trout (Salmo trutta) in daylight and darkness. Sheltering in the streambed by trout was studied in the presence and absence of fine wood bundles.We found that the use of streambed and fine wood was lower in darkness than in daylight. Availability of fine wood significantly decreased sheltering in the streambed, and this effect was more pronounced in daylight than in darkness. The presence of a burbot significantly decreased sheltering in the streambed, had no effect on use of fine wood and resulted in a higher number of exposed trout.Our results indicate that juvenile brown trout decrease streambed sheltering in response to a burrowing, ectothermic predator.

Ort, förlag, år, upplaga, sidor
John Wiley & Sons, 2017
Nyckelord
cover, lotic, predator avoidance, small woody debris, substratum
Nationell ämneskategori
Ekologi
Forskningsämne
Biologi
Identifikatorer
urn:nbn:se:kau:diva-45641 (URN)10.1111/fwb.12854 (DOI)000390146000010 ()
Tillgänglig från: 2016-09-02 Skapad: 2016-09-02 Senast uppdaterad: 2019-07-10Bibliografiskt granskad
Klaminder, J., Hellström, G., Fahlman, J., Jonsson, M., Fick, J., Lagesson, A., . . . Brodin, T. (2016). Drug-Induced Behavioral Changes: Using Laboratory Observations to Predict Field Observations. Frontiers in Environmental Science, 4(81)
Öppna denna publikation i ny flik eller fönster >>Drug-Induced Behavioral Changes: Using Laboratory Observations to Predict Field Observations
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2016 (Engelska)Ingår i: Frontiers in Environmental Science, ISSN 2296-665X, Vol. 4, nr 81Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Behavioral assays constitute important research tools when assessing how fish respond to environmental change. However, it is unclear how behavioral modifications recorded in laboratory assays are expressed in natural ecosystems, a limitation that makes it difficult to evaluate the predictive power of laboratory-based measurements. In this study, we hypothesized that exposure to a benzodiazepine (i.e., oxazepam) increases boldness and activity in laboratory assays as well as in field assays—that is, laboratory results can be used to predict field results. Moreover, we expected the modified behavior to affect other important ecological measures such as habitat selection and home range. To test our hypothesis, we exposed European perch (Perca fluviatilis) to oxazepam and measured subsequent changes in behavioral trials both in laboratory assays and in a lake ecosystem populated with a predatory fish species, pike (Esox lucius). In the lake, the positions of both perch and pike were tracked every 3 min for a month using acoustic telemetry. In the laboratory assay, the oxazepam-exposed perch were bolder and more active than the non-exposed perch. In the lake assay, the oxazepam-exposed perch were also more bold and active, had a larger home range, and used pelagic habitats more than the non-exposed perch. We conclude that ecotoxicological behavioral assays are useful for predicting the effects of exposure in natural systems. However, although individual responses to exposure were similar in both the laboratory and field trials, effects were more obvious in the field study, mainly due to reduced variability in the behavioral measures from the lake. Hence, short-term behavioral assays may fail to detect all the effects expressed in natural environments. Nevertheless, our study clearly demonstrates that behavioral modifications observed in laboratory settings can be used to predict how fish perform in aquatic ecosystems.

Ort, förlag, år, upplaga, sidor
Lausanne, Schweiz: Frontiers Research Foundation, 2016
Nationell ämneskategori
Biologiska vetenskaper
Forskningsämne
Biologi
Identifikatorer
urn:nbn:se:kau:diva-65054 (URN)10.3389/fenvs.2016.00081 (DOI)000458351000081 ()
Tillgänglig från: 2017-11-01 Skapad: 2017-11-01 Senast uppdaterad: 2019-06-10Bibliografiskt granskad
Organisationer
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0003-2220-1615

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