Change search
Link to record
Permanent link

Direct link
BETA
Alternative names
Publications (10 of 174) Show all publications
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
Open this publication in new window or tab >>Effects of temperature and a piscivorous fish on diel winter behaviour of juvenile brown trout (Salmo trutta)
Show others...
2019 (English)In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 64, no 1+, p. 1797-1805Article in journal (Refereed) 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.

Keywords
anti-predator, burbot, climate change, light, predator avoidance
National Category
Ecology
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-74573 (URN)10.1111/fwb.13371 (DOI)000480404400001 ()
Available from: 2019-08-29 Created: 2019-08-29 Last updated: 2019-11-14Bibliographically approved
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
Open this publication in new window or tab >>Life-history variability and conservation status of landlocked Atlantic salmon: an overview
Show others...
2019 (English)In: Canadian Journal of Fisheries and Aquatic Sciences, ISSN 0706-652X, E-ISSN 1205-7533, Vol. 76, no 10, p. 1697-1708Article in journal (Refereed) 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.

Place, publisher, year, edition, pages
Canadian Science Publishing, 2019
National Category
Ecology
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-74675 (URN)10.1139/cjfas-2018-0413 (DOI)000487999200002 ()
Available from: 2019-09-06 Created: 2019-09-06 Last updated: 2019-11-12Bibliographically approved
Abecasis, D., Steckenreuter, A., Reubens, J., Aaestrup, K., Alos, J., Badalamenti, F., . . . Alfonso, P. (2018). A review of acoustic telemetry in Europe and the need for a regional aquatic telemetry network. Animal Biotelemetry, 6, 1-7, Article ID 12.
Open this publication in new window or tab >>A review of acoustic telemetry in Europe and the need for a regional aquatic telemetry network
Show others...
2018 (English)In: Animal Biotelemetry, ISSN 2050-3385, E-ISSN 2050-3385, Vol. 6, p. 1-7, article id 12Article in journal (Refereed) Published
Abstract [en]

Background: Globally, there are a large and growing number of researchers using biotelemetry as a tool to studyaquatic animals. In Europe, this community lacks a formal network structure. The aim of this study is to review the useof acoustic telemetry in Europe and document the contribution of cross-boundary studies and inter-research groupcollaborations. Based on this, we explore the potential benefits and challenges of a network approach to identifyfuture priorities and best practices for aquatic biotelemetry research in Europe.

Results: Over the past decade, there was an approximately sevenfold increase in the number of acoustic telemetrystudies published on marine and diadromous species in Europe compared to a sixfold increase globally. Over 90%of these studies were conducted on fishes and undertaken in coastal areas, estuaries, or rivers. 75% of these studieswere conducted by researchers based in one of five nations (Norway, UK, France, Portugal, and Spain) and, eventhough 34% were based on collaborations between scientists from several countries, there was only one study withan acoustic receiver array that extended beyond the borders of a single country. In recent years, acoustic telemetryin European waters has evolved from studying behavioural aspects of animals (82.2%), into more holistic approachesaddressing management-related issues (10%), tagging methods and effects (5%), and technology and data analysisdevelopment (2.8%).

Conclusions: Despite the increasing number of publications and species tracked, there is a prominent lack ofplanned and structured acoustic telemetry collaborations in Europe. A formal pan-European network structure wouldpromote the development of (1) a research platform that could benefit the acoustic telemetry community throughcapacity building, (2) a centralized database, and (3) key deployment sites and studies on priority species requiringresearch in Europe. A network may increase efficiency, expand the scope of research that can be undertaken, promoteEuropean science integration, enhance the opportunities and success of acquiring research funding and, ultimately,foster regional and transatlantic collaborations. It may also help address research priorities such as the large-scalesocietal challenges arising from climate change impacts and assist the EU’s Marine Strategy Framework Directive viaidentification of good environmental status of endangered or commercially important species.

Place, publisher, year, edition, pages
Springer, 2018
Keywords
European tracking network, acoustic telemetry, flagship species, acoustic arrays, animal movement, spatio-temporal movement, biotelemetry
National Category
Biological Sciences
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-69387 (URN)10.1186/s40317-018-0156-0 (DOI)
Available from: 2018-09-25 Created: 2018-09-25 Last updated: 2018-12-28
Voicu, R., Banaduc, D., Greenberg, L. & Curtean-Banaduc, A. (2018). Caras River Gorge aspects of salmonids' communities management- technical solutions. Management of sustainable development, 10(2), 5-12
Open this publication in new window or tab >>Caras River Gorge aspects of salmonids' communities management- technical solutions
2018 (English)In: Management of sustainable development, ISSN 2066-9380, Vol. 10, no 2, p. 5-12Article in journal (Refereed) Published
Abstract [en]

There are many obstacles in rivers that prevent or hinder passage of fish past barriers. Here, we present a specially designed solution for juvenile and adult brown trout so that they may to swim past discharge-regulating weirs in the upper Caraş River in both the upstream and downstream directions. The proposed solution relies on gravity flow and will have current velocities that will not inhibit weak swimmers swimming upstream to pass the weirs. Corrosion-resistant materials and the absence of components that could potentially injure the fish will be used in the construction of these technical solutions. Although testing of the functionality of this solutions for upstream - downstream and downstream - upstream passage of weirs is needed, we believe that if implemented, it should improve connectivity especially for brown trout and consequently conserve within-stream genetic diversity in the Caraş River and where appropriate in alike other Carpathian lotic systems with similar types of weirs.

Place, publisher, year, edition, pages
Editura Universitatii "Lucian Blaga din Sibiu", 2018
Keywords
Brown trout, Caraş River, Banat, discharge-regulating weirs, habitats fragmentation, fish passages
National Category
Biological Sciences Ecology
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-75146 (URN)10.2478/msd-2019-0001 (DOI)
Available from: 2019-10-08 Created: 2019-10-08 Last updated: 2019-10-28Bibliographically approved
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
Open this publication in new window or tab >>Fishes in a changing world: learning from the past to promote sustainability of fish populations
Show others...
2018 (English)In: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 92, no 3, p. 804-827Article in journal (Refereed) 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.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
National Category
Biological Sciences Other Social Sciences
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-66874 (URN)10.1111/jfb.13546 (DOI)000427477600016 ()29537086 (PubMedID)
Conference
50th Anniversary Annual Symposium of the Fisheries-Society-of-the-British-Isles (FSBI) - Understanding Fish Populations, JUL 03-07, 2017, Univ Exeter, Exeter, ENGLAND
Available from: 2018-03-29 Created: 2018-03-29 Last updated: 2018-04-04Bibliographically approved
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
Open this publication in new window or tab >>Downstream migration and multiple dam passage by Atlantic salmon smolts
Show others...
2017 (English)In: North American Journal of Fisheries Management, ISSN 0275-5947, E-ISSN 1548-8675, Vol. 4, no 37, p. 816-828Article in journal (Refereed) 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.

Place, publisher, year, edition, pages
Taylor & Francis, 2017
Keywords
SALAR SMOLTS; CHINOOK SALMON; FISH PASSAGE; JUVENILE SALMONIDS; DELAYED MORTALITY; COLUMBIA RIVER; SNAKE RIVER; HYDROPOWER SYSTEM; TRUTTA SMOLTS; K+ ATPASE
National Category
Ecology
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-46900 (URN)10.1080/02755947.2017.1327900 (DOI)000407192600012 ()
Available from: 2016-10-19 Created: 2016-10-19 Last updated: 2018-09-10Bibliographically approved
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
Open this publication in new window or tab >>Intake Approach and Dam Passage by Downstream-migrating Atlantic Salmon Kelts
2017 (English)In: Rivers Research and Applications: an international journal devoted to river research and management, ISSN 1535-1459, E-ISSN 1535-1467, Vol. 33, no 5, p. 697-706Article in journal (Refereed) 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.

Place, publisher, year, edition, pages
John Wiley & Sons, 2017
National Category
Ecology
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-46902 (URN)10.1002/rra.3133 (DOI)000402840900006 ()
Note

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"

Available from: 2016-10-19 Created: 2016-10-19 Last updated: 2018-09-10Bibliographically approved
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
Open this publication in new window or tab >>Migratory delay leads to reduced passage success of Atlantic salmon smolts at a hydroelectric dam
Show others...
2017 (English)In: Ecology of Freshwater Fish, ISSN 0906-6691, E-ISSN 1600-0633, Vol. 26, no 4, p. 707-718Article in journal (Refereed) 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.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2017
Keywords
downstream passage, fish passage, landlocked salmon, Salmo salar, smolt migration, nedströmspassage, fiskpassage, smolt, lax
National Category
Ecology
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-46897 (URN)10.1111/eff.12318 (DOI)000409505000019 ()
Available from: 2016-10-19 Created: 2016-10-19 Last updated: 2018-09-10Bibliographically approved
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
Open this publication in new window or tab >>Winter sheltering by juvenile brown trout (Salmo trutta): Effects of stream wood and an instream ecothermic predator
2017 (English)In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 62, no 1, p. 111-118Article in journal (Refereed) 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.

Place, publisher, year, edition, pages
John Wiley & Sons, 2017
Keywords
cover, lotic, predator avoidance, small woody debris, substratum
National Category
Ecology
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-45641 (URN)10.1111/fwb.12854 (DOI)000390146000010 ()
Available from: 2016-09-02 Created: 2016-09-02 Last updated: 2019-07-10Bibliographically approved
Watz, J., Bergman, E., Piccolo, J. & Greenberg, L. (2016). Ice cover affects the growth of a stream-dwelling fish. Oecologia, 181(1), 299-311
Open this publication in new window or tab >>Ice cover affects the growth of a stream-dwelling fish
2016 (English)In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 181, no 1, p. 299-311Article in journal (Refereed) Published
Abstract [en]

Protection provided by shelter is important for survival and affects the time and energy budgets of animals. It has been suggested that in fresh waters at high latitudes and altitudes, surface ice during winter functions as overhead cover for fish, reducing the predation risk from terrestrial piscivores. We simulated ice cover by suspending plastic sheeting over five 30-m-long stream sections in a boreal forest stream and examined its effects on the growth and habitat use of brown trout (Salmo trutta) during winter. Trout that spent the winter under the artificial ice cover grew more than those in the control (uncovered) sections. Moreover, tracking of trout tagged with passive integrated transponders showed that in the absence of the artificial ice cover, habitat use during the day was restricted to the stream edges, often under undercut banks, whereas under the simulated ice cover condition, trout used the entire width of the stream. These results indicate that the presence of surface ice cover may improve the energetic status and broaden habitat use of stream fish during winter. It is therefore likely that reductions in the duration and extent of ice cover due to climate change will alter time and energy budgets, with potentially negative effects on fish production.

Place, publisher, year, edition, pages
Berlin Heidelberg: Springer Berlin/Heidelberg, 2016
Keywords
Climate change, Energy budget, Global warming, Salmonid, Winter
National Category
Ecology
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-39125 (URN)10.1007/s00442-016-3555-z (DOI)000374564000026 ()26787075 (PubMedID)
Available from: 2016-01-25 Created: 2016-01-25 Last updated: 2017-12-06Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-3191-7140

Search in DiVA

Show all publications