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Zimmerman, J. K. M. & Palo, R. T. (2012). Time series analysis of climate-related factors and their impact on a red-listed noble crayfish population in northern Sweden. Freshwater Biology, 57(5), 1031-1041
Open this publication in new window or tab >>Time series analysis of climate-related factors and their impact on a red-listed noble crayfish population in northern Sweden
2012 (English)In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 57, no 5, p. 1031-1041Article in journal (Refereed) Published
Abstract [en]

1. Global climate change is predicted to raise water temperatures and alter flow regimes in northern river systems. Climate-related factors might have profound impacts on survival, reproduction and distribution of freshwater species such as red-listed noble crayfish (Astacus astacus) in its northern limit of distribution.2. In this study, noble crayfish capture data over 27 years from the River Ljungan, Sweden, were examined. Time series of catch per unit effort (CPUE) were analysed in relation to the North Atlantic Oscillation (NAO) index, regional weather factors and water flow. CPUE was assumed to reflect differences in population size. Two models were constructed to explore the relative impact of different climate factors and density dependence on variability of catch sizes.3. The most parsimonious model for CPUE time series, explaining 72% of the variance in CPUE, included density-dependent population dynamics of the crayfish and climate or weather factors. The specific effect from density dependence in the model was 37%, while climate/weather factors contributed with 35% of the variation. The most important climate/weather factors are variations in NAO index and water flow. Temperature did not improve the model fit to capture data.4. The best model was evaluated using independent data sets that gave correlations between model predictions and data ranging from 0.44 to 0.53. The density dependence shows a time lag of 1 year, while climate variables show time lags from 2 to 6 years in relation to CPUE, indicating effects on different cohorts of the crayfish population.5. Both density dependence and climatic factors play a significant role in population fluctuations of noble crayfish. A 6-year time lag for NAO index is puzzling but indicates that some as yet unidentified factors related to NAO might act on the juvenile stages of the population. Water flow shows a 2-year lag to the CPUE, and high flow in the river may affect adult survival. The reasons for fluctuation of crayfish catches in response to climate need to be identified, and fishing quotas should consider the different cohort sizes because of variation in environment. Reintroduction programmes for crayfish need to consider effects of climate change when designing management strategies.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2012
Keywords
catch per unit effort, crayfish, north Atlantic oscillation index, time series, water flow
National Category
Ecology
Identifiers
urn:nbn:se:miun:diva-16144 (URN)10.1111/j.1365-2427.2012.02764.x (DOI)000302397300012 ()2-s2.0-84859431789 (Scopus ID)
Available from: 2012-04-28 Created: 2012-04-28 Last updated: 2017-12-07Bibliographically approved
Zimmerman, J. K. M. & Palo, R. T. (2012). WHERE SHOULD YOU PUT THE CRAYFISH - DOES THE ACTUAL REINTRODUCTION SITE MATTER?. In: : . Paper presented at International Association of Astacology (IAA), 19th Symposium, August 26 – 31, 2012, Innsbruck, Austria.
Open this publication in new window or tab >>WHERE SHOULD YOU PUT THE CRAYFISH - DOES THE ACTUAL REINTRODUCTION SITE MATTER?
2012 (English)Conference paper, Oral presentation only (Refereed)
Keywords
Reintroduction, noble crayfish, upstream, migration
National Category
Ecology
Identifiers
urn:nbn:se:miun:diva-17028 (URN)
Conference
International Association of Astacology (IAA), 19th Symposium, August 26 – 31, 2012, Innsbruck, Austria
Available from: 2012-09-20 Created: 2012-09-20 Last updated: 2015-07-01Bibliographically approved
Zimmerman, J. K. & Palo, T. R. (2011). Reliability of catch per unit effort (CPUE) for evaluation of reintroduction programs – A comparison of mark-recapture method with standardized trapping. Knowledge and Management of Aquatic Ecosystems (401), Art no. 7
Open this publication in new window or tab >>Reliability of catch per unit effort (CPUE) for evaluation of reintroduction programs – A comparison of mark-recapture method with standardized trapping
2011 (English)In: Knowledge and Management of Aquatic Ecosystems, ISSN 1961-9502, E-ISSN 1961-9502, no 401, p. Art no. 7-Article in journal (Refereed) Published
Abstract [en]

Catch per unit effort (CPUE) is used as a standardized trapping method by local fishermen and in monitoring studies. In this study, CPUE was compared with population estimates made with a capture-recapture method based on the passive integrated transponder (PIT-tag) marking of individuals. The results show a stronger positive correlation between the estimated population sizes from the capture-recapture method with an estimated CPUE effort of 120 traps. The fishermen used 15 traps, and even this effort showed a fair correlation with the mark-recapture estimates. This indicates that the standardized way of trapping with 15 traps can be used to evaluate reintroduction programs and monitor crayfish populations

Keywords
Astacus astacus, CPUE, capture-recapture, reintroduction, evaluation
National Category
Ecology
Identifiers
urn:nbn:se:miun:diva-12554 (URN)10.1051/kmae/2011016 (DOI)000297214300007 ()2-s2.0-79956332728 (Scopus ID)
Available from: 2010-12-13 Created: 2010-12-13 Last updated: 2017-12-11Bibliographically approved
Zimmerman, J. K. & Palo, T. R. (2010). Do global cimate or local weather influence influence crayfish catches in the river Ljunjan in Sweden?. In: Allert Annie (Ed.), 18th IAA Symposia, Program and  abstracts. Paper presented at International Astacology Association 18th Symposia (pp. 35-35).
Open this publication in new window or tab >>Do global cimate or local weather influence influence crayfish catches in the river Ljunjan in Sweden?
2010 (English)In: 18th IAA Symposia, Program and  abstracts / [ed] Allert Annie, 2010, p. 35-35Conference paper, Published paper (Refereed)
Keywords
Astacus astacus, crayfish catch, NAO-index, weather
National Category
Ecology
Identifiers
urn:nbn:se:miun:diva-12797 (URN)
Conference
International Astacology Association 18th Symposia
Available from: 2010-12-15 Created: 2010-12-15 Last updated: 2010-12-15Bibliographically approved
Zimmerman, J. & Palo, T. (2010). Influence of water regulation and water flow on Noble crayfish (Astacus astacus) catch yield in Ljungan a Northern Swedish River after building of a power plant. Freshwater Crayfish, 17, 141-144
Open this publication in new window or tab >>Influence of water regulation and water flow on Noble crayfish (Astacus astacus) catch yield in Ljungan a Northern Swedish River after building of a power plant
2010 (English)In: Freshwater Crayfish, ISSN 2076-4324, Vol. 17, p. 141-144Article in journal (Refereed) Published
Abstract [en]

Free-flowing water is thought to be of importance for reproduction and body growth of noble crayfish (Astacus astacus (Linné)) in the northern edge of its distribution area.

A hydroelectric power plant with a bypass tunnel was built in the river Ljungan in 1976.  This reduced the mean water flow in the old river bed from about 60m3/s to 3m3/s. The sites with the largest reduction of water flow had the largest decline in catch per unit effort of crayfish.  At one site the catches were reduced by >60%, but the catch success varied between locations.  In all sites the regulation seemed to have an effect, even though catch per unit effort was possibly affected by a number of other factors.

KEY WORDS: Catch yield, noble crayfish (Astacus astacus), water flow, water level regulation

Keywords
Catch yeld, noble crayfish, water flow, water level regulation
National Category
Ecology
Identifiers
urn:nbn:se:miun:diva-8172 (URN)
Available from: 2009-01-09 Created: 2009-01-09 Last updated: 2013-02-12Bibliographically approved
Zimmerman, J. K. & Palo, T. R. (2010). Reliability of catch per unit effort (CPUE) for evaluation of reintroduction programs – A comparison of mark-recapture method with standardized trapping. In: Souty Grosset Catherine (Ed.), European Crayfish food, Flagships and Ecosystem Services. Paper presented at European Crayfish Food, Flagships and Ecosystem Services (pp. 28-29).
Open this publication in new window or tab >>Reliability of catch per unit effort (CPUE) for evaluation of reintroduction programs – A comparison of mark-recapture method with standardized trapping
2010 (English)In: European Crayfish food, Flagships and Ecosystem Services / [ed] Souty Grosset Catherine, 2010, p. 28-29Conference paper, Published paper (Refereed)
Keywords
Noble Crayfish, reintroduction, evaluation, PIT-tags
National Category
Ecology
Identifiers
urn:nbn:se:miun:diva-12793 (URN)978-2-911320-38-5 (ISBN)
Conference
European Crayfish Food, Flagships and Ecosystem Services
Available from: 2010-12-15 Created: 2010-12-15 Last updated: 2010-12-15Bibliographically approved
Palo, R. T. (2009). Meriteringssystem som utarmar vetenskaplig mångfald [Review]. Tentakel (5)
Open this publication in new window or tab >>Meriteringssystem som utarmar vetenskaplig mångfald
2009 (Swedish)In: Tentakel, no 5Article, book review (Other (popular science, discussion, etc.)) Published
National Category
Social Sciences Interdisciplinary
Identifiers
urn:nbn:se:miun:diva-9650 (URN)
Available from: 2009-09-16 Created: 2009-09-16 Last updated: 2018-01-13Bibliographically approved
Palo, R. T. & Olsson, G. E. (2009). Nitrogen and carbon concentrations in the stomach content of bank voles (Myodes glareolus): Does food quality determine abundance?. The Open Ecology Journal, 2, 86-90
Open this publication in new window or tab >>Nitrogen and carbon concentrations in the stomach content of bank voles (Myodes glareolus): Does food quality determine abundance?
2009 (English)In: The Open Ecology Journal, ISSN 1874-2130, E-ISSN 1874-2130, Vol. 2, p. 86-90Article in journal (Refereed) Published
Abstract [en]

We found that concentrations of nitrogen (N) in the stomach of voles varied between forest sites. Concentrations of nitrogen as well as the ratio of nitrogen to carbon (C) in stomach content were not different between the sexes or with season. Body mass varied between sites and between seasons but were unrelated to N concentration in spite that the body mass of voles in the spring season were on average 4.8 g heavier than in the autumn A positive relationship was found between N and C concentrations in the stomach content implying the diet quality could be related to this ratio. N concentrations in the stomach per unit body mass were positively and significantly related to catch per unit effort of voles. We suggest that sites with high N concentrations in stomach content and with higher NC-ratio imply better habitats that support higher population densities of voles.

Place, publisher, year, edition, pages
Bentham Open, 2009
National Category
Ecology
Identifiers
urn:nbn:se:miun:diva-9652 (URN)10.2174/1874213000902010086 (DOI)
Available from: 2009-09-16 Created: 2009-09-16 Last updated: 2017-12-13Bibliographically approved
Palo, R. T. & Ahlm, C. (2009). The role of small mammals for incidence of zoonotic diseases under climate change. In: The 10th International Congress of Ecology: Ecology in a changing climate.
Open this publication in new window or tab >>The role of small mammals for incidence of zoonotic diseases under climate change
2009 (English)In: The 10th International Congress of Ecology: Ecology in a changing climate, 2009Conference paper, Published paper (Refereed)
Abstract [en]

Animal-borne diseases are likely to be affected by climate change. It is of interest to analyse sensitivity of reservoir species to climate change and how changes in their ecology would affect transmission of zoonoti diseases to man. Elevated temperature in northern hemisphere may have direct effects on reservoir species by greater survival and hence generally higher population densities. Further, warmer climate may make certain key habitats more beneficial for replication and possibly greater transfer of disease. On the other hand, animal responses to climate change may vary among species and changes in their ecology causing increased variability in population size or dependence of timing with certain food resources may adversely affect reservoir species. We analysed the number of human disease cases of tick borne encephalitis (TBE), tularaemia and hantavirus in norhern Sweden in relation to population size of their most common reservoirs, the mountain hare, European hare and the bank vole. We also analysed the effect by a common predator the red fox and we used the NAO index as a proxy for climate variations. The results show that hantavirus infection in man is more dependent on the population density of reservoirs than on the climate variable. In case of tularaemia, we found a more complex ecological situation that may be climate driven.We conclude that the outcome of warmer climate may vary among species but that species adapted to northern winter conditions may be particularly sensitive to climate change.

Keywords
Zooekologi
National Category
Ecology Microbiology in the medical area
Identifiers
urn:nbn:se:miun:diva-9659 (URN)
Projects
zoonoser
Available from: 2009-10-02 Created: 2009-09-17 Last updated: 2018-01-13Bibliographically approved
Palo, T. (2009). Time Series Analysis Performed on Nephropathia Epidemica in Humans of Northern Sweden in Relation to Bank Vole Population Dynamic and the NAO Index. Zoonoses and public health, 56(3), 150-156
Open this publication in new window or tab >>Time Series Analysis Performed on Nephropathia Epidemica in Humans of Northern Sweden in Relation to Bank Vole Population Dynamic and the NAO Index
2009 (English)In: Zoonoses and public health, ISSN 1863-1959, Vol. 56, no 3, p. 150-156Article in journal (Refereed) Published
Abstract [en]

Zoonotic diseases are likely to be affected by climate variations but to reveal such dependence long time series extending over several decades are required. Human cases of Hantavirus infection in Northern Sweden shows regular peaks that occurs every fourth year and the virus is associated with the bank vole (Clethrionomys glareolus). From a perspective of climate change it is important to analyse variations in bank vole population size and human disease incidence and how these interactions is affected by climate forcing. Here I show that a time lag of two years exist between NAO index and response in the vole population and human disease incidence. In some way triggers the NAO index two years previously a build up and peak in vole density and with corresponding peak in human Hantavirus disease. Likewise, high NAO index two years previously is associated with low population density of voles. The change in number of human disease cases is positively correlated to density of bank voles and both bank voles and disease peaks at a regularity of about every fourth year. Further, the time series revealed a match between NAO index, vole population and human disease cases at a longer periodicity of 8.5 years that has not been anticipated.These contrasting climate effects makes it hard to predict how a future warmer climate will affect disease dynamics in this particular system because of complex relationship between long and short term effects.

Keywords
hantavirus climate, bank vole
National Category
Biological Sciences
Identifiers
urn:nbn:se:miun:diva-6453 (URN)10.1111/j.1863-2378.2008.01162.x (DOI)000263910500007 ()18771520 (PubMedID)2-s2.0-61849119172 (Scopus ID)5009 (Local ID)5009 (Archive number)5009 (OAI)
Available from: 2008-11-29 Created: 2008-11-29 Last updated: 2016-09-26Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1894-6059

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