Disentangling local from macroenvironmental effects: quantifying the effect of human encroachments based on historical river catches of anadromous salmonids

In this paper, we use dynamic factor and intervention analysis to identify and quantify the effect of human encroachments on anadromous salmonid catches in 22 Norwegian rivers over a 128-year period. In particular, we address effects of hydropower development, gravel removal, and stock enhancement (fish ladder construction and stocking). The methods allow for quantification of perturbation effects in the river environment on the annual catch, after removing long-term temporal trends at the appropriate spatial scale. The estimated effects of the encroachments differed among rivers, indicating that the mechanisms differ among rivers even for the same type of encroachment. In three rivers where hydropower development and stock enhancement had occurred, a significant increase of 0.8–9.8 tonnes (t) (34%–44%) was estimated, whereas a significant reduction of 11.2 t (38%) was estimated for the river where gravel removal had taken place. For rivers with additional biological information available, we find support...

[1]  A. Jensen,et al.  Infestations of Atlantic salmon, Salmo salar, by Gyrodactylus salaris in Norwegian rivers , 1986 .

[2]  A. Jensen,et al.  The functional relationship between peak spring floods and survival and growth of juvenile Atlantic Salmon (Salmo salar) and Brown Trout (Salmo trutta) , 1999 .

[3]  W. Crozier,et al.  Relationship between freshwater angling catch of Atlantic salmon and stock size in the River Bush, Northern Ireland , 2001 .

[4]  B. Jonsson,et al.  Latitudinal Variation in Life-History Characteristics of Sea-Run Migrant Brown Trout Salmo trutta , 1989 .

[5]  T. Clutton‐Brock,et al.  Noise and determinism in synchronized sheep dynamics , 1998, Nature.

[6]  W. Shearer.  The Atlantic salmon: Natural history, exploitation and future management , 1992, Reviews in Fish Biology and Fisheries.

[7]  A. Zuur,et al.  Dynamic factor analysis to estimate common trends in fisheries time series , 2003 .

[8]  N. A. Hvidsten.  Mortality of pre-smolt Atlantic salmon, Salmo salar L., and brown trout, Salmo trutta L., caused by fluctuating water levels in the regulated River Nidelva, central Norway , 1985 .

[9]  L. Hansen,et al.  Spatial and temporal distribution of post-smolts of Atlantic salmon (Salmo salar L.) in the Norwegian Sea and adjacent areas , 2000 .

[10]  K. Friedland.  Ocean climate influences on critical Atlantic salmon (Salmo salar) life history events , 1998 .

[11]  Hervé Capra,et al.  The influence of hydrological and biotic processes on brown trout (Salmo trutta) population dynamics , 2002 .

[12]  Randall M. Peterman,et al.  Relation Between Sport-Fishing Catchability Coefficients and Salmon Abundance , 1981 .

[13]  Nina Jonsson,et al.  The relative role of density‐dependent and density‐independent survival in the life cycle of Atlantic salmon Salmo salar , 1998 .

[14]  J. A. Jacobsen,et al.  Origin and migration of wild and escaped farmed Atlantic salmon, Salmo salar L., in oceanic areas north of the Faroe Islands , 2003 .

[15]  T. Antonsson,et al.  Relation of grilse to salmon ratio to environmental changes in several wild stocks of Atlantic salmon (Salmo salar) in Iceland , 1995 .

[16]  E. Chadwick.  Fundamental research problems in the management of Atlantic salmon, Salmo salar L., in Atlantic Canada , 1985 .

[17]  Randall M. Peterman,et al.  Spatial correlation patterns in coastal environmental variables and survival rates of salmon in the north‐east Pacific Ocean , 2002 .

[18]  B. Manly.  Randomization, Bootstrap and Monte Carlo Methods in Biology , 2018 .

[19]  Éric Parent,et al.  Setting biological reference points for Atlantic salmon stocks: transfer of information from data-rich to sparse-data situations by Bayesian hierarchical modelling , 2003 .

[20]  S. Einum,et al.  Implications of Stocking: Ecological Interactions Between Wild and Released Salmonids , 2001 .

[21]  Carl J. Walters,et al.  Patterns of covariation in survival rates of British Columbian and Alaskan sockeye salmon (Oncorhynchus nerka) stocks , 1998 .

[22]  B. Finstad,et al.  Does increased abundance of sea lice influence survival of wild Atlantic salmon post-smolt? , 2007 .

[23]  George E. P. Box,et al.  Intervention Analysis with Applications to Economic and Environmental Problems , 1975 .

[24]  N. Stenseth,et al.  Phase coupling and synchrony in the spatiotemporal dynamics of muskrat and mink populations across Canada , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[25]  P. Dalpadado,et al.  Zooplankton biomass variation in relation to climatic conditions in the Barents Sea , 2003, Polar Biology.

[26]  T. G. Heggberget,et al.  An aerial method of assessing spawning activity of Atlantic salmon, Salmo salar L., and brown trout, Salmo trutta L., in Norwegian streams , 1986 .

[27]  S. M. McKinnell,et al.  Spatial and temporal covariation in the recruitment and abundance of Atlantic salmon populations in the Baltic Sea , 1999 .

[28]  A. Sharov,et al.  Cessation of the Norwegian drift net fishery: changes observed in Norwegian and Russian populations of Atlantic salmon , 1999 .

[29]  J. Taggart,et al.  Fitness reduction and potential extinction of wild populations of Atlantic salmon, Salmo salar, as a result of interactions with escaped farm salmon , 2003, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[30]  R. Saunders.  Ecology and Management of Atlantic Salmon , 1991 .

[31]  B. Finstad,et al.  Geographical differences in marine feeding of Atlantic salmon post-smolts in Norwegian fjords , 2004 .

[32]  Thomas P. Quinn,et al.  Pacific Salmon Life Histories , 1992 .

[33]  R. G. Buck,et al.  The relation between stock size and progeny of Atlantic salmon, Salmo salar L., in a Scottish stream , 1984 .

[34]  B. Jonsson,et al.  The marine survival and growth of wild and hatchery‐reared Atlantic salmon , 2003 .

[35]  L. A. Vøllestad,et al.  Spatial and Temporal Variation in the Grilse Proportion of Atlantic Salmon in Norwegian Rivers , 2004 .

[36]  R. Beamish,et al.  Pacific salmon production trends in relation to climate , 1993 .

[37]  J. Lobón‐Cervià,et al.  Environmental determinants of recruitment and their influence on the population dynamics of stream-living brown trout Salmo trutta , 2004 .

[38]  P. A. Larkin.  The stock concept in Pacific salmon , 1972 .

[39]  K. Hindar,et al.  Genetic Effects of Cultured Fish on Natural Fish Populations , 1991 .

[40]  K. Mann,et al.  Dynamics of Marine Ecosystems , 1991 .

[41]  Tan,et al.  Ecology of Fjords and Coastal Waters , 1997 .

[42]  E. Knut,et al.  Paris Meeting of the International Council for the Exploration of the Sea , 1923, Nature.

[43]  J. M. Elliott.  Quantitative ecology and the brown trout , 1995 .

[44]  M R Gross,et al.  Aquatic Productivity and the Evolution of Diadromous Fish Migration , 1988, Science.

[45]  K. H. Mann,et al.  Dynamics of marine ecosystems , 1991 .

[46]  Joseph L. Thorley,et al.  Congruence between automatic fish counter data and rod catches of Atlantic salmon (Salmo salar) in Scottish rivers , 2005 .