Reduced Acid Deposition Leads to a New Start for Brown Trout (Salmo trutta) in an Acidified Lake in Southern Norway
Acid deposition has led to acidification and loss of fish populations in thousands of lakes and streams in Norway. Since the peak in the late 1970s, acid deposition has been greatly reduced and acidified surface waters have shown chemical recovery. Biological recovery, in particular fish populations, however, has lagged behind. Long-term monitoring of water chemistry and fish populations in Lake Langtjern, south-eastern Norway, shows that around 2008, chemical recovery had progressed to the point at which natural reproduction of brown trout (Salmo trutta) reoccurred. The stocked brown trout reproduced in the period 2008–2014, probably for the first time since the 1960s, but reproduction and/or early life stage survival was very low. The results indicate that chemical thresholds for reproduction in this lake are approximately pH = 5.1, Ali = 26 μg l−1, ANC = 47 μeq l−1, and ANCoaa = 10 μeq l−1 as annual mean values. These thresholds agree largely with the few other cases of documented recovery of brown trout in sites in Norway, Sweden, and the UK. Occurrence and duration of acidic episodes have decreased considerably since the 1980s but still occur and probably limit reproduction success.
KeywordsAcidification Acid-neutralizing capacity Fish Recovery
The long-term data series at Langtjern would not have been possible without the enthusiastic and dogged efforts of our emeritus colleagues Arne Henriksen, Magne Grande, and Sigbjørn Andersen and the local help of Kolbjørn Sønsteby.
Monitoring of water chemistry in Lake Langtjern is funded by the Norwegian Environment Agency and, since 2013, also by the Ministry of Climate and Environment through a grant supporting continuation of long time series. This work was funded in part by the Norwegian Research Council project “Lakes in Transition” (244558/E50) and the Norwegian Institute for Water Research (NIVA).
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
- Aas, W., Fiebig, M., Platt, S., Solberg, S., and Yttri, K.E. 2016. Monitoring of long-range transported air pollutants in Norway, Annual Report 2015. Miljødirektoratet rapport, M-562/2016, NILU report, 13/2016. Norwegian Institute for Air Research, Kjeller, Norway.Google Scholar
- de Wit, H. A., Valinia, S., Weyhenmeyer, G. A., Futter, M. N., Kortelainen, P., Austnes, K., Hessen, D. O., Raike, A., Laudon, H., & Vuorenmaa, J. (2016). Current browning of surface waters will be further promoted by wetter climate. Environmental Science & Technology Letters, 3(12), 430–435.CrossRefGoogle Scholar
- Garmo, O. A., Skjelkvale, B. L., de Wit, H. A., Colombo, L., Curtis, C., Folster, J., Hoffmann, A., Hruska, J., Hogasen, T., Jeffries, D. S., Keller, W. B., Kram, P., Majer, V., Monteith, D. T., Paterson, A. M., Rogora, M., Rzychon, D., Steingruber, S., Stoddard, J. L., Vuorenmaa, J., & Worsztynowicz, A. (2014). Trends in surface water chemistry in acidified areas in Europe and North America from 1990 to 2008. Water, Air, and Soil Pollution, 225(3).Google Scholar
- Garmo, Ø., Skancke, L.B., and Høgåsen, T. 2016. Monitoring long-range transboundary air pollution. Water chemical effects 2015. NIVA-rapport 7078, Miljødirektoratet-rapport M-613. Norwegian Institute for Water Research, Oslo.Google Scholar
- Grande, M., Muniz, I. P., & Andersen, S. (1978). Relative tolerance of some salmonids to acid waters. Verhandlungen des Internationalen Verein Limnologie, 20, 2076–2084.Google Scholar
- Gray, C., Hildrew, A. G., Lu, X., Ma, A., McElroy, D., Monteith, D., O'Gorman, E., Shilland, E., & Woodward, G. (2016). Recovery and nonrecovery of freshwater food webs from the effects of acidification. In A. J. Dumbrell, R. L. Kordas, & G. Woodward (Eds.), Advances in ecological research, vol 55: large-scale ecology: model systems to global perspectives (pp. 475–534). San Diego, CA: Elsevier Academic Press Inc.CrossRefGoogle Scholar
- Henriksen, A., and Grande, M. 2002. Lake Langtjern—fish studies in the Langtjern area 1966-2000. Acid Rain Research Report 54/02 SNO 4537-2002. NIVA, Oslo.Google Scholar
- Hesthagen, T., Sevaldrud, I. H., & Berger, H. M. (1999). Assessment of damage to fish populations in Norwegian lakes due to acidification. Ambio, 28, 112–117.Google Scholar
- Hesthagen, T., Fjellheim, A., Schartau, A. K., Wright, R. F., Saksgård, R., & Rosseland, B. O. (2011). Chemical and biological recovery of Lake Saudlandsvatn, a highly acidified lake in southernmost Norway, in response to decreased acid deposition. Science of the Total Environment, 409, 2908–2916.CrossRefGoogle Scholar
- Malcolm, I. A., Bacon, P. J., Middlemas, S. J., Fryer, R. J., Shilland, E. M., & Collen, P. (2014). Relationships between hydrochemistry and the presence of juvenile brown trout (Salmo trutta) in headwater streams recovering from acidification. Ecological Indicators, 37, 351–364.CrossRefGoogle Scholar
- Overrein, L., Seip, H.M., and Tollan, A. 1980. Acid precipitation—effects on forest and fish. Final report of the SNSF-project 1972–1980. FR 19-80. SNSF project, Ås, Norway.Google Scholar
- Rask, M., Vuorenmaa, J., Nyberg, K., Tammi, J., Mannio, J., Olin, M., Kortelainen, P., Raitaniemi, J., & Vesala, S. (2014). Recovery of acidified lakes in Finland and subsequent responses of perch and roach populations. Boreal Environment Research, 19(3), 222–234.Google Scholar
- Snucins, E., Gunn, J., Keller, B., Dixit, S., Hindar, A., & Henriksen, A. (2001). Effects of regional reductions in sulphur deposition on the chemical and biological recovery of lakes within Killarney Park, Ontario, Canada. Environmental Monitoring and Assessment, 67(1–2), 179–194.CrossRefGoogle Scholar
- Stoddard, J. L., Jeffries, D. S., Lükewille, A., Clair, T. A., Dillon, P. J., Driscoll, C. T., Forsius, M., Johannessen, M., Kahl, J. S., Kellogg, J. H., Kemp, A., Mannio, J., Monteith, D., Murdoch, P. S., Patrick, S., Rebsdorf, A., Skjelkvåle, B. L., Stainton, M. P., Traaen, T. S., van Dam, H., Webster, K. E., Wieting, J., & Wilander, A. (1999). Regional trends in aquatic recovery from acidification in North America and Europe 1980-95. Nature, 401, 575–578.CrossRefGoogle Scholar
- UNECE. 2014. Convention on long-range transboundary air pollution. http://www.unece.org/env/lrtap/lrtap_h1.html