Impacts of climate warming on the long-term dynamics of key fish species in 24 European lakes

Abstract

10.1007/s10750-012-1182-1Contact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. form, nor will it be during the first three months after its submission to Hydrobiologia."Corresponding author: Erik Jeppesen (ej@dmu.dk)We dedicate this paper to the late Prof. Jürgen Benndorf, a true pioneer and mentor in lake and reservoir management oriented research, who inspired a number of us to initiate longterm comprehensive experimental ecological studies on lakes and reservoirs. AbstractFish play a key role in the trophic dynamics of lakes. With climate warming, complex changes in fish assemblage structure may be expected owing to direct effects of temperature and indirect effects operating through eutrophication, water level changes, stratification and salinisation. We reviewed published and new long-term (10-100 years) fish data series from 24 European lakes (area: 0.04-5648 km 2 ; mean depth: 1-177m; a north-south gradient from 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 4 Sweden to Spain). Along with an annual temperature increase of about 0.15-0.3 °C per decade profound changes have occurred in either fish assemblage composition, body size and/or age structure during recent decades and a shift towards higher dominance of eurythermal species.These shifts have occurred despite a reduction in nutrient loading in many of the lakes that should have benefited the larger-sized individuals and the fish species typically inhabiting cold-water, low-nutrient lakes. The cold-stenothermic Arctic charr has been particularly affected and its abundance has decreased in the majority of the lakes where its presence was recorded. The harvest of cool-stenothermal trout has decreased substantially in two southern lakes. Vendace, whitefish and smelt show a different response depending on lake depth and latitude. Perch has apparently been stimulated in the north, with stronger year classes in warm years, but its abundance has declined in the southern Lake Maggiore, Italy. Where introduced, roach seems to take advantage of the higher temperature after years of low population densities. Eurythermal species such as common bream, pike-perch and/or shad are apparently on the increase in several of the lakes. The response of fish to the warming has been surprisingly strong and fast in recent decades, making them ideal sentinels for detecting and documenting climate-induced modifications of freshwater ecosystems.

Is Recovery of Large-Bodied Zooplankton after Nutrient Loading Reduction Hampered by Climate Warming? A Long-Term Study of Shallow Hypertrophic Lake Søbygaard, Denmark

“…The shift from large to small species indicates enhanced fish predation on large-bodied zooplankton [13,60], which coincides well with the increased catches of small planktivorous fish in the lake. Less frequent surveys of other similar Danish shallow lakes have also pointed towards reduced fish size despite nutrient loading reduction and this has been implicated to multiple effects of warming [25]. Accordingly, we found that summer air temperatures, especially in April where fish are spawning, have become warmer in the region during the study period, and the changes were significantly correlated with the abundances of small (positive) and large fish (negative).…”

Environmental Impacts—Lake Ecosystems

“…The harvest of whitefish Coregonus spp. has declined substantially in Lake Vättern in Sweden and Lake Peipsi in Estonia (Kangur et al 2007;Jeppesen et al 2012). In the UK and Ireland, a decline in the coregonid pollan Coregonus autumnalis in recent decades has been attributed to changes in temperature (Harrod et al 2002).…”

“…A drastic reduction in the population of smelt has occurred in shallow Lake Peipsi as shown from commercial fishing, with the decline particularly strong in years with heat waves (Kangur et al 2007;Jeppesen et al 2012). In contrast, the abundance of eurythermal species, including the thermo-tolerant carp Cyprinus carpio (Lehtonen 1996;Jeppesen et al 2012) is rising in several lakes in the North Sea region .…”

“…Even within species such differences can be seen along a latitudinal gradient (Blanck and Lamouroux 2007) and within North Temperate lakes (Jeppesen et al 2010b). Thus, changes in life history and size can be expected with warming, and may in fact already have occurred (Daufresne et al 2009;Jeppesen et al 2010bJeppesen et al , 2012.…”

International Perspectives on the Effects of Climate Change on Inland Fisheries

“…Over the last 40 years, water temperature has increased by about 1.5°C (Jeppesen et al 2012), and populations of several species including European Whitefish (Thomas et al 2010) and European Perch (Eckmann et al 2006) have changed. Recently, fisheries yields have decreased drastically (Rösch 2014), and in 2015 yield fell by approximately 50% from the already low yield of 2014.…”