Next Article in Journal
Wood Waste Recycling in Sweden—Industrial, Environmental, Social, and Economic Challenges and Benefits
Previous Article in Journal
Traffic Safety, Fuel Tax Intensity and Sustainable Development Efficiency of Transportation: Evidence from China
Previous Article in Special Issue
Trace Metals in Phytoplankton: Requirements, Function, and Composition in Harmful Algal Blooms
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Sustainability
Volume 16
Issue 14
10.3390/su16145932
sustainability-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Resilience Approach for Assessing Fish Recovery after Compound Climate Change Effects on Algal Blooms

by
Sascha Starck
* and
Christian Wolter
Department of Fish Biology, Fisheries and Aquaculture, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), 12587 Berlin, Germany
*
Author to whom correspondence should be addressed.
Sustainability 2024, 16(14), 5932; https://doi.org/10.3390/su16145932
Submission received: 21 May 2024 / Revised: 2 July 2024 / Accepted: 9 July 2024 / Published: 11 July 2024
(This article belongs to the Special Issue Sustainable Aquatic Food Systems: Harmful Algal Bloom Consequences in a Changing Climate)
Browse Figures
Review Reports Versions Notes

Abstract

:
In Europe, climate change will increase hydrologic extremes, resulting in shorter flood peaks and longer droughts. Extended low flows will significantly alter physico-chemical water quality, paving the way for compound, novel impacts. We analyze the Oder River catastrophe of August 2022, where the complex interplay of increased salinity, temperature, low flows, reduced water volumes and sunlight enabled Prymnesium parvum blooming. This brackish water alga grew to 100 million cells per liter and killed about 1000 tons of fish. We assess the impact on and the recovery potential of the fish population to guide both preventing future catastrophes and enhancing river resilience. Stock decline rates were assessed while accounting for natural population fluctuations. Significant relative declines in both fish and biomass density reached up to 76% and 62%, respectively. The mid-channel was more severely affected than littoral areas. Littoral shelter, depth variability, and especially lateral and longitudinal connectivity appeared essential for fish survival and recovery. The compound nature of this catastrophic event highlights the urgent need to rethink the present mismanagement of rivers. Resilient rivers are the backbone of climate change-resilient landscapes. Therefore, we argue for holistic approaches to water resource management, aiming to increase the resilience of aquatic ecosystems.

1. Introduction

Climate change globally alters the status, processes and dynamics of terrestrial, freshwater, and marine ecosystems, e.g., [1]. Temperature is predicted to increase globally, leading to higher evaporation, more humid air and changes in precipitation regimes [1]. In Europe, these seasonal precipitation shifts will lead to earlier spring and later winter floods [2]. Rivers in the northeastern German lowlands already face increasing trends in the duration and severity of low flows [3]. While the annual mean precipitation has changed less than 0.2% during the last century, its seasonality has substantially shifted from summer (−4%) to winter (+3%) [4]. Climate predictions for the region (IPCC scenario A1B) expect precipitation to increase by 10–20% in winter and to decrease by 10–30% in summer until 2100 [4] (correspondingly, by using IPCC scenario A1B and regional climate models). For the German parts of the Danube, Elbe, Ems, Rhine and Weser rivers, a 20–40% precipitation increase in winter and a 20% decrease in summer for the period 2061–2090 relative to 1981–2010 have been predicted [5]. Accordingly, the length of dry periods will increase from 20% to more than 50% in summer [6].
Despite the global temperature increase still being below the 1.5 K target [1], many river systems are already significantly impacted, because numerous human alterations amplify the climate change effects (e.g., [7]). River regulation by dams significantly increases water temperatures [8]. For example, in the regulated Danube and Elbe rivers, heat stress and the number of days with ≥25 °C water temperature has increased, while spring warming has shifted to two weeks earlier [9]. Higher water temperatures increase the virulence of pathogens and the prevalence of diseases and parasites [10,11,12]. In addition, worldwide, most rivers have become regulated, straightened and shortened, resulting in accelerated flow speeds and depth incisions followed by floodplain dewatering at lower discharges (e.g., [13,14,15]). In straightened incised rivers, flood waves will propagate faster, followed by longer lasting droughts, with impact severity related to drought duration [16]. Correspondingly, droughts and heat waves were identified as major factors deteriorating river water quality [17]. Increasingly, lower discharges have less dilution capacity, which will create challenges in maintaining or improving water quality [17,18,19].
Low discharges in combination with high temperatures, which are inversely related to the dissolved oxygen content, may induce novel, so-far-unexpected, ecological consequences, including harmful algae blooms (HABs). For example, in the River Oder, a large lowland river at the border between Germany and Poland, conductivity has increased by 5.1% per year in the period 2013–2022, with mean values above 1000 µS/cm (25 °C) since 2015 [20]. Since 2006 and 2014, respectively, Poland has not met its threshold value for conductivity (850 µS/cm), and nor has Germany for chloride (200 mg/L) [20,21]. However, the higher conductivity resulting from sodium chloride discharges has received rather little attention over the years, because, albeit well above typical values for large freshwater rivers (300–800 µS/cm), such salinity values were not dangerous for aquatic organisms. However, in August 2022, the complex interplay of salinity, low discharge, high water retention time, high temperatures, sunlight and nutrients allowed for a massive algae bloom (more than 100,000,000 cells per liter) of the brackish water species Prymnesium parvum in the River Oder. Globally, high cell densities of Prymnesium parvum have been linked to multiple large-scale fish kill events [22]. The brackish water alga Prymnesium parvum is able to produce prymnesin-type toxins, which have lethal hemolytic impacts on fish, mussels, and gill-breathing snails [23,24,25]. In the Oder River, the compound effects causing the Prymnesium parvum bloom resulted in an unprecedented massive fish kill—with an estimated 1000 t lost over 200 river kilometers—in August 2022.
HABs are globally increasing [26,27], with about 60–80 species known for their toxicity [28]. Prymnesium parvum is one of the most harmful algal species and is well known for causing HABs. Fish kills in the Netherlands in the early 1900s were later attributed to this species [29]. HABs of Prymnesium parvum have also been reported in Norway, Denmark, and North America [30], whereas a fish-killing algae bloom in the Kleiner Jasmunder Bodden lagoon at the German Baltic coast in 1990 has been attributed to Prymnesium saltans [31]. Irrespective of their global increase, HABs in flowing river systems seem rather uncommon, because both low water retention time and high turbulence hamper algae growth [28].
This study uses a resilience approach to assess the consequences of the River Oder catastrophe for the fish population as well as its recovery potential. Resilience considers the process-based response to environmental fluctuations resulting in natural variation [32]. The two pillars of resilience resistance and recovery are mediated by refuges and dispersal, respectively [33], which are both explicitly considered here. Resilient rivers should allow for quick recovery but also mitigate toxin impacts by providing refuge areas and escape routes. The assessment is based on long-term data on fish community composition since 1998, which allows for disentangling fish losses caused by the catastrophic event from natural population fluctuations [34].
This study aims to explore varying impacts on potamal and littoral fish communities, as well as potential disparities between upstream and downstream river sections. Based on the trajectory of the algae bloom and typical mixing processes in rivers, it was hypothesized that (i) potamal fish species have been affected most and typical littoral fish species least, and that (ii) upstream river sections were more affected than downstream river sections. Applying the resilience approach, it was further hypothesized that (iii) fish disperse from upstream to downstream sections and (iv) move laterally to structured littoral habitats to seek refuge.

2. Materials and Methods

2.1. Study Area

The 854 km long River Oder is the only large Central European river that is free flowing over its lowermost 500 km, without any migration obstacle to the Baltic Sea. This allows for the unhindered immigration and emigration of migratory fish species and for natural fish population dynamics in response to discharge variations. These movement opportunities provide resilience against and foster recovery after disturbances [33]. The free-flowing river section was also crucial for assigning the River Oder to a core area to reintroduce the Baltic sturgeon Acipenser oxyrhinchus [35].
The study was performed in the German part of River Oder between the mouth of the tributary River Neisse at Oder-km 542.4 and the split of the main river into an eastern and western branch at Oder-km 704.1 (Figure 1). The whole river stretch was affected by the fish kill in August 2022. When the river enters the German territory, it is about 80–100 m wide with a 287 m3/s average discharge (years 1981–2010, gauging station Eisenhüttenstadt). At the confluence with the largest tributary, River Warta (Oder-km 617.6), the catchment area, discharge and river width nearly double. The average discharge at gauging station Hohensaaten-Finow is 500 m3/s (years 1981–2010).
The River Warta tributary separates the hydromorphologically different river sections: middle Oder (upstream of the confluence, coming from south) and lower Oder (downstream the confluence flowing northwards) (Figure 1).
Both river sections belong to distinct fish zones, with middle Oder representing the lowland barbel zone and lower Oder the common bream zone [34]. In each zone, the study sites were chosen to be evenly distributed, consistent with other sampling efforts, to allow for transferability between datasets and projects and ensure the representation of all habitat types along the German–Polish river.

2.2. Fish Sampling

The lower and middle sections of the River Oder have been comparably sampled since 1998 and 2006, respectively. Because large rivers offer two main macrohabitats hosting varying species assemblages, with some potamal species preferring the mid-channel section, complementary methods were applied to representatively sample both bank-line and mid-channel habitats [34]. The mid-channel was sampled by trawling, and the bank line was sampled by boat electric fishing.
Trawling was performed using a bottom otter trawl with an 8 × 1.5 m (width × height) net opening and 10 mm mesh size in the cod end, pulled downstream at an 8 km/h speed over ground. Each haul was 1000–2000 m long [34]. Boat electric fishing was performed in a single pass, without stop nets, in an upstream direction, using generator-powered DC electric fishing gear (Type FEG 8000, EFKO-GmbH, Leutkirch, Germany) with a handheld 0.4 m diameter towed ring anode. The usual length fished was at least 400 m, or the complete bank length if a particular bank site was shorter (details in [34]). The sampling time for a 400 m stretch is on average 30 min but is heavily depending upon fish abundance. The average time spent for a trawl is around 10 min. All captured fish were identified, measured for total length and weighed, or body mass was back-calculated from length.
In total, 1103 trawl samples (352 in the middle River Oder and 751 in the lower River Oder) were taken before the fish kill in August 2022, and 93 were taken thereafter (25 in the middle River Oder and 68 in the lower River Oder), until November 2023. Along the banks. in total. 264 samples were taken by electric fishing (99 in the middle River Oder and 165 in the lower River Oder) before the event, and 52 were taken thereafter (27 in the middle River Oder and 25 in the lower River Oder). The period before August 2022 was sampled between June 1998 and May 2022. Samples after the catastrophe were taken between the end of September 2022 and November 2023.

2.3. Data Analysis

Prior analyses of all catches were standardized to find the catch per unit effort (CPUE) according to biomass and fish density, in kilograms, as well as the individuals per hectare fished (kg/ha, CPUEkg and Ind./ha, CPUEInd) respectively. Empirical ecological data are commonly non-normally distributed, with high variances and variance heterogeneity between groups [36,37]. Therefore, a bootstrapping approach was chosen to test for differences between river sections and main habitats [38]. Welch’s test was used to test for significant changes before and after the catastrophe, and Cohen’s d was extracted afterwards. Both fishing methods were separately analyzed because they sampled distinct macrohabitats and differ in gear specific selectivity [39,40,41]. For each macrohabitat, the most common representative species according to [34] were separately analyzed: in the mid-channel, we analyzed silver bream (Blicca bjoerkna), river gudgeon (Romanogobio belingi), common bream (Abramis brama) and blue bream (Ballerus ballerus), and along the banks, we analyzed bleak (Alburnurs alburnus), roach (Rutilus rutilus), burbot (Lota lota), perch (Perca fluviatilis) and gudgeon (Gobio gobio). In addition, individual densities were analyzed for ide (Leuciscus idus), barbel (Barbus barbus), bitterling (Rhodeus amarus), chub (Squalius cephalus), common dace (Leuciscus leuciscus), pike (Esox lucius), ruffe (Gymnocephalus cernua), asp (Leuciscus aspius), rudd (Scardinius erythrophthalmus), tench (Tinca tinca), stone loach (Barbatula barbatula), spined loach (Cobitis taenia), vimba (Vimba vimba), and pikeperch (Sander lucioperca) to assess distributional changes in species because of the algae bloom. All listed species are native to the River Oder.
Bootstrapping was performed using R (RStudio 2022.12.0+353 “Elsbeth Geranium” Release (3 December 2022) for Windows). Plots were generated using the “ggplot2” package [42], which supports enhanced visual data representations. The significance level for all tests was set at α < 0.05.

3. Results

In total, 225,607 fish of 36 species were sampled by electric fishing and 122,258 fish of 39 species were sampled by trawling before August 2022. After the massive fish kill, the much-lower number of samples yielded 61,725 fish of 32 species sampled by electric fishing and 2734 fish of 22 species sampled by trawling. All species present before August 2022 were also recorded afterwards. The complete checklist of species recorded is provided as Supplementary Material (Table S1).

3.1. Abundance

Fish densities expressed as CPUEInd significantly declined in most habitats studied, except along the banks in the lower River Oder, where an 18.5% relative increase was found (Figure 2). The middle River Oder was more affected compared to the lower stretch, with significant, high relative species declines in all macrohabitats (Figure 2). In general, in the mid-channel, relative fish losses were higher compared to along the banks.
In the mid-channel section, typical potamal species experienced significant relative losses >70%, especially in the middle River Oder (Table 1). Only the density of Ballerus ballerus was in the range of its natural variation and did not significantly differ.
Overall, the middle River Oder experienced more severe CPUEInd reduction than the lower River Oder, which was indicated by both relative change in densities and Cohen’s d, with the latter being >0.4 for all species. In the middle River Oder, the significant relative declines ranged between −88.01% for Abramis brama and −92.9% for Romanogobio belingi (Table 1).
Similar trends were observed for species preferring the littoral zone. In the middle River Oder, the densities of all species were significantly reduced by 54.5% after the event (Figure 2), whereas in the lower River Oder, especially Alburnurs alburnus and Gobio gobio relatively increased in density by 297% and 327%, respectively (Table 2). This increase resulted in the observed overall positive tendency of fish densities along the banks in the lower River Oder (Figure 2).
In the lower River Oder, only the density of Lota lota significantly declined by −97.0%. Similar to the mid-channel habitats, along the banks, relative losses in fish densities were also substantially higher in the middle River Oder compared to the lower River Oder, as indicated by the percentage change and Cohen’s d values.

3.2. Biomass

Biomass densities, calculated as CPUEkg, significantly declined in most studied habitats, except in the lower River Oder’s mid-channel, where the 21.9% decline was not significant. Again, the middle River Oder was more severely affected, with significant fish biomass decline in both macrohabitats (Figure 3). Overall, the relative loss in fish biomass was higher along the banks compared to the mid-channel.
Typical potamal species experienced significant relative losses in biomass, which was especially pronounced in the middle River Oder (Table 3). Romanogobio belingi experienced a nearly complete decline, with a 99.4% relative loss in the lower River Oder. Abramis brama showed a significant relative reduction in the middle River Oder (−80.6%) but not the lower River Oder (Table 3). Ballerus ballerus biomass did not significantly change.
In the littoral zone, varying tendencies of relative biomass change were observed. While Alburnurs alburnus and Gobio gobio biomass did not substantially change in the middle River Oder, both species significantly increased by 203% and 1374,2%, respectively, in the lower part (Table 4). Comparable results were obtained for Rutilus rutilus and Perca fluviatilis, which both significantly declined in the middle reach and non-significantly increased in the lower River Oder. Lota lota was the only species significantly declining in biomass everywhere in the German river stretch (Table 4).

3.3. Distribution Changes

Based on relative increases in fish densities, changes in species distribution were identified in response to the toxic algae bloom (Table 5). Shifts in relative abundances indicate the main dispersal processes (i) of potamal species from the mid-channel to littoral refuges, e.g., Barbus barbus, Gymnocephalus cernua and Sander lucioperca in the middle River Oder, and especially (ii) of most species from upstream to downstream river sections. For example, Barbus barbus and Vimba vimba seemingly immigrated from the Polish river section to the banks of the middle River Oder, whereas Leuciscus aspius, Squalius cephalus and Leuciscus idus quite obviously moved from the middle to the lower River Oder, as indicated by relative abundance increase downstream (Table 5).

4. Discussion

Overall, the relative losses in both fish and biomass densities were substantial. In support of the first hypothesis, the relative losses were significantly higher in the middle River Oder. This river stretch is narrower and has lower discharge and potentially less refuges, which might have contributed to higher relative losses. The middle River Oder was first hit by the downstream propagating toxic algae bloom, with the latter further diluted by the River Warta discharge, which additionally explains the relatively lower impacts on fish in the lower River Oder. It must be noted that the relative losses in fish and biomass densities cannot be directly compared between both fish zones. While several potamal, mid-channel species typically show higher densities in the lower River Oder, other littoral habitat-preferring species were more abundant in the middle River Oder (Table 1 and Table 2). Therefore, the relative gains and losses species-specifically refer to different empirical fish densities. However, these species-specific variations between absolute and relative fish losses do not question the significance of the negative impact of the August 2022 fish kill on the fish assemblage. The overall fish densities along the banks were substantially higher in the middle River Oder compared to the lower stretch before the event, so the high relative losses therein correspond to significant absolute negative impacts on the fish assemblage of the lowland barbel region.
In both river stretches, the losses observed in the mid-channel habitat were higher compared to the bank habitat, which supports the second hypothesis. This was further underlined by relatively higher biomass declines compared to abundance changes along the banks, which were especially pronounced in the lower River Oder. Bigger fish tend to orientate more toward the mid-channel during the day [34], which automatically meant they were closer to the algae bloom. In the mid-channel section, the water column was fully mixed. Despite some refuges at the river bottom, fish in the mid-channel were fully exposed to the toxic algae bloom. In contrast, along the banks, wide reed belts probably prevented the complete mixing and intrusion of toxic algae into the very shallow littoral areas. This explains the high densities of mainly juvenile fish along the banks, especially in the lower River Oder after the catastrophe. More generally, this finding indicates the importance of structural complexity, width and depth variability for providing refuges and enhancing the resilience of aquatic communities to water quality stressors.
The River Oder is a free-flowing river without any migration obstacles, so fish can move downstream in low water conditions and thus behaviorally respond to changing discharge conditions, as well as to pollutants [33,43,44]. It must be assumed that many fish escaped by moving downstream to the lowermost river sections, which were not reached by the toxic algae bloom in August 2022. It was further expected that many fish moved on to overwintering sites or started overwintering in the refuges, with very little motivation to return to upstream river sections. This outmigration of fish potentially resulted in an overestimation of killed fish. Therefore, this study combined fish samples obtained in autumn 2022, immediately after the catastrophe, with samples from spring and autumn 2023 to account for spawning migrations and the repopulation of the River Oder from tributaries and the unaffected downstream section. Ballerus ballerus seems to exactly represent this strategy. Although being a potamal, mid-channel species and potentially highly exposed to the algae toxin, no significant differences in fish and biomass densities were observed before and after the catastrophe in August 2022. While we missed Ballerus ballerus in the mid-channel trawl samples in November 2022 a substantial spawning run was observed in Spring 2023, indicating successful escapement and reimmigration. Similar migrations were probably performed by all large-bodied species. Pooling the data after the event accounts for outmigration and reimmigration might mask delayed mortality and increased overwintering mortality because of sublethal toxic effects. Thus, potential species turnover from Autumn 2022 to Spring 2023 remains unknown. Besides this limitation, the occurrence of all species with mature individuals and their high recruitment potential [33,45] will allow for recovery from the fish kill within 2–3 years. The recovery of fisheries’ relevant size classes will take longer. These findings empirically support two out of the three Rs of river resilience: refugia promoting functional redundancy, and recruitment and recolonization promoted by lateral and longitudinal connectivity [33].
It is known that undisrupted river flow highly contributes to river resilience. Furthermore, connected floodplains and side waters strengthen riverine ecosystems for protection against disturbances [46]. In contrast, river management for both inland navigation and technical flood protection still tends towards channelization, straitening and deepening [14,15], at the expense of rivers’ resilience against disturbances. In a changing climate, traditional river engineering and maintenance will accelerate flood pulses and drought durations [16], which will potentially result in novel interactions of environmental factors, leading to compound effects like the one analyzed here, which might even increase in frequency and severity.
In the River Oder, the interplay of salinity, sunlight exposure, high water retention time, low discharge, high temperatures, and high nutrient loadings allowed for a brackish water alga bloom that caused an unprecedented fish kill. Analyzing this compound impact shows, on the one hand, that preconditions for similar events in the future will increase with the changing climate and require more attention in management and research. On the other hand, this study showed that resilient riverine ecosystems might prevent such impacts but will definitely support the resistance and recovery of aquatic communities.
Salinity is increasingly recognized as a critical factor influencing the occurrence and severity of harmful algae blooms. Studies have documented the adaptability of Prymnesium parvum to varying salinity levels, revealing a better understanding of its growth, toxicity, and bloom dynamics [47,48]. However, more research is needed to unravel the factors causing toxin production by Prymnesium parvum [49]. Shifting climate patterns affect water temperature, flow regimes, and salinity levels, with longer, more-severe droughts potentially enhancing favorable conditions for toxic algae blooms. The compound effects of these environmental changes, coupled with anthropogenic pressures, will increase the risk of catastrophic impacts similar to the River Oder event. It is imperative to integrate climate change projections into management and mitigation strategies to ensure the resilience of riverine ecosystems to future ecological threats.
As empirically evidenced here, fluvial processes and unhindered functional longitudinal and lateral connectivity provide resistance against and recovery from disturbances, i.e., the resilience of aquatic communities, in particular of mobile taxa such as fishes. Accordingly, the European Green Deal, which aims, among other things, for at least an additional 25,000 km of free-flowing rivers, exactly addresses the critical component of aquatic biodiversity in resilient rivers and the unhindered functional connectivity of major habitats.

5. Conclusions

In the River Oder, the fish kill was caused by the toxin-producing brackish water alga Prymnesium parvum. That this brackish water species can bloom in freshwaters was primarily caused by saltwater discharge and thus was man-made. While salinity levels were not at all harmful for fish and thus not addressed by management actions, they indirectly promoted novel, potentially toxic organisms. The River Oder catastrophe has now raised awareness for high salinity levels. This needs to be turned into discharge regulations that account for maximum acceptable concentrations instead of discharge-independent loads.
Besides nutrients and sunlight, the most important element for algae development is water retention time. Massive algae blooms are well-known in eutrophic lakes but very uncommon in rivers. Impoundments created by barriers, another human intervention, lower flow velocities and increase water retention times, especially during periods of low discharge, which usually occur in summer, when high temperatures and sunlight support algae growth. Therefore, both damming and river regulation will accelerate the predicted impacts of climate change, like higher temperatures and longer droughts, with detrimental impacts on river resilience.
Climate change is predicted to shift precipitation seasonality with increased low flow periods in summer. Increased droughts increase water retention time and lower the dilution capacity of rivers for all sorts of effluents received, which pave the way for novel impacts that are not yet deemed relevant or are not even recognized.
Fish are mobile, highly fertile organisms with high recovery potential. However, fishes’ inherent recovery traits depend on functional connectivity to shelter habitats, i.e., on free-flowing, diversely structured rivers with well-developed lateral and longitudinal connectivity. The middle and lower River Oder is the last large Central European free-flowing river supporting lateral and (especially) longitudinal connectivity, which is probably the reason that the whole fish-species inventory is still present, even if at species-specifically lower abundance, and that the fish community will recover, as long as the catastrophe does not repeat.
Preventing similar catastrophes not only in the River Oder in the longer run requires enhancing the resilience of rivers to impacts of changing climate, e.g., by revitalizing natural flow dynamics and hydromorphologic processes as well as natural flood protection and water retention in the landscape. The importance of free-flowing rivers for resilient biodiverse aquatic communities has been empirically evidenced by analyzing the recovery potential of the fish community after the River Oder catastrophe. From the results, two practical management implications can be derived: First, in the short run, efforts need to be increased to further reduce nutrient loads and conductivity, especially during elongated periods of low flow. To achieve this, discharge permits must be changed from regulating loads to discharge to maximum allowable concentrations in the receiving water body. Second, in the middle and long run, the resilience of rivers needs to be enhanced by rehabilitating hydromorphologic processes that generate structural complexity and allow for depth and width variability, island creation and anabranching to create functionally connected refuges and resources.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/su16145932/s1, Table S1: Checklist of fish and lamprey species recorded during scientific assessments in the German stretch of River Oder since 1998.

Author Contributions

S.S.: Data Curation, Formal analysis, Investigation, Visualization, Writing—Original Draft, C.W.: Conceptualization, Funding acquisition, Supervision, Validation, Resources, Writing—Review and Editing. All authors have read and agreed to the published version of the manuscript.

Funding

Collecting long-term fish community data was supported by numerous projects and substantial in-house contribution from the Leibniz Institute of Freshwater Ecology and Inland Fisheries. Data analyses and littoral fish sampling after the catastrophe were conducted as part of the project ODER~SO financed by the German Federal Agency for Nature Conservation (BfN-3523570100) with funds from the German Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV).

Data Availability Statement

The raw data supporting the conclusions of this article will be made available by the authors on request.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Intergovernmental Panel on Climate Change (IPCC). Climate Change 2022—Impacts, Adaptation and Vulnerability: Working Group II Contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change, 1st ed.; Cambridge University Press: Cambridge, UK, 2023; ISBN 978-1-00-932584-4. [Google Scholar]
  2. Blöschl, G.; Hall, J.; Parajka, J.; Perdigão, R.A.P.; Merz, B.; Arheimer, B.; Aronica, G.T.; Bilibashi, A.; Bonacci, O.; Borga, M.; et al. Changing Climate Shifts Timing of European Floods. Science 2017, 357, 588–590. [Google Scholar] [CrossRef] [PubMed]
  3. Bormann, H.; Pinter, N. Trends in Low Flows of German Rivers since 1950: Comparability of Different Low-flow Indicators and Their Spatial Patterns. River Res. Appl. 2017, 33, 1191–1204. [Google Scholar] [CrossRef]
  4. Cubasch, U.; Kadow, C. Global Climate Change and Aspects of Regional Climate Change in the Berlin-Brandenburg Region. DIE ERDE–J. Geogr. Soc. Berl. 2019, 142, 3–20. [Google Scholar] [CrossRef]
  5. Hattermann, F.F.; Huang, S.; Koch, H. Climate Change Impacts on Hydrology and Water Resources. Meteorol. Z. 2015, 24, 201–211. [Google Scholar] [CrossRef]
  6. Garack, S.; Wollrab, S.; Jähnig, S.; Günther, K.; Berger, S.A.; Neubert, M.; Albrecht, J.; Friedrichs-Manthey, M.; Sauer, A.; Kirillin, G. Entwicklung Der Ökologischen Beschaffenheit von Oberflächengewässern Im Klimawandel; Umweltbundesamt: Dessau-Roßlau, Germany, 2022; pp. 98–107. [Google Scholar] [CrossRef]
  7. Mantyka-Pringle, C.S.; Martin, T.G.; Moffatt, D.B.; Linke, S.; Rhodes, J.R. Understanding and Predicting the Combined Effects of Climate Change and Land-use Change on Freshwater Macroinvertebrates and Fish. J. Appl. Ecol. 2014, 51, 572–581. [Google Scholar] [CrossRef]
  8. Donadi, S.; Degerman, E.; McKie, B.G.; Jones, D.; Holmgren, K.; Sandin, L. Interactive Effects of Land Use, River Regulation, and Climate on a Key Recreational Fishing Species in Temperate and Boreal Streams. Freshw. Biol. 2021, 66, 1901–1914. [Google Scholar] [CrossRef]
  9. Markovic, D.; Scharfenberger, U.; Schmutz, S.; Pletterbauer, F.; Wolter, C. Variability and Alterations of Water Temperatures across the Elbe and Danube River Basins. Clim. Change 2013, 119, 375–389. [Google Scholar] [CrossRef]
  10. Franke, F.; Armitage, S.A.O.; Kutzer, M.A.M.; Kurtz, J.; Scharsack, J.P. Environmental Temperature Variation Influences Fitness Trade-Offs and Tolerance in a Fish-Tapeworm Association. Parasites Vectors 2017, 10, 252. [Google Scholar] [CrossRef]
  11. Guijarro, J.A.; Cascales, D.; García-Torrico, A.I.; García-Domínguez, M.; Méndez, J. Temperature-Dependent Expression of Virulence Genes in Fish-Pathogenic Bacteria. Front. Microbiol. 2015, 6, 700. [Google Scholar] [CrossRef]
  12. Waldner, K.; Bechter, T.; Auer, S.; Borgwardt, F.; El-Matbouli, M.; Unfer, G. A Brown Trout (Salmo trutta) Population Faces Devastating Consequences due to Proliferative Kidney Disease and Temperature Increase: A Case Study from Austria. Ecol. Freshw. Fish 2020, 29, 465–476. [Google Scholar] [CrossRef]
  13. Brookes, A. The Distribution and Management of Channelized Streams in Denmark. Regul. Rivers Res. Mgmt. 1987, 1, 3–16. [Google Scholar] [CrossRef]
  14. Petts, G.E.; Möller, H.; Roux, A.L. (Eds.) Historical Change of Large Alluvial Rivers: Western Europe; Wiley: Chichester, UK; New York, NY, USA, 1989; ISBN 978-0-471-92163-9. [Google Scholar]
  15. Tockner, K.; Zarfl, C.; Robinson, C.T. Rivers of Europe, 2nd ed.; Elsevier: Amsterdam, The Netherlands, 2022; ISBN 978-0-08-102613-7. [Google Scholar]
  16. Parasiewicz, P.; King, E.L.; Webb, J.A.; Piniewski, M.; Comoglio, C.; Wolter, C.; Buijse, A.D.; Bjerklie, D.; Vezza, P.; Melcher, A.; et al. The Role of Floods and Droughts on Riverine Ecosystems under a Changing Climate. Fish Manag. Ecol. 2019, 26, 461–473. [Google Scholar] [CrossRef]
  17. Van Vliet, M.T.H.; Thorslund, J.; Strokal, M.; Hofstra, N.; Flörke, M.; Ehalt Macedo, H.; Nkwasa, A.; Tang, T.; Kaushal, S.S.; Kumar, R.; et al. Global River Water Quality under Climate Change and Hydroclimatic Extremes. Nat. Rev. Earth Environ. 2023, 4, 687–702. [Google Scholar] [CrossRef]
  18. Arthington, A.H.; Kennen, J.G.; Stein, E.D.; Webb, J.A. Recent Advances in Environmental Flows Science and Water Management—Innovation in the Anthropocene. Freshw. Biol. 2018, 63, 1022–1034. [Google Scholar] [CrossRef]
  19. Li, L.; Knapp, J.L.A.; Lintern, A.; Ng, G.-H.C.; Perdrial, J.; Sullivan, P.L.; Zhi, W. River Water Quality Shaped by Land–River Connectivity in a Changing Climate. Nat. Clim. Change 2024, 14, 225–237. [Google Scholar] [CrossRef]
  20. Wiederhold, J.; Buchinger, S.; Düster, L.; Fischer, H.; Hahn, J.; Helms, M.; Hermes, N.; Jewell, K.; Kleinteich, J.; Krenek, S.; et al. Untersuchungen Zum Fischsterben in Der Oder Im August 2022: Bericht; Bundesanstalt für Gewässerkunde: Koblenz, Germany, 2023. [Google Scholar]
  21. Free, G.; Van de Bund, W.; Gawlik, B.; Van Wijk, L.; Wood, M.; Guagnini, E.; Koutelos, K.; Annunziato, A.; Grizzetti, B.; Vigiak, O.; et al. An EU Analysis of the Ecological Disaster in the Oder River of 2022: Lessons Learned and Research Based Recommendations to Avoid Future Ecological Damage in EU Rivers, a Joint Analysis from DG ENV, JRC and the EEA; Publications Office: Luxembourg, 2023. [Google Scholar]
  22. La, V.T.; Cooke, S.J. Advancing the Science and Practice of Fish Kill Investigations. Rev. Fish. Sci. 2011, 19, 21–33. [Google Scholar] [CrossRef]
  23. Brooks, B.W.; James, S.V.; Valenti, T.W., Jr.; Urena-Boeck, F.; Serrano, C.; Berninger, J.P.; Schwierzke, L.; Mydlarz, L.D.; Grover, J.P.; Roelke, D.L. Comparative Toxicity of Prymnesium Parvum. JAWRA J. Am. Water Resour. Assoc. 2010, 46, 45–62. [Google Scholar] [CrossRef]
  24. Granéli, E.; Salomon, P.S. Factors Influencing Allelopathy and Toxicity in Prymnesium Parvum. JAWRA J. Am. Water Resour. Assoc. 2010, 46, 108–120. [Google Scholar] [CrossRef]
  25. Guo, M.; Harrison, P.J.; Taylor, F.J.R. Fish Kills Related to Prymnesium Parvum N. Carter (Haptophyta) in the People’s Republic of China. J. Appl. Phycol. 1996, 8, 111–117. [Google Scholar] [CrossRef]
  26. Hallegraeff, G.M. A Review of Harmful Algal Blooms and Their Apparent Global Increase. Phycologia 1993, 32, 79–99. [Google Scholar] [CrossRef]
  27. Fu, F.-X.; Tatters, A.; Hutchins, D.A. Global Change and the Future of Harmful Algal Blooms in the Ocean. Mar. Ecol. Prog. Ser. 2012, 470, 207–233. [Google Scholar] [CrossRef]
  28. Smayda, T.J. Harmful Algal Blooms: Their Ecophysiology and General Relevance to Phytoplankton Blooms in the Sea. Limnol. Oceanogr. 1997, 42, 1137–1153. [Google Scholar] [CrossRef]
  29. Lutz-Carrillo, D.J.; Southard, G.M.; Fries, L.T. Global Genetic Relationships Among Isolates of Golden Alga (Prymnesium parvum). J. Am. Water Resour. Assoc. 2010, 46, 24–32. [Google Scholar] [CrossRef]
  30. Roelke, D.L.; Barkoh, A.; Brooks, B.W.; Grover, J.P.; Hambright, K.D.; LaClaire, J.W.; Moeller, P.D.R.; Patino, R. A Chronicle of a Killer Alga in the West: Ecology, Assessment, and Management of Prymnesium Parvum Blooms. Hydrobiologia 2016, 764, 29–50. [Google Scholar] [CrossRef]
  31. Kell, V.V.; Noack, B. Kurze Mitteilung: Fischsterben Durch Prymnesium saltans Massart Im Kleinen Jasmunder Bodden (Rügen) Im April 1990. J. Appl. Ichthyol. 1991, 7, 187–192. [Google Scholar] [CrossRef]
  32. Death, R.G. The Resilience of Riverine Ecological Communities. In Resilience and Riverine Landscapes; Elsevier: Amsterdam, The Netherlands, 2024; pp. 23–39. ISBN 978-0-323-91716-2. [Google Scholar]
  33. Van Looy, K.; Tonkin, J.D.; Floury, M.; Leigh, C.; Soininen, J.; Larsen, S.; Heino, J.; LeRoy Poff, N.; Delong, M.; Jähnig, S.C.; et al. The Three Rs of River Ecosystem Resilience: Resources, Recruitment, and Refugia: The Three Rs of River Resilience: Resources, Recruitment and Refugia. River Res. Appl. 2019, 35, 107–120. [Google Scholar] [CrossRef]
  34. Wolter, C.; Zahn, S.; Gessner, J. Entwicklung, Nutzung Und Schutz Der Fischfauna in Der Brandenburgischen Oder; Schriften Des Inst. Für Binnenfisch. E.V.: Potsdam-Sacrow, Germany, 2023; Volume 65, ISSN 1438-4876. [Google Scholar]
  35. Gessner, J.; Arndt, G.-M.; Kapusta, A.; Shibayev, S.; Gushin, A.; Pilinkovskij, A.; Povliūnas, J.; Medne, R.; Purvina, S.; Tambets, M.; et al. HELCOM Action Plan for the Protection and Recovery of the Baltic Sturgeon (Acipenser Oxyrinchus Oxyrinchus) in the Baltic Sea Area for the Period of 2019–2029; Baltic Sea Environment Proceedings 168; Baltic Marine Environment Protection Commission (Helsinki Commission/HEL-COM): Helsinki, Finland, 2019. [Google Scholar]
  36. Dutilleul, P.; Legendre, P. Spatial Heterogeneity against Heteroscedasticity: An Ecological Paradigm versus a Statistical Concept. Oikos 1993, 66, 152. [Google Scholar] [CrossRef]
  37. Hastings, A.; Hom, C.L.; Ellner, S.; Turchin, P.; Godfray, H.C.J. Chaos in Ecology: Is Mother Nature a Strange Attractor? Annu. Rev. Ecol. Syst. 1993, 24, 1–33. [Google Scholar] [CrossRef]
  38. Stine, R. An introduction to bootstrap methods: Examples and ideas. Sociol. Methods Res. 1989, 18, 243–291. [Google Scholar] [CrossRef]
  39. Achleitner, D.; Gassner, H.; Luger, M. Comparison of Three Standardised Fish Sampling Methods in 14 Alpine Lakes in Austria: Comparison of Fish Sampling Methods for Lakes. Fish. Manag. Ecol. 2012, 19, 352–361. [Google Scholar] [CrossRef]
  40. Fischer, J.R.; Quist, M.C. Characterizing Lentic Freshwater Fish Assemblages Using Multiple Sampling Methods. Environ. Monit. Assess. 2014, 186, 4461–4474. [Google Scholar] [CrossRef] [PubMed]
  41. Mueller, M.; Pander, J.; Knott, J.; Geist, J. Comparison of Nine Different Methods to Assess Fish Communities in Lentic Flood-Plain Habitats: Flood-Plain Monitoring Methods. J. Fish. Biol. 2017, 91, 144–174. [Google Scholar] [CrossRef]
  42. Wickham, H. Ggplot2: Elegant Graphics for Data Analysis, 2nd ed.; Use R!; Springer: Cham, Switzerland, 2016; ISBN 978-3-319-24275-0. [Google Scholar]
  43. Pearsons, T.N.; Li, H.W.; Lamberti, G.A. Influence of Habitat Complexity on Resistance to Flooding and Resilience of Stream Fish Assemblages. Trans. Am. Fish. Soc. 1992, 121, 427–436. [Google Scholar] [CrossRef]
  44. Marques, H.; Dias, J.H.P.; Perbiche-Neves, G.; Kashiwaqui, E.A.L.; Ramos, I.P. Importance of Dam-Free Tributaries for Conserving Fish Biodiversity in Neotropical Reservoirs. Biol. Conserv. 2018, 224, 347–354. [Google Scholar] [CrossRef]
  45. van Treeck, R.; Van Wichelen, J.; Wolter, C. Fish Species Sensitivity Classification for Environmental Impact Assessment, Conservation and Restoration Planning. Sci. Total Environ. 2020, 708, 135173. [Google Scholar] [CrossRef]
  46. Sedell, J.R.; Reeves, G.H.; Hauer, F.R.; Stanford, J.A.; Hawkins, C.P. Role of Refugia in Recovery from Disturbances: Modern Fragmented and Disconnected River Systems. Environ. Manag. 1990, 14, 711–724. [Google Scholar] [CrossRef]
  47. Hartman, K.J.; Wellman, D.I.; Kingsbury, J.W.; Cincotta, D.A.; Clayton, J.L.; Eliason, K.M.; Jernejcic, F.A.; Owens, N.V.; Smith, D.M. A Case Study of a Prymnesium Parvum Harmful Algae Bloom in the Ohio River Drainage: Impact, Recovery and Potential for Future Invasions/Range Expansion. Water 2021, 13, 3233. [Google Scholar] [CrossRef]
  48. Israël, N.M.D.; VanLandeghem, M.M.; Denny, S.; Ingle, J.; Patiño, R. Golden Alga Presence and Abundance Are Inversely Related to Salinity in a High-Salinity River Ecosystem, Pecos River, USA. Harmful Algae 2014, 39, 81–91. [Google Scholar] [CrossRef]
  49. Hill, P.R.; Kumar, A.; Temimi, M.; Bull, D.R. Machine Learning, Remote Sensing-Based Detection of Harmful Algal Blooms. IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens. 2020, 13, 3229–3239. [Google Scholar] [CrossRef]
Sustainability 16 05932 g001
Figure 1. Sampling sites along the German part of the Oder River. Tributary River Warta divides middle Oder (south) and lower Oder section (north); the green line indicates the National Park “Lower Oder Valley”.
Figure 1. Sampling sites along the German part of the Oder River. Tributary River Warta divides middle Oder (south) and lower Oder section (north); the green line indicates the National Park “Lower Oder Valley”.
Sustainability 16 05932 g001
Sustainability 16 05932 g002
Figure 2. Fish density distribution in different macrohabitats of both middle and lower River Oder before and after the fish kill in August 2022. Boxes represent 50% of all observations, whiskers represent 90%, the horizontal line represents the median and black triangles represent the mean (number next to it).
Figure 2. Fish density distribution in different macrohabitats of both middle and lower River Oder before and after the fish kill in August 2022. Boxes represent 50% of all observations, whiskers represent 90%, the horizontal line represents the median and black triangles represent the mean (number next to it).
Sustainability 16 05932 g002
Sustainability 16 05932 g003
Figure 3. Fish biomass density distribution in different macrohabitats of both middle and lower River Oder before and after the fish kill in August 2022. Boxes represent 50% of all observations, whiskers represent 90%, the horizontal line represents the median and black triangles represent the mean (number next to it).
Figure 3. Fish biomass density distribution in different macrohabitats of both middle and lower River Oder before and after the fish kill in August 2022. Boxes represent 50% of all observations, whiskers represent 90%, the horizontal line represents the median and black triangles represent the mean (number next to it).
Sustainability 16 05932 g003
Table 1. Densities (CPUEInd) of typical potamal fish species in the mid-channel of River Oder before and after the fish kills in August 2022. LO = lower River Oder, MO = middle River Oder, sd = standard deviation, n = number of hauls, bold numbers highlight significant results.
Table 1. Densities (CPUEInd) of typical potamal fish species in the mid-channel of River Oder before and after the fish kills in August 2022. LO = lower River Oder, MO = middle River Oder, sd = standard deviation, n = number of hauls, bold numbers highlight significant results.
Before August 2022After August 2022Statistics
SpeciesRegionMeansdnMeansdnChange [%]Cohens dp-Value
Blicca bjoerknaLO76.52220.0985521.5766.6939−71.80.2550.0261
MO17.5240.723521.531.3918−91.20.402<0.005
Romanogobio belingiLO9.6829.748550.060.2839−99.40.3300.0499
MO3.969.203520.280.5318−92.90.410<0.005
Abramis bramaLO20.1644.6885510.5420.2539−47.70.2190.068
MO3.517.853520.420.6118−88.00.404<0.005
Ballerus ballerusLO10.2842.8685511.4411.863911.3-0.7454
MO15.80122.3335212.0810.0218−23.5-0.7684
Table 2. Densities (CPUEInd) of typical littoral fish species along the River Oder banks before and after the fish kills in August 2022. LO = lower River Oder, MO = middle River Oder, sd = standard deviation, n = number of hauls, bold numbers highlight significant results.
Table 2. Densities (CPUEInd) of typical littoral fish species along the River Oder banks before and after the fish kills in August 2022. LO = lower River Oder, MO = middle River Oder, sd = standard deviation, n = number of hauls, bold numbers highlight significant results.
Before August 2022After August 2022Statistics
SpeciesRegionMeansdnMeansdnChange [%]Cohen’s dp-Value
Alburnurs alburnusLO654.621850.392272599.034376.2719297.0−0.908<0.005
MO2323.216986.11100649.12885.6616−72.10.2570.041
Rutilus rutilusLO1320.372706.922271313.641302.1519−0.5-0.9897
MO1660.271571.95100608.72387.2716−63.30.715<0.005
Lota lotaLO515.28626.3122715.4525.4719−97.00.8290.0015
MO48.8790.521002.086.4516−95.70.554<0.005
Perca fluviatilisLO838.021332.53227813.54986.2719−2.9-0.9259
MO635.731070.30100162.46211.6416−74.40.473<0.005
Gobio gobioLO71.03278.73227303.55405.4419327.4−0,820.0053
MO1093.683329.56100228.47295.9416−79.10.2790.033
Table 3. Biomass (CPUEkg) of typical potamal fish species in the mid-channel of River Oder before and after the fish kills in August 2022. LO = lower River Oder, MO = middle River Oder, sd = standard deviation, n = number of hauls, bold numbers highlight significant results.
Table 3. Biomass (CPUEkg) of typical potamal fish species in the mid-channel of River Oder before and after the fish kills in August 2022. LO = lower River Oder, MO = middle River Oder, sd = standard deviation, n = number of hauls, bold numbers highlight significant results.
Before August 2022After August 2022Statistics
SpeciesRegionMeansdnMeansdnChange [%]Cohen’s dp-Value
Blicca bjoerknaLO9.1730.648552.578.0239−72.00.2200.0342
MO3.216.603520.320.4018−90.00.448<0.005
Romanogobio belingiLO0.060.218550.000.0039−99.40.268<0.005
MO0.030.073520.000.0118−90.00.384<0.005
Abramis bramaLO12.8233.7885512.2223.5539−4.7-0.8968
MO3.929.753520.761.3618−80.60.3330.012
Ballerus ballerusLO3.7916.648554.664.853923.0-0.5192
MO5.3638.853525.594.66184.3-0.9554
Table 4. Biomass (CPUEkg) of typical littoral fish species along the River Oder banks before and after the fish kills in August 2022. LO = lower River Oder, MO = middle River Oder, sd = standard deviation, n = number of hauls, bold numbers highlight significant results.
Table 4. Biomass (CPUEkg) of typical littoral fish species along the River Oder banks before and after the fish kills in August 2022. LO = lower River Oder, MO = middle River Oder, sd = standard deviation, n = number of hauls, bold numbers highlight significant results.
Before August 2022After August 2022Statistics
SpeciesRegionMeansdnMeansdnChange [%]Cohen’s dp-Value
Alburnurs alburnusLO1.642.972274.976.9019203.0−0.976<0.005
MO3.516.171002.636.1616−25.1-0.655
Rutilus rutilusLO15.7018.7022716.7414.40196.6-0.7675
MO18.7119.551005.525.3816−70.50.7200.012
Lota lotaLO22.5025.752270.330.8819−98.50.8950.0012
MO1.672.961000.260.7616−84.40.511<0.005
Perca fluviatilisLO14.2019.6322715.3820.34198.3-0.8250
MO17.9837.291003.174.3016−82.40.4100.006
Gobio gobioLO0.311.172274.5711.86191374.2−1.25<0.005
MO2.845.091001.742.4216−38.7-0.260
Table 5. Shifts of relative individual densities (ind/ha) between middle and lower River Oder and along mid-channel and littoral areas before and after August 2022. Relative gains and losses are color-coded.
Table 5. Shifts of relative individual densities (ind/ha) between middle and lower River Oder and along mid-channel and littoral areas before and after August 2022. Relative gains and losses are color-coded.
Middle River OderLower River Oder
SpeciesBeforeAfterChange [%]BeforeAfterChange [%]
Riverbank
Leuciscus idus16.93.5−79.329.632.18.4
Barbus barbus4.79.6104.32.31.3−43.5
Rhodeus amarus108.8377.4246.965.194.945.8
Squalius cephalus59.358.3−1.720.468.2234.3
Leuciscus leuciscus22.517.7−21.36.05.5−8.3
Esox lucius19.811.9−39.915.411.7−24.0
Gymnocephalus cernua3.06.6120.015.07.2−52.0
Leuciscus aspius7.96.1−22.87.310.442.5
Scardinius erythrophthalmus22.828.324.131.239.526.6
Tinca tinca2.24.395.53.12.2−29.0
Barbatula barbatula5.74.2−26.34.50.0−100.0
Cobitis taenia105.292.6−12.0105.772.8−31.1
Vimba vimba3.24.953.12.41.0−58.3
Sander lucioperca1.32.7107.71.51.0−33.3
Mid-channel
Leuciscus idus2.90.0−100.03.91.2−69.2
Barbus barbus1.41.0−28.61.21.0−16.7
Squalius cephalus1.81.2−33.31.51.713.3
Esox lucius1.00.0−100.01.71.6−5.9
Gymnocephalus cernua3.20.0−100.04.22.4−42.9
Leuciscus aspius1.21.0−16.71.41.721.4
Vimba vimba1.31.30.02.11.0−52.4
Sander lucioperca1.40.0−100.04.23.1−26.2
         
≥−100<−75<−50<−250<25<50<75≥100
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Starck, S.; Wolter, C. Resilience Approach for Assessing Fish Recovery after Compound Climate Change Effects on Algal Blooms. Sustainability 2024, 16, 5932. https://doi.org/10.3390/su16145932

AMA Style

Starck S, Wolter C. Resilience Approach for Assessing Fish Recovery after Compound Climate Change Effects on Algal Blooms. Sustainability. 2024; 16(14):5932. https://doi.org/10.3390/su16145932

Chicago/Turabian Style

Starck, Sascha, and Christian Wolter. 2024. "Resilience Approach for Assessing Fish Recovery after Compound Climate Change Effects on Algal Blooms" Sustainability 16, no. 14: 5932. https://doi.org/10.3390/su16145932

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop