Is predation an important selection force in freshwater systems? This question has been a consistent theme in almost all the different projects I have been involved in, throughout my career. My research has involved many different organisms, from snails to piscivorous fish, and I have been working with interactions at different organisational levels, from individual behaviour to the structure and function of ecosystems. At present, I am involved in three different projects where I study the effects of predator-prey interactions on:
- Evolution of inducible defences
- Seasonal migration in freshwater fishes
- Recruitment of juvenile piscivorous fish.
Evolution of inducible defenses
Virtually all animals constitute potential prey and they are hence under strong selection to avoid capture by their natural enemies. Consequently, we see a huge range of fantastic anti-predator defences displayed in prey organisms. Defences could either be constitutive, i.e. they are always expressed by the prey, regardless of predation risk. Or they could be inducible, i.e. they are only expressed in the presence of predators. We have for a number of years studied the costs and benefits of inducible morphological defences in freshwater prey species. The fascinating crucian carp, Carassius carassius, reacts to chemical cues emitted by predatory fish by growing a deeper bodied morphology. The deeper body provides a benefit by reducing vulnerability to predation, but also incur a cost by increasing drag when swimming. We have also shown inducible defence adaptations in the snail Radix balthica – it grows a more rotund shell when exposed to fish cues, a morphology that increase resistance to crushing.
In recent years we have seen considerable development of the theoretical underpinnings as well as empirical studies on the evolution of phenotypically plastic defences, but we still need to identify the proximate, physiological mechanisms behind the expression of defence traits in order to advance our understanding. Further, it is pivotal to study the expression of these adaptations in a multiple trait context, especially with regards to animal personality, and in environments that differ in selection regimes. In our present research we use the unique crucian carp model system to challenge fundamental and exciting research questions, including the proximate, physiological mechanisms behind inducible defences (especially the stress axis and the importance of cortisol), how multiple defence traits combine to produce an adaptive, integrated phenotype and how environmental heterogeneity drives plasticity vs. canalisation of defence traits.
- Brönmark, C. and Miner, J.G. 1992. Predator-induced phenotypical change in body morphology in crucian carp. Science 258: 1348-1350.
- Hulthén, K., Chapman, B. B., Nilsson, P. A., Hollander, J. and Brönmark, C. 2014. Express yourself: bold individuals enhance morphological defences. Proc. R. Soc. Lond. Ser. B 281: 20132703.
Seasonal migration in freshwater fishes
In this project we study the causes and consequences of seasonal migration in a freshwater cyprinid fish, the roach Rutilus rutilus, in lakes in Sweden and Denmark. In the autumn, roach migrate from the lake into streams and wetlands and then return to the lake in early spring. We have shown that this migration is driven by a seasonal change in a cost/benefit trade-off, where the predation costs and growth benefits change seasonally in the lake and stream habitats. The migration is partial and individual properties such as size, condition and personality affects an individual’s migratory drive. Differences in the density and biomass of migratory roach among years may further have repercussions on the dynamics of the whole ecosystem, specifically by affecting the zooplankton dynamics during spring. At present, we are investigating how differences in immune defence affect migratory propensity and overwinter survival.
- Brönmark, C, Skov, C, Brodersen, J, Nilsson, P A and Hansson, L-A 2008. Seasonal migration determined by a trade-off between predator avoidance and growth PloS One 3(4): e1957
- Chapman, B., Hulthén, K., Blomqvist, D., Hansson, L-A., Nilsson, J-Å, Brodersen, J., Nilsson, P. A. Skov, C. and Brönmark, C. 2011. To boldly go: Individual differences in boldness influence migratory tendency. Ecology Letters 14: 871-876.
Environmental effects on piscivore recriutment
Predation by fish is one of the most important structuring forces in lake ecosystems and it has been repeatedly shown that changes in the density and species composition of the piscivore functional group have complex effects on freshwater food chains, thereby affecting the dynamics and function of the whole system. In earlier studies we have shown that changes in the optical environment (light availability) due to increased turbidity or increased humic content (brownification) have a negative effect on foraging and growth rate of adult piscivorous fish. The aim of this project is to study how environmental drivers (temperature and eutrophication) associated with climate change will affect the recruitment success of two of our most important freshwater piscivorous fish, pike and pikeperch, due to singular and synergistic effects on the larval and juvenile life history stages. A temperature increase is predicted to affect growth rate by both a change in foraging rate and through changes in food availability (mismatch of resources), whereas eutrophication will affect prey encounter rates through detoriation of the optical properties of water.
- Ranåker, L., Jönsson, M., Nilsson, P. A. and Brönmark, C. 2012. Effects of brown and turbid water on piscivore-prey fish interactions along a visibility gradient Freshwater Biol 57: 1761-1768.
- Jönsson, M., Ranåker, L. Nilsson, P.A. and Brönmark, C. 2013. Foraging efficiency and prey selectivity in a visual predator: differential effects of turbid and humic water. Can. J. Fish. Aquat. Sci. 70: 1685-1690
Retrieved from Lund University's publications database
- Ecosystem services across the aquatic-terrestrial boundary : Linking ponds to pollination
- Escaping peril: perceived predation risk affects migratory propensity.
- Individual boldness is linked to protective shell shape in aquatic snails.
- Shape up or ship out: migratory behaviour predicts morphology across spatial scale in a freshwater fish.
- What can aquatic gastropods tell us about phenotypic plasticity? A review and meta-analysis.
- Combining limnology and palaeolimnology to investigate recent regime shifts in a shallow, eutrophic lake
- Experimental evidence for a mismatch between insect emergence and waterfowl hatching under increased spring temperatures
- Express yourself: bold individuals induce enhanced morphological defences.
- Fixed and flexible: coexistence of obligate and facultative migratory strategies in a freshwater fish.
- Piscivore-Prey Fish Interactions: Mechanisms behind Diurnal Patterns in Prey Selectivity in Brown and Clear Water.
- Sex identification and PIT-tagging: tools and prospects for studying intersexual differences in freshwater fishes.
- Synthetic estrogen directly affects fish biomass and may indirectly disrupt aquatic food webs
- There and back again: migration in freshwater fishes
- Warming and browning of lakes: consequences for pelagic carbon metabolism and sediment delivery
- A Foraging Cost of Migration for a Partially Migratory Cyprinid Fish
- A lake as a microcosm: reflections on developments in aquatic ecology
- Camouflaged or tanned: plasticity in freshwater snail pigmentation.
- Ekosystemtjänster i det skånska jordbrukslandskapet
- Food-chain length alters community responses to global change in aquatic systems
- Foraging efficiency and prey selectivity in a visual predator: differential effects of turbid and humic water
- Migration confers survival benefits against avian predators for partially migratory freshwater fish
- Costs of Inducible Defence along a Resource Gradient
- Effects of brown and turbid water on piscivore-prey fish interactions along a visibility gradient
- Effects of degraded optical conditions on behavioural responses to alarm cues in a freshwater fish.
- Fleeing towards death - leech-induced behavioural defences increase freshwater snail susceptibility to predatory fish
- Partial migration in fishes: causes and consequences.
- Partial migration in fishes: definitions, methodologies and taxonomic distribution.
- Predicted warming and browning affect timing and magnitude of plankton phenological events in lakes: a mesocosm study
- Prey-type-dependent foraging of young-of-the-year fish in turbid and humic environments
- The impact of catch-and-release on the foraging behaviour of pike (Esox lucius) when released alone or into groups
- Variable individual consistency in timing and destination of winter migrating fish.
- Water brownification may increase the invasibility of a submerged non-native macrophyte
- Foraging success of juvenile pike Esox lucius depends on visual conditions and prey pigmentation
- Interactions between Predation and Resources Shape Zooplankton Population Dynamics.
- Interplay between temperature, fish partial migration and trophic dynamics
- Partial migration: an introduction
- Predator induced morphological plasticity across local populations of a fresh water snail
- Temperature and resource availability may interactively affect over-wintering success of juvenile fish in a changing climate.
- The ecology and evolution of partial migration
- The influence of predator regime on the behaviour and mortality of a freshwater amphipod, Gammarus pulex
- To boldly go: individual differences in boldness influence migratory tendency.
- Habitat structure and juvenile fish ontogeny shape zooplankton spring dynamics
- Influences of environmental cues, migration history, and habitat familiarity on partial migration
- Regime shifts in shallow lakes: the importance of seasonal fish migration
- Waterfowl, macrophytes, and the clear water state of shallow lakes
- Biomanipulation of aquatic ecosystems
- Bioturbation as Driver of Zooplankton Recruitment, Biodiversity and Community Composition in Aquatic Ecosystems
- Competition and facilitation within and between a snail and a mayfly larva and the effect on the grazing process
- Condition-dependent individual decision-making determines cyprinid partial migration
- Ecosystem effects of partial fish migration in lakes
- Inter- and size-specific patterns of fish seasonal migration between a shallow lake and its streams
- Optimal Swimming Speed in Head Currents and Effects on Distance Movement of Winter-Migrating Fish.
- Pikeperch Sander lucioperca trapped between niches: foraging performance and prey selection in a piscivore on a planktivore diet
- Predator-induced morphology enhances escape locomotion in crucian carp
- Seasonal migration determined by a trade-off between predator avoidance and growth
- Tuning in to multiple predators: conflicting demands for shell morphology in a freshwater snail.
- Behavioral interference and facilitation in the foraging cycle shape the functional response
- Consequences of fish predation, migration, and juvenile ontogeny on zooplankton spring dynamics
- Habitat-choice interactions between pike predators and perch prey depend on water transparency
- Predator-prey encounter rates in freshwater piscivores: effects of prey density and water transparency
- Facilitation and interference among three predators affect their consumption of a stream-dwelling mayfly
- Friends and foes in foraging: intraspecific interactions act on foraging-cycle stages
- Satiation effects in piscivore prey size selection
- Size-dependent effects of an invasive herbivorous snail (Pomacea canaliculata) on macrophytes and periphyton in Asian wetlands
- Effects of kinship on growth and movements of brown trout in field enclosures
- Environmental issues in lakes and ponds: current state and perspectives
- Foraging capacities and effects of competitive release on ontogenetic diet shift in bream, Abramis brama
- Foraging capacity and resource synchronization in an ontogenetic diet switcher, pikeperch (Stizostedion lucioperca)
- Prey size selection in piscivorous pikeperch (Stizostedion lucioperca) includes active prey choice
- The declining spadefoot toad Pelobates fuscus: calling site choice and conservation
- The relative importance of lethal and non-lethal effects of fish on insect colonisation of ponds
- Chemical communication in aquatic systems: an introduction
- Influence of predator and dietary chemical cues on the behaviour and shredding efficiency of Gammarus pulex
- Predator recognition and defence strategies in crucian carp, Carassius carassius
- Prey vulnerability to a gape-size limited predator: behavioural and morphological impacts on northern pike piscivory
- The role of gastric evacuation rate in handling time of equal-mass rations of different prey sizes in northern pike
Doctoral students and postdocs
PhD students, main supervisor
PhD students, assistant supervisor
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