If it moves it’s potentially interesting! I’m an aquatic ecologist with a behavioural ecological background. My approach to research often focuses on individual animal, or, most of the time, fish behavioural decisions, performance and success, and generally aims to address higher-order effects of these behavioural attributes. The higher-order processes include forager group formation and dynamics, spatio-temporal distributions of individuals in populations, impact of social foraging on individuals, populations and communities, as well as effects of piscivore and prey behaviours on trophic cascades, oftenmost all linked to management incentives. Recent interests focus on speciation and hybridization processes in Bahamas mosquitofish, causes and concequences of fish migration, host-parasite interactions between fish and mussels, harbour porpoise foraging ecology, win-win solutions for hydropower and the Atlantic eel and salmon, as well as prey movement in a landscape of fear.

Hybridization and speciation in mosquitofish

The Bahamas blue holes are vertical caves filed with water, that have been colonised by the Bahamas mosquitofish. Some of these isolated blue holes also contain piscivorous bigmouth sleepers, and mosquitofish populations have diverged behaviourally and morphologically according to allopatry and predation regime. We evaluate probability of hybridisation between different populations and also hybrid viability, detecting early signs and mechanisms of speciation processes.

Individual movement in a landscape of fear

Most animals trade off growth opportunity against predation risk in behavioural decisions, and the spatio-temporal landscape of this tradeoff should affect prey behaviours. Combining a unique pond infrastructure (iPonds) with high-resolution acoustic telemetry, we study how e.g. animal personality, pharmaceuticals, predator/prey and food distribution, and habitat composition affect spatiotemporal fish behaviour in the physical and chemical landscape of fear.

Harbour porpoise behavioural and predator-prey interactions

Harbour porpoises are regularly sited in Swedish/Danish coastal waters, while surprisingly little is known about their spatio-temporal distribution patterns and interactions with conspecifics and prey. We study behavioural cascades from zooplankton to fish to porpoise spatio-temporal distribution patterns, monitor aspects of porpoise social foraging behaviour, and porpoise responses to recreational motorboating, to enhance our understanding of harbour porpoise prerequisites and protection.

Host-parasite interactions

This project deals with interactions between fish hosts and mussel parasitic larvae in streams. Mussel larvae (glochidia) are ectoparasites on fish before transforming into juvenile mussels and fall of their hosts to bury in the stream sediment. Many freshwater mussels are threatened or locally extinct, and availability of suitable fish hosts for glochidia is pivotal for recruitment. We study e.g. host specificity in glochidia, glochidia growth and survival on different hosts, transferability of glochidia between streams and their fish assemblages (for reintroduction purposes), possible effects of parasites on fish, and habitat composition and suitability for fish and mussels.

Compromised solutions for hydropower and Atlantic eel and salmon

Hydropower produces green energy, but reduces connectivity in rivers, with negative consequences for fish life-histories that include migration between freshwater and ocean systems. Eel and salmon undertake such migrations; eel migrate to freshwater habitats for growth and return to the sea to spawn, while salmon spawn in freshwater and migrate to the sea for foraging and growth opportunity. We collaborate with the hydropower industry to find passage solutions for both up- and downstream migration past migration barriers, and also evaluate distribution patterns and habitat restoration best practises for Atlantic eel and salmon.

Using RAD and eDNA to study river connectivity and invasive round goby

The population effects of different levels of river connectivity can be efficiently monitored by RAD sequencing for genetic differentiation, while community consequences of such river connectivity can be evaluated using eDNA carrying signals of occurring species e.g. up- and downstream migration barriers. eDNA can similarly be used to survey specific species, and a part project focuses on the geographical distribution of potentially invasive round goby in Swedish coastal waters. These projects are undertaken in direct collaboration with the hydropower industry, fisheries agencies, County administrative boards, municipalities and other organisations to approach reliable tools for evaluation and prioritisation of remedial and restoration effforts.

Physiological tradeoffs and processes behind inducible defences

The fascinating crucian carp, Carassius carassius, reacts to chemical cues emitted by predatory fish by growing a deeper bodied morphology; a predator-induced morphological defence. 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. canalization of defence traits.