Per Jonsson

Professor Emeritus

Department of Marine Sciences
Visiting address
Carl Skottsbergs gata 22 B
41319 Göteborg
Postal address
Box 461
40530 Göteborg

About Per Jonsson

Professor at the Department of Marine Sciences.

I am based at the Tjärnö Marine Research Station situated 150 km north of Gothenburg and 130 km south of Oslo (see map).

My research interests include: biohydrodynamics, larval ecology, ecological & evolutionary effects of dispersal, chemical ecology, effects of biodiversity loss and design of Marine Protected Areas.

Research projects

Local adaptation driven by evolution of dispersal traits in marine larvae Most marine invertebrate disperse during a planktonic larval stage that may last for many weeks while drifting with the ocean circulation. A challenge for larvae of coastal species is to stay close to the coastline or return at the time of recruitment. The traditional view is that the expected long-distance larval dispersal in the ocean leads to weak population differentiation and little opportunity for local adaptations. This is in contrast to recent findings of small-scale population structure and increasing reports of local adaptations. One explanation is that larval dispersal is more restricted than previously believed. Most larvae control may control their vertical position in the water column and can perhaps exploit depth-dependent variations in water transport to modify their net dispersal. Dispersal effects of larval behavior is almost unknown and we aim to study larvae of shore crabs (Carcinus maenas) and implications for dispersal and evolution of local adaptations. We will explore: 1. vertical behavior in rhythm with tidal and day/night cycles along an environmental gradient 2. effect of vertical behavior on predation risk 3. genetic differentiation along an environmental gradient. With information from 1-3 we will use biophysical modeling, which includes larval behavior and ocean transport, to test hypotheses about how evolution of specific larval behaviors enhancing recruitment also may provide opportunities for local adaptations through reduced gene flow with distant populations.

Integrating seascape ecology and ecosystem services of eelgrass meadows for marine spatial management Ecosystem-based marine spatial management is presently promoted to halt the declining health of marine ecosystems and maintain their services. However, this approach is seriously impeded by lack of information on dispersal and connectivity between habitats, the value of the ecosystem services, and methods to integrate this information in management. Eelgrass (Zostera marina) meadows are key habitats in coastal ecosystems that provide a range of ecosystem goods and services. However, they are rapidly declining in Sweden and in other European countries and are in immediate need of management measures. With a multidisciplinary team this project, funded by the Swedish Research Council Formas, aims to develop a series of new spatial management tools for protection and restoration of Swedish eelgrass meadows, through 3 main tasks: 1. Assess connectivity between past and present eelgrass meadows using bio-physical models and population genetic methods and to assess genetic diversity with the aim to identify vulnerable and valuable eelgrass areas. 2. Identify key ecosystem goods and services provided by eelgrass ecosystems, and estimate area-specific economic values using model results of juvenile cod distribution and cost of nutrient reduction measures. 3. Develop a new model-approach that integrates the connectivity of eelgrass communities with area-specific values of the ecosystem services to identify the eelgrass beds that promote the largest and most resilient meta-communities, and the highest benefits to society.

Integration of climate-change impacts into the ecosystem based management and planning of the Swedish marine environment (ClimeMarine)

Global climate change will have many effects on the oceans and the marine ecosystems for decades or centuries to come. These challenges will co-exist with present pressures from human activities, such as eutrophication, shipping, fishing and use of coastal areas for harbours, tourism and recreation. To have an effective management of the oceans’ natural resources in place is essential in order to protect and preserve what in many cases represent irrreplaceable values. Due to the major and rapid environmental changes from global warming and complex interactions in marine systems, the management needs to handle both present pressures and climate change. The proposed project will promote an ecosystem-based management of the Swedish seas that will incorporate climate change, uncertainties in data, and climate adaptation issues. It will, through stakeholder dialogues and co-creation of research questions perused, investigate opportunities and hindrances for different sectors’ ability to comprehend and integrate climate-change into the decision making process. Within the project the cumulative impact-assessment tool “Symphony”, developed and used within the Swedish marine management for marine spatial planning, will be further advanced to incorporate climate data. Symphony showcases will be developed and be the base for stakeholder discussions, designed to pinpoint competing interests, obstacles and further needs for an adequate and climate-proofed planning and protection process.

Effects of egg and larval dispersal for evolution of locally adapted fjord populations of cod in Skagerrak/Kattegat Local fjord stocks of cod in the Skagerrak/Kattegat area have declined dramatically since the 1970s. Occasionally there is a high recruitment of juveniles in Skagerrak/Kattegat, without leading to the rebuilding of adult cod stocks despite reduced fishing mortality. Within the EU-Interreg project MarGen, we use biophysical modelling of egg and larval drift coupled to population genetic/genomic analyses to investigate sources and sinks for cod larvae for both extant and historical spawning grounds. In addition, we look for genomic signatures of local adaptations, e.g. traits involved in migration patterns.

Larval dispersal and the design of marine reserve networks Creation of marine reserves or marine protected areas (MPA) is an important instrument for mitigation of biodiversity loss and the management of natural resources, e.g. threatened fish stocks. However, at present the effects of propagule dispersal and population connectivity for optimal MPA design are largely neglected. This may seriously compromise the sustainable protection of environmental values and natural resources that is the goal of MPA networks. This project, funded by the Swedish Agence for Marine and Water Management, features a multidisciplinary team of scientist and managers, including oceanographers, biological modellers, larval ecologists, spatial planners, managers of biodiversity and fish resources will address the critical component of how marine areas in the Arctic Ocean are connected through dispersal. The goal is to deliver tools to include dispersal, self-seeding and connectivity into spatial planning and management and to facilitate the development of an efficient and sustainable network of marine reserves. This is achieved by a combination of oceanographic and biological modelling producing dispersal probabilities. Necessary data on vertical behaviour for some target species is also be incorporated. In dialog with managers of biodiversity and fish resources we will build user-friendly tools designed to assess connectivity in spatial planning of marine reserves.

Publications in Google Scholar

The Linnaeus Centre for Marine Evolutionary Biology