Nurseries and fueling stations

The Intertidal system cluster focuses on the population structure and dynamics of intertidal  macrozoobenthos, especially on feeding and predator-prey relationships with emphasis on factors controlling and regulating recruitment. Knowledge of birth, death and migration rates, as a result of morphological (e.g. size), physiological (e.g. energy reserve, parasitism) and behavioural (e.g. susceptibility to interference) characteristics of the constituent individuals are linked to changes in the environment (characterized in terms of food, competitors, predators, abiotics). Studies vary from the trophic interactions between the main primary producers (phytoplankton and phytobenthos) and primary consumers (bivalves) of shallow temperate waters such as the Wadden Sea, the settlement, growth and survival of juvenile benthos and the energy allocation in reproduction in combination with eco-physiological laboratory experiments on the species-specific environmental conditions for survival and growth, embedded in studies on population genetics, evolutionary ecology, and community and food web dynamics.

Baltic tellin

Sources of biodiversity

The Benthic continental shelf and open ocean system cluster focuses on interactions between environment and structure and functioning of subtidal benthic ecosystems in the Dutch coastal zone, North Sea, and open ocean. High frequency observations are obtained by state-of-the-art landers, allowing long term deployments of benthic observatory (video cameras) and autonomic samplers and sediment traps. In addition to faunal sampling, methods comprise in-situ video observations, analysis of stable isotopes and fatty acids of organisms, analyses of isotopic records in bivalves and potential food sources. Long-term sediment trap moorings are used to compare and quantify particle supply and sources.

Bottom lander after deployment in Dutch coastal zone

The Global shorebird migrations and comparative mudflat ecology cluster aims to mechanistically and evolutionarily understand the distributions and abundances, and changes therein, of coastal predators, especially shorebirds, and more especially the migrant shorebirds that depend on multiple coastal sites in the course of the year. Such an aim warrants work at many different levels, varying from a solid description of the food conditions of birds over large spatial scales (the level of entire coastal systems up to worldwide comparisons), understanding the details of food selection, the role of predation by shorebirds on intertidal foodweb functioning, to understanding the mechanisms of adaptive body composition that reflect the functioning of organisms in natural contexts. The group has a tradition in using state-of-the art telemetry techniques, and the strong embedding of field and experimental observations in (behavioural) ecological theory.

Topics are:

[1] Global shorebird migrations and comparative mudflat ecology
(Theunis Piersma)

[2] Migrant predators structuring prey communities
(Jan van Gils)

Red knots by courtesy of Jan van de Kam

Dr Katja Philippart

“All starts at the bottom”

For many organisms in a shallow sea such as the Wadden Sea, all starts with micro algae: free floating phytoplankton or microphytobenthos in and around the bottom. Our main aim is to investigate how the growth of these micro algae is regulated by nutrients and other resources, and how these resources, thus, shape the composition of a functional group of micro algae. We have shown already that a shift in nutrients, results in a shifting balance in algae also. We try to find out if this shift has implications for different stages of filter-feeding bivalves. We address these questions with experiments, as well as field measurements, some of which are long term measurements with automated equipment. This way we gather essential information on the direction and magnitude of changes in the carrying capacity of the Wadden Sea, as a result of management policies or global change.

For more info on the group and working plan for 2013/14 click here.

Head of the group

Dr Katja Philippart

Postdocs

Mark van Dijk  - “Development of sensor algorithms for estimating primary production” (IN PLACE; NWO/ZKO) in cooperation with Dr J.C. Kromkamp (NIOZ-Yerseke).

Eelke Folmer – “Defining conceptual models on ecological functioning of the Wadden Sea system” (WaLTER; Waddenfonds) in cooperation with CWSS, IMARES, RUG, RUN & SOVON.

PhD students

Annamarie Krieg – “Analyses of factors explaining success and failure in bridging the gap between scientists and policy makers” (SPIRAL; EU FP7) in cooperation with Prof. Dr C.H.R. Heip (NIOZ-Texel).

Viola Lehmpfuhl – “Causes and consequences of selective feeding by juvenile bivalves” as of part of the “Consequences of phosphorus reduction for the dynamic transfer of organic matter” project (P-REDUCE; NWO/ZKO) in cooperation with Prof. Dr P.M.J. Herman (promotor; NIOZ-Yerseke).

Lieke Mulder – “Development of a dynamic biogeochemical sediment nutrient water exchange model” as of part of the “Consequences of phosphorus reduction for the dynamic transfer of organic matter” project (P REDUCE; NWO/ZKO)” in cooperation with Prof. Dr K. Soeteart and Dr J.C. Kromkamp (NIOZ-Yerseke).

Sarina Jung – “Food web model by ecological network analysis (ENA) for a western Wadden Sea ecosystem, the Balgzand area” in cooperation with Dr H.W. van der Veer (NIOZ-Texel) and the Alfred Wegener Institut für Polar und Meeresforschung.

Professor Jaap van der Meer

“Changes in body size can make a crucial difference”

At sea, classic population models, dealing with adults of one, constant size, are of little or no value. As body size of most invertebrates – as well those of fish – constantly changes, more dynamic models, such as the Dynamic Energy Budget theory, are needed. Our group studies the constantly changing interactions between consumer and resource. Body size of individual organisms is the key factor in our research. How does body size influence energy fluxes? How does the size of a predator or the size of a prey influence predation rates and thus: how does body size influence the complete demography of the different organisms? By addressing these questions, our scientists aim to get a better insight in the true dynamics of populations of marine predators and prey, such as invertebrates in the intertidal seas.

Head of the group

Professor Jaap van der Meer

Postdocs

PhD students

Dr. Pieternella Luttikhuizen

“Not everything is everywhere at sea”

'Everything is everywhere'. This is how we used to think about life in the sea. But even without obvious physical barriers that could stop free swimming larvae from distant dispersal, populations differ at much smaller spatial scales than expected. Our group studies the population genetic structure for a range of benthic invertebrates, including bivalves, annelid worms and shrimp. Using a combination of molecular markers and statistical inference, we try to reconstruct how geological history and biological characteristics together, have formed and maintain this genetic structure. We also use molecular identification to map the distribution of several cryptic species; species that are difficult to tell apart by traditional methods. Finally, we examine the implications of a certain population genetic structure for the ecological functioning of different populations. We do this by studying morphological and physiological traits. In the field we describe their distribution and in the lab we estimate their heritability and plasticity.

Click here for more info on the group and working plans for 2013/14.

Head of the group

Dr. Pieternella Luttikhuizen

Dr. Henk van der Veer

“Fish populations are a litmus test for a coastal system”

Coastal systems carry a crucial nursery function for fish species and the abundance and diversity of the fish community is often considered to be a reflection of the carrying capacity and the functioning of the system.  We study the processes determining this carrying capacity and functioning of  coastal systems such as the Wadden Sea. How important are food conditions (bottom up processes) for the productivity of the system. Are fish species food limited or not? And what is the structuring role of the fish fauna on its prey populations (top down impact)? Backbone for our approach is  a unique, continuous series of 50 years of fyke net catches that allows us to identify possible long term (regime) shifts at the ecological community level. For detailed process-oriented studies the bottom dwelling plaice is used as model species. On the one hand we analyze its prey items and impact of predation on the structure of the benthic community. On the other hand we translate the observed growth of the fish to required energy, by means of Dynamic Energy Budgets and compare that to maximum possible theoretic growth. 

Click here for more info on the group and working plans for 2013/2014.

Head of the group

Dr. Henk van der Veer

Post doc projects

Joana Cardoso (in cooperation with CIMAR/CIIMAR, University of Porto)
Age determination in bivalves: validation of the seasonality of shell growth bands along the European coast

Joana Campos (in cooperation with CIMAR/CIIMAR, University of Porto)
Cannibalism as a regulating mechanism in the recruitment of crustaceans over their distributional range in European waters

Vania Freitas (in cooperation with CIMAR/CIIMAR, University of Porto)
Spatial and temporal variability in carrying capacity of estuarine nursery areas at the community level

PhD projects

Els van der Zee (in cooperation with Theunis Piersma)
A regime shift of benthic organisms in the Wadden Sea: causes and consequences for higher trophic levels.

Lodewijk van Walraven (in cooperation with Victor Langenberg; DELTARES)
Natural and anthropogenic impact on North Sea gelatinous zooplankton population dynamics: implications for ecosystem structure and functioning.

Jeltje Jouta (in cooperation with Theunis Piersma)
Food web dynamics across the (Dutch) Wadden Sea intertidal area

Sarina Jung
The impact of biological invasions on the Balgzand food web in the Wadden Sea (INFOWEB)

Dr. David Thieltges

“Parasites can be an important ecological factor”

The sea is full of parasites and there is growing evidence that parasites can be an important ecological factor in marine ecosystems. We strive to understand the extent and importance of parasitism in coastal waters on various spatial and organizational scales. Using correlative and experimental approaches, we study the effects of parasites on host individuals, populations and communities. We are also interested in how parasites influence the topology and dynamics of marine food webs. Another line of research aims to understand the patterns and processes underlying infections of marine hosts. For example, temperature has been shown to be an important trigger for trematode parasites with important implications for climate change scenarios. And finally, we study large-scale patterns in parasitism using extensive databases and phylogenetic, biogeographical and macroecologial approaches in order to understand the forces that have shaped parasitism in the sea.

For more info on the group and working plans for 2013/14 click here.

Head of the group

Dr. David Thieltges

PhD projects 

Jennifer Welsh (in cooperation with Corina Brussard and Jaap van der Meer, NIOZ) - Biodiversity and disease risk in marine ecosystems

Anouk Goedknegt (in cooperation with Pieternella Luttikhuizen, Kees Camphuysen, Jaap van der Meer, NIOZ and Christian Buschbaum, Mathias Wegner (AWI, Germany) - Effects of invasive species on native predator-prey and pathogen-host webs in the Wadden Sea

courtesy of Hans Hillewaert, Network3D Software

Magda Bergman & Rob Witbaard

“With our benthos dredge we can sample organisms that were previously to scattered to sample.”

For most non commercial species living in, at and near the bottom of the sea (benthos), their interactions with their environment are still unclear. Therefore we focus on the processes which determine growth and distribution of selected species, or communities, and explore their relation to water column variables and trophic relations to get understanding of the key processes controlling them. This way we try to explain shifts in ecosystems due to, for instance, fisheries or the effects of climate change. A relatively recent addition to these research themes is the effect of protected areas - such as wind farms- to restore, protect and sustain benthic ecosystems.

In order to answer these questions, we sample low density and often long lived species with the specially developed ‘Triple-D’ benthos dredge. This dredge takes quantitative samples of 20 m2 bottom surface (0-20cm deep), which enables us to estimate densities of less abundant species.

To study larval availability and settlement, autonomous bottom lander technology is used. This technology enables intermittent, high frequency in situ sampling of pelagic larvae of benthic organisms. Similar technology is used to measure near bottom environmental conditions, such as currents, sediment resuspension and food availability. The application of these techniques gives insight in the processes that control performance and distribution of sub-tidal benthos.

Click here for more info on the group and working plans for 2013/14.

Head of the group

Gerard Duineveld

Staff

Magda Bergman

Rob Witbaard

Gerard Duineveld & Marc Lavaleye

“The deep-sea floor as a source of life”

The continental slope and deep-sea basin encompass the largest gradient in environmental conditions (dimensions, temperature, pressure, food) in the marine world. Instead of being a constant and predictable environment, there are many perturbations in the deep-sea such as food dumps, benthic storms, and turbidity currents. Little is known how deep-sea animals cope with these conditions and perturbations in terms of their energy intake, interactions and dispersal, and the role of the high biodiversity in deep-sea sediments for the functioning of the deep-sea. Latter aspect is being studied by us in a large international consortium comparing the Mediterranean and Atlantic deep-sea sites. Another focus of our group are the deep-sea coral reefs built by so-called cold-water corals. These reefs are found throughout the Atlantic Ocean at depths between 200 and 1000 m where they serve as a biodiversity reservoir, hotspot for carbon mineralisation, and nursery for fish. The study of these reefs is carried out in European context and in collaboration with US partners. New and cutting-edge technology (manned and unmanned submersibles, autonomous landers) is being used, and also developed, to study the structure and functioning of the reefs and the role of individual organisms.

Click here for more info on the group and working plans for 2013/14.

Head of the group

Gerard Duineveld

Staff

Marc Lavaleye

Kees Camphuysen:

“Fisheries can both facilitate and threaten seabirds”

Our group studies the distribution and foraging ecology of marine top-level predators, mostly seabirds and marine mammals. In many cases, there is a relationships with fisheries. This can be through facilitation (discards, overfishing), competition (stock depletion), or through a direct threat (bycatch). We organized or participated in a series of international research projects, unraveling the effects of discards production and industrial fisheries in the North Sea on seabirds since the early 1990s.

Currently this – mostly offshore – type of research is connected to onshore studies in breeding seabird colonies. There, we study foraging ecology and the demographic consequences such as breeding success, growth, recruitment and survival, in a context of a changing environment and fishery policy. In a combined colony of herring gulls and lesser black-backed gulls, we apply ‘down-to-earth’ biological techniques such as biometrics of birds, analysis of regurgitated leftovers, and colour-ring studies, with state of the art techniques such as the use of novel GPS dataloggers on foraging and migrating individual birds.

Click here for more details on the group and working plan for 2013/14.

Head of the group

Kees Camphuysen

Professor Theunis Piersma

“Our bird studies show tight ecological links in international chains”

Project Description: Building on half a century of Dutch bird observations and experimental work, the highly attractive and specialized intertidal shorebirds have become our focal models in studies of behaviour and trophic ecology in marine systems. Our studies are built on efforts that describe the changing ‘resource landscapes’ for shorebirds, such as the one for the Wadden Sea intertidal flats, the yearly Synoptic Intertidal Benthic Survey (SIBES).

Covering the whole intertidal area of the Wadden Sea, we map relationships between benthic invertebrates and the distribution of their shorebird predators. Going beyond a focus on molluscivore red knots, we currently study on a more omnivore species with similar life-history traits, the bar tailed godwit. We use high tech miniature tracking devices to follow individual birds while they move through landscapes with their specific resources. The work on red knots and bar-tailed godwits in the Dutch Wadden Sea is part of the Waddenfonds-funded project Metawad, led by Piersma.

Photo courtesy Jan van de Kam

For shorebirds the clash between the plethora of human-related pressures and their habitat choice places them at the forefront of the current biodiversity crisis. Most species of shorebirds are in decline and several face extinction—but interventions can make all the difference. The species currently undergoing precipitous population declines are emblematic of migratory birds in general. This includes the black-tailed godwits of The Netherlands and the red knots in the western Atlantic that travel between Tierra del Fuego and the Canadian High Arctic. To counter the alarming trends in shorebird populations, we need multi-faceted efforts that include conservation action built on solid science. The success in defending birds and their habitats depends on our ability to channel this science into compelling stories that will resonate across societal levels. 

Photo courtesy Jan van de Kam

To facilitate early warning, and to help ensure the scientific underpinning of pertinent conservation actions, BirdLife-Netherlands (VBN) and the Worldwide Fund for Nature-Netherlands (WNF) have established a Chair in Global Flyway Ecology at the University of Groningen. Theunis Piersma started that chair in late 2012. The chair will aim to study the flyway ecology of shorebirds and raise a new generation of students with the ability to perform high-quality ecological research that leads to effective conservation effort. The conduct of these efforts will depend heavily on the involvement of not only the joint and complementary research teams at the University of Groningen and the NIOZ Royal Netherlands Institute for Sea Research, but also of the Global Flyway Network, a worldwide shorebird-demography research consortium co-founded by Piersma in 2006 and now under his direction.

Photo courtesy Jan van de Kam

Click here for more info on the group.

Head of the group

Professor Theunis Piersma

PhD projects:

Allert Bijleveld (NIOZ, post-PIONIER commitment)
Social foraging and information use in red knots in the Wadden Sea

Sjoerd Duijns (NIOZ, post-PIONIER commitment)
Distributional ecology of bar-tailed godwits in the Dutch Wadden Sea

Jeltje Jouta (Waddensleutels, Waddenfonds)
Spatial variation of the structure of the Wadden Sea foodweb, illuminated by the trophic position of spoonbills and other omnivorous birds and fish

Anne Dekinga (NIOZ)
Intertidal foodweb ecology of Bering Strait mudflats

Hong-Yan Yang (NIOZ, post-PIONIER commitment)
Foraging ecology of red knots in Bohai Bay, China

Ying-Chi Chan
Ranging and migration behaviour of red knots in the East-Asian-Australasian Flyway

Dan Ruthrauff (US Geological Survey, Anchorage)
Comparative ecology of a mudflat- and a rocky-shore-specailist subspecies of rock sandpiper

Postdoc projects:

Tanya Compton (NIOZ, NAM- SIBES project)
Community and population ecology of Wadden Sea benthos (SIBES)

Piet van den Hout (NIOZ, Metawad-Waddenfonds)
Population and distributional ecology of red knots in the Dutch Wadden Sea and Banc d’Arguin

Eldar Rakhimberdiev (NIOZ, Metawad-Waddenfonds)
Demography of red knots and bar-tailed godwits

Dr Jan van Gils

“Decapitation of food webs is more than ‘just’ losing predators”

In the current biodiversity decline, predators are often the first to disappear. Predators are thought to play a positive role in biodiversity maintenance as they prevent certain prey species in achieving dominance, relaxing resource competition among prey, hence promoting prey growth rates, prey coexistence and diversity. Losses of species at the highest trophic levels in communities may therefore cause extinctions and shifts in size structure at lower trophic levels. However, this role of predators is still often underappreciated, largely because many ecosystems have already lost their top-predators and/or human-induced disturbances now blur the positive predation effects. Most of all, the role of migrant predators structuring communities along their migratory route has mostly been neglected.

Aiming to fill this knowledge gap, we study the role of molluscivore shorebirds for intertidal benthic communities, with a focus on the pristine and uninhabited Banc d’Arguin (Mauritania). On their way to and from Mauritania, these shorebirds (re)fuel in the Dutch Wadden Sea, an area that has lost much of its value due to human disturbance (notably bottom-disturbing fisheries). Therefore, molluscivore shorebird numbers are on the decline, both in the Wadden Sea and in West-Africa, and we are investigating whether the benthic community changes observed at Banc d’Arguin may in fact represent ‘spatial knock-on effects’ of human disturbance in the Wadden Sea. Recently, in parallel with the project in Mauritania, a project on crustacean-eating crab plovers in Barr al Hikman (Oman) has started.

Click here for more info on the group and work plan for 2013/14.

Head of the group

Jan van Gils

PhD students

Roeland Bom (ALW) - Cascading predator-prey effects in a pristine seagrass-based food web

Jim de Fouw (VIDI) - The community structuring role of shorebirds in a seagrass based ecosystem

Thomas Oudman (VIDI) - Impact of predation by molluscivore shorebirds on species diversity and size structure of their prey in the Banc d’Arguin (Mauritania)

Middle photograph by courtesy of Jan van de Kam