Institute for Biodiversity and Ecosystem Dynamics

Photographer: Jan van Arkel

dr. B. (Benjamin) Müller


  • Faculty of Science
    IBED
  • Visiting address
    Science Park A
    Science Park 904  Amsterdam
  • Postal address:
    Postbus  94248
    1090 GE  Amsterdam
  • B.Muller@uva.nl

I am a marine biologist, working as a post-doctoral researcher in the working group of Jasper de Goeij at the department of Freshwater and Marine Ecology. In our research group we investigate the role of sponges as key ecosystem engineers of shallow- and deep-sea reef ecosystems and aim to develop sponges as animal models. Besides conducting research, my main tasks include the coordination of field and lab activities, as well as the supervision and guidance of Ph.D., M.Sc. and B.Sc. students in our research group.

Research Interests

  • Energy and nutrient cycling through sponge- and microbe-mediated pathways
  • Effect of environmental parameters on dissolved organic matter release mechanisms and consequences for ecosystem functioning
  • DOM dynamics on pristine and phase shifting reefs
  • Role of DOM in coral-algal competitions
  • Bioeroding sponges on phase-shifting reefs

Current Projects

SPONGE ENGINE — Fast and efficient sponge engines drive and modulate the food web of reef ecosystems

The aim of this ERC project awarded to Jasper de Goeij is to systematically establish a novel reef food web framework including:

          Corals and algae, releasing DOM “fuel” to run the engine

          Sponges, the “engine”, taking up DOM and converting energy and nutrients stored in it into particulate detritus

          Detrivores, which feed on the sponge detritus and serve as food for higher trophic levels, the “driven communities”

Corals and algae release DOM. Sponges take up this “fuel” and convert energy and nutrients stored in it into particulate detritus. Detritivores feed on the detritus, serve as food for higher trophic levels, the “driven communities”, and release inorganic nutrients that are taken up by the fuelling communities.

In this project we evaluate (1) how the morphology of sponges and their associated microbes contribute to the processing of DOM, (2) which roles sponge cells themselves and associated microbes play in the DOM uptake. These physiological tasks are complimented by (3) assessing carbon and nitrogen fluxes from fuelling communities, through sponges, to the driven communities.

 

 

SponGES — Deep-sea Sponge Grounds Ecosystems of the North Atlantic: an integrated approach towards their preservation and sustainable exploitation

As part of this multi-lateral EU project SponGES, our team aims to assess carbon fluxes and transfer through deep-sea sponges, and to test the existence of a sponge loop pathway on deep-sea sponge grounds.

By combining in situ and ex situ incubations using natural food and isotopically labelled food sources we will quantify carbon and oxygen fluxes of different deep-sea sponge species and trace the carbon and nitrogen from dissolved and particulate food sources, through sponges, sponge detritus, and ultimately detrivores, that feed on sponge detritus.

Our results will contribute to develop an integrated ecosystem-based approach to preserve and sustainably use deep-sea sponge grounds within the SponGES project.

Field Trip Curacao_February - March 2017

Left: M.Sc. student Koen Tomson and B.Sc. student Mainah Folkers bringing cages to the study site. Right: Cages with set ups to determine in situ detritus production by encrusting sponges.

Koen and Mainah setting up cages and working under water.

Left: Sponges hanging upside-down over funnels to determine detritus production by encrusting sponges. Right: Three of the investigated sponge species growing next to each other - Chondrilla caribensis (red), Scopalina ruetzleri (orange), and Halisarca caerulea (purple).

Left: Growth experiment with the encrusting sponge Haliclona vansoesti. Right: Koen and Mainah getting back on the boat after a dive.

 

 

Field work as Researcher at the CARMABI research station on Curacao_April 2015 - December 2016

Left: Investigating the combined effects of light and nutrient availability in turf algal-coral interactions. Right: Determining community changes in cryptic sponge communities in permanent quadrats.

In collaboration with Emma George and other researchers of the Rohwer and Wegley-Kelly Lab, San Diego, we investigated the outcome of coral-algal interactions (left) and the role of the over geometry for this outcome.

Coral spawning of Orbicella faveolata (left) and Diplora strigosa (right) captured with fluorescence photography.

Left: Outplaning of lab-fertilized coral settlers on artificial substrates with SECORE volunteers Natalia Hurtado and Emily Chappell. Right: Investigating the day and night release of DOM released by turf algae in collaboration with researchers from the Max-Planck Institute for Marine Microbiology, Bremen, University of Amsterdam, and Rohwer and Wegley-Kelly Lab, San Diego.

 

 

Field work on Curacao and Bonaire during my Ph.D. at the Royal Netherlands Institute for Sea Research (NIOZ)_February 2010 - December 2015 

Taking water samples (left) and measuring light intensity (right) in close proximity to corals and algae on the reef.

Left: Drilling cores with bioeroding sponges out of coral rock. Middle: Incubation experiment with turf algae growing on plastic bottles. Right: Sealing DOC vials with a bunsen burner in the lab.

Left: Testing the Vacu SIP device with Jasper de Goeij. Right: Sampling of the in- and out-flowing water of the bioeroding sponge Cliona delitrix with the Vacu SIP device.

  • No ancillary activities

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