Dr.ir. Jasper de Goeij, IBED, University of Amsterdam – 14 May 2019

Sponge holobionts bring life — or destruction? — to shallow and deep reef ecosystems


How can tropical coral reefs be so diverse and productive? And how do sponges in the deep-sea create biological hotspots? Sponges are indeed important animals in a variety of marine and freshwater ecosystems (they even occur in the canals of Amsterdam). Apart from their ecological significance, sponges are found to be interesting organisms in a wide variety of scientific fields. From an evolutionary point of view, they are the oldest known multicellular organism on Earth, approximately 700 Million years old. Moreover, they show a striking resemblance to the human gastro-intestinal tract and from a biotechnological point of view, they are considered to be chemical factories, potentially producing the medicines of the future.

Ever since Darwin’s first descriptions of coral reefs, it has been a mystery how one of Earth’s most productive and diverse ecosystems thrives in oligotrophic seas, as an oasis in a marine desert. The common view on how highly productive systems cope with oligotrophic conditions has changed completely with the discovery of the sponge loop by our group. Analogue to the well-established microbial loop, sponge holobionts shunt dissolved organic matter to higher trophic levels, but much faster that pelagic microbes. In this presentation I will discuss to what extent sponges are a driving force in structuring shallow- to deep-sea reef ecosystems. As climate change causes the onset of alterations in the community structure and food web of reef ecosystems, there is evidence accumulating that certain biological pathways are triggered, such as the sponge loop and the microbial loop, that may shift reef ecosystems faster than their original stressors, such as warming oceans and ocean acidification.

Nature of Life seminars

Date       :   14 May 2019

Time       :   15.45 hours

Location:   Room WN-C147, W&N building VU Amsterdam