A team of researchers part of the European project SponGES is in the middle of a busy summer performing experiments on two research cruises and in lab facilities in Bergen (Norway). PhD student Martijn Bart, Post-Doc Benjamin Mueller and MSc students Titus Rombouts and Clea van de Ven (all from UvA-IBED) report from the field.
The SponGES project aims to shed light on the physiology and ecological function of deep-sea sponges. Marine biologist Jasper de Goeij at the Institute for Biodiversity and Ecosystem Dynamics (UvA-IBED) is team leader for the project and received a prestigious ERC starting grant last year for his proposal 'SPONGE ENGINE: Fast and Efficient Sponge Engines Drive and Modulate the Food Web of Reef Ecosystems'.
Deep-sea sponges are ancient animals that dominate the bottom of the seafloor. They play important roles in our oceans as structural components, being nurseries and feeding grounds of various commercial fish species and may have an important role in the cycling of vital elements on Earth, such as carbon, oxygen and sillicon.
Since they can become very old and take many years to grow they are extremely vulnerable to human disturbances, such as oil and gas exploration, seafloor installations and bottom trawling. At present, deep-sea sponge grounds have received little to no attention as to how they function. The SponGES team works towards a better understanding of these vulnerable ecosystems and how to preserve and sustainably use them in the future.
On 20 July, the team set out to sea with the Norwegian research vessel G.O. Sars. The expedition went to the Schultz massive (located between at the Mid-Atlantic ridge between Greenland and Spitsbergen) and the Barentz Sea (South-East of Spitsbergen).
A tour of the research vessel G.O. Sars:
Together with colleagues from various Dutch (e.g., Royal Netherlands Institute for Sea Research NIOZ) and international research groups (e.g. University of Bergen, Natural History Museum of London, Bangor University), IBED’s Jasper de Goeij, Ben Müller and Martijn Bart performed experiments to study respiration rates and the uptake of several food sources (sugars, plankton, bacteria, viruses) by deep-sea sponges at the seafloor.
In collaboration with Dr. Furu Mienis from the Royal NIOZ, the team designed special incubation chambers that can be deployed by the robot arms of a highly sophisticated Remote Operated Vehicle (ROV; the Aegir 6000) that can reach a depth of 6000 m.
The team gathered one-of-a-kind information on 17 sponges between 300 – 1000 meters. The pre-programmed chambers are capable of taking water samples by itself and continuously measure oxygen. Water samples are then later analysed in the lab and will give us information on what sponges feed upon, how much oxygen they respire and what role they play in the nutrient and energy cycling in the deep-sea. Additionally, the ROV was used to collect sponges and study them on-board the ship.
Euronews visited the team on board:
Full article and links here:
The G.O. Sars returned to Bergen on 6 August, where MSc-students Titus Rombouts and Clea van de Ven joined the team to perform additional experiments on the collected sponges to see how they behave in controlled lab-based set ups. The focus is on finding differences and similarities between different deep-sea sponge species and how they interact with other deep-sea fauna.
Students Titus and Clea give a tour of their month in Bergen (click the image for video):
On 30 August, Martijn Bart and Clea van de Ven boarded the Canadian research vessel Martha Black to find different sponge species on the other side of the North-Atlantic. During this cruise to the Emerald basin off the coast of Nova Scotia, more seafloor based experiments are performed with an ROV and specialised incubation chambers. Ben Mueller and Titus Rombouts stay in the lab at the University of Bergen to continue the ex-situ experiments. The Martha Black will return on 7 September.
You can follow the adventures of the SponGES team online: