DDMS · Differential DOM-cycling through Microbes and Sponges
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2020-08-15 → 2023-08-14
- EU contribution
- €253,052
- Participants
- 2
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Differential DOM-cycling through Microbes and Sponges
Coral reefs are a hotspot of biodiversity and productivity in the oceans and provide a plethora of ecosystem services including the support of fisheries, tourism, coastal protection, building materials, and pharmacological products with an estimated value of 352,249 $ ha-1 yr-1. Manmade disturbances, including nutrient pollution and overfishing, threaten these services by compromising the health of corals and at the same time stimulating the growth of algae. Algae release large amounts of dissolved organic matter (DOM). This algal-DOM has been associated with growth of pathogenic bacteria and overall coral reef degradation—the “microbialization of reefs”. Sponges have been proposed to catalyze this reef degradation by feeding on algal-DOM, releasing nutrients, and thereby fertilizing further algal growth at the expense of corals. The aim of this project is to investigate whether bacteria and sponges compete over DOM as food source. Thereto, the composition of coral- and algal-DOM, as well as mixtures representing past, current, and future DOM-producing communities was determined and the uptake and utilization of these DOM-types/-mixtures by bacteria and sponges were tested.
Data: CORDIS, © European Union
Project objective
Anthropogenic disturbances, such as nutrient pollution and overfishing, threaten coral reefs by facilitating community shifts from reef-building corals to algae, increasing production of algal-derived dissolved organic matter (DOM). DOM is the largest food source on reefs, but cannot be consumed by most reef animals. Instead, microbes and sponges transform DOM into particles that re-enter the food web. These recycling pathways, termed the “microbial and sponge loops”, are understood as crucial ecosystem adaptations for reefs to thrive as biological hotspots under nutrient-poor conditions. However, the increased load of algal-DOM on degraded reefs has been associated with the inefficient growth of pathogenic microbes—the “microbialization of reefs”.Sponges have been hypothesized to further stimulate this microbialization by feeding on increased algal-DOM and accelerating algal proliferation via the subsequent release of nutrients. Through this “vicious circle”, microbes and sponges may jointly promote the degradation of coral reefs even faster than the usual, and much more studied, suspects of climate change (i.e., rising seawater temperature and ocean acidification).I aim to determine whether planktonic microbes and sponges compete over DOM (i.e., feed on same or different DOM components) under past, present, and future projections of available DOM. Thereto, I will characterize the composition of different DOM types (e.g., coral- and algal-DOM) and mixtures of DOM representing past, present and future DOM-producing communities and assess their availability (uptake) and utilization (metabolic processing) by planktonic microbes and sponges. I will further assess the ability of planktonic microbes to utilize sponge-processed water and vice versa. With this project I will lay the foundation to integrate microbes and sponges as understudied key ecosystem engineers into coral reef food web frameworks that will allow to elucidate the fate of future coral reefs.
Original text from CORDIS.
Participants
- UNIVERSITEIT VAN AMSTERDAM · AmsterdamCoordinatorNetherlands
- UNIVERSITY OF HAWAII · HonoluluUnited States
Links
Data: CORDIS, © European Union