To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L −1 ), and its subsets (2 depth types and 3 climatic...

Sponges are commonly divided into high (HMA) and low (LMA) microbial‐abundance species according to the bacterial biomass in their tissue. These two groups reflect distinct aquiferous structures and feeding strategies. In the NW Mediterranean coralligenous community, HMA and LMA sponges are often packed in dense, multispecies assemblages that cover many pinnacles and overhangs. We investigated the metabolism of HMA and LMA spe...

Microbes are known to form intricate and intimate relationships with most animal and plant taxa. Microbe–host symbiotic associations are poorly explored in comparison with other species interaction networks. The current paradigm on symbiosis research stems from species‐poor systems where pairwise and reciprocally specialized interactions between a single microbe and a single host that coevolve are the norm. These symbioses inv...

Summary Most marine sponges establish a persistent association with a wide array of phylogenetically and physiologically diverse microbes. To date, the role of these symbiotic microbial communities in the metabolism and nutrient cycles of the sponge‐microbe consortium remains largely unknown. We identified and quantified the microbial communities associated with three common Mediterranean sponge species, Dysidea avara , Agelas...

Late in summer 2003, extensive mass mortality of at least 25 rocky benthic macro‐invertebrate species (mainly gorgonians and sponges) was observed in the entire Northwestern (NW) Mediterranean region, affecting several thousand kilometers of coastline. We were able to characterize the mortality event by studying six areas covering the main regions of the NW Mediterranean basin. The degree of impact on each study area was quant...