Geochemical cycles and biodiversity are altered at transition zones of chemosynthetic ecosystems, chemotones. We asked if burrowing alters the functionality of these habitats. We surveyed the seafloor, analyzed sediment properties, and explored microbial communities in ghost shrimp burrows. We made an exciting discovery of chemosynthetic biofilms, linking them to macromolecule turnover and nutrient cycling, using metagenomics. This phenomenon may play an important role in biogeochemical cycles.

The investigation of a 9 m long sediment core recovered at ca. 300 m water depth demonstrates that cold-water coral mound build-up within the East Melilla Coral Province (southeastern Alboran Sea) took place during both interglacial and glacial periods. Based on the combination of different analytical methods (e.g. radiometric dating, micropaleontology), we propose that corals never thrived but rather developed under stressful environmental conditions.

Biochemical reactions related to hydrocarbon seepage are known to induce carbonates in marine sediments. Seep carbonates may act as seals and force lateral deviations of rising hydrocarbons. However, crustacean burrows may act as efficient vertical fluid channels allowing hydrocarbons to pass through upward, thereby allowing the vertical growth of carbonate stacks over time. This mechanism may explain the origin of carbonate columns in marine sediments throughout hydrocarbon provinces worldwide.

This study describes the development of a cold-water Coral mound in the southeast alboran sea over the last 300 ky. Mound development follows interglacial-glacial cycles.