Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8871705 | Marine Pollution Bulletin | 2018 | 9 Pages |
Abstract
The coastal waters of the southeastern Mediterranean-Sea (SEMS) are routinely enriched with naturally-occurring and anthropogenic land-based nutrient loads. These external inputs may affect autotrophic and heterotrophic microbial biomass and activity. Here, we conducted 13 microcosm bioassays with different additions of inorganic NO3-(N), PO4-(P) and Si(OH)4-(Si) in different seasons along the Mediterranean coast of Israel. Our results indicate that cyanobacteria are mainly N-limited, whereas N or Si (or both) limit pico-eukaryotes. Furthermore, the degree to which N affects phytoplankton depends on the ambient seawater's inorganic N and N:P characteristics. Heterotrophic bacteria displayed no response in all treatments, except when all nutrients were added simultaneously, suggesting a possible co-limitation by nutrients. These results contrast the NÂ +Â P co-limitation of phytoplankton and the P-limitation of bacteria in the open waters of the SEMS. These observations enable the application for a better science-based environmental monitoring and policy implementation along the SEMS coast of Israel.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Oceanography
Authors
Eyal Rahav, Ofrat Raveh, Or Hazan, Nurit Gordon, Nurit Kress, Jacob Silverman, Barak Herut,