Coastal ecosystems are susceptible to eutrophication and deoxygenation, which may alter their nitrogen cycle dynamics. Here, we investigated the microbial nitrogen cycling potential in the sediment of a seasonally euxinic coastal ecosystem (Lake Grevelingen, NL) in winter and summer. Activity tests revealed ammonium (NH 4 + ) oxidation potential with maximum potential rates up to 53 μmol g −1 day −1 , even in anoxic sediment l...

Enhanced nutrient input and warming have led to the development of low oxygen (hypoxia) in coastal waters globally. For many coastal areas, insight into redox conditions prior to human impact is lacking. Here, we reconstructed bottom water redox conditions and sea surface temperatures (SSTs) for the coastal Stockholm Archipelago over the past 3000 yr. Elevated sedimentary concentrations of molybdenum indicate (seasonal) hypoxi...

Summary The stoichiometry of prokaryotes ( B acteria and A rchaea ) can control benthic phosphorus ( P ) fluxes relative to carbon ( C ) and nitrogen ( N ) during organic matter remineralization. This paper presents the first experimental data on benthic microbial stoichiometry. We used X ‐ray microanalysis to determine C : N : P ratios of individual prokaryotes from C ‐limited B altic S ea sediments incubated under oxic or an...

Invasive species and bottom‐water hypoxia both constitute major global threats to the diversity and integrity of marine ecosystems. These stressors may interact with unexpected consequences, as invasive species that require an initial environmental disturbance to become established can subsequently become important drivers of ecological change. There is recent evidence that improved bottom‐water oxygen conditions in coastal ar...

The present study examines oxygen and phosphorus dynamics at a seasonally hypoxic site in the Arkona basin of the Baltic Sea. A coupled benthic–pelagic reactive‐transport model is used to describe the evolution of bottom‐water solute concentrations, as well as pore‐water and sediment profiles. Aerobic respiration dominates remineralization, with iron reduction, denitrification, and sulphate reduction playing secondary roles, w...