https://eartharxiv.org/, ss.1-27, 2021 (Hakemsiz Dergi)
Abstract
The Coastal ecosystem of the
Northeastern (NE) Mediterranean has been affected by nutrient inputs originated
from regional rivers and wastewater discharges leading to development of
eutrophication. Atmospheric nutrient inputs have also remarkable contribution
to marine nutrient pool in the NE Mediterranean, especially in dry periods.
Sediment porewater nutrient fluxes into the deep waters are strongly associated
with eutrophic and suboxic/anoxic conditions. There was only limited number of
studies performed on the porewater and solid-state sediment biogeochemistry in
the NE Mediterranean Sea having oxic conditions in the deep waters. In this
study, therefore, sediment porewater (PW) nutrient (Si, N, P) and sediment
organic matter biogeochemistry were studied. The study results indicated a
series of redox reactions (oxic respiration, denitrification, iron reduction)
as well as remarkable contribution of porewater diffusive nutrient fluxes to
the total nutrient budget in the NE Mediterranean Sea. Lower Si/N
and higher N/P molar
ratios in the total nutrient inputs
are very likely to modify phytoplankton composition and abundance in the phosphorus deficient NE Mediterranean productive shelf waters
leading to development of mesotrophic/eutrophic conditions in the NE
Mediterranean Sea.
Keywords: Sediment organic matter, porewater nutrients, nutrient
fluxes, Northeastern Mediterranean Sea