A long term physical and biogeochemical database of a hyper-eutrophicated Mediterranean micro-estuary

Abstract

Ruppin's Estuarine and Coastal Observatory (RECO) is a Long-Term Ecological Research station positioned on the East Mediterranean shoreline between Tel-Aviv and Haifa, Israel. We present a comprehensive online database and an accompanying website that provides direct access to the physical, chemical, and biological characteristics of the local coastal marine ecosystem and the Alexander micro estuary. It includes three databases that are updated continuously since 2014: a) In situ stationary sensors data (10 min intervals) of surface and bottom temperature, salinity, oxygen and water level measured at three stations along the estuary. b) Monthly profiles and discrete biogeochemical samples (surface and bottom water) of multiple parameters at four stations located at the inland part of the estuary. Measured parameters include concentrations of chlorophyll-a, microalgae and bacteria (counted with a flow cytometer), Nitrate, Nitrite, Ammonium, Phosphate, total N, total P, particulate organic matter (POM), total suspended solids (TSS), biochemical oxygen demand (BOD), as well as Secchi depth in each station c) Bi-weekly profiles, chlorophyll-a concentrations and cell counts at two marine stations adjacent to the estuary, (1, and 7 Km from the estuary mouth, at bottom depths of 8 and 48 m). The database also includes historical data for the Taninim micro-estuary (2014–2016). The RECO observatory provides a unique data set documenting the interaction of highly eutrophicated estuarine water with the ultra-oligotrophic seawater of the Eastern Mediterranean. This combination results in sharp gradients of salinity, temperature, dissolved oxygen, and nutrients over very small scales (centimeters to meters) and therefore offers an important data set for the coastal shelf research community. The data set also provide a long-term baseline of the estuary hydrography and geochemistry with the hope to foster effective science-based management and environmental planning of this and similar systems.

Selection of mesophotic habitats by Oculina patagonica in the Eastern Mediterranean Sea following global warming

“…Therefore, we suggest that the rise in sea surface temperature in this region of ca. 3 °C in three decades, reaching 31 °C in the summer 36 , maybe forcing O. patagonica to migrate to deeper waters within the Israeli Mediterranean, which can be 1–2 °C cooler in the summer months 64 (Fig. 1 C).…”

Invading bivalves replaced native Mediterranean bivalves, with little effect on the local benthic community

“…In the lab, the bulk of the algae biomass was scraped into a glass jar using a putty knife, the remaining material was removed using high-pressure jets of NaCl solution (Waterpik, Magic-Jet®, 40 g L −1 NaCl) and collected onto a glass fiber filter, GF/D 47 mm diameter (Whatman®). The scrapings and filter were extracted together with the Hot DMSO (Dimethyl Sulfoxide) method as described in Suari et al ( 2019 ), with some modifications. Briefly, the GF/D filter and algae scraping were transferred to 40 mL EPA vials (Cat No: 9-105, Thermo Fisher Scientific®), eight mL DMSO was added to each vial, and the vials were tightly closed and incubated in the dark at 60 °C for 20 min.…”

Significant SAR11 removal by a hard-bottom community

“…Sampling was conducted off Michmoret, Israel (32° 24′N, 34° 52′E) in the Eastern Mediterranean Sea. The oligotrophic Israeli shoreline is characterized by extremely low nutrient levels (Nitrate 0.5-1 µM, Phosphate 0.05-0.1 µM, Krom and Suari 2015), high salinity (38.3 to 40.0 PSU) and relatively warm waters (16.5 to 30.8°C) (Suari et al 2019) that is dominated in terms of numbers and biomass by pico- and nanoplankton sized organisms (Herut et al 2000, Raveh et al 2015). Water stratification appears usually in spring following a deep winter mixing that is enhanced by the high salinity of surface waters.…”