A long term physical and biogeochemical
database of a hyper-eutrophicated
, Ayelet Dadon-Pilosof
, Tal Sade
, Tal Amit
, Sarig Gafny
, Tom Topaz
, Hadar Zedaka
, Gitai Yahel
Faculty of Marine Science, Ruppin Academic Center, Michmoret, Israel
Porter School of Environmental Studies, Tel Aviv University, Tel Aviv, Israel
Dept. of Soil and Water Sciences, Faculty of Agriculture, Food and Environment, The Hebrew University of
Jerusalem, Rehovot, Israel
Received 11 October 2019
Received in revised form 6 November 2019
Accepted 7 November 2019
Available online 15 November 2019
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 Alex-
ander 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 cy-
tometer), 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-aconcentrations 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
(2014e2016). The RECO observatory provides a unique data set
E-mail addresses: firstname.lastname@example.org,email@example.com (Y. Suari).
Contents lists available at ScienceDirect
Data in brief
journal homepage: www.elsevier.com/locate/dib
2352-3409/©2019 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://
Data in brief 27 (2019) 104809
documenting the interaction of highly eutrophicated estuarine
water with the ultra-oligotrophic seawater of the Eastern Mediter-
ranean. 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.
©2019 The Author(s). Published by Elsevier Inc. This is an open
access article under the CC BY license (http://creativecommons.
Subject Environmental Science (General)
Speciﬁc subject area Long-term database of physical, chemical and biological water properties of a
hyper-eutrophic micro-estuary and the adjacent coastal water
Type of data Tables
How data were
1. Sampling campaigns for CTD, chemical and biological properties.
2. Laboratory analysis of surface and bottom water for water chemistry and biology
3. Continuous sensor sampling for temperature, salinity, oxygen and water level.
Detailed protocols are provided in the website protocols section
Data format Raw and plots
Parameters for data
Data are intended to provide a good temporal and special coverage of
biogeochemical parameters in the estuary.
Description of data
The data are divided into three separate databases and data collection campaigns.
A. Stationary sensors Data.
B. Monthly surveys of water physical and biogeochemical properties along the estuary.
C. Bi-weekly surveys of water physical and biogeochemical properties at marine
stations facing the estuary mouth B and C Data are available as an Ocean
Data View (ODV) ready table that is updated on a monthly basis
Alexander estuary, Israel. Sampling stations:
Station Description Sampling type Lon Lat Bottom Depth (m)
A5 Alexander outfall Monthly 34.865 32.396 ~ 0.2
A4 Michmoret Bridge Monthly, Sensors 34.869 32.393 ~2.4
A3 Mid Estuary Monthly, Sensors 34.891 32.386 ~1.6
A2 Maabarot Monthly 34.905 32.368 ~0.3
A1 Estuary Head Monthly, Sensors 34.908 32.367 ~0.2
S1 Deep marine station ~Biweekly 34.802 32.423 48
S2 Fish cage station ~Biweekly 34.834 32.412 32
S3 Shallow marine station ~Biweekly 34.858 32.402 7
Data accessibility All data are freely available for research and educational purposes. Other usages require
written permission from the author
Data are directly accessible through the project website.
A. Sensors data sensors data can be plotted or downloaded here
B. Inland estuarine stations data can be accessed here:
C. Marine stations data can be accessed here:
Since the monitoring is an on-going process, the data is stored and distributed using a
dedicated website (http://reco.ruppin.ac.il/). Monthly and weekly survey data are
provided in google sheet format (to download select “download as”from the ﬁle menu).
To download or plot continuous sensor data use the self-explanatory interface on the link
Y. Suari, T. Amit, M. Gilboa, T. Sade, M.D. Krom, S. Gafni, T. Topaz, G. Yahel, Sandbar
breaches control of the biogeochemistry of a micro-estuary, Front. Mar. Sci. 6 (2019) 224.
Y. Suari et al. / Data in brief 27 (2019) 1048092
The data we publish at the RECO website originate from a long-term, multi-parameter monitoring
program that covers physical, chemical, and biological water properties at several stations along a
Levantine micro-estuary and its neighboring coastal sea. A summary of the measured parameters,
sampling frequencies, and locations is presented in Table 1 and Fig. 1.
1.1. The data are divided into three separate databases
A. In situ stationary sensors data located 0.2 m below the surface and above the bottom at three
stations along the estuary (near the head, at the middle and near the mouth). These sensors record
temperature, salinity, dissolved oxygen, and water level at 10 minutes intervals. Sensors are
retrieved, serviced and calibrated at least monthly.
B. Monthly surveys of water properties along the estuary. These surveys include water column CTD
proﬁles and data that was obtained from discrete water samples (Table 1).
C. Bi-weekly surveys of water properties at two marine stations ~1 and 6.6 Km from the estuary mouth
at bottom depths of 8 and 48 m. These surveys includewatercolumn CTD proﬁles and data that was
obtained from discrete water samples (Table 1).
2. Experimental design, materials, and methods
2.1. Stationary sensors
A stationary array of moored sensors was used to measure temperature and salinity using DST CT
salinity &temperature loggers (Star Oddi) and dissolved oxygen concentration that were initially
measured with U26-001 data loggers (HOBO, Onset) and later with RBR Solo DO loggers (RBR). The
sensors were positioned at three stations along the estuary. Where bottom depth was deeper than 1 m,
the array consisted of two sets of sensors, one for surface water and one for the “deep”water (~2 m).
The bottom water sensors were connected to a cable and were kept near the bottom by a lead weight.
The surface sensors were connected to a ﬂoat which held them at ~20 cm below the water surface. The
cable carrying the sensors was inserted into a perforated plastic tube canister to protect it from fouling,
vandalism and objects carried by the ﬂow. All sensors were programmed for 10-min measurement
intervals and were serviced and calibrated monthly or more frequently when needed. Retrieval/
deployment cycle took few hours, and then the sensors were returned to the exact same position.
Retrieved data were inspected within few days after retrieval and after a quality check were uploaded
to the online database.
2.2. Marine sampling
An effort was made to conduct the marine surveys on a weekly basis, but sea conditions and
sampling logistics resulted in a sparser sampling scheme, roughly biweekly. Sampling was initially
(starting January 2014) made at three stations in front of the Michmoret anchorage, 1.1e6.6 km
seaward of the estuary mouth at bottom depths of 8, 30 and 48 m but due to the high similarity of the
30 and 48 m stations and the proximity of the 30 m station to a ﬁsh farm, we stopped the sampling at
Value of the Data
Micro-estuaries with a surface area of less than one square kilometer are very abundant and are expected to become more
abundant due to global warming and increased water utilization
This ﬁve-year time series represents typical processes in highly eutrophicated micro-estuary in semi-arid environments
This database can be used to study the effect of environmental conditions on the biogeochemistry of a eutrophicated
The marine database can be used to characterize the climatology along the east Mediterranean continental shelf
Managerial changes planned for the estuary might make this dataset a dataset of reoligotrophication 
Y. Suari et al. / Data in brief 27 (2019) 104809 3
the 30 m depth station at May 1st
2017. Marine surveys were conducted using a small skiff. Vertical
proﬁles of temperature, salinity, oxygen concentration, chlorophyll-aﬂuorescence, and optical back-
scatter were measured using a SeaBird, SBE19Plus V2 CTD equipped with a dissolved oxygen sensor
(SBE43, Seabird) chlorophyll ﬂuorometer (Cyclops 7, Turner Design) and an optical backscatter sensor
(OBS3þ, Campbell Scientiﬁc). Seawater was collected using a 5 L Niskin bottle (Model 110B, OceanTest)
at 10 m depth. Water were collected onboard into dark BOD glass bottles and kept in a dark cool box
until they were ﬁltered or preserved in the lab within 3 hours from collection. Samples were preserved
for extracted Chlorophyll-a(300 ml duplicates) and ﬂow cytometry counts (1.8 mL) as described below.
2.3. Estuarine sampling
Water Sampling was conducted monthly along the estuary during the last week of the month,
starting from January 2014. Both physical and chemical parameters were measured in each station.
Vertical proﬁles of temperature, salinity, oxygen concentration, chlorophyll-a ﬂuorescence and optical
backscatter were measured using the same CTD conﬁguration described for marine sampling. Discrete
water samples were taken in each station using a horizontal water sampler (5L Niskin bottle, Model
110B, OceanTest Equipment). Where and when water depth exceeded 0.5 m, samples were taken from
surface water (~20 cm below surface) and deep water (~20 cm above bottom) otherwise, only one
water sample was collected.
Water samples for inorganic nutrients (Nitrate, Nitrite, Ammonium, and Phosphate) were drawn
directly from the sampler spigot into a disposable syringe and ﬁltered at the ﬁeld through a 0.2
Fig. 1. The location of (a) The Alexander estuary at the Mediterranean Levantine basin denoted by white dot. (b) Coastal streams
along the Israeli coast and speciﬁcally, the Alexander. (c) Sampling points (black dots) along the Alexander estuary (in blue) and near
sea. Position of both marine and estuarine sampling stations is given in kilometers from coastline (The exact station positions are
given in the data sheets at the website, http://reco.ruppin.ac.il/eng/template/?Pid¼26).
Y. Suari et al. / Data in brief 27 (2019) 1048094
syringe ﬁlter (32 mm, PALL Acrodisc). Samples for biological oxygen demand (BOD), total and organic
suspend matter, and chlorophyll-a were collected into dark bottles. All samples were kept in a cool box
on ice. Upon arrival to the laboratory, within 3 hours after collection, 10 mL of the water was ﬁltered
onto glass ﬁbers ﬁlters (25 mm, Whatman GF/F) for chlorophyll-a analysis. Similarly, samples for TSS
and POM were ﬁltered (normally 100e200 mL) on a 47 mm GF/F ﬁlters (Whatman). Chlorophyll
samples and nutrient samples were kept frozen in 20
C until further analysis.
Samples for BOD 5 were aerated to saturation (at least one hour), diluted to 1:5 ratio with air
saturated double distilled water (DDW), transferred into 330 mL BOD bottles and analyzed using a YSI
5100 (YSI) according to the standard method (SM-5210).
2.4. Laboratory analysis
2.4.1. Marine samples analysis
22.214.171.124. Flow cytometry counts.
Flow cytometry was the standard method used to quantify total con-
centrations of the microbial community in the seawater. Samples (1.8 mL) were ﬁxed with Glutaral-
dehyde (EM grade, 50%) to ﬁnal concentration of 0.1% (0.4% for estuarine samples), incubated for 15min
at room temperature, frozen in liquid nitrogen, and stored in 80
C until further analysis with ﬂow
cytometry. An Attune®Acoustic Focusing Flow Cytometer (Applied Biosystems) equipped with a sy-
ringe based ﬂuidic system and 488 and 405 nm lasers, was used to measure the concentration and cell
characteristics of non-photosynthetic microbes and the three dominant autotrophic groups in the
Mediterranean waters: Prochlorococcus,Synechococcus, and eukaryotic algae. Taxonomic discrimina-
tion is based on orange ﬂuorescence of phycoerythrin and red ﬂuorescence of Chlorophyll , side-
Index and meta-data for data collected during monitoring of the Alexander an available at the RECO website.
Parameter Type Sampling type Sampling location Sampling intervals
Temperature þSalinity Physical Moored sensor A1, A3, A4 Surface þbottom 10 min
Water Level Moored sensor A4 10 min
Temperature þSalinity Proﬁles A1, A2, A3, A4 Month
Temperature þSalinity Proﬁles S1, S3 ~Two weeks
Dissolved Oxygen Geochemical Moored sensor A1, A3, A4 Surface þbottom 10 min
Dissolved Oxygen Proﬁles A1, A2, A3, A4 Month
Dissolved Oxygen Proﬁles S1, S3 ~Two weeks
Optical Backscatter Proﬁles A1, A2, A3, A4 Month
Optical Backscatter Proﬁles S1, S3 ~Two weeks
Secchi Depth A1, A2, A3, A4 Month
Suspended Solids Discrete, Surface and bottom A1, A2, A3, A4 Month
Particulate Organic A1, A2, A3, A4 Month
Particulate Inorganic A1, A2, A3, A4 Month
A1, A2, A3, A4 Month
A1, A2, A3, A4 Month
A1, A2, A3, A4 Month
A1, A2, A3, A4 Month
Chl. aFluorescence Biological Proﬁles A1, A2, A3, A4 Month
Chl. aFluorescence Proﬁles S1, S3 ~Two weeks
Extracted Chl. AProﬁles A1, A2, A3, A4 Month
Extracted Chl. AProﬁles S1, S3 Week
Fecal Streptococcus Surface A1 Month
Fecal Coliform Surface A1 Month
Total Bacteria CFU Surface A1 Month
Phytoplankton Surface þbottom A1, A2, A3, A4 Month
Bacteria count Surface A1, A2, A3, A4 Month
Bacteria Surface S1, S3 ~Two weeks
Synechococcus Surface S1, S3 ~Two weeks
Picoeukariotes Surface S1, S3 ~Two weeks
Prochlorococcus Surface S1, S3 ~Two weeks
Y. Suari et al. / Data in brief 27 (2019) 104809 5
scatter (a proxy of cell volume , and forward-scatter (a proxy of cell size, [3,4]. Each sample is
analyzed twice. First, for determination of ultra-phytoplankton with the discriminator (threshold) set
on the red in both the blue and violet lasers. Next, a second run is used to analyze cells with no
autoﬂuorescence, using the nucleic acid stain SYBR Green I and a threshold set on the green in both
lasers. Reference microspheres were used as an internal standard in each sample and all cellular at-
tributes were normalized to the beads.
126.96.36.199. Chlorophyll-a extraction:.
The samples (300 mL duplicates for marine stations and 10 mL for
estuarine stations) were preﬁltered using 100
m net to remove large zooplankton and benthic debris
and ﬁltered onto a Whatman GF/F ﬁlter. Filters were kept frozen at 20
C until processing. To insure
efﬁcient Chlorophyll-a extraction from hardy coastal and estuarine algae we used the Dimethyl Sulf-
oxide (DMSO) extraction method of Burnison , with small modiﬁcations. Brieﬂy, after samples
ﬁltration, the glass ﬁber ﬁlters were placed in 20 mL glass scintillation vials with Teﬂon lined screw
caps. Two mL of DMSO (reagent grade) was added and the vials were incubated at 60
C at dark for 20
minutes. The vials were cooled to room temperature, and 4 mL of buffered aqueous Acetone (90%
Acetone, 10% saturated MgCO
solution) were added to the vials. The vials were vortexed and left for all
precipitation to sink. Fluorometric readings were taken using a Trilogy ﬂuorometer (Turner designs).
Chlorophyll concentration was read using the non-acidiﬁcation ﬂuorometric method  on a Turner
Designs Trilogy ﬂuorimeter calibrated using chlorophyll standards (Sigma C6144). The hot DMSO
extraction method was tested at the study sites against the standard oceanographic method of cold
extraction in 90% acetone and was found to preform similarly on open sea samples but was up to 10
folds more efﬁcient in extracting chlorophyll from estuarine and some nearshore samples (Yahel,
2.4.2. Estuary water analysis
Nutrients determination was carried out manually following standard methods . Starting from
January 2016, duplicates of certiﬁed reference material (Supelco QC3179) was analyzed with every batch
of samples. Brieﬂy, water for nitrite analysis were diluted X10 and nitrate samples were diluted X100 with
prior to analysis with double distilled water (DDW). Nitrate and nitrite concentration was determined
after reduction to nitrite on a cadmium-copper column. The nitrite producedreacts with sulfanilamide in
an acid solution. The resulting diazonium compound is coupled with N-(I-Naphthyl)-ethylenediamine
dihydrochloride to form a colored azo dye, the extinction of which was measured spectrophotometrically
. The precision of the method was estimated at ±14 (8% )
for nitrate and ±2.5
for nitrite based on the variability of triplicates taken in each sampling session.
Phosphate concentration was also measured spectrophotometrically following the molybdate blue
method  after x10 dilution with DDW. The precision is estimated as ±1.5
Ammonium concentration was determined using a modiﬁed version of the Holmes ﬂuorometric
protocol  as described in Supplement 1 of Meeder et al. [11 ] after X1000 dilution with DDW. Brieﬂy,
the method uses a stable working reagent, ortho-phthalaldehyde (OPA) that forms a ﬂuorescent
complex with ammonium. To account for the variability of the estuarine water that results with highly
variable matrix effect, an internal calibration curve was produced for each water sample by spiking
known concentration of ammonium standard solution to 3 of the four 2 mL aliquots drawn from each
water sample that is being analyzed. After all samples were spiked, 0.5 mL of OPA solution was added to
each aliquot and samples were incubated at room temperature in the dark for 4 hr. Fluorescence of the
OPA-ammonium complex was read using the ammonium channel of an Aquaﬂuor ﬂuorometer (Turner
Designs). Corrections for background ﬂuorescence were determined by measuring the ﬂuorescence
on additional aliquots immediately after the addition of OPA. The precision is estimated as ±14
Total and particulate nitrogen, and phosphorus were determined using standard methods 
(4500-N B. and 4500-P J) respectively. Brieﬂy, 15 mL of sample water (for total) and the GF/F ﬁlters (for
particulate) were oxidized with persulfate solution at 120
C for 50 minutes. After digestion, the
digestion product was diluted with DDW (1:10 for phosphate and 1:100 for nitrate). Then, the Nitrate
and Phosphate concentration in the digested solution was determined using the phosphate and nitrate
Y. Suari et al. / Data in brief 27 (2019) 1048096
methods that were described earlier. For the purpose of particulate and total measurements, a cali-
bration curve was measured using increasing dGTP (Guanosine 5
Chlorophyll-a concentration was determined as described for the marine samples above with
precision estimated as ±14
Total suspended solids and particulate organic mater were measured using the standard methods
after minor modiﬁcations (ASTM 2540-B and 2540-E respectively) brieﬂy, before sampling, ﬁlters
(Whatman GF/F) were burned at 300
C for two hours and weighted, then, sampled water were ﬁltered
until the ﬁlters were clogged. The ﬁlters were dried at 60
C for 24 hours and weighted again. TSS
concentration was calculated using equation (1).
is the dry ﬁlter mass after sampling, M
is the ﬁlter mass before sampling, and Vis the
volume of sample water that were ﬁltered. Later, the ﬁlters were ignited in furnace for four hours at
C. POM concentration was calculated using equation (2).
POM ¼TSS Mi
is the ﬁlter mass after ignition. Particulate inorganic matter (PIM) was calculated by sub-
tracting POM from TSS.
We would like to thank to R. Rosenblatt for technical assistance and for accompanying all our
sampling, to the students of the Faculty of Marine Sciences at the Ruppin academic center for helping in
the production of this data, an anonymous fund who ﬁnanced the research in the estuary and the
Ruppin Academic Center who sponsors the website and marine sampling. Partial funding was also
provided by ISF grant No. 1280/13 and BSF grant 2012089 to GY. We would also want to thank the JNF
who will be sponsoring the monitoring during coming years.
Conﬂict of Interest
The authors declare that they have no known competing ﬁnancial interests or personal relation-
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