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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. Keywords: Micro-estuary, Eutrophication, Marine, Levantine, Coastal
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Data Article
A long term physical and biogeochemical
database of a hyper-eutrophicated
Mediterranean micro-estuary
Yair Suari
a
,
*
, Ayelet Dadon-Pilosof
a
, Tal Sade
a
, Tal Amit
a
,
b
,
Merav Gilboa
a
, Sarig Gafny
a
, Tom Topaz
a
,
c
, Hadar Zedaka
a
,
Shira Boneh
a
, Gitai Yahel
a
a
Faculty of Marine Science, Ruppin Academic Center, Michmoret, Israel
b
Porter School of Environmental Studies, Tel Aviv University, Tel Aviv, Israel
c
Dept. of Soil and Water Sciences, Faculty of Agriculture, Food and Environment, The Hebrew University of
Jerusalem, Rehovot, Israel
article info
Article history:
Received 11 October 2019
Received in revised form 6 November 2019
Accepted 7 November 2019
Available online 15 November 2019
Keywords:
Micro-estuary
Eutrophication
Marine
Levantine
Coastal
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 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
proles 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 ow 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 proles, 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
*Corresponding author.
E-mail addresses: yairsuari@gmail.com,yairs@ruppin.ac.il (Y. Suari).
Contents lists available at ScienceDirect
Data in brief
journal homepage: www.elsevier.com/locate/dib
https://doi.org/10.1016/j.dib.2019.104809
2352-3409/©2019 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://
creativecommons.org/licenses/by/4.0/).
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.
org/licenses/by/4.0/).
Specications Table
Subject Environmental Science (General)
Specic 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
acquired
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
collection
Data are intended to provide a good temporal and special coverage of
biogeochemical parameters in the estuary.
Description of data
collection
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
(http://reco.ruppin.ac.il/eng/template/?Pid¼26).
Data source
location
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
(http://reco.ruppin.ac.il/eng/sensor/)
B. Inland estuarine stations data can be accessed here:
(https://docs.google.com/spreadsheets/d/1-VLXmOMOggn9lV7SBsMzbjeVaFEdWHEINmV1
WL0D0t0/edit?usp¼sharing)
C. Marine stations data can be accessed here:
(https://docs.google.com/spreadsheets/d/1dPFwHSzlA6y6NRV4k1hLH39wZ7hGTjSvUHyin
hBMV-s)
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 asfrom the le menu).
To download or plot continuous sensor data use the self-explanatory interface on the link
(http://reco.ruppin.ac.il/eng/sensor/)
Related research
article
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.
doi: https://doi.org/10.3389/fmars.2019.00224
Y. Suari et al. / Data in brief 27 (2019) 1048092
1. Data
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
proles 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 proles 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 deepwater (~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 oat 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 ow. 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 sh 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 ve-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
micro-estuary
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 [1]
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
proles of temperature, salinity, oxygen concentration, chlorophyll-auorescence, and optical back-
scatter were measured using a SeaBird, SBE19Plus V2 CTD equipped with a dissolved oxygen sensor
(SBE43, Seabird) chlorophyll uorometer (Cyclops 7, Turner Design) and an optical backscatter sensor
(OBS3þ, Campbell Scientic). 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 ltered or preserved in the lab within 3 hours from collection. Samples were preserved
for extracted Chlorophyll-a(300 ml duplicates) and ow 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 proles of temperature, salinity, oxygen concentration, chlorophyll-a uorescence and optical
backscatter were measured using the same CTD conguration 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 ltered at the eld through a 0.2
m
m
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 specically, 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 lter (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 ltered
onto glass bers lters (25 mm, Whatman GF/F) for chlorophyll-a analysis. Similarly, samples for TSS
and POM were ltered (normally 100e200 mL) on a 47 mm GF/F lters (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
2.4.1.1. 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 xed with Glutaral-
dehyde (EM grade, 50%) to nal 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 ow
cytometry. An Attune®Acoustic Focusing Flow Cytometer (Applied Biosystems) equipped with a sy-
ringe based uidic 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 uorescence of phycoerythrin and red uorescence of Chlorophyll [5], side-
Table 1
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 Proles A1, A2, A3, A4 Month
Temperature þSalinity Proles S1, S3 ~Two weeks
Dissolved Oxygen Geochemical Moored sensor A1, A3, A4 Surface þbottom 10 min
Dissolved Oxygen Proles A1, A2, A3, A4 Month
Dissolved Oxygen Proles S1, S3 ~Two weeks
Optical Backscatter Proles A1, A2, A3, A4 Month
Optical Backscatter Proles 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
PO
4
A1, A2, A3, A4 Month
NH
4
A1, A2, A3, A4 Month
NO
2
A1, A2, A3, A4 Month
NO
3
A1, A2, A3, A4 Month
Chl. aFluorescence Biological Proles A1, A2, A3, A4 Month
Chl. aFluorescence Proles S1, S3 ~Two weeks
Extracted Chl. AProles A1, A2, A3, A4 Month
Extracted Chl. AProles 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 [2], 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
autouorescence, 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.
2.4.1.2. Chlorophyll-a extraction:.
The samples (300 mL duplicates for marine stations and 10 mL for
estuarine stations) were preltered using 100
m
m net to remove large zooplankton and benthic debris
and ltered onto a Whatman GF/F lter. Filters were kept frozen at 20
C until processing. To insure
efcient Chlorophyll-a extraction from hardy coastal and estuarine algae we used the Dimethyl Sulf-
oxide (DMSO) extraction method of Burnison [5], with small modications. Briey, after samples
ltration, the glass ber lters were placed in 20 mL glass scintillation vials with Teon 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
3
solution) were added to the vials. The vials were vortexed and left for all
precipitation to sink. Fluorometric readings were taken using a Trilogy uorometer (Turner designs).
Chlorophyll concentration was read using the non-acidication uorometric method [6] on a Turner
Designs Trilogy uorimeter 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 efcient in extracting chlorophyll from estuarine and some nearshore samples (Yahel,
unpublished data).
2.4.2. Estuary water analysis
Nutrients determination was carried out manually following standard methods [7]. Starting from
January 2016, duplicates of certied reference material (Supelco QC3179) was analyzed with every batch
of samples. Briey, 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
[8]. The precision of the method was estimated at ±14 (8% )
m
mol L
1
for nitrate and ±2.5
m
mol L
1
(10%)
for nitrite based on the variability of triplicates taken in each sampling session.
Phosphate concentration was also measured spectrophotometrically following the molybdate blue
method [9] after x10 dilution with DDW. The precision is estimated as ±1.5
m
mol L
1
(±4%).
Ammonium concentration was determined using a modied version of the Holmes uorometric
protocol [10] as described in Supplement 1 of Meeder et al. [11 ] after X1000 dilution with DDW. Briey,
the method uses a stable working reagent, ortho-phthalaldehyde (OPA) that forms a uorescent
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 Aquauor uorometer (Turner
Designs). Corrections for background uorescence were determined by measuring the uorescence
on additional aliquots immediately after the addition of OPA. The precision is estimated as ±14
m
mol L
1
(±4%).
Total and particulate nitrogen, and phosphorus were determined using standard methods [7]
(4500-N B. and 4500-P J) respectively. Briey, 15 mL of sample water (for total) and the GF/F lters (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
0
-triphosphate, C
10
H
16
N
5
O
14
P
3
PCR
grade) concentration.
Chlorophyll-a concentration was determined as described for the marine samples above with
precision estimated as ±14
m
mol L
1
(±14%).
Total suspended solids and particulate organic mater were measured using the standard methods
after minor modications (ASTM 2540-B and 2540-E respectively) briey, before sampling, lters
(Whatman GF/F) were burned at 300
C for two hours and weighted, then, sampled water were ltered
until the lters were clogged. The lters were dried at 60
C for 24 hours and weighted again. TSS
concentration was calculated using equation (1).
TSS ¼MaMb
V(1)
where, M
a
is the dry lter mass after sampling, M
b
is the lter mass before sampling, and Vis the
volume of sample water that were ltered. Later, the lters were ignited in furnace for four hours at
450
C. POM concentration was calculated using equation (2).
POM ¼TSS Mi
V(2)
where M
I
is the lter mass after ignition. Particulate inorganic matter (PIM) was calculated by sub-
tracting POM from TSS.
Acknowledgments
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 nanced 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.
Conict of Interest
The authors declare that they have no known competing nancial interests or personal relation-
ships that could have appeared to inuence the work reported in this paper.
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Y. Suari et al. / Data in brief 27 (2019) 104809 7
... The external inputs of nutrients from atmospheric inputs (Ben-Ezra et al., 2021) and from riverine input (Herut et al., 2000;Suari et al., 2019) to the ICS are higher in winter. Thus the pelagic and ICS have similar atmospheric inputs, which are higher in winter (57%) compared with summer (Ben Ezra et al., 2021). ...
... Thus the pelagic and ICS have similar atmospheric inputs, which are higher in winter (57%) compared with summer (Ben Ezra et al., 2021). As is typical of a Mediterranean climate area, the rivers and streams tend to flow with much greater volume and nutrient flux in winter (Suari et al., 2019). Although there is no direct evidence it is likely that both SGD and domestic waste discharge would be higher in winter than in summer. ...
... The database presents concentrations of organic pollutants (columns I-CH) measured during two consecutive years at the head and mouth of the Alexander micro-estuary, Israel. Metadata (columns A-I) includes flow type (baseflow, flood event), the event ID code (B for baseflow, F for flood, two first digits for year, and the following digit for the order of the event within that year), Station (A0 for estuary head, A4 for estuary mouth, see [1] ), Sample number, Date, Hour, the measured section duration (in minutes), Average discharge for the section measured (in m 3 sec −1 ), and the section volume (duration multiplied by discharge, in m 3 ). Columns J-CH present pollutants concentrations in μg L −1 . ...
... The dynamics and toxicity of pollutants in the system were described by Topaz et al. [ 1 , 2 , 6 ]. A comprehensive database that contains 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, monthly CTD profiles, and discrete biogeochemical samples (surface and bottom water) of multiple biogeochemical parameters at four stations along the estuary is provided by Ruppin's Estuarine and Coastal Observatory (RECO), see [1] . ...
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... The scrapings and lter were extracted together with the Hot DMSO (Dimethyl Sulfoxide) method as described in Suari et al. (2019), with some modi cations. Brie y, the GF/D lter and algae scraping were transferred to 40 mL EPA vials (cat no:9-105, Thermo Fisher Scienti c®), eight mL DMSO was added to each vial, and the vials were tightly closed and incubated in the dark at 60℃ for 20 minutes. ...
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Constructing the Suez Canal connected the Red Sea and the Mediterranean Sea, allowing rapid marine bio-invasion. Over the last century, several bivalve species have invaded the Levantine basin, yet their distribution and impact on the benthic community have not been thoroughly studied. Large-scale benthic surveys along the rocky substrate of the Israeli Mediterranean coastline indicate that invading bivalves now dominate the rocky environment, reaching densities of tens to hundreds of individuals per m ² . No native bivalve specimens were found in any of the transects surveyed. The small-scale ecological effects of the established invading populations on the benthic community were examined using in-situ exclusion experiment where all invading bivalves were either physically removed or poisoned and kept in place to maintain the physical effect of the shells. Surprisingly, the experimental exclusion showed little measurable effect of bivalve presence on the invertebrate community in close vicinity (~1 m). Bivalves presence had a small, but statistically significant, effect only on the community composition of macroalgae, increasing the abundance of some filamentous macroalgae, and reducing the cover of turf. The generally low impact of invading bivalves could be due to (1) wave activity and local currents dispersing the bivalve excreta, (2) high grazing pressure, possibly by invading herbivorous fish, reducing the bottom-up effect of increased nutrient input by the bivalves, or (3) the natural complexity of the rocky habitat masking the contribution of the increased complexity associated with the bivalve’s shell. We found that established invading bivalves have replaced native bivalve species, yet their small-scale effects on the benthic community seem to be negligible.
... Along the Israeli Mediterranean shoreline at the SE Mediterranean Sea, the bathymetry of the lower parts of several coastal streams enables the penetration of seawater and the formation of ecologically unique highly stratified small-size estuaries up to a few kilometers inland [13][14][15][16][17][18]. These small estuarine water systems are exposed to severe anthropogenic pressures and low natural water flow, holding high nutrient contamination and low water quality conditions, and may induce HABs [19,20]. ...
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Nutrient pollution may negatively affect the water quality and ecological status of rivers and estuaries worldwide, specifically in stratified and small inland estuaries. We present a long-term, two-decade data set of dissolved inorganic nutrient concentrations, chlorophyll-a (chl-a), dissolved oxygen (DO), and potentially toxic algal cell concentrations at the Kishon River estuary (Israel) as a case study for assessing nutrient ecological thresholds in such type of estuaries, prevalent along the Mediterranean coast of Israel. In-situ measurements and water samples were collected at 3 permanent stations at the lower part of the estuary every March and October/November in 40 campaigns over the years 2002 to 2021. In spite of an improvement in nutrient loads and concentrations as recorded over the last 2 decades, the nutrient and chl-a levels at the Kishon estuary surface water represent mostly a ‘bad’ or ‘moderate’ ecological state, considering the recommended thresholds discussed in this study. It is suggested to develop a combined suite of nutrient and biological variables for assessing Good Environmental Status (GES), considering the relatively high residence time of such small, low-flow estuarine water bodies.
... 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. ...
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The construction of the Suez Canal connected the Red Sea and the Mediterranean Sea, which allowed rapid marine bio-invasion. Over the last century, several bivalve species have invaded the Levantine basin, yet their distribution and impact on the benthic community have not been thoroughly studied. Large-scale benthic surveys along the rocky substrate of the Israeli Mediterranean coastline indicate that invading bivalves, such as Spondylus spinosus, Brachidontes pharaonis, and Pinctada radiata, now dominate the rocky environment, with densities of tens to hundreds of individuals per m². No native bivalve specimens were found in any of the transects surveyed. The small-scale ecological effects of the established invading populations on the benthic community were examined over a year using an in-situ exclusion experiment where all invading bivalves were either physically removed or poisoned and kept in place to maintain the physical effect of the shells. Surprisingly, the experimental exclusion showed a little measurable effect of bivalve presence on the invertebrate community in close vicinity (~ 1 m). Bivalve presence had a small, but statistically significant, effect only on the community composition of macroalgae, increasing the abundance of some filamentous macroalgae and reducing the cover of turf. The generally low impact of bivalves removal could be due to (1) wave activity and local currents dispersing the bivalve excreta, (2) high grazing pressure, possibly by invading herbivorous fish, reducing the bottom-up effect of increased nutrient input by the bivalves, or (3) the natural complexity of the rocky habitat masking the contribution of the increased complexity associated with the bivalve’s shell. We found that established invading bivalves have replaced native bivalve species, yet their exclusion has a negligible small-scale effect on the local benthic community.
... Along the Israeli Mediterranean shoreline at the SE Mediterranean Sea, the bathymetry of the lower parts of several coastal streams enables the penetration of seawater and the formation of ecologically unique highly stratified small-size estuaries up to a few kilometers inland [13][14][15][16][17][18]. These small estuarine water systems are exposed to severe anthropogenic pressures and low natural water flow, holding high nutrient contamination and low water quality conditions, and may induce HABs [19,20]. ...
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Seaweeds may contain significant amounts of essential proteins, carbohydrates, and minerals, offering an alternative, sustainable, healthy food source from the sea. However, there are yet challenges impending their full exploitation. Our study presents an innovative, two-step aquaculture approach integrating seaweeds and finfish, dedicated to enrich seaweeds with nutritional compounds. The approach involves diverting fish effluents rich in nutrients into a series of seaweed cultivation tanks. Then, the seaweeds were exposed to short-term abiotic stressors (namely, high irradiance, nutrient starvation, and high salinity) to stimulate synthesis of desired ingredients in their tissues. Our methodology enabled high growth rates of up to 25% seaweed biomass increase per day, with significant enhancements in the amount of protein, starch, and minerals within days. Moreover, the seaweeds presented elevated bioremediation capabilities assimilating the ammonia nitrogen, NO3 and PO4 with high uptake rates, and with 50–75% removal efficiencies. Industrial relevance The rising public awareness to quality of healthier food products has stimulated growing demand for seaweed supply. Our new approach suggests a promising direction toward the transition from seaweed production of raw, commodity seaweed biomass, to a tailored production of functional seaweeds, enriched with valued compounds that can be utilized in the emerging food and health industries.
... Previous work has shown that, regardless of the prevailing thermal regime, O. patagonica has a fixed thermal threshold of 32 °C 7 . 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. 1C). ...
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Data from a bathymetric mapping project conducted in seven Israeli coastal micro-estuaries (Lachish, Sorek, Yarkon, Alexander, Hadera, Taninim, and Kishon) is presented. The data were collected by rowing a kayak along an S-shaped track through the estuaries. An echosounder equipped with a Global Positioning System (GPS) unit were mounted on the kayak. The data preparation consisted of a) manual removal of outliers, mostly caused by instrument echo in water depths below the instrument's 0.5 m minimum; b) correction of the measured water level to sea level; and c) interpolation of the sampling points into a regular grid using a terrain-following interpolation algorithm. For each of the estuaries, the raw measurements as a text (csv) file and the interpolated data both as a text (CSV) file and a GeoTiff file were produced.
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A heterogeneous reduction method is described for the determination of nitrate in sea water. Nitrate is reduced to nitrite with 91% efficiency by passing the water through a column of amalgamated cadmium filings. The nitrite produced is determined spectrophotometrically by the method of BENDSCHNEIDER and ROBINSON. The method has a coefficient of variation of ca. 2% and is free from salt error. Temperature in the range o°-35° has no effect on the reduction. Interference from nitrite is discussed and a method is described for its destruction if necessary. Sulphide does not interfere.
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A heterogeneous reduction method is described for the determination of nitrate in sea water. Nitrate is reduced to nitrite with 91% efficiency by passing the water through a column of amalgamated cadmium filings. The nitrite produced is determined spectrophotometrically by the method of BENDSCHNEIDER and ROBINSON. The method has a coefficient of variation of ca. 2% and is free from salt error. Temperature in the range o°–35° has no effect on the reduction. Interference from nitrite is discussed and a method is described for its destruction if necessary. Sulphide does not interfere.RésuméUne méthode est décrite pour le dosage des nitrates dans l'eau de mer. Les nitrates sont réduits en nitrites par passage de l'eau à travers une colonne remplie d'amalgame de cadmium. Le nitrite formé est dosé spectrophotométriquement par la méthode de BENDSCHNEIDER et ROBINSON. L'influence des nitrites est examinée; une méthode est proposée pour leur destruction, si nécessaire. Les sulfures ne gênent pas.ZusammenfassungEs wird cine Methode zur Bestimmung von Nitrat im Meerwasser beschrieben. Das Nitrat wird zum Nitrit reduziert, indem das Wasser durch eine Kolonne mit amalgamierten Kadmiumspänen läuft. Das gebildete Nitrit wird nach der Methode von BENDSCHNEIDER und ROBINSON spektralphotometrisch bestimmt. Die Methode hat einen Variationskoeffizienten von ca. 2% und ist frei von Salzfehlern. Der Einfluss des im Meerwasser enthaltenen Nitrits wird diskutiert und eine Methode für scine Zerstörung beschrieben. Sulfid stört nicht.
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The concentration of chlorophyll in laboratory grown cultures of marine phytoplankton and in oceanic samples has been determined both by measurement of fluorescence and by measurement of light absorption. The lower limit for detection of chlorophyll by fluorescence with the instrumentation described is about 0·01 μg chlorophyll a, which is about 5% that required for a spectro-photometric determination. Through choice of appropriate filters, the amount of fluorescence reflects either the chlorophyll a concentration or the sum of chlorophylls a and c. By measurement of fluorescence before and after acidification, the ratio of chlorophyll to phaeophytin can be readily determined. Dilute HCl is superior to oxalic acid for acidification of pigment extracts. As the fluorometric determination of chlorophyll and phaeophytin is fast, reliable and sensitive, it will be very useful in field studies of productivity.
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This new extraction procedure eliminates the need for grinding glass fiber filters by heating the filter in DMSO (4 mL) for 10 min at 65 °C and subsequently filtering or centrifuging the sample after dilution with 90% acetone (6 mL). Scenedesmus and Selenastrum species gave about 20% higher concentrations of chlorophyll a using this method as compared to the standard 90% acetone procedure or grinding in DMSO only. The difference between heated DMSO and 90% acetone was reduced when natural phytoplankton were analyzed.Key words: chlorophyll, Chlorophyta, dimethyl sulfoxide, acetone, extraction
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A single solution reagent is described for the determination of phosphorus in sea water. It consists of an acidified solution of ammonium molybdate containing ascorbic acid and a small amount of antimony. This reagent reacts rapidly with phosphate ion yielding a blue-purple compound which contains antimony and phosphorus in a 1:1 atomic ratio. The complex is very stable and obeys Beer's law up to a phosphate concentration of at least 2 μg/ml.The sensitivity of the procedure is comparable with that of the stannous chloride method. The salt error is less than 1 %.RésuméUne méthode spectrophotométrique est décrite pour le dosage du phosphate dans l'eau de mer, an moyen de molybdate d'ammonium, en présence d'acide ascorbique et d'antimoinc. Il se forme rapidement un composé violet bleu, renfermant antimoine et phosphore dans un rapport atomique de 1:1.ZusammenfassungBeschreibung einer Methode zur Bestimmung von Phosphat in Mecrwasser mit Hilfe von Ammoniummolybdat in Gegenwart von Ascorbinsäure und Antimon. Der gebildete blau-violette Komplex wird spektrophotometrisch gemessen.
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Single-cell forward light scattering patterns have been examined for four algal species (one pennate diatom, two green flagellates and one filamentous cyanobacterium), mounted statically in a focused laser beam. In all cases, the distribution of light intensity at narrow angles (within the first scattering lobe) is well described by diffraction theory. Narrow-angle forward scattering measurements can therefore be used in principle to deduce the size and approximate shape of algal cells. The feasibility of using this technique in flow cytometry has been tested using an instrument which orientates elongated cells uniformly in the flow stream, and uses fibre optics to make azimuthally resolved forward scatter measurements at sub-degree polar angles. With this instrument it is possible to discriminate between species with similar volume and fluorescence characteristics using forward light scattering as a shape-sensitive parameter.