Patterns of phytoplankton community structure and diversity in offshore finfish cages in the Mediterranean Sea (Monastir Bay, Tunisia, 2018)

Sampling event
Latest version published by Hellenic Center for Marine Research on Apr 27, 2026 Hellenic Center for Marine Research

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Description

The dataset includes measurements of key environmental parameters such as temperature, salinity, dissolved oxygen, and nutrient concentrations, together with data on phytoplankton composition and abundance. These data can be used to evaluate the influence of aquaculture activities on water quality and phytoplankton dynamics in coastal Mediterranean ecosystems.

Data Records

The data in this sampling event resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 64 records.

2 extension data tables also exist. An extension record supplies extra information about a core record. The number of records in each extension data table is illustrated below.

Event (core)
64
Occurrence 
3325
ExtendedMeasurementOrFact 
374

This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.

Versions

The table below shows only published versions of the resource that are publicly accessible.

How to cite

Researchers should cite this work as follows:

Challouf R, Medhioub W, Rallis I, Medhioub M N (2026). Patterns of phytoplankton community structure and diversity at finfish offshore cage in the Mediterranean Sea (Bay of Monastir, Tunisia). University of Carthage, National Institute of Marine Sciences and Technologies (INSTM), Salammbô, Tunisia.

Rights

Researchers should respect the following rights statement:

The publisher and rights holder of this work is Hellenic Center for Marine Research. This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License.

GBIF Registration

This resource has been registered with GBIF, and assigned the following GBIF UUID: 7d70a250-4507-4a60-b5c6-ef778ed38fa2.  Hellenic Center for Marine Research publishes this resource, and is itself registered in GBIF as a data publisher endorsed by Ocean Biodiversity Information System.

Keywords

Samplingevent; Phytoplankton; Diversity; Species composition; Toxic microalgae; Aquaculture; Mediterranean Sea

Contacts

Rafika Challouf
  • Metadata Provider
  • Originator
  • Point Of Contact
General Engineer
University of Carthage, National Institute of Marine Sciences and Technologies (INSTM), Marine Biodiversity Laboratory
Salammbô, Tunisia
5000 Monastir
TN
21622700897
Walid Medhioub
  • Originator
  • Point Of Contact
Assistant professor
University of Carthage, National Institute of Marine Sciences and Technologies (INSTM), Aquaculture Laboratory
50000 Monastir
TN
Mohamed Néjib Medhioub
  • Originator
Professor
University of Carthage, National Institute of Marine SciUniversity of Carthage, National Institute of Marine Sciences and Technologies (INSTM), Aquaculture Laboratoryences and Technologies (INSTM), Aquaculture Laboratory
5000 Monastir
TN
Ioannis Rallis
  • Custodian Steward
Data Manager - Marine Biologist
Institute of Marine Biology, Biotechnology and Aquaculture - Hellenic Centre for Marine Research (IMBBC-HCMR)
Heraklion
GR
Dimitra Mavraki
  • Custodian Steward
Data manager
HCMR-IMBBC
Thalassocosmos, Former American Base
71003 Heraklion
Crete
GR

Geographic Coverage

Sampling took place in the Bay of Monastir (Mediterranean Sea, Tunisia)

Bounding Coordinates South West [35.617, 10.803], North East [35.826, 11.121]

Taxonomic Coverage

All phytoplankton were identified to genus or species, including dinoflagellates, diatoms, cyanobacteria, and euglenophytes. Silicoflagellates, foraminifera, and ciliates were identified to genus. Zooplankton and bivalve larvae were recorded as broad taxonomic categories.

Temporal Coverage

Start Date / End Date 2018-02-20 / 2018-10-26

Project Data

Investigating the potential for mussel aquaculture off the coast of Monastir, including assessment of environmental conditions, growth potential, and sustainable farming practices for Mytilus galloprovincialis and Perna perna.

Title Study on the possibilities for exploitation and farming of mussels (Mytilus galloprovincialis and Perna perna) off the coast of Monastir (Tunisia)
Funding This work was supported by the National Institute of Marine Sciences and Technologies (INSTM)
Study Area Description Mediterranean Sea
Design Description The research tasks within this project were carried out by researchers from the National Institute of Marine Sciences and Technologies (INSTM). The team was responsible for field sampling, environmental monitoring, phytoplankton identification, and data analysis. Activities included the collection of plankton samples, laboratory identification of phytoplankton taxa, and the evaluation of environmental conditions related to the potential farming of the mussels Mytilus galloprovincialis and Perna perna off the coast of Monastir (Tunisia).

Sampling Methods

This study was conducted at a sea bream and sea bass aquaculture farm (35°45.902′ N, 10°55.548′ E) located in Monastir Bay near the Monastir-Kuriates Islands, approximately 15 km from the Tunisian Mediterranean coast, at a water depth of 28 m. The farm has been in operation since 2008. Sampling was carried out at four stations in the offshore waters of Monastir (Tunisia, Mediterranean Sea). Stations S1, S2, and S3 were located within the aquaculture farm, whereas station S4 was situated outside the farm and served as a control site. Sampling was conducted seasonally from February to October 2018. Seawater samples were collected using a 5-L Niskin bottle at three depths (0 m, 15 m, and 25 m). The collected samples were preserved and transported to the laboratory for phytoplankton identification and physicochemical analyses.

Study Extent The study was conducted in the offshore fish farm in Monastir, Tunisia (Mediterranean Sea) from February to October 2018. The project focused on phytoplankton taxa .Water samples were collected with a 5-L Niskin bottle.
Quality Control Water samples (1 L) to be used for phytoplankton enumeration were preserved with formol solution (3‰) and stored in the dark at 4 °C.Water samples for nutrient analyses (60 mL) were collected and preserved immediately at − 20 °C in the dark. Water samples for suspended matter analysis were filtered by vacuum filtration through Whatman GF/C glass fiber filters, and the filters were immediately stored at − 20 °C.

Method step description:

  1. Seawater temperature and dissolved oxygen (DO) were measured directly in situ using an electronic thermometer (LUTRON®BC-4308) and a DO meter (PCE®-WO2 10), respectively. To determine the concentration of SM, 1.5 liters of seawater was collected and filtered on pre-weighed GF/C 0.45 µm filters (WHATMAN®). Subsequently, filters were dried in an oven at 100 ◦C for 24 h and total SM weight (mg L-1) was estimated according to the differential weighing method of Aminot and Chaussepied (1983). Transparency of the water (in meters) was measured using a Secchi Disk as described by Testa et al. (2019). Nutrients (i.e., NO2−, NO3−, NH4+, PO43−, and Si(OH)4) were analyzed with a Bran+Luebbe type 3 auto-analyzer and concentrations were determined colorimetrically, using a UV-visible (6400/6405) spectrophotometer. For Chlorophyll a (Chl a), two liters of seawater were filtered, through 200–250 µm pore size membrane filters to remove large particulate matter and zooplankton. The eluate was filtrated on GF/C 0.45 µm filters (WHATMAN®). Chl a was extracted with 10 ml of acetone 90% for 24 hours at 4 ◦C then the absorbance at two wavelengths (665 µm and 750 µm) were determined before and after acidification using 100 µl of HCL 0.3 M according to Aminot and Chaussepied, (1983). The identification and enumeration of phytoplankton (including dinoflagellate cysts) and the estimate of abundance of the different algal groups were made using an inverse phase microscope based on the Utermohl (1931) and Sournia (1987) methods. The identification of the various phytoplankton taxa was achieved through the determination keys of Trégouboff and Rose (1957), Huber-Pestalozzi (1968) and Balech (1988). Phytoplankton density (expressed in cells l-1) is determined using the following formula: N = (n*1000)/V N: Total number of phytoplankton cells contained in one liter n: number of cells V: Volume of sedimentation cuve (ml)

Bibliographic Citations

  1. Medhioub, W., Challouf, R., Laabir, M., Limayem, Y., Bchir, S., Slimeni, W., ... & Azaza, M. S. (2023). Potential to produce brown mussel integrated to a net-cage fish farm in a Mediterranean bay. Aquaculture Reports, 31, 101674. https://doi.org/10.1016/j.aqrep.2023.101674

Additional Metadata

Alternative Identifiers 10.25607/7asluk
10.25607/tzbgyk
7d70a250-4507-4a60-b5c6-ef778ed38fa2
https://ipt.medobis.eu/resource?r=phytomonastirbay2018