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IOLR Seaweed Herbarium is an online, digitalized collection of marine macroalgae and includes images, biodata and geo-reference of macroalgal specimens collected from the shores of the Israel Mediterranean Sea. Over the past century, the southeastern Mediterranean Sea experiences enormous ecological changes. The main drivers are the continuous arrival of alien species, mostly from tropical regions and climate change; the Levantine basin being one of the fastest warming regions in the world. Data provided through this collection will contribute in the understanding of macroalgal biodiversity in the region, and specifically, how this taxonomic group has changed over the past decades as a result of climate change, bio-invasions, and a wide range of additional human activities. Each seaweed specimen is a piece of evidence that shows that a species was at a particular place, at a particular point in time. These data create a powerful tool for research, for example to track changes in species distributions.


Collections, Collectors and photos


The oldest samples in our collection are back from 1953 but, unfortunately, the majority of the collector(s) are unaccounted for. Followed by a big gap in time, the second eldest samples are from the 80’s and 90’s, and were mostly organized by Dr. Michael Friedlander and Mrs. Corina Maxim. From about the year 2010, a more systematized and consistent sampling has been in operation at IOLR. Most seaweed samples are collected from the intertidal zone down to ca. 20 m deep, all year around. The National Monitoring Program (, coordinated by IOLR, is a useful platform for collection.

Initially, about 900 specimens will be accessible, with more to be added as they are classified and organized, or as new specimens enter the collection. We have taken images of each specimen so that they can be viewed in detail along with their associated data. An increasing number of the species are being preserved in silica-gel, or cryopreserved at -20 and -70°C, for on-going DNA storage and barcoding, following the vision of IOLR Barcoding Initiative (

Species chosen for the project include non-natives, indicators of environment change, large brown seaweeds, and those of conservation concern. Data are easily accessible by selecting PHYLA followed by alphabetic access of the species. Species and specimen information includes relevant taxonomic information, date of collection, collector and locality, and you soon will be able to browse images of each plate in the media gallery.

Preparing the Specimens

From the time seaweed specimens are collected to the time they are placed in the herbarium cabinets, there is a weeks-long process to prepare them for mounting and storage. After seaweed samples are collected, they are rinsed in freshwater to remove excessive salts. When it is time for pressing, a special herbarium paper is used to mount the seaweed. The specimens are laid on the herbarium paper, covered with a layer of cloth, and placed between blotting papers. In parallel, samples taken from the same collection day are preserved in silica-gel for DNA extractions.

Once all of the specimens have been mounted on herbarium paper, they are then pressed together in a plant press. They are pressed for a week or two before they are completely dried out and ready to be labeled.

After the seaweed is labeled with the scientific name, the location where it was found, collection date, and name of collector, it is cataloged and placed in the herbarium cabinets. These seaweed specimens will be stored and preserved in the cabinets for future use in scientific studies and education.

IOLR Seaweed Herbarium is officially registered at Index Herbariorum



Many people have contributed in the sampling and photographing of seaweed samples, and still do. IOLR is thankful to Rachel Einav for donating valuable preserved material from the Israeli Mediterranean and Red Seas, as well as dried pressed samples from Sicily and France. IOLR is also grateful to the following people for their contribution in seaweed field collections, photography, artwork and advise: Nimrod Krupnik, Gil Rilov, Nir Stern, Tamar Guy-Haim, Eyal Rahav, Guy Paz, Hana Bernard, Hagai Nativ, Doron Ashkenazi, Paula Mohlenkamp, Shahar Matt, Annie Vichik, Elad Israeli, Maura Schonwald, Dar Golomb, Lior Bartal, Andrei Aharonov, Ohad Peled, Noam Israel, Galit Zellermayer, Martina Mulas, Simona Noe, Omri Nahor, Ayala Porat, Jessica Guershon, Andi Qarri and Barbro Lundberg.

Seaweed Herbarium- אוסף אצות 


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