TASCMAR is an international collaborative research project funded under the EU's Horizon 2020 programme for research and innovation. Through a collaboration between 13 academic and commercial project partners in eight countries, TASCMAR seeks to discover novel marine-derived biomolecules with industrial applications, looking to the ocean's under explored mesophotic zone. To find out more about the project and its consortium: http://www.tascmar.eu
The deep blue biodiversity has no limit: new species of octocorals discovered by TASCMAR scientists from mesophotic reefs of Eilat (northern Red Sea)
Hudi Benayahu, Tel Aviv University Mesophotic coral-reef ecosystems (MCEs), which comprise the light-dependent communities of corals and other organisms found at depths between 30 to ~ 150 m, have received very little study to date. However, current technological advances now enable their thorough investigation. Following the reef-building stony corals (=hard corals), octocorals (= soft corals) are the second most common living component on many reefs, the Red Sea included. Octocorals are uniquely characterized by polyps featuring eight pinnate tentacles used by them to sieve food particles from the seawater and/or harvest their symbiotic unicellular algae (zooxanthellae). Their skeleton is comprised of microscopic calcite-made sclerites embedded in their soft tissues. The two latter features make them do distinct from the hard corals, which is their sister group. TASCMAR researchers are conducting the first thorough survey on octocoral communities at the MCEs based on species-level identification, also in comparison to shallower reef zones there. The study was carried out at Eilat (Gulf of Aqaba, northern Red Sea), using belt-transects at the upper MCE sites (30-45 m), in the reef flat and upper fore-reef zone and video recording data at deeper reef sites down to >150 m. We used technical diving for the upper mesophotic surveys and ROV (remote operating vehicle) video recording for the lower mesophotic depths.
So far, more than 45 octocoral species were identified, with higher species richness in the MCEs compared to the shallower reefs. TASCMAR scientists, in their exploration of Eilat's MCEs, have discovered species of octocorals previously unknown to science. Two major discoveries were made, first, a new octocoral, called Altumia delicata was identified as both a new genus and new species of the octocoral family Clavulariidae. The generic name is derived from the Latin ‘altum’, deep, referring to the habitat of the new genus at MCE depths and beyond. This octocoral lives on colonies of dead black corals (Antipatharia) and on artificial substrates at depth deeper than 60 m down to 140 m. It is thus considered to be a lower mesophotic octocoral. The second is a new species of the speciose and widespread tropical genus Sinularia, called Sinularia mesophotica, thus indicating its MCE habitat. This species is the deepest species of that genus recorded in all reefs and suggested to be uniquely adapted to the environmental conditions prevailing in this depth. So far TASCMAR researchers revealed an almost exclusive dominance of zooxanthellate (symbiotic) species at the upper MCE reefs, thus indicating the prevalence of an adequate light regime for photosynthesis there. In deeper MCEs the asymbiotic octocoral species are dominant, becoming the only ones deeper than 55-60 m. The findings should promote similar studies on other reefs, aimed at understanding the octocoral spatio-temporal features and ecological role in reef ecosystems down to the deepest limit of the MCEs.
Credits: Tel Aviv University team in TASCMAR (both images above)
TASCMAR collection mission in Rodrigues island yields a rich collection of sponges, including species new to science
Anne Bialecki, Université de la Réunion
During a TASCMAR collection mission to Rodrigues island organised in October 2016 by Dr Anne Bialecki of the University of Reunion Island, about 25 sponge species were collected. The identification was carried out by Dr Nicole de Voogd, based at Naturalis Biodiversity Center, the Netherlands. The results obtained from this collection were partly incorporated in a manuscript “Calcareous sponges of the Western Indian Ocean and Red Sea” by Rob van Soest & Nicole de Voogd and will be submitted to the journal Zootaxa. Past taxonomic studies of calcareous sponges from this
region have been few and sporadic and lacked sufficient details for reliable identification. The collection from Rodrigues yielded a rich collection of calcareous sponges with in situ photos and the fresh material was selected for DNA sequencing. In the above-mentioned manuscript, we describe three sponge species NEW to science, Borojevia pirella, Leucetta sulcata and Clathrina rodriguenses. In addition, we recorded two other calcareous sponges from Rodrigues, that were recently described in Indonesia (Ernstia naturalis (in 2015) and Australia (Clathrina luteoculcitella in 1999). We expect to record additional new sponge species belonging to the class Demospongiae as well. Although Rodrigues island does not possess high sponge diversity, it does have a unique sponge fauna because of its remote location.
Top left (from left to right): Anne Bialecki, Stéphan Aubert, Jean-Pierre Bellanger, Christian Desseigne, Nicole de Voogd. Bottom right: Clathrina rodriguensis sp. nov. Top right and bottom left: the team during the diving mission. Photos taken by Stéphan Aubert and Nicole de Voogd.
First ever study on MCE soft coral reproduction
Ronen Liberman, Tel Aviv University
We studied the sexual reproduction of the octocoral Rhytisma fulvumfulvum found on Eilat's reefs along a wide depth gradient, including the upper MCE there. It has been found that the shallow colonies (5-10 m) spawned gametes five days prior to the July full moon, whereas none occurred at that time in any of the upper MCE colonies until two weeks later.
These results exhibit the first ever study on MCE soft coral reproduction in a tropical environment. Planula-larvae were removed from the MCE breeding colonies and successfully reared under captivity into juveniles (primary polyps) indicating the potential of farming this species thus becoming a source for biomass production. On day four prior to the new moon, colonies with embryos were observed at 38-45 m (Figure 1), featuring a unique mode of reproduction known as surface brooding.
Colony of Rhytisma fulvum fulvum with surface brooded larvae at Eilat's MCE. Credits: Ronen Liberman
Screening of marine-derived fungi for biodegradation of persistent organic pollutants
Evangelos Topakas, University of Athens The screening of 44 marine-derived microorganisms provided by TASCMAR partners – having been isolated from mesophotic marine invertebrates – led to five candidates that could transform over 50% of initial 2,4-dichlorophenol (dCP) concentration, while seven were capable of transforming over 97% of saturated water with 2,4,5-trichlorobiphenyl (PCB29). dCP and PCB29 are both pollutants presenting severe toxicity to living organisms such as humans or animals, with PCB29 to be considered as Persistent Organic Pollutant (POP). This POP has been well documented since the well-known Stockholm Convention of the United Nations. The main prerequisites for a substance to be considered as a POP are the target molecule to be persistent, bioaccumulative, to have the ability of long-range transport and adverse effects on human health. Seven of the above-mentioned fungi were chosen for further studies since has shown potential in degrading such lethal compounds.
A series of metabolites were identified using special analytical techniques,
such as liquid chromatography-mass spectrometry (LC-MS), following the resting cell biocatalytic reaction utilizing four fungi against dCP. LC-MS is an analytical chemistry technique that combines the physical separation capabilities of liquid chromatography with the mass analysis capabilities of mass spectrometry. These marine microorganisms could transform dCP into less toxic compounds, while one of them could also perform the ‘phenolic ring opening’ of the starting compound, underpinning its potential for the degradation of phenolic compounds. In organic chemistry, phenols or phenolics, are a class of chemical compounds consisting of a hydroxyl group (—OH) bonded directly to an aromatic hydrocarbon group. Such chemical structures are stable and therefore hard to degrade. This ability is crucial for TASCMAR project, since novel marine-derived fungal species could have the potential to degrade POPs. At the moment, the group of University of Athens (UoA) is in progress to elucidate the metabolites created by the bioremediation of PCB29. Searching for such degradation products in the biocatalytic reaction is a difficult task, since their concentration is extremely low reaching the level of 1 ppb (parts per billion). One ppb is like adding a pinch of salt to a 10-ton bag of potato chips…
Major milestone reached - TASCMAR "TARMIC" library now completed
Jamal Ouazzani, CNRS The TASCMAR TARMIC (TARget MICrooraganisms) library is now finalized. It is composed of 302 actinomycetes and fungi from marine mesphotic coral ecosystems (30 to 150m depth). Each strain has been grown under the LSF/SPE and SSF/SSE and extracted with two solvents offering 4 different extracts. Thus 1208 extracts are ready and will soon be submitted to TASCMAR's bioassays intended to discover anti-aging
molecules for pharmaceutical, cosmetic and nutraceutical applications. 100 fungi were selected from this mesphotic microbial collection to be screened for efficient enzymatic activities on selected target substrates covening different recalcitrant organic scaffolds and substituants.
The 100 first actinomycetes from the gulf of Eilat, Israel, were identified and submitted to phylogenic investigation revealing a unique richness and biodiversity. This activity will be extended soon to the whole library. The initial results were presented during the 52nd European Marine Biology Symposium, Portorož (Slovenia), 25-29,September 2017.
Credits: all rights reserved to CNRS-ICSN Pilot Unit
TASCMAR mesophotic session @ EMBS 52
The TASCMAR consortium organized a session of the 52nd European Marine Biology symposium in Portorož, Slovenia (25-29 September 2017), focussing on the theme of mesophotic ecosystems: mysteries and research challenges. The session was a great success, with keen participation both from TASCMAR and specialists in mesophotic ecosystems from diverse institutions accross the globe. More details to follow in a coming TASCMAR newsletter...!