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Black coral farming: the potential is real / Elevage de corail noir : le potentiel est réel

October 12, 2021 Comments Off on Black coral farming: the potential is real / Elevage de corail noir : le potentiel est réel By administrateur

Depuis 2014, l’exploitation de coraux noirs (Tangoaraky) est devenue une activité illicite à Madagascar (En savoir …). Mais les services de pêche continuent à appréhender les braconiers de la mer qui risquent leur vie en plongée quasiment sans protection à une profondeur qui va jusqu’à 80m pour recolter des coraux noirs sauvages, souvent agés de plusieurs centaines d’années.

Pourquoi ne pas élever des coraux noirs ?

Des chercheurs ont découvert qu’il est possible de faire l’aquaculture des coraux noirs, malgré leur croissance lente.

Résumé de la publication

Afin de tester la faisabilité de la transplantation de l’espèce de corail noir fouet Cirrhipathes anguina (Dana, 1846) de Madagascar, des transplants ont été installés sur des tables de culture dans deux sites (la passe Nord et la Grande Vasque du Grand Récif de Toliara) caractérisés par des conditions environnementales distinctes. Après la transplantation, les greffons ont été suivis pour les capacités de cicatrisation à court terme (20 jours) et les taux de mortalité et de croissance à moyen terme (200 jours). Les résultats montrent une transplantation réussie dans les deux sites avec 0% de mortalité (sauf sous forme de fragments manquants) et une certaine croissance sur 200 jours. Les taux de croissance maximaux étaient respectivement de 3,4 cm/mois et 2,0 cm/mois dans la Passe Nord et dans la Grande Vasque. De plus, le temps moyen de cicatrisation totale a été retardé dans la Grande Vasque par rapport aux transplants de la Passe Nord (10 jours). Les différences entre les sites sont probablement liées à des différences dans les paramètres environnementaux. Dans l’ensemble, les résultats prometteurs obtenus avec le protocole simple utilisé dans cette étude encouragent l’utilisation de greffes de corail noir dans d’autres expériences in situ et projets de restauration.

Ces résultats encouragent également à poursuivre les recherches sur l’élevage de ces animaux inscrits dans l’annexe 2 de la convention sur le commerce international des espèces de faune et de flore sauvages menacées d’extinction (CITES), afin de palier aux problèmes de menaces et satisfaire le besoin du marché de squelettes de coraux noirs avec des produits provenant de l’aquaculture respectueuse de l’Environnement.

Lire l’article complet: Mathilde Godefroid, Gildas Georges BoleslasTodinanahary, Philippe Dubois, IgorEeckhaut, NicolasSturaro, GillesLepoint, LucasTerrana (2021) Perspectives on working underwater with black coral nubbins (Cnidaria: Antipatharia): The case of Cirrhipathes anguina (Dana, 1846). Journal of Experimental Marine Biology and Ecology 545 (2021) 151645 (DOI: https://doi.org/10.1016/j.jembe.2021.151645)

Black corals experimental farming overview
Aperçu de l’élevage expérimental de coraux noirs

English

Since 2014, the exploitation of black corals (Tangoaraky) has become an illegal activity in Madagascar (Read more …). But the Fisheries department continue to apprehend the poachers of the sea who risk their lives diving almost unprotected at a depth of up to 80m to harvest wild black corals, often several hundred years old.

Why not breed black corals?

Researchers have discovered that it is possible to aquaculture black corals, despite their slow growth.

Abstract of the research paper

In order to test the feasibility of transplantation of the whip black coral species Cirrhipathes anguina (Dana, 1846)  from Madagascar, transplants were installed on cultivation tables in two sites (the North Pass and the Grande Vasque) characterized by distinct environmental conditions. Following transplantation, the transplants were followed for short-term (20 days) healing capacities and medium-term (200 days) mortality and growth rates. Results show a successful transplantation in both sites with 0% mortality (except in the form of missing fragments) and a certain growth over 200 days. Maximum growth rates were 3.4 cm/month and 2.0 cm/month in the North Pass and in the Grande Vasque, respectively. In addition, mean time to total healing was delayed in the Grande Vasque compared to the transplants in the North Pass (10 days). Differences between sites are likely to be related to differences in environmental parameters. Altogether, the promising results obtained with the easy protocol used in this study encourage the use of black coral transplants in further in situ experiments and restoration projects.

These results also encourage further research on the breeding of these organisms listed in Annex 2 of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), in order to overcome the problems of threats and satisfy the market need for black coral skeletons with products from environmentally friendly aquaculture.

 

Read the full article: Mathilde Godefroid, Gildas Georges BoleslasTodinanahary, Philippe Dubois, IgorEeckhaut, NicolasSturaro, GillesLepoint, LucasTerrana (2021) Perspectives on working underwater with black coral nubbins (Cnidaria: Antipatharia): The case of Cirrhipathes anguina (Dana, 1846). Journal of Experimental Marine Biology and Ecology 545 (2021) 151645 (DOI: https://doi.org/10.1016/j.jembe.2021.151645)

 

Corals and black corals: check out these 2 new articles published

October 6, 2021 Comments Off on Corals and black corals: check out these 2 new articles published By administrateur

Check out these two new articles published on corals and black corals … Enjoy reading

Découvrez ces deux nouveaux articles publiés sur les coraux et les coraux noirs … Bonne lecture

Article 1

“Spatial Patterns of Coral Community Structure in the Toliara Region of Southwest Madagascar and Implications for Conservation and Management”

Cite the article: Botosoamananto RL, Todinanahary G, Razakandrainy A, Randrianarivo M, Penin L, Adjeroud M. Spatial Patterns of Coral Community Structure in the Toliara Region of Southwest Madagascar and Implications for Conservation and Management. Diversity. 2021; 13(10):486. https://doi.org/10.3390/d13100486 (Download PDF)
Received: 30 August 2021 / Revised: 26 September 2021 / Accepted: 2 October 2021 / Published: 5 October 2021

Abstract

The Great Reef of Toliara, on the southwestern coast of Madagascar, has been documented as harbouring flourishing reef communities in the 1960s, but has since been affected by various threats, causing a coral decline last reported in 2008. In 2017, we examined the spatial heterogeneity in coral community structure in the region of Toliara. Coral assemblages were characterized by a marked spatial variability, with significant variation for most of the descriptors among the three major habitats and also among stations within habitats. We recorded high coral cover, with values >40% at six of the 10 stations, which was associated with high abundance of coral colonies. We also documented the return to an Acropora-dominated coral assemblage. While these positive results suggest a recent return to healthier coral assemblages, they must be tempered, as the diversity that we recorded was lower than in the 1960s. Moreover, we found a high cover of algae at several stations, suggesting that the ecosystem is likely close to the tipping point toward a phase shift. Finally, the population size-structure of major coral taxa was positively skewed, with few large colonies to ensure the replenishment of local populations. The marked spatial variation suggests that marine protected areas should integrate a sufficiently large area to capture the scale of this spatial heterogeneity.
Keywords: coral reefs; scleractinian corals; community structure; spatial variability; Madagascar

Article 2

Ecomechanics of black corals (Cnidaria: Anthozoa: Hexacorallia: Antipatharia): A comparative approach

First published: 05 October 2021 https://doi.org/10.1111/ivb.12347 (Read the article here)
Abstract
Mechanical properties of the skeleton of four antipatharians (the whip species Cirrhipathes anguina and Stichopathes cf. maldivensis, and the branched species Cupressopathes abies and Cupressopathes cf. pumila) living in shallow waters off the southwestern coast of Madagascar were investigated using a three-point bending test. The Young’s modulus did not differ according to species but was significantly higher in the distal segment of colonies, compared with the basal and median segments. By contrast, the flexural stiffness was significantly higher in whip species compared with branched ones, and in the whip species, flexural stiffness was higher in the basal segment compared with the other two segments, an observation consistent with a specific adaptation of the species to a strong current environment. Although both species cohabit identical flow conditions, whip species are able to maintain their stalk in vertical position, whereas branched species can readily bend over. This suggests that the specific flexural stiffness is linked to contrasting feeding strategies of species with different morphologies in a similar strong current environment.

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New published article on the “First evaluation of coral recruitment in Madagascar”

August 30, 2021 Comments Off on New published article on the “First evaluation of coral recruitment in Madagascar” By administrateur

Des chercheurs de l’IH.SM, avec leurs partenaires, ont évalué la distribution des larves et le recrutement des coraux constructeurs de récifs dans la région sud-ouest de Madagascar. Cette étude réalisée entre octobre 2013 et Septembre 2014 constitue la première du genre dans le pays et a ouvert la voie à de multitudes d’investigations concernant la dynamique des assemblages des coraux et la capacité de résilience des récifs coralliens à Madagascar.

Lire l’article ici

Résumé

Les auteurs de l’article ont commencé par un suivi hebdomadaire de la présence de larves de corail (planula) dans le plancton, suivi d’une évaluation mensuelle des recrues (des bébés corail de moins de 1 an) et une estimation du taux de recrutement des juvéniles (1 <Juveniles <2 ans). Les larves de coraux ont été observé dans le plancton 9 mois sur 12. Leur abondance a été plus élevée au début de la saison chaude et humide et des pics de densité ont été observé en Novembre et Décembre suggérant que la plupart des coraux libèrent leurs œufs fécondés quelques jours ou quelques semaines avant cette période. Le taux de recrutement observée dans le sud-ouest de Madagascar était élevé est comparable à d’autres régions du monde avec plus ou moins 100 recrues par mètre carré sur le site ou le recrutement est le plus élevé. Il varie aussi selon les saisons.

Nous avons observé des pics de recrutement entre Octobre et Décembre. Nous avons également observé une différence significative entre l’abondance des recrues et celle des juvéniles. Les résultats de l’évaluation de l’abondance des juvéniles ont révélé des taux élevés (> 10 juvéniles de m-2) par rapport à d’autres régions et au seuil théoriques, mais il a également permis de relever une forte mortalité des recrues.

Les résultats de cette étude suggèrent que malgré la dégradation sans précédente des récifs coralliens, particulièrement ceux du Grand récif de Toliara, l’observation d’un recrutement naturel avec un taux élevé est un bon signe et pourrait favoriser une résilience des assemblages coralliens, bien que plusieurs facteurs post-recrutement puissent induire une mortalité importante des recrues et des juvéniles de corail.

Les chercheurs de l’IH.SM avec leur partenaire de par le monde continue de travailler sur le sujet afin d’approfondir la connaissance sur la reproduction et la dynamique des assemblages de coraux à Madagascar.

Photographs of scleractinian at the different development stages

Abstract

The distribution of larvae and recruitment of scleractinians in the southwest region of Madagascar were evaluated for the first time between October 2013 and September 2014 at 3 sites. The presence of coral larvae (planulae) was monitored through weekly sampling using a plankton net and the recruitment rate evaluated by monthly sampling of the newly settled corals (<1 year stage) on recruitment tiles and by a monitoring of the recruitment of juveniles (1< Juveniles < 2 years) using the quadrat method. Planulae were present in the plankton for 9 months during the survey.

The recorded mean annual density of planula varied from 0.43 ± 0.41 larvae m-3 to 3.23 ± 5.72 larvae m-3 depending on site, with a peak in larval density towards the end of November and the beginning of December. The variability in the occurrence of planula is very high and implied that the density observed in the year does not present a significant difference between the sites (pKW=0.33). The average density of total recruits was 620.13 ± 621.30 recruits m-2, 40.28 ± 50.97 recruits m-2 and 36.34 ± 33.82 recruits m-2, respectively at the sites of Nosy Tafara, Grande Vasque and Rose Garden. Seasonal distribution of coral recruitment was different between the sites. The mean annual density of newly settled recruits (< 1 month stage) was significantly higher at Nosy Tafara with 94.91±101.08 recruits m-2 compared to Grande Vasque and Rose Garden with 18.75±34.32 recruits m-2 and 11.57±18.47 recruits m-2 (pKW<0.001), respectively.

The highest density of newly settled recruits was observed between October to December. Higher density of recruits was also observed in March at Nosy Tafara and in May at all three sites. Results of juvenile monitoring showed high rates (> 10 juveniles m-2) compared to other regions and the threshold, but it revealed high mortality among recruits. Coral recruitment in the southwest region of Madagascar was found to be high and could result in increased resilience of the coral reef assemblages.

Download the full article here (DOI: 10.4314/wiojms.v20i1.5)

Todinanahary GGB, HasintantelyN, Eeckhaut I, Lavitra T (2021) First evaluation of coral recruitment in Madagascar. Western Indian Ocean Journal of Marine Science, 20(1):47-62

 

Rakotomahazo et al., 2021

June 28, 2021 Comments Off on Rakotomahazo et al., 2021 By administrateur

Title: Community Perceptions of a Payment for Ecosystem Services Project in Southwest Madagascar: A Preliminary Study.

Journal: Land (2021) 10: 597

Authors: Rakotomahazo C, Razanoelisoa J, Ranivoarivelo NL, Todinanahary GGT, Ranaivoson E, Remanevy ME, Ravaoarinorotsihoarana LA and Lavitra T

Abstract. Despite the popularity of Payment for Ecosystem Services (PES) schemes as a new paradigm to enhance conservation of natural resources, evidence of their benefits to people and nature is often illustrated from desk-based reviews, but rarely investigated from the local sites where they have been implemented. We investigated local perceptions of a PES scheme implemented in the Baie des Assassin’s mangroves of southwest Madagascar with particular focus on its perceived future effects. To meet our goal, we first collated socioeconomic and mangrove ecological information through extensive literature research, and key informant interviews with 35 peoples within the
10 villages surrounding the bay to be used as reference conditions. Following this, a workshop with 32 participants from local communities was conducted, using participatory scenario planning to predict the effects of the PES project, and to identify concerns surrounding its implementation. Local communities perceived the PES scheme as a potentially valuable approach for the sustainable management of their mangroves, and perceived that it would address major socioeconomic issues and mangrove management problems in the bay as a result of the carbon offsetting from their mangroves. We conclude that to achieve acceptance and good governance of a PES project by local communities, needs and concerns surrounding the implementation of the PES project need be addressed.

Keywords: mangroves; biodiversity; ecosystem services; scenario planning; Baie des Assassins

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A new article > From fundamental to applied research: The history of the Indian Ocean Trepang company

March 11, 2021 Comments Off on A new article > From fundamental to applied research: The history of the Indian Ocean Trepang company By administrateur

Read this newly published article, by Igor Eeckhaut, on the history of sea cucumber farming in Madagascar. And discover the submerged part of the iceberg! Enjoy reading.

Lire cet article qui vient d’être publié par Igor Eeckhaut sur l’histoire de l’holothuriculture à Madagascar. Et découvrez la partie immergée de l’iceberg ! Bonne lecture. >>> La version française ci-dessous.

The three pillars of university actions are the development of fundamental, focused and applied researches for the reasoned development of our society, the provision of high-quality education by integrating this research into the courses given to students and researchers, and concrete effects (direct and indirect) of research results in civil society. The history of sea cucumber aquaculture in Madagascar is a fine example of academic research and the establishment of direct application in civil society.

Special thanks to the late Dr Man Wai Rabenevanana (see featured image), one of the founders of the Fishery and Marine Sciences Institute of Toliara, for his great contribution to the success of these projects.

Download the full article here

 

De la recherche fondamentale à la recherche appliquée: l’histoire de la société Indian Ocean Trepang.

Les trois piliers de l’action universitaire sont le développement de recherches fondamentales, ciblées et appliquées pour le développement raisonné de notre société, l’offre d’une éducation de qualité en intégrant cette recherche dans les cours dispensés aux étudiants et chercheurs, et des effets concrets (directs et indirect) des résultats de la recherche dans la société civile. L’histoire de l’aquaculture des holothuries à Madagascar est un bel exemple de recherche académique et de mise en place d’une application directe dans la société civile.

Remerciements particuliers au regretté Dr Man Wai Rabenevanana (Voir photo en couverture), l’un des fondateurs de l’Institut des pêches et des sciences marines de Toliara, pour sa grande contribution au succès de ces projets.

Télécharger l’article complet ici