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Marechal J.-P.,Observatoire du Milieu Marin Martiniquais | Hellio C.,University of Portsmouth
International Biodeterioration and Biodegradation | Year: 2011

Larvae of many benthic invertebrates settle on surfaces where they metamorphose into juveniles if suitable substrata are available, and are responsible for the major costs of biofouling. When assessing new formulations or compounds for potential antifouling (AF) application, constraints such as seasonal availability may restrict most bioassays to relatively few taxa and species. For example, amongst barnacles, Amphibalanus amphitrite is popular as a test organism but is it really representative of other barnacle species? In order to test this hypothesis, we have chosen to work with marine natural extracts as a probe. Indeed, one substitution technology to toxic metal-based coatings to control fouling is the development of AF coatings with active compounds derived from marine organisms or analogues of the lead compounds. In this study, the AF activity and toxicity of extracts from 30 algae from the North East Atlantic coast were investigated for their potential anti-settlement activities against larvae of two species of barnacle, A. amphitrite and Semibalanus balanoides. As a trend, most of the active extracts displayed activity towards S. balanoides, only few displayed targeted activity against A. amphitrite, or against both species. In order to better understand if this tendency could be linked to chemical ecology, surface extracts were prepared on a selection of species. The results highlight that surface extracts of algae all displayed highest levels of activity than total extracts when tested on S. balanoides. This difference illustrates that specific compounds in their ecological context can have potentially a better efficacy on target species. © 2010 Elsevier Ltd. Source

Marechal J.-P.,Observatoire du Milieu Marin Martiniquais | Marechal J.-P.,University of Portsmouth | Matsumura K.,Marine Biological Association of The United Kingdom | Matsumura K.,Hong Kong University of Science and Technology | And 2 more authors.
International Biodeterioration and Biodegradation | Year: 2012

Amphibalanus (=Balanus) amphitrite is a tropical/sub-tropical barnacle species which is naturally exposed to sea temperatures of 16-27 °C throughout its larval development. An established technique widely employed by investigators of A. amphitrite settlement involves the storage of cyprids at 4-6 °C prior to their use in bioassays. Our study focuses on the effects on ageing temperature on settlement and discrimination of A. amphitrite larvae. Using cyprids aged at 2 temperatures, 6° and 23 °C, we confirmed the general trend in the literature that young d0 cyprids of this species do not appear competent to settle. Performing cyprid settlement assays at 20, 25 or 28 °C, we observed that the proportion of settled cyprids when incubated at 28 °C was greater than that of cyprid incubated at 25 °C and 20 °C. Settlement rates of cyprids aged at 6 °C and 23 °C increased relative to age from d1 to d10 irrespective of temperature. Cyprids lost the ability to undergo attachment and metamorphosis at d14 or d15 when aged at 6 °C or 23 °C respectively.In the choice assays executed in this study, cyprids generally chose to settle on adult extract-treated areas. But localised settlement on adult extract-treated areas decreased with time. Choice settlement assays at set age intervals during the cypris larval stage showed that cyprids were able to discriminate between con- and allospecific adult extracts. The duration and the temperature of cyprids storage influenced selectivity. © 2012 Elsevier Ltd. Source

El Hattab M.,Blida University | Genta-Jouve G.,University of Nice Sophia Antipolis | Genta-Jouve G.,University of Paris Descartes | Bouzidi N.,Blida University | And 7 more authors.
Journal of Natural Products | Year: 2015

Cystophloroketals A-E (1-5), five new phloroglucinol-meroditerpenoid hybrids, have been isolated together with their putative biosynthetic precursor, the monocyclic meroditerpenoid 6, from the Mediterranean brown alga Cystoseira tamariscifolia. They represent the first examples of meroditerpenoids linked to a phloroglucinol through a 2,7-dioxabicyclo[3.2.1]octane moiety. The chemical structures, including absolute configurations, were elucidated on the basis of extensive spectroscopic analysis (HR-ESIMS, 1D and 2D NMR, and ECD) and TDDFT ECD calculations. Compounds 1-6 were tested for their antifouling activity against several marine colonizing species (bacteria, fungi, invertebrates, micro- and macroalgae). Compound 6 showed high potency for the inhibition of macrofoulers (invertebrates and macroalgae), while cystophloroketals B (2) and D (4) displayed strong inhibition of the germination of the two macroalgae tested and moderate antimicrobial activities (bacteria, microalgae, and fungi). (Chemical Equation Presented). © 2015 The American Chemical Society and American Society of Pharmacognosy. Source

Marechal J.-P.,Observatoire du Milieu Marin Martiniquais | Marechal J.-P.,University of Portsmouth | Meesters E.H.,Institute for Marine Resources and Ecosystem Studies | Vedie F.,British Petroleum | Hellio C.,University of Portsmouth
Marine Biodiversity Records | Year: 2013

The occurrence of the tropical seagrass Halophila stipulacea (Hydrocharitaceae) is recorded for the first time on the Caribbean coast of Martinique (French West Indies, Caribbean Sea). Specimens were observed, since a large survey in 2006, on sandy substrates between 3 m and 32 m depths in this area. The species was found in mono-specific patches or mixed with other macrophytes as Syringodium filiforme (seagrass) and/or Ulva intestinalis (green alga). Halophila stipulacea was previously identified on the coasts of Dominica and St Lucia, two islands nearby our study area. While its presence was presumed to be in Martinique, it was never officially recorded. These findings off the coast of Martinique further define the distribution and widespread occurrence of this alien species within the Caribbean Sea. © Marine Biological Association of the United Kingdom 2013. Source

Eakin C.M.,National Oceanic and Atmospheric Administration | Morgan J.A.,Systems Watch | Heron S.F.,ReefSense Pty. Ltd | Heron S.F.,James Cook University | And 67 more authors.
PLoS ONE | Year: 2010

Background: The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. Methodology/Principal Findings: Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the iming and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. Conclusions/Significance: Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate. Source

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