The potential of Indonesian bays as alginate producers was assessed by determining the stock of wild brown algae and exploring their biomass as alginophytes at the scale of entire bay, using a combination of field observations, remote sensing high resolution data and GIS tools. Ekas Bay in Lombok Island presented a stock of brown macroalgae which varied with season and species: for Padina the biomass reached 97.85 +/- 12.63 and 79.54 +/- 2.53 tons in May/June and November respectively; for Sargassaceae species, it reached 669.70 +/- 109.64 and 147.70 +/- 77.97 tons in May/June and November respectively. The best alginate yields occurred during the May/June period: Padina could produce 9.10 +/- 0.06 tons DW of alginates. Interestingly, Sargassurn/Turbinaria together allow 207.61 +/- 0.42 tons DW of alginates. This study suggests that wild Sargassaceae represent an interesting stock in terms of biomass, alginate yield and M/G ratio.

The potential of Indonesian bays as alginate producers was assessed by determining the stock of wild brown algae and exploring their biomass as alginophytes at the scale of entire bay, using a combination of field observations, remote sensing high resolution data and GIS tools. Ekas Bay in Lombok Island presented a stock of brown macroalgae which varied with season and species: for Padina the biomass reached 97.85±12.63 and 79.54±2.53tons in May/June and November respectively; for Sargassaceae species, it reached 669.70±109.64 and 147.70±77.97tons in May/June and November respectively. The best alginate yields occurred during the May/June period: Padina could produce 9.10±0.06tons DW of alginates. Interestingly, Sargassum/Turbinaria together allow 207.61±0.42tons DW of alginates. This study suggests that wild Sargassaceae represent an interesting stock in terms of biomass, alginate yield and M/G ratio.

Despite a growing scientific attention on ecological impact of emerging pollutants (EPs) such as pharmaceuticals, personal care products, and pesticides, knowledge gaps remain regarding mixture toxicity and effects on aquatic organisms. Several EPs were screened in seawater (Normandy, France), and the ecotoxicity of five compounds, chosen on their occurrence in ecosystems and use worldwide, was assessed and were the biocides methylparaben (MP) and triclosan (TCS), a pesticide degradation product (AMPA), and the pharmaceuticals venlafaxine (VEN) and carbamazepine (CBZ). The acute or sub-chronic toxicity, alone or in binary/ternary mixtures of three of them (CBZ, AMPA, and MP), was assessed on one marine and two freshwater organisms: Crassostrea gigas, Pseudokirchneriella subcapitata, and Daphnia magna. TCS and AMPA were, respectively, the most (EC50 < 1 mg L−1) and the least (EC50 > 50 mg L−1) toxic chemicals for the four endpoints (algal growth inhibition, daphnia immobilization, oyster embryotoxicity, and metamorphosis). The anxiolytic VEN (EC50 < 1 mg L−1) was particularly toxic to oyster larvae showing sensitivity difference between freshwater and marine organisms. If all the mixtures appeared to be in the same range of toxicity, the joint-toxic effects mainly led to synergistic or antagonistic interactions compared to single-compound toxicity. The data also highlighted species-dependent differing models of toxicity and underscored the need for an awareness of cocktail effects for better ecological risk assessment.

Despite a growing scientific attention on ecological impact of emerging pollutants (EPs) such as pharmaceuticals, personal care products, and pesticides, knowledge gaps remain regarding mixture toxicity and effects on aquatic organisms. Several EPs were screened in seawater (Normandy, France), and the ecotoxicity of five compounds, chosen on their occurrence in ecosystems and use worldwide, was assessed and were the biocides methylparaben (MP) and triclosan (TCS), a pesticide degradation product (AMPA), and the pharmaceuticals venlafaxine (VEN) and carbamazepine (CBZ). The acute or sub-chronic toxicity, alone or in binary/ternary mixtures of three of them (CBZ, AMPA, and MP), was assessed on one marine and two freshwater organisms: Crassostrea gigas, Pseudokirchneriella subcapitata, and Daphnia magna. TCS and AMPA were, respectively, the most (EC₅₀ < 1 mg L⁻¹) and the least (EC₅₀ > 50 mg L⁻¹) toxic chemicals for the four endpoints (algal growth inhibition, daphnia immobilization, oyster embryotoxicity, and metamorphosis). The anxiolytic VEN (EC₅₀ < 1 mg L⁻¹) was particularly toxic to oyster larvae showing sensitivity difference between freshwater and marine organisms. If all the mixtures appeared to be in the same range of toxicity, the joint-toxic effects mainly led to synergistic or antagonistic interactions compared to single-compound toxicity. The data also highlighted species-dependent differing models of toxicity and underscored the need for an awareness of cocktail effects for better ecological risk assessment.

Revegetation of abandoned aquaculture regions should be a priority for any integrated coastal zone management (ICZM). This paper examines the potential of a matchless time series of 20 very high spatial resolution (VHSR) optical satellite images acquired for mapping trends in the evolution of mangrove forests from 2001 to 2015 in an estuary fragmented into aquaculture ponds. Evolution of mangrove extent was quantified through robust multitemporal analysis based on supervised image classification. Results indicated that mangroves are expanding inside and outside ponds and over pond dykes. However, the yearly expansion rate of vegetation cover greatly varied between replanted ponds. Ground truthing showed that only Rhizophora species had been planted, whereas natural mangroves consist of Avicennia and Sonneratia species. In addition, the dense Rhizophora plantations present very low regeneration capabilities compared with natural mangroves. Time series of VHSR images provide comprehensive and intuitive level of information for the support of ICZM.

International audience | Revegetation of abandoned aquaculture regions should be a priority for any integrated coastal zone management (ICZM). This paper examines the potential of a matchless time series of 20 very high spatial resolution (VHSR) optical satellite images acquired for mapping trends in the evolution of mangrove forests from 2001 to 2015 in an estuary fragmented into aquaculture ponds. Evolution of mangrove extent was quantified through robust multitemporal analysis based on supervised image classification. Results indicated that mangroves are expanding inside and outside ponds and over pond dykes. However, the yearly expansion rate of vegetation cover greatly varied between replanted ponds. Ground truthing showed that only Rhizophora species had been planted, whereas natural mangroves consist of Avicennia and Sonneratia species. In addition, the dense Rhizophora plantations present very low regeneration capabilities compared with natural mangroves. Time series of VHSR images provide comprehensive and intuitive level of information for the support of ICZM.