Contamination of the marine environment by human-made plastic litter is a growing and global problem. Our study attempts to explain the presence of two plastic bottles beached on the Ouvéa Island, in the southwest Pacific Ocean, with trademarks from the Solomon Islands and Papua New Guinea (PNG). We simulate the oceanic drift tracks and associated transit times with a Lagrangian interpretation of the surface currents of a high-resolution ocean model. Our results show that it takes less than 2–3 months for drifting objects to connect these archipelagos (New Caledonia, Solomon Islands and PNG) and highlight the role of the meridional component of the circulation rather than the dominant zonal jets. This study shows that the origin or traceability of trash represent valuable information that can be used to test and, ultimately, improve our understanding of ocean circulation.

Contamination of the marine environment by human-made plastic litter is a growing and global problem. Our study attempts to explain the presence of two plastic bottles beached on the Ouvéa Island, in the southwest Pacific Ocean, with trademarks from the Solomon Islands and Papua New Guinea (PNG). We simulate the oceanic drift tracks and associated transit times with a Lagrangian interpretation of the surface currents of a high-resolution ocean model. Our results show that it takes less than 2–3months for drifting objects to connect these archipelagos (New Caledonia, Solomon Islands and PNG) and highlight the role of the meridional component of the circulation rather than the dominant zonal jets. This study shows that the origin or traceability of trash represent valuable information that can be used to test and, ultimately, improve our understanding of ocean circulation.

International audience | New Caledonia is a widely recognised marine and terrestrial biodiversity hot spot. However, this unique environment is under increasing anthropogenic pressure. Major threats are related to land cover change and include fire, urban sprawling and mining. Resulting habitat loss and fragmentation end up in serious erosion of the local biodiversity. Mining is of particular concern due to its economic significance for the island. Open cast mines were exploited there since 1873, and scraping out soil to access ores wipes out flora. Resulting perturbations on water flows and dramatic soil erosion lead to metal-rich sediment transport downstream into rivers and the lagoon. Conflicting environmental and economic aspects of mining are discussed in this paper. However, mining practices are also improving, and where impacts are inescapable ecological restoration is now considered. Past and ongoing experiences in the restoration of New Caledonian terrestrial ecosystems are presented and discussed here. Economic use of the local floristic diversity could also promote conservation and restoration, while providing alternative incomes. In this regard, Ecocatalysis, an innovative approach to make use of metal hyperaccumulating plants, is of particular interest.

New Caledonia is a widely recognised marine and terrestrial biodiversity hot spot. However, this unique environment is under increasing anthropogenic pressure. Major threats are related to land cover change and include fire, urban sprawling and mining. Resulting habitat loss and fragmentation end up in serious erosion of the local biodiversity. Mining is of particular concern due to its economic significance for the island. Open cast mines were exploited there since 1873, and scraping out soil to access ores wipes out flora. Resulting perturbations on water flows and dramatic soil erosion lead to metal-rich sediment transport downstream into rivers and the lagoon. Conflicting environmental and economic aspects of mining are discussed in this paper. However, mining practices are also improving, and where impacts are inescapable ecological restoration is now considered. Past and ongoing experiences in the restoration of New Caledonian terrestrial ecosystems are presented and discussed here. Economic use of the local floristic diversity could also promote conservation and restoration, while providing alternative incomes. In this regard, Ecocatalysis, an innovative approach to make use of metal hyperaccumulating plants, is of particular interest.

International audience | Increasing pressure on mineral resources has drawn research efforts into innovative supply and recycling. Metal-rich biomass produced in phytoextraction recently proved an interesting starting material for green chemistry. It allows the production of new catalysts, referred to as ecocatalysts. Ecocatalysts provide increased yields in chemical production and increased regio- and chemo-selectivity, which result in high added value. This new approach to using metal-rich biomass could spur the development of phytoextraction, a technique considered promising for long, yet without credible economic outlets. In this regard, metallophyte biodiversity hotspots, such as New Caledonia, are of particular interest for biomass supply. Potential phytoextraction from mine spoils using two species endemic to New Caledonia is discussed here. Geissois pruinosa, a hypernickelophore, and Grevillea exul, a Mn accumulator, were selected for these original experiments. The results presented here 20 months after plantation of young trees from a nursery show the interest of the approach. Mean Ni concentrations of up to 1513 mg kg−1 are reported in G. pruinosa, as well as 2000 mg kg−1 Mn in G. exul. Concentrations of Ni and Mn in the leaves of each species appear to be correlated with leaf age. Plantation of these species may also ensure mine reclamation, and experiments were conducted with the principles of ecological restoration in mind adding a further dimension to the approach.

Increasing pressure on mineral resources has drawn research efforts into innovative supply and recycling. Metal-rich biomass produced in phytoextraction recently proved an interesting starting material for green chemistry. It allows the production of new catalysts, referred to as ecocatalysts. Ecocatalysts provide increased yields in chemical production and increased regio- and chemo-selectivity, which result in high added value. This new approach to using metal-rich biomass could spur the development of phytoextraction, a technique considered promising for long, yet without credible economic outlets. In this regard, metallophyte biodiversity hotspots, such as New Caledonia, are of particular interest for biomass supply. Potential phytoextraction from mine spoils using two species endemic to New Caledonia is discussed here. Geissois pruinosa, a hypernickelophore, and Grevillea exul, a Mn accumulator, were selected for these original experiments. The results presented here 20 months after plantation of young trees from a nursery show the interest of the approach. Mean Ni concentrations of up to 1513 mg kg⁻¹are reported in G. pruinosa, as well as 2000 mg kg⁻¹Mn in G. exul. Concentrations of Ni and Mn in the leaves of each species appear to be correlated with leaf age. Plantation of these species may also ensure mine reclamation, and experiments were conducted with the principles of ecological restoration in mind adding a further dimension to the approach.

International audience | Relationships between the trace-elements (TE) content of plants and associated soil have been widely investigated especially to understand the ecology of TE hyperaccumulating species to develop applications using TE phytoextraction. Many studies have focused on the possibility of quantifying the soil TE fraction available to plants, and used bioconcentration (BC) as a measure of the plants ability to absorb TE. However, BC only offers a static view of the dynamic phenomenon of TE accumulation. Accumulation kinetics are required to fully account for TE distributions in plants. They are also crucial to design applications where maximum TE concentrations in plant leaves are needed. This paper provides a review of studies of BC (i.e. soil-plant relationships) and leaf-age in relation to TE hyperaccumulation. The paper focuses of Ni and Mn accumulators and hyperaccumulators from New Caledonia who were previously overlooked until recent Ecocatalysis applications emerged for such species. Updated data on Mn hyperaccumulators and accumulators from New Caledonia are also presented and advocate further investigation of the hyperaccumulation of this element. Results show that leaf-age should be considered in the design of sample collection and allowed the reclassification of Grevillea meisneri known previously as a Mn accumulator to a Mn hyperaccumulator.

Relationships between the trace-elements (TE) content of plants and associated soil have been widely investigated especially to understand the ecology of TE hyperaccumulating species to develop applications using TE phytoextraction. Many studies have focused on the possibility of quantifying the soil TE fraction available to plants, and used bioconcentration (BC) as a measure of the plants ability to absorb TE. However, BC only offers a static view of the dynamic phenomenon of TE accumulation. Accumulation kinetics are required to fully account for TE distributions in plants. They are also crucial to design applications where maximum TE concentrations in plant leaves are needed. This paper provides a review of studies of BC (i.e. soil-plant relationships) and leaf-age in relation to TE hyperaccumulation. The paper focuses of Ni and Mn accumulators and hyperaccumulators from New Caledonia who were previously overlooked until recent Ecocatalysis applications emerged for such species. Updated data on Mn hyperaccumulators and accumulators from New Caledonia are also presented and advocate further investigation of the hyperaccumulation of this element. Results show that leaf-age should be considered in the design of sample collection and allowed the reclassification of Grevillea meisneri known previously as a Mn accumulator to a Mn hyperaccumulator.

Non-PR | IFPRI5 | MTID

We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (Apis mellifera) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section “other invertebrates” review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. There is a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large-scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.

We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (Apis mellifera) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section “other invertebrates” review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. There is a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large-scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.

International audience | We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (<em>Apis mellifera</em>) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section “other invertebrates” review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. There is a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large-scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.

We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (Apis mellifera) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section “other invertebrates” review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. Thereis a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large-scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.

Identification of a suitable overlay and index method to map vulnerable zones for pollution in weathered rock aquifers was carried out in this study. DRASTIC and four models derived from it, namely Pesticide DRASTIC, modified DRASTIC, modified Pesticide DRASTIC and Susceptibility Index (SI) were compared by applying them to a weathered rock aquifer in southern India. The results were validated with the measured geochemical data. This study also introduces the use of temporal variation in the groundwater level and nitrate concentration in groundwater as input and for validation respectively to obtain more reliable and meaningful results. Sensitivity analysis of the vulnerability index maps highlight the importance of one parameter over another for a given hydrogeological setting, which will help to plan the field investigations based on the most or the least influential parameter. It is recommended to use modified Pesticide DRASTIC for weathered rock regions with irrigation practises and shallow aquifers (<20 m bgl). The crucial input due to land use should not be neglected and to be considered in any hydrogeological setting. It is better to estimate the specific vulnerability wherever possible rather than the intrinsic vulnerability as overlay and index methods are more suited for this purpose. It is also necessary to consider the maximum and minimum values of input parameters measured during a normal year in the models used for decision making.

Identification of a suitable overlay and index method to map vulnerable zones for pollution in weathered rock aquifers was carried out in this study. DRASTIC and four models derived from it, namely Pesticide DRASTIC, modified DRASTIC, modified Pesticide DRASTIC and Susceptibility Index (SI) were compared by applying them to a weathered rock aquifer in southern India. The results were validated with the measured geochemical data. This study also introduces the use of temporal variation in the groundwater level and nitrate concentration in groundwater as input and for validation respectively to obtain more reliable and meaningful results. Sensitivity analysis of the vulnerability index maps highlight the importance of one parameter over another for a given hydrogeological setting, which will help to plan the field investigations based on the most or the least influential parameter. It is recommended to use modified Pesticide DRASTIC for weathered rock regions with irrigation practises and shallow aquifers (<20 m bgl). The crucial input due to land use should not be neglected and to be considered in any hydrogeological setting. It is better to estimate the specific vulnerability wherever possible rather than the intrinsic vulnerability as overlay and index methods are more suited for this purpose. It is also necessary to consider the maximum and minimum values of input parameters measured during a normal year in the models used for decision making.

Identification of a suitable overlay and index method to map vulnerable zones for pollution in weathered rock aquifers was carried out in this study. DRASTIC and four models derived from it, namely Pesticide DRASTIC, modified DRASTIC, modified Pesticide DRASTIC and Susceptibility Index (SI) were compared by applying them to a weathered rock aquifer in southern India. The results were validated with the measured geochemical data. This study also introduces the use of temporal variation in the groundwater level and nitrate concentration in groundwater as input and for validation respectively to obtain more reliable and meaningful results. Sensitivity analysis of the vulnerability index maps highlight the importance of one parameter over another for a given hydrogeological setting, which will help to plan the field investigations based on the most or the least influential parameter. It is recommended to use modified Pesticide DRASTIC for weathered rock regions with irrigation practises and shallow aquifers (<20mbgl). The crucial input due to land use should not be neglected and to be considered in any hydrogeological setting. It is better to estimate the specific vulnerability wherever possible rather than the intrinsic vulnerability as overlay and index methods are more suited for this purpose. It is also necessary to consider the maximum and minimum values of input parameters measured during a normal year in the models used for decision making.