Assessment of reliability of fish consumption as an indicator of reef fish catches in small Pacific islands : the example of Ouvea Island in New Caledonia

Fishing pressure on reef fish stocks, in relation to exploitable biomass, is a useful parameter for fishery resource management but difficult to assess in subsistence fisheries. A methodology for indirect fishery output assessment in island environments is proposed based on estimates of consumption and the relevant seafood trade. Ouvea atoll in the South Pacific (Loyalty Islands, New Caledonia), where subsistence fishing is the main activity, was used as the IPF experimental site. A consumer survey of the islands' households was conducted in June 2000. The sampling plan was determined on the basis of data already available on the population concerned, making it possible to give quantitative and qualitative information on catches. Total catch is estimated to be 212 ty(-1) composed mainly of Lethrinidae, Serranidae and Gerreidae. Subsistence activity is the main source of supply for two-thirds of households. These results were validated by a survey carried out on fishers at the same time that confirms the reliability of fish Consumption as an indicator of reef fish catches. This study also showed that shoreline fishing remains the main activity in Ouvea: it's practised by 71% of households and provides almost 48% of total landings. A second stage was the identification of variables liable to influence consumption patterns: fishing practice (frequency and gear type), income, and household size seemed to be the main determining factors. These variables were integrated into a multi-dimensional analysis in order to define types Of Consumers. This consumption-based approach underlies a sampling strategy that could be a extrapolated to other small South Pacific islands. It involves advantages of various kinds-accuracy, reliability, and cost-effective implementation-that make it a powerful tool for monitoring island fishery development.La pression de pêche, reliée à la biomasse exploitable, est un paramètre utile pour la gestion des stocks de poissons récifaux, mais elle est difficile à évaluer pour la pêche de subsistance. Une méthodologie d'évaluation indirecte de la production halieutique est proposée, basée sur des estimations de consommation et d'échanges de produits de la mer. L'atoll d'Ouvéa dans le Pacifique sud (îles Loyauté, Nouvelle-Calédonie), où la pêche de subsistance est l'activité principale, a servi de site expérimental. Une enquête de consommation a été conduite chez les ménages de l'île en juin 2000. Le plan d'échantillonnage, défini à partir de données disponibles sur la population, a permis d'apporter des informations quantitatives et qualitatives sur les captures: la production totale, estimée à 212 t par an, se compose principalement de Lethrinidés, Serranidés et Gerréidés. La pêche de subsistance représente la principale source d'approvisionnement pour les deux tiers des foyers. Ces résultats ont été validés par une enquête conduite simultanément auprès des pêcheurs qui a confirmé la fiabilité de la consommation de poisson comme indicateur des captures de poissons récifaux. Cette étude de la production halieutique a également montré que la pêche littorale reste l'activité principale à Ouvéa: 71 % des ménages la pratiquent et elle représente près de 48 % des débarquements. Dans un second temps, l'étude a porté sur les variables susceptibles d'influencer la consommation de produits de la mer: la pratique de la pêche (fréquence et types d'engins utilisés), les revenus et la taille des ménages semblent être les facteurs déterminants. Ces variables ont été introduites dans une analyse multi-dimensionnelle afin de définir des types de consommateurs. Cette méthode basée sur la consommation de poisson décrit une stratégie d'échantillonnage qui pourrait être extrapolée à d'autres petites îles du Pacifique sud. Elle présente divers avantages (précision, fiabilité, facilité et rapidité de mise en œuvre) qui en font un outil performant pour suivre le développement des pêcheries insulaires

Discovery of a Mid-L Dwarf Companion to the L 262-74 System

We present the discovery of CWISE J151044.74$-$524923.5, a wide low-mass companion to the nearby ($\sim$24.7 pc) system L 262-74, which was identified through the Backyard Worlds: Planet 9 citizen science project. We detail the properties of the system, and we assess that this companion is a mid-L dwarf, which will need to be verified spectroscopically. With an angular separation of 74\farcs3, we estimate a projected physical separation of $\sim$1837 au from the central system

Review of fisheries and management of sea cucumbers in the Indian Ocean

Several sea cucumber species (Echinodermata: Holothuroidea) are fished, mostly for export of the dried product for Oriental consumers. Previous studies had analysed the historical trends at the world-scale until 2014. In the Western Indian Ocean (WIO) holothurian fisheries have a long history and several programmes have tried to ameliorate their management. Information has been recently gathered through a questionnaire and access to the most recent, yet unpublished available data (2015 to 2021) from different countries, through the evaluation of catches and/or processed product, present management systems, the imports of beche de mer and other products from Indian Ocean (IO) countries into the major market hub of Hong Kong SAR, and the Food and Agricuture Organisation (FAO) yearly statistics. The results are first presented for WIO countries, highlighting recent improvements in management. Imports from 16 WIO countries into the Hong Kong market (2017-2020 data) indicate the importance of the hub. The FAO world statistics are used to present the changes for the last few years, concentrating on the WIO countries. The recent trends show that demand for holothurians is still very high. Inconsistencies in the unit used in the reported statistics (fresh or dry weight) exist, and this needs to be addressed. The national data should be collected at the species level, to be able to follow the changes and the stock status. A regional approach is needed to encourage use of comparable management tools and follow future trends

Seagrass macroinvertebrate bycatches support mosquito net trawl fishery in Madagascar

The use of mosquito nets, primarily for targeting small and/or juvenile fish, has rapidly increased in Western Indian Ocean shallow seagrass beds and coral reefs over the last 20 years. However, to date, invertebrate by-catch by locally-made fishing gear has not been reported. We studied the mosquito net trawl fishery in seagrass areas in the Bay of Toliara, Southwest Madagascar through the GPS tracking of fishers from August 2018 to February 2019. Catches were monitored through monthly landing surveys to characterize spatial temporal patterns in the abundance and diversity of macroinvertebrates in the seagrass beds. Fishing was carried out at low tide, mostly at night, by fishers pulling a hand-made trawl net of varying dimensions. Overall, 43 macroinvertebrate taxa were identified out of 217,080 individuals collected from 109 catch samples. Catches were generally composed of crustaceans (mainly Portunidae, Processidae, Penaeidae, and Alpheidae). The crab Thalamita mitsiensis largely dominated the abundance and biomass of the macroinvertebrate assemblage (from 6% to 100% and from 5 to 100% of the overall density and biomass, respectively). Macroinvertebrates composed 1.5% to 100% of the total catch per trip (i.e., 4–55 kg trip−1). They were sold for human consumption or animal feed, which provided additional income to fishers (USD 1–24 trip−1 and 1–72% of catch income per trip). This study revealed that macroinvertebrate resources provide valuable by-catch to small-scale fishers in Southwest Madagascar. This bycatch generates income that further encourages the use of mosquito net trawls and exacerbates their negative effects on coastal seagrass ecosystems and fisheries

Spitzer Follow-up of Extremely Cold Brown Dwarfs Discovered by the Backyard Worlds: Planet 9 Citizen Science Project

We present Spitzer follow-up imaging of 95 candidate extremely cold brown dwarfs discovered by the Backyard Worlds: Planet 9 citizen science project, which uses visually perceived motion in multiepoch Wide-field Infrared Survey Explorer (WISE) images to identify previously unrecognized substellar neighbors to the Sun. We measure Spitzer [3.6]–[4.5] color to phototype our brown dwarf candidates, with an emphasis on pinpointing the coldest and closest Y dwarfs within our sample. The combination of WISE and Spitzer astrometry provides quantitative confirmation of the transverse motion of 75 of our discoveries. Nine of our motion-confirmed objects have best-fit linear motions larger than 1'' yr⁻¹; our fastest-moving discovery is WISEA J155349.96+693355.2 (μ ≈ 2.”15 yr⁻¹), a possible T-type subdwarf. We also report a newly discovered wide-separation (~400 au) T8 comoving companion to the white dwarf LSPM J0055+5948 (the fourth such system to be found), plus a candidate late T companion to the white dwarf LSR J0002+6357 at 5 5 projected separation (~8700 au if associated). Among our motion-confirmed targets, five have Spitzer colors most consistent with spectral type Y. Four of these five have exceptionally red Spitzer colors suggesting types of Y1 or later, adding considerably to the small sample of known objects in this especially valuable low-temperature regime. Our Y dwarf candidates begin bridging the gap between the bulk of the Y dwarf population and the coldest known brown dwarf

Analyse écorégionale marine de Nouvelle-Calédonie : atelier d'identification des aires de conservation prioritaires

Dans le cadre de l'initiative pour les récifs coralliens du Pacifique sud (CRISP), le WWF-France a souhaité développer un projet pour la protection des récifs et des lagons néo-calédoniens. L'atelier, qui s'est déroulé les 10 et 11 août à Nouméa, avait pour objectif de rassembler les scientifiques et les experts du lagon néocalédonien pour identifier, sur la base de leur connaissance experte, les zones les plus remarquables du lagon (richesse, endémisme, originalité des faunes et flores, espèces emblématiques, zones d'intérêt fonctionnel) sur lesquelles doivent porter en priorité les efforts de conservation. Il a permis d'identifier 20 aires prioritaires pour la conservation, parmi lesquelles 6 ont un intérêt mondial, 4 ont un intérêt sur le plan régional, les autres ayant un intérêt local