Meiofauna, nematodes and associated sediment characteristics of the mangrove-colonized banks of Cayenne estuary (French Guiana) during the wet season of 2022

Registros de Dados

Os dados deste recurso de evento de amostragem foram publicados como um Darwin Core Archive (DwC-A), que é o formato padronizado para compartilhamento de dados de biodiversidade como um conjunto de uma ou mais tabelas de dados. A tabela de dados do núcleo contém 391 registros.

Também existem 2 tabelas de dados de extensão. Um registro de extensão fornece informações adicionais sobre um registro do núcleo. O número de registros em cada tabela de dados de extensão é ilustrado abaixo.

This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.

Versões

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Como citar

Pesquisadores deveriam citar esta obra da seguinte maneira:

Spedicato A, Michaud E, Thouzeau G, Zeppilli D, Le Bec T, Gauchot C, Traunspurger W, Poullaouec M, Devesa J, Michel L, Chauvet P (2026). Meiofauna, nematodes and associated sediment characteristics of the mangrove-colonized banks of Cayenne estuary (French Guiana) during the wet season of 2022. Version 1.7. Institut Universitaire Européen de la Mer. Samplingevent dataset. https://ipt.data-terra.org/resource?r=biodiversity_meiofauna_cayenneestuary_2022&v=1.7

Direitos

Pesquisadores devem respeitar a seguinte declaração de direitos:

O editor e o detentor dos direitos deste trabalho é Institut Universitaire Européen de la Mer. This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License.

GBIF Registration

Este recurso foi registrado no GBIF e atribuído ao seguinte GBIF UUID: 989d55c1-1913-4e1f-bb50-414df53e02ba.  Institut Universitaire Européen de la Mer publica este recurso, e está registrado no GBIF como um publicador de dados aprovado por GBIF France.

Palavras-chave

Samplingevent; Specimen; Nematoda; Mangrove; Benthic habitats; Invertebrates; Meiofauna; French Guiana

Contatos

Cobertura Geográfica

Near Cayenne estuary river (French Guiana)

Cobertura Taxonômica

N/A

Cobertura Temporal

Dados Sobre o Projeto

Meiofauna distribution in mangroves is uneven and, when identified at phylum level, its diversity patterns are not consistent from one study area to another, and the structuring variables are different. Nematodes are the most abundant taxon in the meiofauna, and identification at genus level has proved to be more informative. The β-diversity of nematodes on a global scale is determined by the turnover between the biogeographical zones of mangrove distribution (Atlantic and Pacific) and by the nestedness between higher and lower latitudes. On a local scale, the presence or absence of mangroves, tree species and substrate type (sediment, roots or leaves) regulate nematode α-diversity and functional diversity. The micro-scale heterogeneity of mangrove habitats is rarely studied, even though it determines the functional diversity of nematodes. In Mayotte, Martinique and Guadeloupe, the heterogeneity of nematode α-diversity corresponds to the heterogeneity of sedimentary conditions, and anthropogenic activities have a major influence on nematodes. Along the Cayenne estuary, the β-diversity of nematodes is determined by marine inputs downstream and fluvial inputs upstream. Between microhabitats, diversity was highest in the forest. Appropriate redefinition of significant functional traits is required before their use, and a detailed study of a given study area is necessary for the definition of bioindicators.

O pessoal envolvido no projeto:

Métodos de Amostragem

Samples were collected along three transects positioned at increasing distance from the sea and the town of Cayenne, thus constituting a “site” gradient. The transects were perpendicular to the water flow. - Site “Cri” (4°54’53"N, 52°20’15"W) was located at the mouth of Crique Fouillée, an inlet crossing Cayenne and draining water close to industrial, commercial, and urban activities. - Site “Conf” (4°53’49"N; 52°22’27"W) was located at the intersection between the Montsinery and Cayenne rivers, not far from the Larivot. - Site “Ty” (4°51’31"N, 52°23’59"W) was located in the Cayenne river, 10 km upstream of the estuary mouth. Three stations were sampled per transect, representing a “habitat” gradient: - “BM” on the muddy shore facing the mangrove - “F” in adult mangrove stands behind the shore - “IN” on the transitional area between BM and F, characterized by small roots. Samples were collected one hour before low tide. For each station, we sampled three sediment cores (replicates A, B, C; diameter = 12 cm, height = 20 cm). We collected sub-sample in each core with a syringe of 2 cm diameter and 10 cm length. We then sliced the small syringe in 4 layers from 0-1 cm, 1-3 cm, 3-5 cm, and 5-10 cm depth. Variables measured by core: - Grain size = core A - Meiofauna, pigments (chlorophyll a and phaeophytin a), microbial abundance and biomass, Total Carbon (TC) and Total nitrogen (TN) contents = cores A, B and C An other sediment core was dedicated to Redox potential, pH and temperature measurement. Measurement were made for each sediment layer (0-1 cm, 1-3 cm, 3-5 cm and 5-10 cm) using the WTW MultiLineTM3420 portable digital multiparameter system equipped with redox (Sensolyt ORP900P) and pH-temperature (SenTixTM 950) probes. Instrument precision was 0.01 mV (Eh) and 0.001 pH, the latter calibrated with NIST Buffers. Pore-water salinity was directly measured using a refractometer (1 ppt; practical salinity scale) after extracting a drop of filtered pore water from each layer of sediment (Michaud et al., 2022). After collection, samples for biogeochemical and grain size analyses were frozen at -80°C, while the meiofauna samples were fixed in 10% buffered formalin.

Descrição dos passos do método:

1. Samples for granulometry, total carbon (TC), total nitrogen (TN) and microbial analyses were freeze-dried (24h at 60°C), gently crushed to powder and homogenized for bulk sediment analyses. Grain size fractions were analyzed with a laser beam diffraction analyzer (Malvern Mastersizer-S2000). Prior to analysis, organic matter was removed and aggregated particles were deflocculated following Sperazza et al. (2004). Grain size fractions were quantified as clay, silt and sand. TC and TN were analyzed by combustion at 930°C using a CHN carbon analyzer (Flash-2000; Thermo Fisher Scientific Inc., Milan, Italy). Due to the lack of carbonates on the FG coast, the organic fraction largely dominates total carbon (Marchand et al., 2003); thus, only the total fraction (TC) was measured (Michaud et al., 2022). The molar TC:TN ratio was calculated and used as a proxy of the refractory or labile nature of the organic matter. Pigment concentrations were determined fluorometrically on a Turner 10-AU fluorometer (Turner design, San Jose, CA, USA), using an acidification step to separate phaeopigments from chlorophyll a. The Chl:Phaeo ratio was determined as an index of the state of pigment degradation. The size of bacterial and archaeal populations was estimated by quantifying the copy number of 16S rRNA genes using qPCR, according to protocols detailed in Fiard et al. (2022). Total DNA extracts quantified by fluorometric assay using a Quantifluor dsDNA kit (Promega) were used as a proxy of microbial biomass.
2. Samples for meiofauna were sieved on 32 µm and 1 mm mesh, stained with Bengal Rose and stored in 4% formaldehyde. The meiofauna was sorted directly on sieved samples using a stereomicroscope (ZEISS Stemi 508), as extraction by the Ludox density gradient method was not efficient due to the high presence of plant debris in the supernatant after centrifugation. During sorting, 150 nematodes were collected randomly per sample, or all individuals if total abundance did not reach 150. We set up to 150 the number of picked nematodes in order to have at least 100 nematodes identifiable, considering that during the mounting procedure some nematodes can be damaged or can be positioned in an unidentifiable way (Bianchelli et al., 2013; Semprucci et al., 2018; Liang et al., 2020). The nematodes were mounted on permanent slides following De Grisse (1969) and identified at genus level with a Leica DM2500 LED microscope according to Platt et al. (1985, 1988), the pictorial key of Warwick et al. (1988), Schmidt-Rhaesa et al. (2014), and the NeMys Online World Database of Nematodes (NeMys eds. 2023).

Metadados Adicionais