Epipelagic zooplankton diversity in the deep water region of the Gulf of Mexico: a metabarcoding survey

Abstract

Zooplankton is a key component in marine ecosystem health assessment. Here, we present a taxonomically comprehensive description of the zooplankton community (0–200 m) based on metabarcoding of the V9 hypervariable region of the 18S rRNA gene of 47 samples collected in the Gulf of Mexico (GoM) during summer 2015. Fourteen phyla were identified Arthropoda were dominant, with Calanidae, Metridinidae, and Euphausiidae as the most conspicuous families. Other abundant phyla were Cnidaria (Hydrozoa), Chordata (Tunicata), and Chaetognatha. The V9-18S sequence data were clustered into 1888 Operational Taxonomic Units (OTUs), of which 39 were cosmopolitan and belonging to various phyla, suggesting the presence of a core community with high local diversity throughout the GoM. Evaluation of metabarcoding sequences abundance showed overall positive correlations with morphologically quantified abundances except for specific groups. Cluster analysis of OTU distributions indicated two primary biographically distinctive groups of stations: one restricted to the Bay of Campeche, while the other occurred in the Central-West GoM, similar to previous descriptions of regional variation of the GoM based on environmental variables. Together these results provide a foundation for broad-scale zooplankton molecular biodiversity assessments in the southern GoM allowing evaluation of the effects of environmental changes on zooplankton communities.

Environmental conditions drive zooplankton community structure in the epipelagic oceanic water of the southern Gulf of Mexico: A molecular approach

“…Moreover, metabarcoding abundances should be interpreted with caution, as the read patterns often do not correspond to the original proportions of species in the community (Günther et al, 2018;Piñol et al, 2015). However, we previously reported consistent abundance patterns between metabarcoding and morphological surveys for the oceanic waters of the GoM based on a detailed analysis of XIXIMI-4 (Martinez et al, 2021).…”

“…Studies on patterns of diversity and abundance of dominant taxa (e.g., copepods, euphausiids, salps, hyperiid amphipods) showed a relationship between species distribution and hydrological characteristics mostly imposed by prevailing mesoscale structures (Biggs et al, 1997; Castellanos & Gasca, 1999; Gasca, 2009; Hereu et al, 2020). Foregoing studies in this region showed a broad regional pattern in zooplankton assemblages partly explained by the environmental variables such as temperature, salinity and fluorescence (Hereu et al, 2020; Martinez et al, 2021).…”

Response of microbial eukaryote community to the oligotrophic waters of the Gulf of Mexico: a plausible scenario for warm and stratified oceans

“…In the northern GoM, the abundance of Syndiniales is positively correlated with copepod abundance, which are known hosts for this zooplankton group (Brannock et al, 2016). In addition, the Calanidae family was highly abundant in the water column during the oceanographic campaign XIXIMI-5 (Martinez et al, 2021). Despite their low abundance (Fig.…”

“…Most of the studies performed on microbial eukaryotes in the Mexican Exclusive Economic Zone of the GoM (MEEZ) have focused on phytoplankton communities and employed microscopy analyses (Durán-Campos et al, 2017;Hernández-Becerril and Flores-Granados, 1998;Hernández-Becerril et al, 2008;Licea et al, 2016;Linacre et al, 2021;Merino-Virgilio et al, 2013;Okolodkov, 2003;Parra-Toriz et al, 2011); flow cytometry to detect Prochlorococcus, Synechococcus, heterotrophic bacteria, and picoeukaryotes (Linacre et al, 2019;2015); and molecular analyses, such as FISH-TSA, to detect picoeukaryotes like M. pusilla (Hernández-Becerril et al, 2012). In contrast, metabarcoding analyses are scarce and have focused on evaluating the bacterial composition of the water column (Raggi et al, 2020) and zooplankton communities (Martinez et al, 2021). Indeed, evaluations employing metabarcoding approaches to evaluate the entire protist community in the oceanic waters of the MEEZ have not yet been conducted.…”

A gulf-wide synoptic isoscape of zooplankton isotope ratios reveals the importance of nitrogen fixation in supporting secondary production in the central Gulf of Mexico

“…Grijalva-Usumacinta River System nitrogen X -24.4 ± 2.8 4.6± 0.6 models incorporate estimates of the variability in the isotope composition of the sources and trophic discrimination factors. The model inputs were (1) the d 15 N and d 13 C values of zooplankton, (2) the isotope ratios of suspended POM (mean and SD values, see Table 1) of the potential N sources for each region, and (3) the trophic discrimination factor for crustacean zooplankton of d 13 C = 1.0 ± 0.6‰, d 15 N= 2.0 ± 0.5‰ (Davenport and Bax, 2002;Vanderklift and Ponsard, 2003;Henschke et al, 2015); crustacean zooplankton are typically the dominant component of the community in the GM (Hopkins, 1982;Martinez et al, 2021). The model was applied to the zooplankton isotope ratios for all stations within each region.…”