Effects of a Light Crude Oil Spill on a Tropical Coastal Phytoplankton Community.

Oiling scenarios following spills vary in concentration and usually can affect large coastal areas. Consequently, this research evaluated different crude oil concentrations (10, 40, and 80 mg L) on the nearshore phytoplanktonic community in the southern Gulf of Mexico. This experiment was carried out for ten days using eight units of 2500 L each; factors monitored included shifts in phytoplankton composition, physicochemical parameters and the culturable bacterial abundance of heterotrophic and hydrocarbonoclastic groups.

Spatial Trends of the Potential Association Between Benthic Macrofauna and non-Source Point Sediment Pollutants in the Yucatán Continental Shelf.

Here we explored the potential association of the benthic macrofauna species composition with aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and metals concentration detected in the sediments of the Yucatan continental Shelf (YCS), Mexico. The main objective was to provide insights on the temporal and spatial changes of such association in the function of the longitudinal and depth gradient. Benthic species composition, Al, Ni and Pb showed significant differences among YCS sub-regions (Western Caribbean, Mid-Yucatan and West Yucatan), and depth.

Shelf and deep-water benthic macrofauna assemblages from the western Gulf of Mexico: Temporal dynamics and environmental drivers.

Shelf and deep-water soft-bottom macrofauna were explored in the western Gulf of Mexico in terms of species and functional trait assemblages. Their variation was analysed as functions of depth and time, and the relationship with sea-bottom environmental conditions was examined to disentangle their association with potential environmental drivers. Four consecutive cruises (two per year, at the end of the dry and rainy seasons) were performed during 2016-2017 at 27 fixed stations distributed from 42 to 3565 m depth.

Assessing the Diversity of Benthic Sulfate-Reducing Microorganisms in Northwestern Gulf of Mexico by Illumina Sequencing of dsrB Gene.

This study investigates the community composition, structure, and abundance of sulfate-reducing microorganisms (SRM) in surficial sediments of the Northwestern Gulf of Mexico (NWGoM) along a bathymetric gradient. For these purposes, Illumina sequencing and quantitative PCR (qPCR) of the dissimilatory sulfite reductase gene beta subunit (dsrB gene) were performed. Bioinformatic analyses indicated that SRM community was predominantly composed by members of Proteobacteria and Firmicutes across all the samples.

A multi-taxonomic framework for assessing relative petrochemical vulnerability of marine biodiversity in the Gulf of Mexico.

A fundamental understanding of the impact of petrochemicals and other stressors on marine biodiversity is critical for effective management, restoration, recovery, and mitigation initiatives. As species-specific information on levels of petrochemical exposure and toxicological response are lacking for the majority of marine species, a trait-based assessment to rank species vulnerabilities to petrochemical activities in the Gulf of Mexico can provide a more comprehensive and effective means to prioritize species, habitats, and ecosystems for improved management, restoration and recovery. To initiate and standardize this process, we developed a trait-based framework, applicable to a wide range of vertebrate and invertebrate species, that can be used to rank relative population vulnerabilities of species to petrochemical activities in the Gulf of Mexico.

Testing marine regional-scale hypotheses along the Yucatan continental shelf using soft-bottom macrofauna.

Different hypotheses related to the regional-scale configuration of the Yucatan Continental Shelf (YCS) between the Gulf of Mexico (GoM) and the Caribbean Sea have been proposed. Hypotheses regarding its regional boundaries include: (i) an ecoregional boundary at Catoche Cape, dividing the Western Caribbean and the Southern GoM ecoregions; and (ii) a boundary within the Southern GoM ecoregion at 89°W, separating the West and Mid-Yucatan areas. We tested the hypothesis of no variation in benthic macrofaunal assemblages between regions delimited by the former boundaries using the species and functional traits of soft-bottom macrofauna.

Changes in the Bacterioplankton Community Structure from Southern Gulf of Mexico During a Simulated Crude Oil Spill at Mesocosm Scale.

The southern Gulf of Mexico (sGoM) is highly susceptible to receiving environmental impacts due to the recent increase in oil-related activities. In this study, we assessed the changes in the bacterioplankton community structure caused by a simulated oil spill at mesocosms scale. The 16S rRNA gene sequencing analysis indicated that the initial bacterial community was mainly represented by Gamma-proteobacteria, Alpha-proteobacteria, Flavobacteriia, and Cyanobacteria.

Metazoan parasite infracommunities of the dusky flounder (Syacium papillosum) as bioindicators of environmental conditions in the continental shelf of the Yucatan Peninsula, Mexico.

Background: We assessed metrics of the metazoan parasite infracommunities of the dusky flounder (Syacium papillosum) as indicators of aquatic environmental health of the Yucatan Shelf (YS) prior to oil extraction. We sampled the dusky flounder and its parasites along the YS, mostly during the 2015 north wind season (November-April). Our aims were: (i) to determine whether the parasite infracommunity metrics of S.

Gammaropsis elvirae sp. nov., a widely distributed amphipod (Amphipoda: Photidae) in the Yucatan Shelf, with ecological comments and a key for the genus in tropical America.

Gammaropsis elvirae sp. nov. is described and illustrated here, as a new species of the family Photidae Boeck, 1871, occurring on sites widely distributed in the soft-sediment habitats from the Yucatan shelf, southern Gulf of Mexico.

Variation in species diversity of deep-water megafauna assemblages in the Caribbean across depth and ecoregions.

Diversity patterns of the deep-sea megafauna in the Caribbean Basin and the Guiana ecoregion were analyzed in order to test the hypothesis of species richness variation as a function of depth and the hypothesis of non-differences between ecoregions by analyzing spatial patterns of five taxa and a merged assemblage. Collections of five taxa (corals, sea stars, sea urchins, sea lilies and gastropods) were obtained from seven oceanographic expeditions aboard the R/V Pillsbury at 310 stations between 60 and 7500 m depth. Data were sorted according to depth zones and ecoregions and were analyzed in order to estimate species richness, changes in species composition and distinction of β-diversity by species turnover or by nestedness.

A dataset on the species composition of amphipods (Crustacea) in a Mexican marine national park: Alacranes Reef, Yucatan.

Background: Alacranes Reef was declared as a National Marine Park in 1994. Since then, many efforts have been made to inventory its biodiversity. However, groups such as amphipods have been underestimated or not considered when benthic invertebrates were inventoried.

A ten-month diseases survey on wild Litopenaeus setiferus (Decapoda: Penaeidae) from Southern Gulf of Mexico.

The development of shrimp aquaculture in Mexican coasts of the Gulf of Mexico began to be explored using the Pacific white shrimp Litopenaeus vannamei in the mid 90's. Many concerns over the risk of disease transmission to the economically important native penaeids, have been the main deterrent for the aquaculture of L. vannamei in the region.

Spatial structure of the helminth parasite communities of the tonguefish, Symphurus plagiusa, from the Campeche coast, southern Mexico.

The goals of this paper were to determine whether the helminth communities of the blackcheek tonguefish, Symphurus plagiusa, exhibit a spatial structure and, if so, to determine the relative influence of selected environmental and spatial variables. The parasite communities of tonguefish and environmental data (e.g.

Rainfall induces time-lagged changes in the proportion of tropical aquatic hosts infected with metazoan parasites.

Rainfall serves as a powerful driving force, shifting temporal abundance and prevalence patterns in parasites and free-living aquatic organisms in tropical environments. However, there is a lack of sound evidence showing the temporal scales at which rainfall influences infection parameters of parasites in the tropics either directly by affecting the parasite life cycle or indirectly by modifying host population abundance. In the present study, we demonstrate that changes in rainfall patterns lead to changes in the proportion of infected hosts with several parasite species, causing immediate or lagged favourable conditions for an increase in levels of infection.

Can parasites really reveal environmental impact?

This review assesses the usefulness of parasites as bioindicators of environmental impact. Relevant studies published in the past decade were compiled; factorial meta-analysis demonstrated significant effects and interactions between parasite levels and the presence and concentration of various pollutants and/or environmental stressors. These effects and interactions were also evident in subsets of studies that used different methods such as field surveys or experimental exposure.

The checkered puffer (Spheroides testudineus) and its helminths as bioindicators of chemical pollution in Yucatan coastal lagoons.

The suitability of using helminth communities as bioindicators of environmental quality of the Yucatan coastal lagoons status was tested on the checkered puffer (Spheroides testudineus) in four coastal lagoons along the Yucatan coast. The concentration of chemical pollutants in sediments, water quality parameters, helminth infracommunity characteristics, as well as fish physiological biomarkers, including EROD (7-ethoxyresorufin-O-deethylase) and catalase activities, were measured. Results from sediment analyses demonstrated the presence of hydrocarbons, organochlorine pesticides and polychlorinated biphenyls at varying concentrations, some of which exceeded the Probability Effect Level (PEL).