Elsa Norena-Barroso

National Autonomous University of Mexico | UNAM · School of Chemistry

The whale shark (Rhincodon typus) is a filter-feeding organism that can be considered a sentinel species, and Bahía de los Ángeles (BLA) in the Gulf of California is an important sighting site for these elasmobranchs. This filter-feeding organism can be considered a pollutant sampler from the marine environment. Persistent organic pollutants are to...

Benzophenone-3 (BP-3) is an active ingredient in sunscreen lotions and personal-care products that protects against the damaging effects of ultraviolet rays. Given its worldwide dissemination, it has been linked with harmful effects on aquatic biota; however, its impact is not fully understood calling for further studies. To understand the impacts...

No ecotoxicological information exists on phenanthrene (Phe) exposure in cephalopods, animals of commercial and ecological importance. This study investigated the effect of Phe on two B-esterases, Acetylcholinesterase (AChE) and Carboxylesterases (CbE), in Octopus maya embryos. Octopus embryos were exposed to different treatments: control (seawater...

The major nesting sites for the endangered green turtle ( Chelonia mydas ) are in Campeche, Mexico: Carmen, Isla Aguada, and Sabancuy. Although they are in a natural reserve, these nesting sites are threatened by agricultural activities and oil extraction. This study aimed to determine the presence and concentration of organochlorine pesticides (OC...

Microalgae can accumulate lipids during the stationary growth phase, but little information is available about fatty acid profile changes during this phase to determine the best harvesting time in respect to lipid content. In this study, Dunaliella sp. was cultured in F/2 medium at three different photon flux densities (380, 226 and 8.2 μmol photon...

Due to karstic bedrock geology and poor wastewater management practices, anthropogenic activities are impacting water quality in Yucatan’s aquatic systems. Specifically, raw wastewater inputs to the aquifer subsequently flow to coastal lagoons through groundwater fluxes. This study establishes the presence of anthropogenic wastewater by measuring c...

Benzophenone-3 (BP-3) is one of the most used UV filters. The present study aimed to evaluate the toxic effects of BP-3 during embryo stages of zebrafish four hours post-fertilization (4hpf). Embryos were exposed to 0, 1, and 10 µg L−1 of BP-3 for 72 h. We investigated biochemical and molecular biomarkers of neurotoxicity (AChE) and the antioxidant...

Finding new alternatives to traditional live preys such as Artemia and rotifers, which do not always promote optimal fish growth and survival, is required for the successful aquaculture of highly specialized predatory species, including seahorses. The present study assessed the nutritional value of an interesting marine amphipod ( Parhyale hawaiens...

Benzophenone-3 (BP-3) is one of the most used UV filters. This study aimed to evaluate the toxic effects of BP-3 during embryo stages of zebrafish, four hours post-fertilization (4hpf). Embryos were exposed to 0, 1, and 10 µg L ⁻¹ of BP-3, for 72 hours. We investigated biochemical and molecular biomarkers of neurotoxicity (AChE) and the antioxidant...

The biodiversity of the coastal ecosystems in the Gulf of Mexico is threatened by anthropogenic activities of various kinds. The predominant portion of the land-sea margin in the State of Yucatán consists of exposed sandy beaches. This ecosystem is threatened by several activities that vary in spatial scales, at a local: cargo/fishing ports, touris...

Whale shark (Rhincodon typus, Smith, 1828) is an endangered species with anthropogenic pressures due to increasing demand of encounter tourism activities. Research efforts to identify management and conservation strategies for this species are needed. The Northern Mexican Caribbean is one of the most important feeding aggregation sites of whale sha...

Merida is the largest urban center in the Mexican State of Yucatan. Here domestic sewage is deposited in poorly built septic tanks and is not adequately treated. Because of contamination from such waste, water from the top 20 m of the aquifer is unsuitable for human consumption. Given this situation and because children are highly vulnerable to env...

Coastal zones are vital for their ecosystem services and socioeconomic value. Accordingly, several zones have been protected to limit anthropogenic development and to avoid environmental degradation. Nevertheless, some of these protected areas keep deteriorating probably related with anthropogenic contributions not considered in legislation. Specif...

The relative contributions of feed sources were determined through the isotopic signal (δ¹³C and δ¹⁵N) and fatty acid profile of feed items, shrimp muscle, and eggs of Litopenaeus vannamei reared in a biofloc system. In the growout phase, the isotope analysis showed the biofloc particle size class ≥250 μm contributed 55–100%; size ≥50 < 250 μm cont...

The aim of this study was to use the natural dietary markers (stable isotopes and fatty acids) during grow-out in a biofloc system and for the egg production of Farfantepenaeus brasiliensis shrimp. Egg production was compared for two broodstock origins: biofloc and a wild origin. To delineate the relative contribution to shrimp muscle and eggs, Iso...

The inhibition of cholinesterase (ChE) activity has been used as a biomarker of exposure to organophosphate and carbamate insecticides. ChE of nesting female green turtles (Chelonia mydas) were biochemically characterized using two substrates, acetylthiocholine iodide and butyrylthiocholine iodide, and three ChE inhibitors (eserine sulfate, BW284C5...

Studies investigating the correlation between metal content in water and metal levels in children are scarce worldwide, but especially in developing nations. Therefore, this study investigates the correlation between arsenic, chromium, and mercury concentrations in drinking and cooking water and in blood and urine samples collected from healthy and...

Background In the Mexican Northern Caribbean, whale sharks feed on abundant plankton. Assessing the trophic role of this species is key to understanding its general ecology. Non-lethal sampling combined with biochemical methods such as analysis of fatty acids (FA) are promising approaches for investigating the assimilated diet of the whale shark. A...

This study examined the effects of mixed diets (with the crab Callinectes spp. as the main component of the diet) on embryonic development and hatchling quality of O. maya. Several O. maya females were fed one of 4 different diets being 1) crab, 2) crab and squid, 3) crab and mussel and 4) crab and fish heads, in a 7:3 ratio. The effects of each di...

This study investigated the influence of geochemical and environmental factors on seasonal variation in metals in Yucatan's Chelem lagoon. Anthropogenic activities discharge non-treated wastewater directly into it with detrimental environmental consequences. Accordingly, this study established the spatial and temporal patterns of fine grain sedimen...

The effects of feeding two alternative live prey Hyalella azteca (freshwater gammarids) and Hyale media (marine gammarids) to Octopus maya hatchlings were compared with feeding adult Artemia sp., traditionally used during the first weeks of the life cycle. Hatchlings were fed ad libitum these three live preys during the first 15 days, and a paste e...

Octopus maya is an endemic species located on the continental shelf of the Yucatán peninsula. This area is located between the Caribbean Sea and the Gulf of Mexico, two ecosystems linked by the Yucatán Channel, in which the temperature in the benthos community is regulated by summer upwelling. Despite being part of a tropical ecosystem, O. maya's n...

A 30-day trial was performed to evaluate the reproductive performance of wild and 2nd generation domesticated Farfantepenaeus duorarum broodstock. Changes in biochemical composition and fatty acids (FA) profile in the 1st and 4th spawn order females were used as indicators of nutritional condition. Wild population of F. duorarum presented significa...

Bay of Chetumal is a transboundary priority area for the Mesoamerican Barrier Reef Systems project, which has been studied because it is the receiving body of pollutants from a large agricultural area and the city of Chetumal. Levels of persistent organic pollutants in sediments from the Bay were assessed a few years after a mass mortality event of...

Livers of catfish (Ariopsis assimilis) from the Bay of Chetumal were analyzed for organochlorine compounds and hydrocarbons as part of a study to diagnose the environmental health of the Bay after a catfish mass mortality that occurred in 1996. The presence of histological lesions in several organs of the fish as result of chemical exposure was als...

The effect of pollutants on the intensity of infection of metazoan parasites in the Mayan catfish, Ariopsis assimilis was investigated. Data were collected on pollutants and metazoan parasites from 76 catfish from five localities in Chetumal Bay in October, 1996. Nineteen pollutants (pesticides, polychlorinated biphenyls (PCBs) and polycyclic aroma...

The effect of environmental pollutants present in sediments obtained from Bahía de Chetumal, a bay on the border between Mexico and Belize, was studied in nile tilapia (Oreochromis niloticus) intraperitoneally injected with sediment extracts from six different sites of the Bay. Sediment samples used for the study contained a variety of organic chem...

The concentrations of polynuclear aromatic hydrocarbons in oyster tissues from one of the most productive shrimp-fishing and oyster-farming areas in the coastal Gulf of Mexico, the Terminos Lagoon, were measured to assess the impact that offshore crude oil production on the continental shelf of Campeche might have on local resources. Total PAH conc...

The southeastern portion of the Yucatan Peninsula is characterized by high diversity, interlinked ecosystems. It has been estimated that 25% of the total reptile and mammalian species are of conservation value, either because they are endangered, threatened, or endemic (Dotherow et al. 1995). In this area is the Bay of Chetumal, along the border be...

Laguna de Terminos is a 2,500 km{sup 2} coastal lagoon in the southern Gulf of Mexico, located between 18{degrees} 20` and 19{degrees} 00` N, and 91{degrees} 00` and 92{degrees} 20` W (Figure 1). It is a shallow lagoon, with a mean depth of 3.5 m and connected to the Gulf of Mexico through two permanent inlets, Puerto Real to the east and Carmen to...