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This study reports for the first time the presence of Rhizoprionodon terraneovae neonates in a coastal lagoon in the southeastern Gulf of Mexico. The observations suggest the presence of neonates was due to the salinity values being similar to those of the coastal zone (32 ppt) and that they may have been attracted by the high presence of penaeid shrimp. The presence of this species in this lagoon supports the knowledge of the biology and ecology of the species, which will contribute to its proper fishing management.

Epikarst estuary response to hydroclimate change remains poorly understood, despite the well-studied link between climate and karst groundwater aquifers. The influence of sea-level rise and coastal geomorphic change on these estuaries obscures climate signals, thus requiring careful development of paleoenvironmental histories to interpret the paleoclimate archives. We used foraminifera assemblages, carbon stable isotope ratios (δ13C) and carbon:nitrogen (C:N) mass ratios of organic matter in sediment cores to infer environmental changes over the past 5300 years in Celestun Lagoon, Yucatan, Mexico. Specimens (> 125 µm) from modern core top sediments revealed three assemblages: (1) a brackish mangrove assemblage of agglutinated Miliammina and Ammotium taxa and hyaline Haynesina (2) an inner-shelf marine assemblage of Bolivina, Hanzawaia, and Rosalina, and (3) a brackish assemblage dominated by Ammonia and Elphidium. Assemblages changed along the lagoon channel in response to changes in salinity and vegetation, i.e. seagrass and mangrove. In addition to these three foraminifera assemblages, lagoon sediments deposited since 5300 cal yr BP are comprised of two more assemblages, defined by Archaias and Laevipeneroplis, which indicate marine Thalassia seagrasses, and Trichohyalus, which indicates restricted inland mangrove ponds. Our data suggest that Celestun Lagoon displayed four phases of development: (1) an inland mangrove pond (5300 BP) (2) a shallow unprotected coastline with marine seagrass and barrier island initiation (4900 BP) (3) a protected brackish lagoon (3000 BP), and (4) a protected lagoon surrounded by mangroves (1700 BP). Stratigraphic (temporal) changes in core assemblages resemble spatial differences in communities across the modern lagoon, from the southern marine sector to the northern brackish region. Similar temporal patterns have been reported from other Yucatan Peninsula lagoons and from cenotes (Nichupte, Aktun Ha), suggesting a regional coastal response to sea level rise and climate change, including geomorphic controls (longshore drift) on lagoon salinity, as observed today. Holocene barrier island development progressively protected the northwest Yucatan Peninsula coastline, reducing mixing between seawater and rain-fed submarine groundwater discharge. Superimposed on this geomorphic signal, assemblage changes that are observed reflect the most severe regional wet and dry climate episodes, which coincide with paleoclimate records from lowland lake archives (Chichancanab, Salpeten). Our results emphasize the need to consider coastal geomorphic evolution when using epikarst estuary and lagoon sediment archives for paleoclimate reconstruction and provide evidence of hydroclimate changes on the Yucatan Peninsula. [ABSTRACT FROM AUTHOR]

Se evaluó la abundancia y recambio de las especies ícticas que habitan en la laguna de Celestún en función de los ciclos de luz y oscuridad y del tipo de hábitats. Para ello se realizaron 6 muestreos bimestrales en una red de 4 estaciones; 2 localizadas en la boca y 2 en la zona interna de la laguna. Los sitios de cada zona comprenden un fondo con vegetación acuática y otro sin ésta (VAS, FSV). En cada sitio se registraron parámetros hidrológicos para determinar su relación con la estructura de la comunidad. Los peces se recolectaron con un chinchorro (15 × 1.5 m, 2.5cm luz de malla) en un periodo diurno (10:00-3:00), crepuscular (18:00-21:00) y nocturno (02:00-05:00). Para su análisis se utilizaron diferentes estadísticos multivariados no parámetricos (NPMANOVA, NMDS, betadisper). Se encontraron diferencias en composición de especies de peces entre hábitats con VAS y FSV (F=2.6108, p=0.0114). La tasa de recambio de especies es baja entre hábitats y entre ciclos de luz-oscuridad. Los ensamblajes de peces entre hábitats son más dinámicos que nictimeralmente, debido a que las praderas de vegetación sumergida soportan un mayor número de especies por su función en la alimentación y/o como protección.The abundance and turnover of fish species inhabiting Celestún lagoon were evaluated according to day-night cycles, as well as habitat type. Bimonthly sampling was done at 4 sites of the lagoon, 2 at the mouth and 2 at the inner zone. The sites for each zone include bottoms with and without submerged aquatic vegetation (VAS, FSV). At each site hydrologic parameters were registered to determine their relationship with fish community structure. Fish specimens were collected using a beach seine (15 ×1.5 m, 2.5cm mesh) at day (10:00-13:00), twilight (18:00-21:00) and night (02:00-05:00). Multivariate non-parametric (NPMANOVA, NMDS, betadisper) statistics were used for the analysis. Difference in fish species were found between habitats with VAS and FSV (F=2.6108, p=0.0114). The betadisper test indicated that species rate of replacement is low between habitats and during day-night cycles. Fish assemblages between habitats are more dynamic than day-night cycles, due to seagrass meadows that host great numbers of species providing protection and food availability.

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La nativa Cichlasoma urophtalmus fue estudiada utiliando la técnica de electrofóresis en geles de poliacrilamida. Para obtener el articulo completo pueden contactar al Editor de la Revista Ecosistemas y Recursos Agropecuarios en el siguiente correo electrónico era@ujat.mx y se les enviará sin algún costo.

Copyright of Desacatos is the property of Centro de Investigaciones y Estudios Superiores en Antropologia Social and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: In September 2002, Hurricane Isidore devastated the Yucatán Peninsula, Mexico. To understand its effects on the parasites of aquatic organisms, we analyzed long-term monthly population data of the horn snail Cerithidea pliculosa and its trematode communities in Celestún, Yucatán, Mexico before and after the hurricane (February 2001 to December 2009). Five trematode species occurred in the snail population: Mesostephanus appendiculatoides, Euhaplorchis californiensis, two species of the genus Renicola and one Heterophyidae gen. sp. Because these parasites use snails as first intermediate hosts, fishes as second intermediate hosts and birds as final hosts, their presence in snails depends on food webs. No snails were present at the sampled sites for 6months after the hurricane. After snails recolonised the site, no trematodes were found in snails until 14months after the hurricane. It took several years for snail and trematode populations to recover. Our results suggest that the increase in the occurrence of hurricanes predicted due to climate change can impact upon parasites with complex life cycles. However, both the snail populations and their parasite communities eventually reached numbers of individuals and species similar to those before the hurricane. Thus, the trematode parasites of snails can be useful indicators of coastal lagoon ecosystem degradation and recovery. [Copyright &y& Elsevier]

This paper proposes a new way of looking at development theory. Its specific aim is to problematise post-development theories by thinking through an ecotourist development strategy put into practice in the Biosphere Reserve Ría Celestún (Yucatán, Mexico). Post-development studies have tended to rely on a narrow theoretical perspective in which development is understood as a global discourse resisted by local Others. A focus on discourse has abstracted the lived and conflictual experiences of development ethnographies. This article claims that moving between the study of discourses and the study of practices, ‘complex mobile connections’ and ‘multi-sited global ethnographies’, furthers considerably our understanding of development. This attention to both discourses and practices may enable new ways of thinking about how development is empirically, locally and materially performed. The complex practices through which Celestún is performed as an ecotourist destination, as a place undergoing development, and as a fishing community provides empirical evidence for the main theoretical points explored in the article. [ABSTRACT FROM AUTHOR]