Fish species richness in the Terminos Lagoon: An occurrence data compilation of four sampling campaigns along a multidecadal series.

Luis Alejandro Yáñez‐Arancibia 1944–2016

Introduction: There are scarce information about the movements and patterns of residence of bottlenose dolphins in the southern part ofthe Gulf of Mexico and the objective of this study is to have information on this subject, Terminos lagoon area is the zone with more effort to study in the region and it is possible that the dolphins move along the coast. Methods: During 1994 to 1999 systematic surveys were carried out to study the movements and residence patterns of bottlenose dolphin populations in four different localities along the coast of the southern Gulf of Mexico, Holbox Island, Quintana Roo, Celestun in Yucatan, Terminos lagoon in Campeche and oriental Tabasco. Results: In total, 2,889 dolphins were photo-identified in the four areas, the majority in the Terminos lagoon (1,987); in this same area one dolphin was recorded within 10 years and nine months, thus having a multi-annual residency pattern. Other dolphin was photo-identified during 1997 in Holbox and 247 days later in Tabasco; another four animals moved from Terminos lagoon to Tabasco, travelling on average 270 km. Discussion and conclusions: These are the first long-term residence patterns and migration records for the species along the southern Gulf of Mexico. Bottlenose dolphins use the coastal lagoons as feeding and shelter areas for calving. The long movements recorded along the Yucatan peninsula between Quintana Roo and Tabasco may evidence a continuous coastal population along the southern Gulf of Mexico. Key words: Bottlenose dolphins; Gulf of Mexico; movements; residence; Tursiops truncatus .

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 342:217-226 (2007) - doi:10.3354/meps342217 Spatiotemporal segregation regulates species richness along biomass gradients in estuarine fish assemblages Atahualpa Sosa-Lopez1, David Mouillot2,* 1Centro EPOMEX, Universidad Autónoma de Campeche, Av. Agustín Melgar s/n, Campeche, CP 24030, Campeche, Mexico 2UMR CNRS-UM2 5119 Ecosystèmes Lagunaires, Université Montpellier 2, CC 093, 34095 Montpellier Cedex 5, France *Corresponding author. Email: mouillot@univ-montp2.fr ABSTRACT: The number of fish species in subtropical and tropical estuaries is much greater than in temperate regions and is greater in large estuaries than in small ones. Thus, large estuaries of the tropics are of primary interest for biodiversity conservation, and the processes underpinning the distribution of fish diversity in these ecosystems deserve attention. Factors controlling biodiversity patterns have been the focus of numerous recent investigations and include species interactions, speciation, environmental gradients and heterogeneity, with all of these operating differently at each observation scale. Today, the question is no longer whether particular biodiversity patterns occur, but why they occur and whether they are consistent across scales and organisms under study. In this study we combined the results of 2 classical ecological patterns, namely diversity–biomass relationships and species co-occurrences, into a common framework. Fish sampling was carried out in the coastal Terminos Lagoon (southern Gulf of Mexico) during 2 periods (1980–1981 and 1998–1999) using 408 tows. A total of 22834 individuals representing 106 fish species were collected. Our study revealed that both diversity–biomass relationships and species co-occurrences show inconsistent patterns across years, seasons and zones. However, taken together, our results show that C-score values, which measure spatiotemporal segregation among species, were closely related to the shape of observed richness–biomass relationships. When fish assemblages showed positive C-score values (species segregation), the relationship between species richness and fish biomass was either hump-shaped or non-significant. Conversely, negative C-score values (species aggregation) were associated with an increase in fish species richness along the total biomass gradient. Our results support the idea that species segregation due to competition or spatiotemporal partitioning can be an important determinant of biodiversity patterns in species-rich tropical fish assemblages, but only during some periods and for some spatial strata. KEY WORDS: Terminos Lagoon · Co-occurrence · C-score index · Randomization · Species segregation Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 342. Online publication date: July 24, 2007 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2007 Inter-Research.

The pink shrimp Farfantepenaeus duorarum and white shrimp Litopenaeus setiferus are species of high ecological and commercial value, therefore, studies that analyze their temporal variability and their relationship with the physical ambient in the long term becomes necessary. The aim of this is study was to assess the impact of some environmental factors on the temporal variability of the postlarvae of both species in Terminos Lagoon, Southern Gulf of Mexico, a region recognized for being the refuge, breeding and feeding habitat for these species. Organisms were collected at three different depths (1.5, 4 and 9 m) using a multiple net system (trapezium-type nets, 50 cm of mouth diameter, 1.5 m in length, and mesh size of 505 mm) in a fixed location at the junction between the lagoon and the open waters of the Gulf of Mexico during nocturnal sampling expeditions executed from May 2010 to September 2013. In each sampling expedition, hydrographic data (e.g., temperature, salinity) were recorder using a multiparameter sonde, meteorological data (e.g., precipitation, wind velocity) were acquired from a local meteorological station, while the surface circulation pattern was obtained from a numerical model. The results showed changes in the environmental factors, with highest precipitation (250 mm) in 2010. The surface temperature revealed values of ~30 ºC with slight variations throughout the study period. Salinity showed minimum values (< 30) in the seasons of highest precipitation, increasing during the dry season with values of > 33. Strong currents (> 0.25 m s-1) in a north to south direction that reached the coast and then the interior of the lagoon were observed in specific dates. Mesoscale anticyclonic eddies (with a diameter of ~30 km) were also observed in the southern gulf. High density values of both species were observed, reaching 33,619 ind 100 m-3 for L. setiferus, and 57,948 ind 100 m-3 for F. duorarum. Peaks were associated when strong surface currents were observed reaching the interior of the lagoon, which was confirmed from multivariate statistical techniques. The results presented here contribute to the understanding of the role that some environmental factors exert on the density of two species with high, both economic and ecological, value in the Terminos Lagoon, which is of critical relevance in regions recognized for their high biological diversity.

Terminos Lagoon is recognized as an ecosystem of great diversity and productivity in the southern Gulf of Mexico. It is also the site of various anthropogenic activities in the lagoon as well as in its surroundings. In addition, in recent years this lagoon has showed variations in temperature and salinity as a result of global warming and/or watershed management. This has generated variations in the structure and function of fish communities, among other taxonomic groups. IIn this work, we analyze the changes in abundance and distribution associated with modifications in the salinity of fish species from two key families (Ariidae y Gerreidae) during the years 1980, 1998, and 2011. Salinity is analyzed in the three periods (ANOVA, Tukey (HSD); the abundance of species, environmental breadth according to salinity (Levins Index), environmental overlap (Pianka Index), and co-occurrence (C-score) are also analyzed. Statistical differences were tested using the null model. The results showed high variability in salinity, with a tendency to increase during the studied period with 24.7, 27.9, and 28.4 UPS for each year, respectively (p < 0.0001). The abundance of both families increased from 1980 to 1998 and decreased in 2011 (82% for Ariidae and 62% for Gerreidae). The C-score ranged from 1.07 in 1980 to 0.78 in 1998 and 2.71 in 2011. The observed averages were significantly lower than the simulated average (P <0.0001). In conclusion, the increase in salinity is probably one of the causes of a variation in the abundance of fish species. According to a possible more limited competition for space, fish abundance and C-score fluctuated inversely, indicating a trend towards a more generalist fish community. Keywords: Environmental breadth, environmental overlapping, co-ocurrence, and salinity gradient.

This study evaluated the ingestion of microplastics (MP) by copepods in Terminos Lagoon (TL), a RAMSAR-listed site in the southern Gulf of Mexico. The evaluation was carried out in two contrasting seasons of 2022, as follows: the dry (April) and the rainy (October). Copepods were collected using a conical plankton net (mesh size of 200 μm). In the laboratory, a pool of all pelagic adult copepod taxa was picked, and the MP inside the organisms were extracted, classified, and photographed using traditional optical and scanning electron microscopy. A total of 268 MP particles were extracted from the interior of copepods; among them, 149 and 119 corresponded to the dry and rainy seasons, respectively. The ingestion rate in the dry season was 0.14, while in the rainy season, it was 0.11. In addition, fibers, plastic fragments, and microspheres with different colors (blue, red, black, green, transparent, and multicolored), sizes, forms (angular, round, triangular, and twisted), and textures were also detected. Fibers were the most abundant MP found in a proportion of more than 85%. In addition, in some sampling sites, microspheres were observed with high relative abundance values (80%). In some sites, fragments reach 20% of the total abundance. Significant differences were observed between the two seasons. The sites closest to the urban area adjacent to TL observed high diversity and abundance of MP. The higher abundance of MP in the dry season is due to lower river discharge, on the other hand. Thus, MP particles accumulate and become available for consumption by copepods. This is the first study that has revealed that the MP was ingested by the copepods in TL. Furthermore, this study provides a baseline information for future research on the abundance of MP in the Gulf of Mexico region.

10 - Estuarine Primary Producers: Laguna de Terminos—a Study Case

In a natural world increasingly trans- formed by human activities, the contemporary acceler- ation of biodiversity loss is now widely accepted. Coastal and estuarine environments are some of the most productive ecological systems on Earth and are able to provide many essential ecosystem goods and services, such as protein from fish or nutrient exports to adjacent marine ecosystems. Unfortunately, coastal lagoons are under increasing human pressure, and constraints on fish biodiversity are of major concern. Using fish samples from the Terminos coastal lagoon (southern Gulf of Mexico), we found a significant de- crease in taxonomic diversity over 18 yr while varia- tions in richness and evenness were mainly associated with seasonal and spatial variations. In other words, 2 randomly chosen individuals or 2 randomly chosen spe- cies within a fish assemblage were more likely to be closely related in the 1998 to 1999 period than in the 1980 to 1981 period. This result suggests a loss of func- tional diversity and a biotic homogenization in the lagoon fish community. At the same time, we observed a significant salinity increase between the 1980 to 1981 period and the 1998 to 1999 period, and the water tem- perature and transparency increased between the 2 annual periods. These results suggest a loss of estuar- ine conditions in the Terminos lagoon between the 1980 to 1981 and the 1998 to 1999 periods and a shift in hydrological conditions from hypohaline to euhaline/ hyperhaline status. In parallel, some fish families such as Mugilidae, Serranidae, Lobotidae, Achiridae, Belon- idae, Elopidae and Stromatide are better represented within the Terminos lagoon now than they were in the past. As a feedback, this loss of taxonomic diversity can lead to a loss of ecological responsiveness to environ- mental fluctuations and a loss of ecological functioning.

Catfishes of the Family Ariidae are characterized as eurythermal and euryhallne inhabitants of estuarine waters. In the Southern Gulf of Mexico (Terminos Lagoon) there are 3 species: Arius felis, A. melanopus, and Bagre rnarinus. Juveniles of A. melanopus occur in the fluvial-lagoon system (FLS) in areas with oysters Crassostrea virginica, while adults occur throughout the lagoon. A. melanopusreaches sexual maturity at 160 mm total length (TL) and reproduces in FLS in salinities 12 ppt, temperatures 2 30 C, and in less turbid areas dominated by Thalassia testudi~~um eadows. Males with eggs and/or embryos in their mouths are found In September. After the incubation period adults migrate toward the eastern inlet (marine) and luveniles toward the western inlet (estuarine). B. marjnus is found only in the western inlet (estuarine), central basin, and FLS of Terminos Lagoon. This specles reproduces along the coastline and enters the lagoon at the end of the rainy and winter storm or nortes season. Juveniles use the lagoon as nursery area. The Terminos Lagoon has a high diversity of habitats due to ecological interchange with rivers, swamps and the inner shelf. Three main strategies in the use of the system by catfishes in relation to reproduction and feeding may be characterized as: (1) spawning in the rivers and swamps followed by a migration of juveniles toward the central part of the estuarine system; (2) spawning in the estuarine system; and (3) s p a w ~ n g in the sea followed by migration of juveniles to the FLS for feeding. Estuarine fish that have separate reproduction, growth, and feeding areas generally occur in great abundance and have adapted by reducing interspecific competition and temporal and spatial niche partition. In tropical high diversity ecosystems, biological cycles are closely related to high productivity of coastal waters, large supply of organic matter, increased food availability, and protection from predators. The estuary-inner shelf or swamp-estuary migrations can be interpreted as small-scale anadromous adaptations.

Status of shark resources in the southern Gulf of Mexico and Caribbean: implications for management

The trophic structure of the fish community ecosystem in the Terminos Lagoon (southern Gulf of Mexico) has shown a range of functional changes. The description of the heterogeneity of functional traits in a biological community allows the identification of the relevant functions in an ecosystem. An analysis was conducted of the functional traits (trophic level, reproductive and trophic guild, habitat, estuary use, essential habitat, salinity tolerance, body shape, mouth type, caudal fin type, and maximum length) of the fish community of the lagoon for three different years (1980, 1998 and 2011). We developed a new index to analyze the variation of functional diversity called the functional traits diversity index (FADI). This index takes into account the abundance of traits and emphasizes less common traits (i.e., those that are less redundant). The functional redundancy was different in the three periods studied. The FADI value for 1998 was the highest and was outside of the expected probability distribution, indicating a greater abundance of species with unique functional traits. A principal components analysis was performed to assess the relative contribution of functional traits to the overall variance of functional diversity over the three periods. We found that the trophic level, body shape, and mouth type were the most influential traits in the functional diversity changes. The environmental changes were correlated with the variability of the functional structure. Depth was the most influential environmental variable in the principal component analysis. The results indicate a reorganization of the functional structure of the fish community in the Terminos Lagoon. The FADI was helpful in explaining these changes observed throughout the three periods studied.

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 the west. Several rivers, most of them from the Grijalva-Usumacinta basin (the largest in Mexico and second largest in the Gulf of Mexico), drain into the lagoon with a mean annual discharge of 6 X 10{sup 9} m{sup 3}/year. This lagoon has been studied systematically, and is probably one of the best known in Mexico. An excellent overview of this lagoon can be found in Yanez-Arancibia and Day. The continental shelf north of Terminos, the Campeche Bank, is the main oil-producing zone in Mexico with a production of about 2 X 10{sup 6} barrels/day. It is also the main shrimp producer in the southern Gulf, with a mean annual catch of 18,000 tonnes/year, which represents 38 to 50% of the national catch in the Gulf of Mexico. The economic importance of this region, along with itsmore » extremely high biodiversity, both in terms of species and habitats, has prompted the Mexican government to study the creation of a wildlife refuge around Terminos. Thus, it is very important to know the current levels of pollutants in this area, as a contribution to the management plan of the proposed protected area. This paper looks at hydrocarbon concentrations in oyster tissue. 14 refs., 3 figs., 21 tabs.« less

Accumulation and fluxes of potentially toxic elements in a large coastal lagoon (southern Gulf of Mexico) from 210Pb sediment chronologies

Hernandez-Alcantara, P., Cortes-Solano, J.D., Medina-Cantu, N.M., Aviles-Diaz, A.L. and Solis-Weiss, V. 2014. Polychaete diversity in the estuarine habitats of Terminos Lagoon, Southern Gulf of Mexico. Memoirs of Museum Victoria 71: 97–107. In order to establish the status of the biodiversity of the polychaete fauna inhabiting the soft bottoms in the largest lagoon-estuarine system from the southern end of the Gulf of Mexico, Terminos Lagoon, we collected and identified 3,398 specimens belonging to 119 species and 33 families of polychaetes. The soft bottom fauna was then compared with records of polychaetes collected in other habitats in the lagoon such as seagrass beds and mangroves. In all, 190 species from 34 families of polychaetes previously recorded there were taken into account. The families Nereididae (20 spp.), Spionidae (15 spp.) and Syllidae (14 spp.) were the most diverse. The soft bottom habitat has by far the largest number of species (119) followed by the seagrass beds and mangroves with 75 and 42 species respectively. Large spatial heterogeneity in polychaete composition was observed, as only 5% of the species (Melinna maculata, Capitella sp., Mediomastus californiensis, Schistomeringos rudolphii, Marphysa sanguinea, Alitta succinea, Diopatra cuprea, Scoloplos treadwelli, Prionospio heterobranchia and Scolelepis squamata) were widely distributed in the lagoon. The polychaete fauna living in the mangroves is quite similar to that from seagrasses and soft bottoms (R(ANOSIM) = 0.247 and 0.3 respectively), but the polychaetes in the seagrasses and soft bottoms are clearly different from each other (R(ANOSIM) = 0.622). The 119 polychaete species identified in this study represent a significant increase in the records of biodiversity recorded so far in Terminos Lagoon, while the total of 190 species recorded for the whole lagoon represents a larger number than any other recorded for an American tropical estuary.

Spatial configuration of seagrass community attributes in a stressed coastal lagoon, southeastern Gulf of Mexico