Red Drum \u3ci\u3e(Sciaenops ocellatus)\u3c/i\u3e Trophic Web Reconstruction Using Stable Isotopes in Two Systems in the Northwestern Gulf of Mexico

Estuaries act as nurseries for many important fishes, including predators like Red Drum (Sciaenops ocellatus). Using gut content and stable isotope analyses to better understand juvenile S. ocellatus’ diet and role within the trophic web, a full year of data was collected on a quarterly basis to illustrate a change in diet based on resource availability at two study sites and for two non-overlapping S. ocellatus sizes. Panopeidae and Penaeidae were the most abundant prey items found in S. ocellatus stomachs for both sizes, sites, and four quarters representing over 50% of the diet. Stable isotope analyses from 80 fish show that S. ocellatus are feeding in very similar trophic levels but nonetheless there are significant differences for all quarters in δ15N between sites and δ13C between sizes, sites, and quarters. Differences may be linked to changing resources throughout the year, site composition differences, and seasonal changes in productivity

Biodiversity of forage fishes in the Lower Laguna Madre, southernmost Texas

Coastal estuarine ecosystems serve as nursery habitats for many commercially and recreationally important fishes. Biodiversity is a structural indicator and has been used as a metric for conservation and management. In the hypersaline Lower Laguna Madre of Texas, a variety of organisms makes their living in and around the dominant seagrass vegetation. This study provides a general assessment of forage fishes biodiversity collected seasonally with bag seines in two sites: Holly Beach (HB) and South Bay (SB) within the most southern Texas bay system as part of a broader study on fish biology. A total of 15,880 fishes representing 32 species were collected during four quarterly samplings through a year (11,795 from HB and 4,085 from SB). Both sites are interconnected as no fishes similarities difference were found, nonetheless, the sites’ variable characteristics (i.e. basin area, seagrasses coverage, connection to the Gulf of Mexico) resulted in significant greater species richness, relative abundances, and diversity in HB than SB for most of the year, suggesting differences in habitat quality or at the very least variation in the availability of habitat types, which are known to contribute to differences in fish diversity attributes. - Los ecosistemas de estuarios costeros sirven como hábitats de crianza para muchos peces de importancia comercial y recreativa. La biodiversidad es un indicador estructural y se ha utilizado como métrica para la conservación y la gestión. En la hipersalina Laguna Madre Inferior de Texas, una variedad de organismos vive en y alrededor de la vegetación de pastos marinos dominante. Este estudio proporciona una evaluación general de la biodiversidad de peces de forraje recolectados estacionalmente con redes de cerco en dos sitios: Holly Beach (HB) y South Bay (SB) dentro del sistema de bahías al sur de Texas, como parte de un estudio más amplio sobre la biología de peces. Durante cuatro muestreos trimestrales a lo largo de un año, se recolectaron un total de 15.880 peces (11.795 de HB y 4.085 de SB) que representan 32 especies. Ambos sitios están interconectados, ya que no se encontraron diferencias en las similitudes de peces; sin embargo, las características variables de los sitios (es decir, área de la cuenca, cobertura de pastos marinos, conexión con el Golfo de México) dieron como resultado una riqueza de especies, abundancias relativas y diversidad significativamente mayores en HB que en SB durante la mayor parte del año, lo que sugiere diferencias en la calidad del hábitat o, al menos, variación en la disponibilidad de tipos de hábitat, que se sabe que contribuyen a las diferencias en los atributos de diversidad de peces

Biodiversity of forage fishes in the Lower Laguna Madre, southernmost Texas

Coastal estuarine ecosystems serve as nursery habitats for many commercially and recreationally important fishes. Biodiversity is a structural indicator and has been used as a metric for conservation and management. In the hypersaline Lower Laguna Madre of Texas, a variety of organisms makes their living in and around the dominant seagrass vegetation. This study provides a general assessment of forage fishes biodiversity collected seasonally with bag seines in two sites: Holly Beach (HB) and South Bay (SB) within the most southern Texas bay system as part of a broader study on fish biology. A total of 15,880 fishes representing 32 species were collected during four quarterly samplings through a year (11,795 from HB and 4,085 from SB). Both sites are interconnected as no fishes similarities difference were found, nonetheless, the sites’ variable characteristics (i.e. basin area, seagrasses coverage, connection to the Gulf of Mexico) resulted in significant greater species richness, relative abundances, and diversity in HB than SB for most of the year, suggesting differences in habitat quality or at the very least variation in the availability of habitat types, which are known to contribute to differences in fish diversity attributes