Checklist of invertebrates and conspicuous fishes in rocky reefs and Sargassum beds in the North Pacific of Costa Rica

Introduction: The marine biodiversity is well known in some areas and for some marine ecosystems of the Pacific coast of Costa Rica. The marine sector of Área de Conservación Guanacaste, in the North Pacific of the country, is a priority area for conservation of marine and coastal biodiversity. Objective: Our aim was to increase the knowledge of marine biodiversity in a conservation priority site in Costa Rica and in poorly or scarcely studied marine ecosystems, such as rocky reefs and Sargassum beds, respectively. Methods: The study was conducted in Bahía Salinas and Golfo de Santa Elena in 2013. In January, four rocky reefs were visited; while in February three rocky reefs and one Sargassum bed were visited. We identified the macroinvertebrates and conspicuous fish species through underwater visual census methods (timed swim and band transects). The mean density of each species was estimated through band transects method. Results: A total of 25 invertebrates and 34 fish species were identified. We found a high number of species of invertebrates (23) and fish species (33) in rocky reefs, but few species on Sargassum beds (eight invertebrates and ten fish species). Species composition differed between marine ecosystems. Conclusions: Our study further evidence the limited knowledge of invertebrates and fish communities in these marine ecosystems in the North Pacific of Costa Rica. Considerably more surveys and field work are required to support management decisions that are backed by sound scientific knowledge.

Introducción: La biodiversidad marina es bien conocida en algunas áreas y para algunos ecosistemas marinos de la costa Pacífica de Costa Rica. El sector marino del Área de Conservación Guanacaste, en el Pacífico norte del país, es un área prioritaria para la conservación de la biodiversidad marina y costera. Objetivo: Nuestro objetivo fue el de incrementar el conocimiento de la biodiversidad marina en un sitio prioritario de conservación de Costa Rica y en ecosistemas marinos poco o nulamente estudiados, como son los arrecifes rocosos y mantos de Sargassum, respectivamente. Métodos: El estudio se realizó en Bahía Salinas y Golfo de Santa Elena en el 2013. En enero, cuatro arrecifes rocosos fueron visitados; mientras que en febrero tres arrecifes rocosos y un manto de Sargassum fueron visitados. Identificamos las especies de invertebrados y peces conspicuos a través métodos de censos visuales submarinos (buceos cronometrados y transectos de banda). La densidad promedio de cada especie se estimó mediante el método de transectos de banda. Resultados: Se registró un total de 25 invertebrados y 34 especies de peces. Encontramos un mayor número de especies de invertebrados (23) y peces (33) en los arrecifes rocosos, pero pocas especies en el manto de Sargassum (ocho especies de invertebrados y diez de peces). La composición de especies difirió entre ecosistemas marinos. Conclusiones: Nuestro estudio evidencia el limitado conocimiento de las comunidades de invertebrados y peces en estos ecosistemas marinos en el Pacífico Norte de Costa Rica. Considerablemente más encuestas y trabajo de campo son requeridos para apoyar decisiones de manejo que sean respaldados por conocimientos científicos solidos.

Development and characterization of 20 polymorphic microsatellite loci in the deep sea squat lobster, Munida isos Ahyong and Poore, 2004 and cross-amplification in two congeneric species

Munida isos is a deep sea squat lobster species that is widely distributed across the New Zealand and east Australian region, and is often associated with deep sea vulnerable marine ecosystems. To investigate its population genetic structure and patterns of regional connectivity, microsatellite loci were developed for M. isos from two genomic libraries using the Illumina HiSeq 2500 sequencing platform. Twenty-six loci amplified consistently in M. isos from the Tasman Sea, among which 20 were polymorphic and selectively neutral. Evidence of null alleles was observed at eight loci. Most loci exhibited moderate to high levels of polymorphism, with an average polymorphic information content value of 0.482. The mean number of alleles per locus was 7.45, with a mean expectedheterozygosity of 0.520. Thirteen loci exhibited significant deviation from Hardy–Weinberg equilibrium, while only one locus pair was in linkage disequilibrium after false discovery rate correction for multiple testing (P < 0.05). Cross-species amplification tests revealed that the transferability of 14 loci (70%) was positive for the two congeners M. endeavourae and M. gracilis. The accessibility to new polymorphic microsatellite loci will facilitate population genetic studies and aid in developing conservation and management strategies for vulnerable marine ecosystems.

Inhibition of Nitzschia ovalis biofilm settlement by a bacterial bioactive compound through alteration of EPS and epiphytic bacteria

Background: Marine ecosystems contain benthic microalgae and bacterial species that are capable of secreting extracellular polymeric substances (EPS), suggesting that settlement of these microorganisms can occur on submerged surfaces, a key part of the first stage of biofouling. Currently, anti-fouling treatments that help control this phenomenon involve the use of biocides or antifouling paints that contain heavy metals, which over a long period of exposure can spread to the environment. The bacterium Alteromonas sp. Ni1-LEM has an inhibitory effect on the adhesion of Nitzschia ovalis, an abundant diatom found on submerged surfaces. Results: We evaluated the effect of the bioactive compound secreted by this bacterium on the EPS of biofilms and associated epiphytic bacteria. Three methods of EPS extraction were evaluated to determine the most appropriate and efficient methodology based on the presence of soluble EPS and the total protein and carbohydrate concentrations. Microalgae were cultured with the bacterial compound to evaluate its effect on EPS secretion and variations in its protein and carbohydrate concentrations. An effect of the bacterial supernatant on EPS was observed by assessing biofilm formation and changes in the concentration of proteins and carbohydrates present in the biofilm. Conclusions: These results indicate that a possible mechanism for regulating biofouling could be through alteration of biofilm EPS and alteration of the epiphytic bacterial community associated with the microalga.

Concentración de Hg, Pb, Cd, Cr y As en hígado de Carcharhinus limbatus (Carcharhiniformes: Carcharhinidae) capturado en Veracruz, México

Concentration of Hg, Pb, Cd, Cr and As in liver Carcharhinus limbatus (Carcharhiniformes: Carcharhinidae) captured in Veracruz, Mexico. Pollution by heavy metals in marine ecosystems in the Gulf of Mexico is one of the hardest conservation issues to solve. Sharks as top predators are bioindicators of the marine ecosystem health, since they tend to bioaccumulate and biomagnify contaminants; they also represent a food source for local consumption. Thus, the objective of this study was to study the possible presence of heavy metals and a metalloid in livers of Carcharhinus limbatus. For this, a total of 19 shark livers were taken from animals captured nearby Tamihua, Veracruz, Mexico from December 2007 to April 2008. 12 out of the 19 captured sharks were males, one was an adult female, three were juvenile males, and three juvenile females. Four heavy metals (Hg, Pb, Cd, and Cr) and one metaloid (As) were analyzed in shark livers using an atomic absorption spectrophotometry with flame and hydride generator. Our results showed that the maximum concentrations found were: Hg=0.69mg/kg, Cd=0.43mg/kg, As=27.37mg/kg, Cr=0.70mg/kg. The minimum concentrations found were: As=14.91mg/kg, Cr=0.35mg/kg. The Pb could not be determined because the samples did not have the spectrophotometer minimum detectable amount (0.1mg/kg). None of the 19 samples analyzed showed above the permissible limits established by Mexican and American laws. There was a correlation between shark size and Cr and As concentration (Pearson test). The concentration of Cr and As was observed to be higher in bigger animals. There was not a significant difference in heavy metals concentration between juveniles and adults; however, there was a difference between males and females. A higher Cr concentration was found in females when compared to males. None of the samples exceed the maximum limit established by the laws of Mexico and the United States of America. Much longer studies are needed with C. limbatus and other species caught in the region, in order to determine the degree of contaminants exposure in aquatic ecosystems and to identify potential health risks to consumers.

La contaminación de los ecosistemas marinos y costeros por metales pesados en el Golfo de México es uno de los problemas que afectan a los recursos naturales del medio acuático. Los tiburones por situarse en niveles tróficos superiores de la red alimenticia acumulan y magnifican cantidades considerables de contaminantes. Por esta razón, el objetivo de este trabajo fue determinar la concentración de cuatro metales pesados (Hg, Cd, Pb y Cr) y un metaloide (As) en el tiburón punta negra (Carcharhinus limbatus) por medio de espectrofotometría de absorción atómica con flama y generador de hidruros. Se muestrearon 19 hígados de tiburones capturados cerca de Tamiahua, Veracruz entre noviembre 2007 y marzo 2008, de los cuales 12 fueron machos adultos, una hembra adulta, tres machos jóvenes y tres hembras jóvenes. Las concentraciones máximas registradas para cada metal fueron: Hg=0.69mg/ kg, Cd=0.43mg/kg, As=27.37mg/kg, Cr=0.35mg/kg. El Pb no fue detectado, no al menos la cantidad mínima de detección requerida por el espectrofotómetro de absorción atómica (0.1mg/kg). Ninguna de las muestras analizadas rebasó los límites máximos permisibles por las leyes mexicanas y americanas.

Bibliografía sobre investigaciones marinas, oceanográficas, geológicas y atmosféricas en el Parque Nacional Isla del Coco y aguas adyacentes, Pacífico de Costa Rica / Bibliography on marine, oceanographic, geological and atmospheric research at Isla del Coco Nacional Park and adjacent waters, Pacific Costa Rica

Isla del Coco (also known as Cocos Island), Pacific Costa Rica, has been visited and written about since the 16th Century, and since the late 1800’s many expeditions and scientists have carried out research in the Island. Here I compiled publications on marine biological, geological, oceanographic and atmospheric research done at Isla del Coco. A list of 599 scientific papers and chapters were compiled, together with 41 books, reports, Special Issues, theses and web sites, and ten historic books with descriptions of marine animals or environemnets. A mayority of the publications (425 or 66.4%) are related to marine biodiversity topics (species descriptions and lists of species); the most published groups are gastropods (81 papers), decapods (67) and bony fishes (66). There are no publications of several groups of animals that have been observed in the Island, for example free-living flat worms, parasites and nemerteans among others. Other topics with a large number of publications are, biogeography with 65, ecology (61) and geology (48); the most studied ecosystem are coral reefs with 14 papers. More publications are needed on many topics, such as impact of ilegal fishing and climate change on Isla del Coco National Park marine flora and fauna.

Isla del Coco, Pacífico de Costa Rica, ha sido visitada y se ha escrito sobre ella desde el Siglo XVI. Desde finales del Siglo XIX muchas expediciones han desarrollado investigaciones en el Isla. Aquí compilo las publicaciones sobre biología y geología marina, oceanografía física y química, ciencias atmosféricas y algunos temas sociales. Una lista de 599 artículos y capítulos, 41 libros, Suplementos, tesis, informes y un sitio de internet es incluida, y diez libros históricos donde se describen organismos y ambientes marinos de la Isla del Coco. La mayoría de las publicaciones (425 o 66.4%) son sobre biodiversidad marina (descripciones, listas y distribuciones de especies). De los grupos que más publicaciones hay son de los gasterópodos (81 trabajos), decápodos (67) y peces óseos (66). No hay publicaciones de varios grupos de animales que han sido observados en Isla del Coco, por ejemplo, gusanos planos de vida libre, parásitos o nemertinos, entre otros. Temas con muchas publicaciones son: biogeografía con 65, ecología (61) y geología (48); los ecosistemas más estudiados son los arrecifes coralinos con 14 trabajos. Se necesitan más publicaciones en muchos tópicos, tales como el impacto sobre la flora y fauna del Parque Nacional Isla del Coco de la pesca ilegal y el cambio climático.