scholarly journals Residency of bull sharks, Carcharhinus leucas (Carcharhiniformes: Carcharhinidae), at San Pedrillo Islet in Islas Murciélago, North Pacific of Costa Rica

2021 ◽  
Vol 69 (Suppl.2) ◽  
pp. S246-S255
Author(s):  
Andrés López-Garro ◽  
Ilena Zanella
Keyword(s):  
Costa Rica ◽  
North Pacific ◽  
Light Cycle ◽  
Feeding Behaviors ◽  
Conservation Area ◽  
Total Period ◽  
The North ◽  
Carcharhinus Leucas ◽  
Aggregation Site ◽  
Bull Shark

Introduction: The bull shark, Carcharhinus leucas, is particularly vulnerable to anthropogenic actions because of its permanence in coastal ecosystems; populations depletion is registered in different places around the world. Aggregations of bull sharks have been reported in the North Pacific of Costa Rica, at Islas Murciélago, within the Guanacaste Conservation Area. Objective: To study the residency of bull sharks at San Pedrillo islet, Islas Murciélago. Methods: During the study period (June 2013 to February 2015) we used passive telemetry to tag 10 bull sharks. Results: All the sharks tagged were females, they were detected on 59 798 occasions by the acoustic receiver deployed in San Pedrillo. Acoustic signals from tagged sharks were received for a total period of 1 to 229 days (mean = 73.9 ± 71.3 days), with the last detections occurring on 9 January 2015. The Residency Index for each tagged shark across the entire monitoring period ranged from 0.41 to 1.00. The bull shark activity showed a significant pattern throughout the day at the receiver that specifically corresponded with the daily light cycle. Conclusions: This study concludes that San Pedrillo is an aggregation site (cleaning station) for bull sharks (C. leucas), possibly related to reproduction and not feeding behaviors.

scholarly journals La experiencia del cultivo comercial de camarones marinos en estanques de producción en Costa Rica

2013 ◽  
Vol 5 ◽  
pp. 87
Author(s):  
José A. Valverde-Moya ◽  
Jorge Alfaro-Montoya
Keyword(s):  
Costa Rica ◽  
North Pacific ◽  
Management Plan ◽  
Average Weight ◽  
Pacific Region ◽  
Long Cycle ◽  
The North ◽  
North Pacific Region ◽  
Gulf Of Nicoya ◽  
The North Pacific

El cultivo de camarones marinos en estanques de producción en Costa Rica ha estado restringido a una pequeña fracción del territorio (1 000 ha), siendo el sector del Pacífico Norte, a ambas márgenes del Golfo de Nicoya, uno de los más productivos. En los últimos 2 años se ha logrado implementar en estas fincas un Plan de Manejo, que ha permitido obtener de manera continua y predecible niveles adecuados de producción convencional de camarón. El presente estudio describe los resultados de un Plan de Manejo utilizando densidades de siembra de 10 camarones/m2 en tres ciclos cortos (90-120 días) y 15 camarones/m2 en un ciclo largo (180 días), durante los años 2011 y 2012, en 11 estanques de fincas ubicadas en Colorado de Abangares, Guanacaste. La sobrevivencia fue mejor en los ciclos del 2011 (75% y 80%) con respecto a los del 2012 (58% y 51%) y el peso promedio final fue inferior en los ciclos cortos (11-14 g) en relación con el peso promedio ponderado, tomando en cuenta las raleas, en el ciclo largo (cerca de 20 g). Debido a que no hubo compensación en el crecimiento y la biomasa en el último ciclo con la sobrevivencia más baja, la productividad decayó a 600 kg/ha después de haberse venido dando incrementos considerables (de 1 118 a  1 263 y 1 730 kg/ha) en los tres ciclos anteriores. Se discuten posibles factores causantes de la baja productividad en este ciclo realizado a finales del 2011 e inicios del 2012.AbstractThe culture of marine shrimp in earthen ponds in Costa Rica has been restricted to a small portion of theterritory (1 000 ha), being the North Pacific region, at both margins of the Gulf of Nicoya, one of the mostproductive areas. During 2011-2012 these farms implemented a Management Plan that has allowed forcontinuously and predictably obtaining adequate levels of conventional shrimp production. The presentstudy describes the results obtained with the Management Plan used at stocking densities of 10 shrimp/m2in three short cycles (90-120 days) and 15 shrimp/m2 in one long cycle (180 days) during 2011 and 2012in 11 ponds located in Colorado de Abangares, Guanacaste. Survival was better in the 2011 cycles (75%and 80%) as compared to the 2012 cycles (58% and 51%); the final average weight was lower for the shortcycles (11-14 g) in relation to the long cycle (approximately 20 g). Because there was no compensationon growth and biomass in the last cycle with the lowest survival, productivity decreased to 600 kg/ha afterhaving obtained remarkable increments (from 1 118 to 1 263 and 1 730 kg/ha) in the three previous cycles.The possible factors causing low productivity in this cycle at the end and at the beginning of the year arediscussed in this paper.

scholarly journals Cuando la conservación no puede seguir el ritmo del desarrollo: Estado de salud de los ecosistemas coralinos del Pacífico Norte de Costa Rica

2018 ◽  
Vol 66 (1-1) ◽  
pp. 280 ◽  
Author(s):  
Juan José Alvarado ◽  
Andrés Beita-Jiménez ◽  
Sebastián Mena ◽  
Cindy Fernández ◽  
Jorge Cortés ◽  
...  
Keyword(s):  
Costa Rica ◽  
Coral Reefs ◽  
North Pacific ◽  
Coral Cover ◽  
Actual State ◽  
Live Coral ◽  
The North ◽  
Invasive Seaweed ◽  
Live Coral Cover ◽  
The North Pacific

Abstract: When conservation can keep up with development´s pace: Health status of coral ecosystems in the North Pacific of Costa Rica. Coral reefs are diverse and productive ecosystems, despite this, they are being threatened by human activities that enhance the detrimental impact of the natural phenomenon’s like Harmful Algal Blooms (HAB). The north Pacific of Costa Rica has been characterized as one of the best regions for the coral reefs development in the country. However, many of these ecosystems are being lost as a result of eutrophication, overfishing, invasive species and others impacts that affect the region. In the present study, live coral cover in the north Pacific was 5.0 ± 10.4(s.d.) %, with a domination in the ecosystems by turf algae. Twenty-six invertebrate taxa were registered in the region with the predominance of the sea urchin Diadema mexicanum. Ninety-four species of reef fish were identified. Snappers and some planktivores species were the groups with the highest frequency and abundance. The localities previously studied in the 1990 decade, presented a mean live coral cover between 40-50 %, whereby the actual state of the reef reflect a significant deterioration. This decline in coral cover is due to natural events like the El Niño, as well as the decrease in water quality in the region. In recent years, proliferations of the invasive seaweed Caulerpa sertularioides and high densities of bioerosive sea urchins have been reported, mainly associated with HAB events. Likewise, fish communities have low biomass, especially in the vicinity of fishing villages. The state of the reefs in the North Pacific is worrying and requires actions for its recovery and conservation, for which there must be better planning of the development of projects and activities on the coast. Rev. Biol. Trop. 66(Suppl. 1): S280-S308. Epub 2018 April 01. 

scholarly journals Strain diversity of Rickettsia amblyommatis in ticks infesting birds in the North Huetar conservation area of Costa Rica

2019 ◽  
Vol 10 (5) ◽  
pp. 1109-1112 ◽  
Author(s):  
Gaby Dolz ◽  
Ruth Castro ◽  
Ana E. Jiménez-Rocha ◽  
Mónica Retamosa ◽  
Alberto Alberti
Keyword(s):  
Costa Rica ◽  
Conservation Area ◽  
Strain Diversity ◽  
The North

scholarly journals La experiencia del cultivo comercial de camarones marinos en estanques de producción en Costa Rica

2013 ◽  
Vol 5 ◽  
pp. 87 ◽  
Author(s):  
José A. Valverde-Moya ◽  
Jorge Alfaro-Montoya
Keyword(s):  
Costa Rica ◽  
North Pacific ◽  
Management Plan ◽  
Average Weight ◽  
Pacific Region ◽  
Long Cycle ◽  
The North ◽  
North Pacific Region ◽  
Gulf Of Nicoya ◽  
The North Pacific

El cultivo de camarones marinos en estanques de producción en Costa Rica ha estado restringido a una pequeña fracción del territorio (1 000 ha), siendo el sector del Pacífico Norte, a ambas márgenes del Golfo de Nicoya, uno de los más productivos. En los últimos 2 años se ha logrado implementar en estas fincas un Plan de Manejo, que ha permitido obtener de manera continua y predecible niveles adecuados de producción convencional de camarón. El presente estudio describe los resultados de un Plan de Manejo utilizando densidades de siembra de 10 camarones/m2 en tres ciclos cortos (90-120 días) y 15 camarones/m2 en un ciclo largo (180 días), durante los años 2011 y 2012, en 11 estanques de fincas ubicadas en Colorado de Abangares, Guanacaste. La sobrevivencia fue mejor en los ciclos del 2011 (75% y 80%) con respecto a los del 2012 (58% y 51%) y el peso promedio final fue inferior en los ciclos cortos (11-14 g) en relación con el peso promedio ponderado, tomando en cuenta las raleas, en el ciclo largo (cerca de 20 g). Debido a que no hubo compensación en el crecimiento y la biomasa en el último ciclo con la sobrevivencia más baja, la productividad decayó a 600 kg/ha después de haberse venido dando incrementos considerables (de 1 118 a  1 263 y 1 730 kg/ha) en los tres ciclos anteriores. Se discuten posibles factores causantes de la baja productividad en este ciclo realizado a finales del 2011 e inicios del 2012.AbstractThe culture of marine shrimp in earthen ponds in Costa Rica has been restricted to a small portion of theterritory (1 000 ha), being the North Pacific region, at both margins of the Gulf of Nicoya, one of the mostproductive areas. During 2011-2012 these farms implemented a Management Plan that has allowed forcontinuously and predictably obtaining adequate levels of conventional shrimp production. The presentstudy describes the results obtained with the Management Plan used at stocking densities of 10 shrimp/m2in three short cycles (90-120 days) and 15 shrimp/m2 in one long cycle (180 days) during 2011 and 2012in 11 ponds located in Colorado de Abangares, Guanacaste. Survival was better in the 2011 cycles (75%and 80%) as compared to the 2012 cycles (58% and 51%); the final average weight was lower for the shortcycles (11-14 g) in relation to the long cycle (approximately 20 g). Because there was no compensationon growth and biomass in the last cycle with the lowest survival, productivity decreased to 600 kg/ha afterhaving obtained remarkable increments (from 1 118 to 1 263 and 1 730 kg/ha) in the three previous cycles.The possible factors causing low productivity in this cycle at the end and at the beginning of the year arediscussed in this paper.

scholarly journals Ascidian diversity of Costa Rica, including new records for the North Pacific

2021 ◽  
Vol 69 (Suppl.2) ◽  
pp. S234-S245
Author(s):  
Kaylen González-Sánchez ◽  
Bryan Flores-Alvarado ◽  
Paula Montiel-Barrantes ◽  
Gonzalo Gómez-Arce ◽  
Juan-José Alvarado
Keyword(s):  
Costa Rica ◽  
North Pacific ◽  
Common Species ◽  
Field Trips ◽  
The North ◽  
New Material ◽  
Almost All ◽  
Available Information ◽  
Santa Elena ◽  
The North Pacific

Introduction: The class Ascidiacea has about 3 000 species, which fulfill various roles in the ecosystem, for example, they filter high amounts of particles, and are shelter and food for other animals. Furthermore, the group has a high number of invasive species reported. In Costa Rica, ascidians have been barely studied. Objective: In this study, we aim to describe the diversity of ascidians in Costa Rica from new samplings in Área de Conservación Guanacaste, North Pacific, and by compiling previous reports for the entire country in order to improve the group’s state of knowledge. Methods: Samples were collected during two field trips between 2018 and 2019, at six sites within the Gulf of Santa Elena and three sites near the Murcielago Islands area. The specimens were dissected and analyzed in detail to determine the species. All the identifications were compared with the available information from literature and from museum collections. Literature, collections databases of the National Museum of Natural History, Smithsonian Institution and the new material collected were used to create an updated taxonomic list. Results: A total of eight species were obtained from 70 specimens. Of these, five are new reports for the country, which increase to 22 species the total number reported for Costa Rica. The most common species was Rhopalaea birkelandi, whose presence was higher in Santa Elena Bay. Conclusions: This study improved the knowledge of ascidian diversity in Costa Rica. Polyandrocarpa anguinea, reported for the first time, is considered invasive in other areas, which suggests the necessity of a continuous monitoring of its population. It is necessary to include more areas of the country since almost all the reported species come from the North Pacific; the diversity of ascidians from other parts of the country, especially the Caribbean, is still unknown.

Does proximity to freshwater refuge affect the size structure of an estuarine predator (Carcharhinus leucas) in the north-western Gulf of Mexico?

2020 ◽  
Vol 71 (11) ◽  
pp. 1501 ◽  
Author(s):  
Philip Matich ◽  
Robert J. Nowicki ◽  
Jonathan Davis ◽  
John A. Mohan ◽  
Jeffrey D. Plumlee ◽  
...  
Keyword(s):  
Life Histories ◽  
Environmental Variability ◽  
Size Structure ◽  
Distribution Patterns ◽  
Freshwater Inflow ◽  
The North ◽  
Carcharhinus Leucas ◽  
Freshwater Habitats ◽  
Bull Shark ◽  
River Mouths

The life histories of estuarine species are often adapted to the environmental variability they experience. However, estuaries are increasingly vulnerable to natural and anthropogenic changes, necessitating an understanding of how shifting conditions affect the survival, behaviour and population structure of estuarine-dependent animals. In this study we used data from fisheries-independent surveys collected across six estuaries with variable salinity regimes in Texas, USA, from 1975 to 2016 to investigate the role sources of freshwater inflow play in shaping juvenile bull shark Carcharhinus leucas size structure. High frequencies of co-occurrence with similarly sized conspecifics (59% of capture events) suggest bull sharks segregated within Texan estuaries based on body size. Bull shark sizes increased with distance to the nearest source of freshwater inflow, although effect sizes were small and access to freshwater habitats may be more important in shaping size-dependent distribution patterns. River mouths were disproportionately used by smaller juveniles (<90-cm total length, TL) and avoided by larger juveniles (>135cm TL). However, the use of river mouths decreased in estuaries characterised by limited freshwater inflow and greater variability in salinities at river mouths, highlighting geographic differences in the functions these habitats provide as potential environmental and predator refugia. Young-of-the-year (i.e. age-0) sharks also increased their use of river mouths throughout the 40-year study period, revealing the growing importance of river mouths as potential nursery habitats.

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

2021 ◽  
Vol 69 (Suppl.2) ◽  
pp. S180-S193
Author(s):  
Alvin Suárez ◽  
Rafael Riosmena-Rodríguez ◽  
Jorge Cortés
Keyword(s):  
Costa Rica ◽  
Fish Species ◽  
North Pacific ◽  
Field Work ◽  
Marine Ecosystems ◽  
Marine Biodiversity ◽  
Underwater Visual Census ◽  
The North ◽  
Rocky Reefs ◽  
The North Pacific

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.

scholarly journals Study of the diversity of culturable actinomycetes in the North Pacific and Caribbean coasts of Costa Rica

2009 ◽  
Vol 96 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Godofredo Solano ◽  
Keilor Rojas-Jiménez ◽  
Marcel Jaspars ◽  
Giselle Tamayo-Castillo
Keyword(s):  
Costa Rica ◽  
North Pacific ◽  
The North ◽  
The North Pacific

scholarly journals Forcing of cool and warm subsurface water events in Bahía Salinas, Costa Rica

2021 ◽  
Vol 69 (Suppl.2) ◽  
pp. S127-S141
Author(s):  
Eric-J. Alfaro ◽  
Jorge Cortés
Keyword(s):  
Costa Rica ◽  
North Pacific ◽  
Large Scale ◽  
Subsurface Water ◽  
Trade Wind ◽  
Subsurface Temperature ◽  
Sea Temperature ◽  
Temperature Index ◽  
The North ◽  
Cold Events

Introduction: Bahía Salinas, on the north Pacific coast of Costa Rica, is a seasonal upwelling area. Sea temperature in Bahía Salinas could be modulated by synoptic and other large-scale systems. This region belongs to the Central American Dry Corridor (CADC), a sub-region in the isthmus that is relatively drier than the rest of the territory, which extends along the Pacific littoral from western Guatemala through northern Costa Rica. Objective: To study the warm and cold events that could be inferred by studying the sea subsurface temperature in Bahía Salinas, and also analyzing the large-scale conditions and synoptic systems of the historical sources when they occurred in order to identify the atmospheric mechanisms that favored their appearance. Methods: A Sea Subsurface Temperature Index was calculated using hourly data from seven stations located at three different points in Bahía Salinas. Records range from June 19, 2003 to December 5, 2017. Additionally, six meteorological stations, with hourly wind records, were used to create two wind indices. The Sea Subsurface Temperature Index was used to identify the warmest and coldest events in the bay. Wind indices and monthly meteorological bulletins were used to analyze the large-scale conditions and synoptic systems in which cold and warm events occurred in Bahía Salinas. Results: Mean sea temperature in Bahía Salinas is 25.2°C. Colder temperatures were observed in February-March, below 21°C. There were two maxima in May-June and August-October with temperatures above 27°C. In four of the five cold events studied, Northeasterly wind anomalies were observed in the Costa Rican North Pacific, associated with trade wind reinforcements; meanwhile westerly anomalies were observed in all the warm events, associated with weaker trade wind conditions. Conclusions: The main seasonal climate driver in Bahía Salinas is the North Atlantic Subtropical High because its latitudinal migration is associated with the strength of the trade winds over Central America. Seasonal upwelling is modulated also by two synoptic scale climate features, the boreal winter arrival of cold front outbreaks and the winter maximum of the easterly Caribbean Low-Level Jet. El Niño-Southern Oscillation is also an important modulator of the sea temperature variability, since warm and cool events are related with positive and negative sea temperature anomalies.

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