Monitoring of the mangrove forest at Gandoca, Costa Rica (CARICOMP site)

The mangrove forest at Gandoca, Refugio Nacional de Vida Silvestre Gandoca-Manzanillo, Caribbean coast of Costa Rica, has been monitored since 1999, following the CARICOMP protocol. The dominant species was the red mangrove, Rhizophora mangle. The peak of productivity and flowering was in July. The mangrove productivity decline from 2001 to 2004 while the temperature rised. Biomass (14 kg/m2) and density (9 trees/10 m2) in Gandoca were relatively low compared to other CARICOMP sites, while productivity in July in Costa Rica (4 g/m2/day) was intermediate, similar to most CARICOMP sites.     

The dystrophinopathies in Costa Rica

A five-years long study aiming to describe the basic genetic epidemiology of the dystrophinopathies in Costa Rica recruited 31 patients with clinical symptoms of DMD/BMD at the National Children's Hospital (HNN). This center is the obligate reference hospital of the national health system for genetic diseases, however, the geographic origin of the patients, a low percentage of deletions and a high proportion of de novo mutations found among them indicate that a significant ascertainment bias impedes a substantial scientific approach to confront and alleviate the problems posed by these severe diseases in Costa Rica.     

The bathymetry of Coco's Island, Costa Rica

The bathymetry of Coco's Island (UNESCO Natural and Cultural World Patrimony), located approximately 500 km from the Pacific coast of Costa Rica, is not well known. It has a high marine biodiversity and also represents a meeting site for many species traveling throughout the Pacific Ocean. The insular shelf is irregular in extension and also in bathymetric features. The northeast limit is defined by the 109.8-128.1 m contours (60-70 fathoms) while the 183 m contour (100 fathoms) practically defines the rest of the island, from which the depth gradient is steep. The maximum extension is to the northeast with a longitude of 13 km. In this context the present limits of the marine park (5 km), are insufficient to protect the whole insular shelf. Current regulation should be modified to prevent fishing activities less than 15 km from the Island.     

Population dynamics of mangrove Avicennia bicolor on the Pacific coast of Costa Rica

Deterministic and stochastic class structured population models were used to simulate the life cycle of Avicennia bicolor of the Pacific coast of Costa Rica. The models were based on an extensive data set collected during a 6 year period in a 0.52 ha plot of monospecific A. bicolor. This data set included density, growth, mortality and transition rates of seedlings, saplings and trees of eight different diameter classes, as well as propagule production for the reproductive tree classes. Model simulations carried out over a 100 year period indicated a stable size class structure of the forest. Sensitivity analysis showed a significantly greater sensitivity of the model population to simulated changes in the mortality of seedlings, in comparison with the mortality of saplings and trees. An increase of 1% in the mortality of seedlings, for example, was sufficient to cause significant changes in the density of individual size classes. In contrast, neither a 10% increase in the mortality of saplings and trees nor a 20% decrease in the propagule production of fecund trees significantly affected the overall forest structure.     

Abundance and morphometry of tuberculosa Anadara and A. similis (Mollusca: Bivalvia) in the Manglar de Purruja, Dulce Gulf, Costa Rica

The density, population, length, yield and sex proportion of the mollusks Anadara tuberculosa and A. similis were studied in Bahía de Golfito, Golfo Dulce, Pacific coast of Costa Rica from February 1998 to February 1999. A. tuberculosa was more abundant (0.9 units m(-2)), than A. similis (0.2 units m(-2)); the highest abundance was found at the canal mouths. The average lengths were 43.3 mm for A. tuberculosa and 42.8 mm for A. similis (both under the Costa Rican legal minimal length for exploitation: 47 mm). Maximum lengths were measured in the middle and upstream Canal Mayor, respectively: 43.0 mm and 43.4 mm. The correlation between length and fresh weight was 0.81 (Pearson). The average total weights were 26.2 g for A. tuberculosa and 19.1 g for A. similis. The condition index (a meat yield measurement) was higher in A. similis (21.2%) than in A. tuberculosa (17.2%). The maximum yield for both species lies in the 31-35 mm range. The male ratio was 43.7%. A species recovery plan is urgent because these results suggest both a decrease in density and illegal exploitation.     

Planktonic primary production in a tidally influenced mangrove forest on the Pacific coast of Costa Rica

The seasonal variation of planktonic primary productivity was measured during one year in the main channel in the interior part of the mangrove forest of the Estero de Morales (Estero de Punta Morales), a mangrove system located in the Golfo de Nicoya at the Pacific coast of Costa Rica. Samples were incubated at the surface, 0.5 m and 1.0 m depth and the "light and dark bottle technique" was employed. The annual gross primary productivity (PPg) was 457 and the net primary productivity (PPn) was 278 g C m(-2) a(-1). Daily PPg ranged from 0.29 to 3.88 and PPn from 0.12 to 2.76 g C m(-2) d(-1). The highest rates observed in May and September were due to red tide blooms. The seasonal variation of primary productivity inside the mangrove forest depends closely on the PP in the adjacent area of the upper Golfo de Nicoya. Obviously the PP was light-limited since the compensation depth in the ebb current was found at only 1 m depth. In the flood current it was somewhat deeper. The planktonic primary productivity inside the mangrove forest was completely restricted to the open channels. A simultaneous measurement demonstrated that PPn of the phytoplankton could not take place under the canopy of the mangroves. Additional studies on the time course of the oxygen concentration in the mouth of the main channel over 24 hrs demonstrated a relation between the O2 and the tidal curves. The ebb current had always lower O2 concentrations than the flood current, regardless of the time of the day. The difference to the foregoing high tide, however, was much smaller when the low tide occurred during the day. This indicates that under the canopy the net primary production and hence O2 liberation of the attached macro- and microalgae, together with the high PPn of the phytoplankton in the channels, helped the oxygen concentration not to decrease as far as during the night. Nevertheless it shows that the consumtion of organic material in the submersed part of the mangrove forest exceeds always its production.     

A biogeochemical model for the Gulf of Nicoya, Costa Rica

In agreement with the Broecker and Penn two-boxes model, I generated a biogeochemical balance model for the Gulf of Nicoya (Guanacaste, Costa Rica) using two nutrient reservoirs: surface water and deep water. The mixing zone was located at a depth of 20 m. There is a balance between surface waters descending to the bottom and upwelling waters that carry nutrients and other chemical elements to the surface. The main source of nitrogen (nitrate), was the outlet of the Tempisque and Tárcoles rivers. The Gulf of Nicoya is a net source of Dissolved Inorganic Nitrogen (DIN) with an availability rate of 87 x 10(3) mol day(-1) in the dry season and 3044 x 10(3) mol day(-1)in the rainy season. Dissolved Inorganic Phosphate (DIP) was estimated in 27 mol day(-1) in the dry season and 207 mol day(-1) in the rainy season. The dynamics of these biolimited nutrients, in relation to runoff seasonal variations, fits the biological processes reported for the gulf, for example, for variations in primary productivity levels, and maturity and reproduction seasons for species with short and long life cycles.     

The nation-state,identity management,and indigenous crafts: Constructing markets and opportunities in Northwest Costa Rica

A British Perspective on Nathan Glazer & Daniel P. Moynihan (eds) Ethnicity: Theory and Experience. (Cambridge, Harvard Univ. Press, 1975.)     

Aristolochia translucida,a new species from Costa Rica

A new species from Costa Rica,Aristolochia translucida, is described and its relationships to other species detailed.     

Influence of puffer predation on vertical distribution of mangrove littorinids in the Gulf of Nicoya, Costa Rica

The eastern Pacific puffer fish Sphoeroides rosenblatti (family Tetraodontidae) preys on the mangrove periwinkles Littorariafasciata and L. varia up to 13 cm above the water surface. Puffers capture snails by jumping partially out of the water and removing them by mouth from Rhizophora spp. prop roots. Field predation trials suggested puffer predation is intense, averaging 40.6% h⁻¹ on L. fasciata tethered at the water surface. L.fasciata <∼8 mm in shell length and L. varia <∼12 mm remained near or below the water surface and were easily crushed by puffers; gut content analyses showed that these snails were commonly eaten by puffers. L.fasciata >∼8 mm and L. varia∼12–16 mm were also crushed by puffers, but were generally located above their reach; these snails were much less abundant in puffer guts. L.varia >∼16 mm were abundant and some were submerged at high tide; however, none were found in puffer guts presumably because puffers encounter difficulty crushing these snails. S.rosenblatti is an important predator of L. fasciata and L. varia and appears to affect their vertical distributions. Received: 21 April 1998 / Accepted: 10 August 1998     

The therapeutic exception: abortion, sterilization and medical necessity in Costa Rica

Based on the case of Rosa, a nine-year-old girl who was denied a therapeutic abortion, this article analyzes the role played by the social in medical practice. For that purpose, it compares the different application of two similar pieces of legislation in Costa Rica, where both the practice of abortion and sterilization are restricted to the protection of health and life by the Penal Code. As a concept subject to interpretation, a broad conception of medical necessity could enable an ample use of the therapeutic exception and a liberal use of both surgeries. The practice of therapeutic sterilization has been generalized in Costa Rica and has become the legitimate way to distribute contraceptive sterilization. In contrast, therapeutic abortion is very rarely practiced. The analysis carried out proposes that it is the difference in social acceptance of abortion and sterilization that explains the different use that doctors, as gatekeepers of social morality, make of medical necessity.     

The phytoplankton community of Punta Morales, Nicoya Gulf, Costa Rica

Three daily samplings of the phytoplankton community were made at two consecutive days in March, April, May, September, October, November and December 1997, at Punta Morales, Golfo de Nicoya, Costa Rica. Samples were collected during each tide at depths of 50% and 10% of light penetration using a Niskin bottle. A total of 43 taxa were identified. Centric diatoms, pennates and flagellates represented 90% of total phytoplankton abundance. In the phytoplankton fraction (cells > 30 microm), diatoms were the most abundant group, and Skeletonema costatum (32%) dominated. In nannophytoplankton (cells < 30 microm), Chaetoceros (23.7%) was the most abundant taxon, followed by flagellates (23%) and Cylindrotheca closterium (13.1%). These results agree with previous surveys and suggest that a typical net phytoplankton community persist through time in the Punta Morales zone. The number of nannophytoplankton fraction cells varied seasonally and suggests quantitative changes in species abundance, with possible modifications of cellular size or chain length in filamentous species. The codominance between S. costatum and Chaetoceros spp. during the rainy season suggested the ocurrence of an early ecological sucession, and nutrients could be the factor generating such population changes.     

Differential sex mortality in a rural nineteenth-century population: Escazu, Costa Rica.

Cross-cultural studies of sex-specific mortality indicate that, whereas males experience their greatest mortality in industrialized societies, females experience their greatest mortality in populations with low life expectancy. The higher mortality of females in low-life-expectancy communities has been interpreted as a reflection of nutritional and health-care discrimination against females. Cross-cultural demographic studies also indicate that males have a higher frequency of violent and accidental deaths, possibly because of more frequent risky behaviors. This study focuses on Escazu, a rural nineteenth-century population from Costa Rica with low life expectancy. I investigate whether Escazu males had higher violent and accidental deaths and whether females had higher diarrhea-related deaths, an indication of nutritional discrimination. An analysis of mortality by cause of death indicates that males and females did not experience significantly different diarrhea-related death rates, although males did experience greater violent mortality. This study illustrates that more anthropological community-specific studies of mortality are needed to elucidate variation of death rates within large national or international regions.     

Limnology of Botos Lake, a tropical crater lake in Costa Rica

Botos Lake, located at the Poas Volcano complex (Costa Rica) was sampled eight times from 1994 to 1996 for physicochemical conditions of the water column and phytoplanktonic community composition. Depth was measured at fixed intervals in several transects across the lake to determine its main morphometric characteristics. The lake has an outlet to the north. It is located 2580 m above sea level and is shallow, with a mean depth of 1.8 m and a relative depth of 2.42 (surface area 10.33 ha, estimated volume 47.3 hm3). The lake showed an isothermal water column in all occasions, but it heats and cools completely according to weather fluctuations. Water transparency reached the bottom on most occasions (> 9 m). The results support the idea that the lake is polymictic and oligotrophic. The lake has at least 23 species of planktonic algae, but it was always dominated by dinoflagellates, especially Peridinium inconspicuum. The shore line is populated by a sparse population of Isoetes sp. and Eleocharis sp. mainly in the northern shore where the bottom has a gentle slope and the forest does not reach the shore.     

The genus Neotherina Dognin (Geometridae, Ennominae) in Costa Rica

So far, two species of Neotherina Dognin have been recorded in Costa Rica. Neotherina imperilla (Dognin) occurs primarily at altitudes between 1100 and 1700 meters and Neotherina callas (Druce) which is widely distributed above 1100 meters. A third, new species, Neotherina xanthosa Sullivan and Chacón is described from altitudes above 2400 meters. Heterogeneity of the genus is discussed.     

Rare hemoglobinopathies in Costa Rica]

Among the rare hemoglobinopathies found in Cost Rica are those of the Alfa, Beta, and Delta chains. Among these, Hb Cubujuquí, an undescribed variant, is of special interest. There was an association between the different thalassemic syndromes and their combinations with abnormal hemoglobins.     

The species of Phora (Diptera: Phoridae) of Costa Rica

The Phora of Costa Rica were reviewed and three species, all belonging to Schmitz's Group III, were recognized: P. americana Schmitz and Wirth, P. truncata new species and P. paramericana new species. Of the three species, P. americana is by far the most abundant, with the other two species being rarely collected. All specimens were collected in the central highlands of the country. The previous record of the Holarctic Region species P. stictica Meigen from Costa Rica was found to be based on a misidentification of P. truncata.