Monitoring coral reefs, seagrasses and mangroves in Costa Rica (CARICOMP)

The coral reefs, seagrasses and mangroves from the Costa Rican Caribbean coast have been monitored since 1999 using the CARICOMP protocol. Live coral cover at Meager Shoal reef bank (7 to 10 m depth) at the Parque Nacional Cahuita (National Park), increased from 13.3% in 1999, to 28.2% in 2003, but decreased during the next 5 years to around 17.5%. Algal cover increased significantly since 2003 from 36.6% to 61.3% in 2008. The density of Diadema antillarum oscillated between 2 and 7ind/m2, while Echinometra viridis decreased significantly from 20 to 0.6ind/m2. Compared to other CARICOMP sites, live coral cover, fish diversity and density, and sea urchin density were low, and algal cover was intermediate. The seagrass site, also in the Parque Nacional Cahuita, is dominated by Thalassia testudinum and showed an intermediate productivity (2.7 +/- 1.15 g/m2/d) and biomass (822.8 +/- 391.84 g/m2) compared to other CARICOMP sites. Coral reefs and seagrasses at the Parque Nacional Cahuita continue to be impacted by high sediment loads from terrestrial origin. The mangrove forest at Gandoca, within the Refugio Nacional de Vida Silvestre Gandoca-Manzanillo (National Wildlife Refuge), surrounds a lagoon and it is dominated by the red mangrove, Rhizophora mangle. Productivity and flower production peak was in July. Biomass (14 kg/m2) and density (9.0 +/- 0.58 trees/100 m2) in Gandoca were relatively low compared to other CARICOMP sites, while productivity in July in Costa Rica (4 g/m2/d) was intermediate, similar to most CARICOMP sites. This mangrove is expanding and has low human impact thus far. Management actions should be taken to protect and preserve these important coastal ecosystems.     

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.     

Biomass, productivity and density of the seagrass Thalassia testudinum at three sites in Cahuita National Park, Costa Rica

The basic ecology of seagrass beds was investigated by comparing biomass, productivity and density of Thalassia testudinum (turtle grass) at three sites: Puerto Vargas, Punta Cahuita and Rio Perezoso, in Cahuita National Park, Limón, Costa Rica, over a two month period (March-April 1999). Above ground biomass, density, and productivity were highest in the Puerto Vargas site while Punta Cahuita had the least non-green above ground biomass was significantly lower in total biomass than Puerto Vargas. Punta Cahuita was distinguished by the largest grain size, a very hard substrate, and shallower water. Rio Perezoso, on the other hand, had extremely fine sediment and lower salinity, while Puerto Vargas was intermediate both in sediment size and environmental conditions. It appears, therefore, that higher biomass and productivity result from a combination of moderate environmental characteristics and an intermediate sediment size.     

Monitoring of the Meager Shoal coral reef, Cahuita National Park, Costa Rica (CARICOMP site)

The coral reefs at Cahuita National Park, Caribbean coast of Costa Rica, specifically at the CARICOMP site Meager Shoal, have been monitored since 1999. Complete data sets from 2000 and 2004 have shown that live coral cover has increased less than 3 % (from 15 to 17 %), but non-coralline algae cover has increased much (63 to 74 %) and coralline algae cover has decreased (17 to 5 %) significantly. The proportion of affected colonies by diseases, injuries and bleaching decreased from 24 % in 2000 to 10 % in 2004, but the difference was not statistically significant. Densities of the urchin Diadema antillarum increased, and are probably help to maintain the macroalgae biomass low, while those of Echinometra viridis decreased significantly. The coral reef at Cahuita National Park continues to be impacted by chronic terrigenous sediments and does not show a significant recovery since the late 1970's.     

Diversity and abundance of echinoderms from the reef lagoon at Cahuita National Park, Caribbean from Costa Rica

A total of 15 species of echinoderms (one asteroid, seven ophiuroids, five echinoids and two holothurians) were recorded at the Cahuita National Park reef lagoon, between September and October 2003, using a 1 m2 quadrant. The sites with coral substrate and algae were the most diverse, while those with seagrass and sand were the least. Ophiuroids were the most abundant group with 170 individuals, asteroids were the least abundant. Adding other studies and reports of echinoderms to this study, a total of 23 species have been found at Cahuita National Park, which is the most diverse area on the Caribbean of Costa Rica. We report nine new echinoderm records for Costa Rica's Caribbean.     

Bleaching and mortality of reef organisms during a warming event in 1995 on the Caribbean coast of Costa Rica

Coral reefs at the Caribbean coast of Costa Rica were affected during a bleaching event associated with the 1995 warming of the Western Caribbean. During doldrum weather in late August 1995, reef organisms at Parque Nacional Cahuita were 62% and 7.4% bleached and dead respectively, whilst 67.6% bleached and 8.2% died in the Refugio Nacional de Vida Silvestre Gandoca-Manzanillo. However, Cahuita had the highest mean number of bleached (257 +/- 51.1) and dead (30.5 +/- 5.6) colonies in the surveyed transects, and bleaching was observed down to a depth of 20 m. The most affected species (>10% of dead colonies) were the hydrocoral Millepora complanata and the scleractinian corals Montastraea spp. at Cahuita, and Porites furcata, Porites porites and M. complanata at Gandoca-Manzanillo. Mean seawater temperature was between 30.5 and 31.1 degrees C (0-18 m depth) during four days of observation at the end of August 1995. Coral reefs of the Costa Rican Caribbean coast have shown a rapid decline during the last 20 years due to natural and anthropogenic disturbances. The effect of the 1995 warming added more pressure to the already deteriorated reefs.     

Requiem for an eastern Pacific seagrass bed

Few papers concerning seagrasses of the eastern Pacific have been published. This paper presents the first ecological data on the seagrass, Ruppia maritima, from a non-lagoonal setting in the eastern Pacific. A 5000 m2 patch formed by R. maritima, at Playa Iguanita, Bahía Culebra, Pacific coast of Costa Rica was studied. Plant density and leaf length of R. maritima were determined along two transects on different dates. Above and below ground biomass were calculated along one transect. Plant density ranged from 1590 to 8630 individuals m(-2) along the two transects, with means of 5990 +/- 1636 and 6100 +/- 1876 plants m(-2) for transect 1 and 2, respectively. Longest leaf length per plant varied between 0.5 and 23.0 cm. Leaf biomass (LB) ranged from 10 to 97 gm(-2), and root-rhizome biomass (RB) from 31 to 411 gm(-2), resulting in RB:LB ratios of 3.07 to 15.27. Total biomass at Bahía Culebra was lower than at tropical lagoons on the Pacific coast of Mexico, but higher than in the Gulf of Mexico. The below ground: above ground biomass ratio was much higher at Bahía Culebra than at other sites on the Pacific coast of Mexico and the Gulf of Mexico. Another seagrass present at Bahía Culebra was Halophila baillonii, with low densities on the deepest section of the patch. At least 44 invertebrate species associated with the seagrass bed have also been identified. The patch at Playa Iguanita and other sites within Bahía Culebra, as well as their associated organisms, disappeared after a severe storm in June 1996. No seagrasses have been found in the area or in any other location on the Pacific coast of Costa Rica since then.     

Spatial distribution of light and nutrients in some coral reefs of Costa Rica during January 1997

The proximity of coral reefs to areas of present and future coastal development in Costa Rica highlights the need for assessing environmental conditions important to maintaining healthy corals. In January 1997 a survey of light penetration, inorganic nutrient concentrations, temperature, and salinity was conducted in the patch reefs of Bahía Culebra (Pacific Ocean) and on the Caribbean coast in the fringing reef at Parque Nacional Cahuita and near Limón. Temperature was 28 degrees C at all sites, and salinity ranged from 33 to 36 psu. Light attenuation coefficients ranged from 0.12 to 0.29 m(-1) in reef areas. Seawater nutrient concentrations were within the range of concentrations reported for tropical reef waters; combined NO3- and NO2- and PO4(3-) were each below 1 microM. NH4+ ranged from 0.2 to 7 microM, representing a significant source of nitrogen. The ratio of total dissolved inorganic nitrogen to phosphate averaged 27 for all reef waters. The high nitrate (3.6 microM) and light attenuation (0.95 m(-1)) values from the surface waters of the La Estrella plume (Caribbean coast) show that this river represents a significant source of nitrogen and light attenuation for the neighboring reefs at Cahuita. This survey provides a useful baseline for future studies, which should monitor these important coastal coral reef areas during both wet and dry seasons.     

The structure and productivity of the Thalassia testudinum community in Bon Accord Lagoon, Tobago

The Thalassia testudinum dominated seagrass community in the Buccoo Reef/ Bon Accord Lagoon Marine Park, measures 0.5 km(2) and is part of a contiguous coral reef, seagrass bed and mangrove swamp system in southwest Tobago. 7 testudinum coverage, productivity and percent turnover rates were measured from February 1998 to February 1999 at four sample locations, while total T. testudinum biomass was measured at two locations in the lagoon from 1992-2002. Productivity and turnover rates varied spatially and seasonally. They were higher in the back-reef area than in the mangrove-fringed lagoon, and were lowest at locations near to a sewage outfall. 7 testudinum coverage ranged from 6.6% in the lagoon to 68.5% in the back-reef area while productivity ranged from 3.9 to 4.9 g dry wt m(-2) d(-1) . Productivity and percentage turnover rates were higher in the dry season (January-June) than in the wet season (July-December). Productivity ranged from 3.0 in the wet season to 5.0 g dry wt m2 d-' in the dry season while percentage turnover rates ranged from 4.2% to 5.6%. Total Thalassia biomass and productivity in Bon Accord Lagoon were compared to six similar sites in the Caribbean that also participate in the Caribbean Coastal Marine Productivity Program (CARICOMP). This seagrass community is being negatively impacted by nutrient-enriched conditions.     

Environmental state and tendencies of the Puerto Morelos CARICOMP site, Mexico

The CARICOMP site at Puerto Morelos, Mexico was monitored from 1993 to 2005. No significant changes in air temperature, wind patterns, periodicity and quantity of rainfall, sea-surface temperature and water transparency were observed between sampling years. During the study four hurricane impacts were registered. At the coral reef site overall mean cover of fleshy algae (47%) and turf algae (36%) were high, whereas cover of corals (2%) and sponges (3%), and abundance of sea-urchins (0.04 org m(-2)) were consistently low. Gorgonians were dominant and showed changes in their community structure; the number of species increased from 1993 to 1995, their abundance decreased after Hurricane Roxanne (1995) and recovered by 2001. At four seagrass sites total community biomass remained constant (707.1-929.6 g dry m(-2)) but the above-ground biomass of the seagrass Syringodium filiforme and fleshy algae increased gradually. Total biomass (531-699 g dry m(-2)) and leaf productivity (0.89-1.56 g dry m(-2) d(-1)) of the seagrass Thalassia testudinum remained constant, but the species invested proportionally more biomass in above-ground leaf tissues at the end of the study. The minor hurricanes from 1993 until 2005 had no detectable impacts on the seagrass beds, however, the major Hurricane Wilma (October 2005) changed the community composition at three stations and caused complete burial of the vegetation at a coastal station. The gradual changes in the seagrass and reef communities recorded in the 12 years of continuous monitoring of the CARICOMP site may reflect the increased pollution caused by the rapid augment in urban and tourist developments along the coasts and inland from Puerto Morelos, coupled with poor water management practices.     

Biomass, litterfall and decomposition rates for the fringed rhizophora mangle forest lining the Bon Accord Lagoon, Tobago

The mangrove forest that fringes the Bon Accord Lagoon measures 0.8 km(2) and is dominated by red mangrove (Rhizophora mangle). This forest forms the landward boundary of the Buccoo Reef Marine Park in Southwest Tobago, and is part of a mangrove-seagrass-coral reef continuum. Biomass and productivity, as indicated by litterfall rates, were measured in seven 0.01 ha monospecific plots from February 1998 to February 1999, and decomposition rates were determined. Red mangrove above-ground biomass ranged between 2.0 and 25.9 kg (dry wt.) m(-2). Mean biomass was 14.1+/-8.1 kg (dry wt.) m(-2) yielding a standing crop of 11 318+/-6 488 t. Litterfall rate varied spatially and seasonally. It peaked from May to August (4.2-4.3 g dry wt. m(-2) d(-1)) and was lowest from October to December (2.3-2.8 g dry wt. m(-2) d(-1)). Mean annual litterfall rate was 3.4+/-0.9 g dry wt. m(-2) d(-1). Leaf degradation rates ranged from 0.3% loss d(-1) in the upper intertidal zone to 1% loss d(-1) at a lower intertidal site flooded by sewage effluent. Mean degradation rate was 0.4+/-1% loss d(-1) . The swamp produces 2.8 t dry wt. of litterfall and 12 kg dry wt. of decomposed leaf material daily. Biomass and litterfall rates in Bon Accord Lagoon were compared to five similar sites that also participate in the Caribbean Coastal Marine Productivity Programme (CARICOMP). The Bon Accord Lagoon mangrove swamp is a highly productive fringed-forest that contributes to the overall productivity of the mangrove-seagrass-reef complex.     

Marine biodiversity of Costa Rica, the microcrustacea: Copepoda (Crustacea: Maxillopoda)

This report is part of a series that summarizes the species and localities of Costa Rican marine taxa. A review of the literature on copepods, both pelagic and benthic for the Pacific and Caribbean coast of Costa Rica, includes eighty species. Sixty seven pelagic species have been found, distributed between sixteen calanoid, one cyclopoid, three harparticoid and four poecilostomatoid families. Moreover, thirteen benthonic species distributed into six families, all harparticoids, are reported. Among the pelagic families, Pontellidae has six species, while Paracalanidae and Eucalanidae had five each. Other families, like Calanidae, Pseudodiaptomidae and Acartiidae had four species and most families only one. Forty five species are reported only for the Pacific coast, thirteen for the Caribbean coast, only nine species occurred in both coasts; being a direct consequence of the more intensive research effort in the Pacific. Pelagic copepod biodiversity reflects different oceanographic conditions in both coasts. Typical estuarine species were found in the lower region of the Gulf of Nicoya, while a mixture of estuarine and oceanic species were found in Golfo Dulce. Diversity in the Caribbean, specially at the Cahuita coral reef is lower in comparison with the copepod diversity found in other regions in the Caribbean sea. This may be due to the high sediment resuspension rate characteristic of the Cahuita coral reef, which could affect the reproduction of many holozooplankters, specially copepods. Although sixty seven pelagic copepod species appears to be in low numbers, in terms of specific biodiversity it is as high when compared to numbers found in other tropical areas. Thirteen species are reported in the literature, all harparticoids. Five species, three sub-species and one genera were new to science. Balacopsylla is reported for the first time from a neotropical regions, while the genus Karllangia, represented by two coexisting species in the Caribbean coast, belong to a few circumtropical-subtropical genera. The most diverse family was Tetragonicipitidae. This is the first effort to summarize the available information about the biodiversity of marine copepods for Costa Rica's coasts.     

Marine biodiversity of Costa Rica: Crustacea: Infraorder Anomura

The anomuran crabs are among the best known crustacean groups from the Pacific coast. However, this group is poorly known from the Caribbean coast of Costa Rica. In this compilation based on the literature and the collection at the Zoology Museum, Biology School, University of Costa Rica, we report the presence of 114 species of the Infraorder Anomura for Costa Rica, 20 species from the Caribbean, 96 species from the Pacific (two are present on both coasts). Twenty-nine species are new reports for Costa Rica, 15 from the Caribbean coast (74% of the total of species from that coast) and 14 from the Pacific (15% of the total from the Pacific). The range often species is extended to Costa Rica, siete from the Caribbean and three from the Pacific. Six species are reported for the first time from Cocos Island, where there are also four endemic species.     

New records of benthic marine algae and Cyanobacteria for Costa Rica,and a comparison with other Central American countries

We present the results of an intensive sampling program carried out from 2000 to 2007 along both coasts of Costa Rica, Central America. The presence of 44 species of benthic marine algae is reported for the first time for Costa Rica. Most of the new records are Rhodophyta (27 spp.), followed by Chlorophyta (15 spp.), and Heterokontophyta, Phaeophycea (2 spp.). Overall, the currently known marine flora of Costa Rica is comprised of 446 benthic marine algae and 24 Cyanobacteria. This species number is an under estimation, and will increase when species of benthic marine algae from taxonomic groups where only limited information is available (e.g., microfilamentous benthic marine algae, Cyanobacteria) are included. The Caribbean coast harbors considerably more benthic marine algae (318 spp.) than the Pacific coast (190 spp.); such a trend has been observed in all neighboring countries. Compared to other Central American countries, Costa Rica has the highest number of reported benthic marine algae; however, Panama may have a similarly high diversity after unpublished results from a Rhodophyta survey (Wysor, unpublished) are included. Sixty-two species have been found along both the Pacific and Caribbean coasts of Costa Rica; we discuss this result in relation to the emergence of the Central American Isthmus.     

Population of Lytechinus variegatus (Echinoidea: Toxopneustidae) and structural characteristics of seagrass of Thalassia testudinum in Mochima Bay,Venezuela)

To compare the general features of Thalassia testudinum seagrass at Mochima Bay with sea urchin (Lxtechinus variegatus) abundance and distribution, three T. testudinum seagrass beds were selected, from the mouth (strong wave exposure) to the inner bay (calm waters). Each site was surveyed by using 5 line transects (20 m long) parallel to the coast and 1 m2 quadrats. In situ measurements of T. testudinum cover, shoot and leaf density were taken. Estimation of dry biomass for each seagrass fraction (leaves, rhizomes and roots) and leaf length were obtained from 25 vegetation samples extracted per site using cores (15 cm diameter). A multivariate analysis of variance (Manova) and a less significative difference test (LSD) were performed to examine differences between sites and within sites at different depths. A stepwise multiple regression analysis was done, dependent variable was sea urchin density; independent variables: vegetation values at each site. The only seagrass species found in the three sites was T. testudinum, and cover was 56-100%, leaf density 100-1000 leaf/m2, lengths 6-18.8 cm and shoot density 20-475 shoots/m2. The highest sea urchin densities were found at Isla Redonda and Ensenada Toporo (1-3.6 ind/m2), the lowest at Playa Colorada (0.6-0.8 ind/m2). Significant differences in seagrass features between sites were obtained (Manova p < 0.001), but not between depths (Manova p < 0.320). The regression coefficient between sea urchin density and seagrass parameters was statistically significant (r2 = 0.154, p < 0.007), however, total biomass was the only variable with a significant effect on sea urchin distribution (beta = 0.308, p < 0.032). The other variables did not explain satisfactorily L. variegatus abundance and distribution.     

Temporal variation of biomass and productivity of Thalassia testudinum (Hydrocharitaceae) in Venezuela, Southern Caribbean

Annual biomass and productivity of Thalassia testudinum were determined during a year at a seagrass bed located in the Parque Nacional Morrocoy, Venezuela. Leaf, rhizome and root biomass were determined monthly, together with short-shoot density, from February 1992 to January 1993, from nine replicated core samples. Productivity was measured using the methodology by Zieman (1974) with minor modifications, and leaf turnover rate was calculated. Leaf biomass values ranged between 101.73 dry g m(-2) in February and 178.11 dry g m(-2) in August. Productivity ranged from 1.69 dry g m(-2) d(-1) in April and October to 3.30 dry g m(-2) d(-1) in July, showing two annual peaks: one in July and one in March. The leaf turnover rate showed the highest value in June (2.41% d(-1)) and the lowest in May (1.23% d(-1)). Sampling time differences in leaf biomass, productivity and turnover rate were statistically significant. Short-shoot density values varied between 811.10 shoots m(-2) in April and 1226.08 shoots m(-2) in December, but the differences were not significant along the year. These results indicated seasonal trends for leaf biomass, productivity and turnover rate of T. testudinum in the Southern Caribbean (latitude 10 degrees N).     

Trace metals in coastal sediments from Costa Rica

Marine sediment samples from four coastal ecosystems in Costa Rica were taken between the years 2000-2002 and their iron, lead, copper and zinc concentrations were determined by the atomic absorption technique with flame or graphite furnace. In the Pacific coast, Culebra Bay (Papagayo Gulf), Gulf of Nicoya, and Golfito Bay (Dulce Gulf), were selected as representative sites, and Moín Bay, at the Caribbean coast. Mean metal concentrations for all ecosystems followed the same pattern: Fe > Zn > Cu > Pb. No temporal pattern was found for any metal. Iron and copper mean concentrations were higher in Golfito Bay (5.8% and 87 microg/g, respectively) and lower in Moín Bay (3.4% and 52 microg/g, respectively). Zinc mean concentration was also higher in Golfito Bay (96 microg/g), but lower in Culebra Bay (66 microg/g). Lead mean concentration was higher in Moín Bay (6.4 microg/g) and lower in Culebra Bay (3.0 microg/g). Lead highest concentrations occurred in the Caribbean and in Golfito Bay, and for the rest of the elements the maximum values were found in Golfito Bay. On the basis of data obtained in this work, Culebra Bay was considered a relatively unpolluted location; Golfito Bay was more contaminated, and Moín Bay and the Gulf of Nicoya showed an intermediate condition.     

Effects of hyposalinity in Thalassia testudinum (Hydrocharitaceae) from Parque Nacional Morrocoy, Venezuela

The year 1996 had a high pluviosity in Morrocoy National Park (western coastal zone, Venezuela) and low salinity in December 1996 affected the seagrass beds, dominated by Thalassia testudinum. Patches without T. testudinum were observed in localities of the park that used to have very dense populations of this plant. Sampling was done at Las Luisas to determine leaf productivity, turnover rate, short shoot density and relative biomass of plant sections, in order to compare with data obtained in September 1996, previous to the event. Green leaves, roots and rhizomes were the most affected parts. Mean green leaf biomass decreased in January and February 1997 to 5% of the plant's total biomass; mean root biomass decreased in March to 40% and mean rhi zome biomass decreased in February to 30%. The density of the active short shoots decreased to a minimum in February, but in April it reached a value similar to that of September 1996. The density of the inactive short shoots decreased to a minimum in March, and they dissappeared in April, matching the increasing density of the active short shoots between these two months. In February 1997, 56% of the inactive short shoots showed evidence of leaf initiation. In January 1997 the leaf productivity and turnover rate values (2.72 +/- 0.35 g/m2/d and 2.15% leaf DW/d) were similar to the annual mean previously determined from Las Luisas (2.35 +/- 0.72 g/m2/d and 1.96% leaf DW/d). Nevertheless, the values of productivity and turnover rate detected at Las Luisas in April 1997 (4.88 +/- 2.14 g/m2/d and 4.66% leaf DW/d) were higher than those values previously reported for this location. In response to the mortality episode, the leaf productivity and turnover rate of T. testudinum increased and the leaf initiation was activated in the inactive short shoots.     

Tectonic survey of the Central Pacific coast of Costa Rica

Three fossil coral samples (Pocillopora elegans and Pocillopora damicornis) were collected from a beachrock in Puerto Escondido, central Pacific coast of Costa Rica. The age of the samples ranged from 1272+/-60 to 2010+/-60 years BP. They represent some of the few Holocene fossil corals known from the Pacific coast of the Americas. The uplift rate for the central Pacific coast of Costa Rica was calculated in 0.4 to 2.1 mm year(-1).     

Biomass and density of 2 seagrass species in southern Quintana Roo, Mexico

The biomass and productivity of a seagrass community are useful for determining the ecological status of the coast. Leaf biomass and shoot density in beds of Thalassia testudinum Banks & Sol. ex K. D. Koenig, were compared for two environments in the Mexican Caribbean coast (N = 6 quadrants/site) in November 1998. Shoot and leaf biomass values were lower in the mangrove-associated meadow than in the reef lagoon meadow. This could be related to the higher percentage of epiphytes on the leaves. In addition, T. testudinum had more biomass than Syringodium filiforme Kütz in the reef lagoon.