Andrés Beita - Profile on Academia.edu (original) (raw)

Papers by Andrés Beita

Studies of mixed-species groups of animals can reveal emergent complexities of collective behavio... more Studies of mixed-species groups of animals can reveal emergent complexities of collective behaviors. In this study we collected data on mixed-species hunting groups composed primarily of piscivorous fishes (species composition, abundance, behavioral interactions) and used both multivariate and network analyses to quantify pair-wise and guild level behavioral relationships. Our results indicate that such collective behaviors exhibit consistent patterns of associations (33 species with 282 pair-wise links within the observed network) with 10 dominant species accounting for 60% of pair-wise interactions. Species richness within groups varied (mean = 2.4, range 2-6 species) as did group size (mean = 8.1 individuals, range 2-80). Mixed-species groups, in general, were composed of species representing morphologically diverse forms that appeared to enhance access to shelter sites and implement diverse strategies for prey capture. It is noteworthy that the composition of groups did not reflect the relative abundances of their component species within the overall community of fishes, suggesting that group membership was an elective choice. The identification of these patterns, assuming they are persistent features of these communities, can be used as a foundation for studies to assess dynamics of mixed-species relationships, rates of predator success based on group membership, demographic consequences, and responses to variations in habitat attributes and associated prey resources. Such information could be used to interpret the nature of multispecies interactions within predator communities and potentially aid in conservation and management.

Revista de Biología Topical, 2018

When conservation can't keep up with development´s pace: Health status of coral ecosystems in th... more When conservation can't 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.

Revista de Biología Tropical, 2016

Coloration patterns of reef fishes are an important trait for mediating intra and interspecific i... more Coloration patterns of reef fishes are an important trait for mediating intra and interspecific interactions, as well as for taxonomic identifications. Here we report a specimen of Stegastes arcifrons that presented
a previously unobserved and anomalous color variation on a coral reef at Isla del Coco, Pacific Costa Rica.
This color variation is known as xanthism and has been reported in some damselfishes, usually associated with
genetic anomally

Osa Conservation Area (Costa Rica) coral ecosystems: structure and conservation needs. Costa Rica... more Osa Conservation Area (Costa Rica) coral ecosystems: structure and conservation needs. Costa Rica is considered one of the 20 most biodiverse countries in the world, which includes it´s well known reefs ecosystems. Specifically, the South Pacific region, the Osa Conservation Area (ACOSA), holds one of the richest reefs of the country. Even though many of these reefs have been studied since the 1980´s, most of them had focused mainly on coral cover condition. Therefore, the present research aims to complete and update an evaluation of the main biological components of ACOSA´s reefs ecosystems, using a standard methodology. Between 2013 and 2014, five localities were visited: Dominicalito, Marino Ballena National Park, Caño Island Biological Reserve, Osa Peninsula and Golfo Dulce, on which 27 sites were evaluated. Transects at two depths in each site were done to estimate substrate cover, reef rugosity, macroinvertebrates diversity and density, and reef fishes composition and biomass. Results indicate that ACOSA´s reef are moderately complex and on most of them the substrate is dominated by turf (62.7%) and live coral cover is moderate (16.5%). Substrate cover was significantly different between localities, which can be attributed to adverse environmental conditions for reef development (e.g. sedimentation, pollution). However, reefs in Golfo Dulce and Caño Island BR showed a significant coral cover recovery since last studied. Of 35 taxa of macroinvertebrates identified, 58% had low abundance or were observed occasionally. Golfo Dulce presented the highest diversity and density of macroinvertebrates and significant differences were observed between localities. On this group, this study is providing an information baseline of most sites analyzed. The echinoids Diadema mexicanum and Eucidaris thouarsii were the most abundant and the conch (Lobatus galeatus) was reported for many of the sites. Of the 90 species of reef fishes documented, ten were common and with the highest densities. There were no significant differences in the diversity and richness of the reef fishes between localities, but fishes' biomass and composition of fish community were different between sites. Caño Island´s sites were the most diverse of ACOSA, and presented the highest biomass and trophic levels of the region. Golfo Dulce´s reef fish composition differs from the other localities. According to the results, ACOSA´s reef ecosystems have a high biodiversity. The ecosystems conditions observed indicate that more conservation efforts, sustainable use and effective management of land and marine resources should be implemented. Ecological monitoring will provide the information about trends and the relationship between reef ecosystems state and environmental conditions. Rev. Biol. Trop. 63 (Suppl. 1): 219-259. Epub 2015 April 01.

Revista de Biología Tropical, 2014

Economic activities that depend on ichthyofauna in the North Pacific of Costa Rica. The North Pac... more Economic activities that depend on ichthyofauna in the North Pacific of Costa Rica. The
North Pacific of Costa Rica is characterized by a large diversity of fish species. This diversity sustains two of
the main economic activities developed there: fishing and tourism. We synthesized information from: semistructured
interviews with local stakeholders, biodiversity database from the Museo de Zoología, Universidad
de Costa Rica, landings database from Costa Rican government (INCOPESCA) and the literature. A total of 424
fish species are reported from the area and the main target species for each fishery are: mahi-mahi, silky shark,
hammerhead shark, tuna, sailfish, swordfish for longline fisheries; snappers, croakers, snook and groupers for
artisanal fisheries; invertebrates and ornamental fish in dive-fisheries; shrimp in trawl fisheries; and wahoo,
yellow-fin tuna, rooster fish, mahi-mahi, swordfish, sailfish, marlin in tourism fisheries. INCOPESCA does
not take into account fishing effort but most species landings are decreasing, especially mahi-mahi, groupers
and snappers. Conflicts between fisheries and tourism are arising due to competition for resources and overexploitation.
The main conflicts found were: (1) between sport and longline fisheries, (2) between recreational
diving and dive-fisheries, (3) between the artisanal and shrimp trawling fisheries, and (4) among artisanal fishermen
from different zones of the Pacific. These conflicts demonstrate the urgency of developing and effectively
implementing management strategies that will guarantee the sustainability of fish resources in the area. Future
studies should focus on generating information that will guide and support these management efforts

Studies of mixed-species groups of animals can reveal emergent complexities of collective behavio... more Studies of mixed-species groups of animals can reveal emergent complexities of collective behaviors. In this study we collected data on mixed-species hunting groups composed primarily of piscivorous fishes (species composition, abundance, behavioral interactions) and used both multivariate and network analyses to quantify pair-wise and guild level behavioral relationships. Our results indicate that such collective behaviors exhibit consistent patterns of associations (33 species with 282 pair-wise links within the observed network) with 10 dominant species accounting for 60% of pair-wise interactions. Species richness within groups varied (mean = 2.4, range 2-6 species) as did group size (mean = 8.1 individuals, range 2-80). Mixed-species groups, in general, were composed of species representing morphologically diverse forms that appeared to enhance access to shelter sites and implement diverse strategies for prey capture. It is noteworthy that the composition of groups did not reflect the relative abundances of their component species within the overall community of fishes, suggesting that group membership was an elective choice. The identification of these patterns, assuming they are persistent features of these communities, can be used as a foundation for studies to assess dynamics of mixed-species relationships, rates of predator success based on group membership, demographic consequences, and responses to variations in habitat attributes and associated prey resources. Such information could be used to interpret the nature of multispecies interactions within predator communities and potentially aid in conservation and management.

Revista de Biología Topical, 2018

When conservation can't keep up with development´s pace: Health status of coral ecosystems in th... more When conservation can't 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.

Revista de Biología Tropical, 2016

Coloration patterns of reef fishes are an important trait for mediating intra and interspecific i... more Coloration patterns of reef fishes are an important trait for mediating intra and interspecific interactions, as well as for taxonomic identifications. Here we report a specimen of Stegastes arcifrons that presented
a previously unobserved and anomalous color variation on a coral reef at Isla del Coco, Pacific Costa Rica.
This color variation is known as xanthism and has been reported in some damselfishes, usually associated with
genetic anomally

Osa Conservation Area (Costa Rica) coral ecosystems: structure and conservation needs. Costa Rica... more Osa Conservation Area (Costa Rica) coral ecosystems: structure and conservation needs. Costa Rica is considered one of the 20 most biodiverse countries in the world, which includes it´s well known reefs ecosystems. Specifically, the South Pacific region, the Osa Conservation Area (ACOSA), holds one of the richest reefs of the country. Even though many of these reefs have been studied since the 1980´s, most of them had focused mainly on coral cover condition. Therefore, the present research aims to complete and update an evaluation of the main biological components of ACOSA´s reefs ecosystems, using a standard methodology. Between 2013 and 2014, five localities were visited: Dominicalito, Marino Ballena National Park, Caño Island Biological Reserve, Osa Peninsula and Golfo Dulce, on which 27 sites were evaluated. Transects at two depths in each site were done to estimate substrate cover, reef rugosity, macroinvertebrates diversity and density, and reef fishes composition and biomass. Results indicate that ACOSA´s reef are moderately complex and on most of them the substrate is dominated by turf (62.7%) and live coral cover is moderate (16.5%). Substrate cover was significantly different between localities, which can be attributed to adverse environmental conditions for reef development (e.g. sedimentation, pollution). However, reefs in Golfo Dulce and Caño Island BR showed a significant coral cover recovery since last studied. Of 35 taxa of macroinvertebrates identified, 58% had low abundance or were observed occasionally. Golfo Dulce presented the highest diversity and density of macroinvertebrates and significant differences were observed between localities. On this group, this study is providing an information baseline of most sites analyzed. The echinoids Diadema mexicanum and Eucidaris thouarsii were the most abundant and the conch (Lobatus galeatus) was reported for many of the sites. Of the 90 species of reef fishes documented, ten were common and with the highest densities. There were no significant differences in the diversity and richness of the reef fishes between localities, but fishes' biomass and composition of fish community were different between sites. Caño Island´s sites were the most diverse of ACOSA, and presented the highest biomass and trophic levels of the region. Golfo Dulce´s reef fish composition differs from the other localities. According to the results, ACOSA´s reef ecosystems have a high biodiversity. The ecosystems conditions observed indicate that more conservation efforts, sustainable use and effective management of land and marine resources should be implemented. Ecological monitoring will provide the information about trends and the relationship between reef ecosystems state and environmental conditions. Rev. Biol. Trop. 63 (Suppl. 1): 219-259. Epub 2015 April 01.

Revista de Biología Tropical, 2014

Economic activities that depend on ichthyofauna in the North Pacific of Costa Rica. The North Pac... more Economic activities that depend on ichthyofauna in the North Pacific of Costa Rica. The
North Pacific of Costa Rica is characterized by a large diversity of fish species. This diversity sustains two of
the main economic activities developed there: fishing and tourism. We synthesized information from: semistructured
interviews with local stakeholders, biodiversity database from the Museo de Zoología, Universidad
de Costa Rica, landings database from Costa Rican government (INCOPESCA) and the literature. A total of 424
fish species are reported from the area and the main target species for each fishery are: mahi-mahi, silky shark,
hammerhead shark, tuna, sailfish, swordfish for longline fisheries; snappers, croakers, snook and groupers for
artisanal fisheries; invertebrates and ornamental fish in dive-fisheries; shrimp in trawl fisheries; and wahoo,
yellow-fin tuna, rooster fish, mahi-mahi, swordfish, sailfish, marlin in tourism fisheries. INCOPESCA does
not take into account fishing effort but most species landings are decreasing, especially mahi-mahi, groupers
and snappers. Conflicts between fisheries and tourism are arising due to competition for resources and overexploitation.
The main conflicts found were: (1) between sport and longline fisheries, (2) between recreational
diving and dive-fisheries, (3) between the artisanal and shrimp trawling fisheries, and (4) among artisanal fishermen
from different zones of the Pacific. These conflicts demonstrate the urgency of developing and effectively
implementing management strategies that will guarantee the sustainability of fish resources in the area. Future
studies should focus on generating information that will guide and support these management efforts