RESUMO

Gualaxo do Norte River (GNR), in southeastern Brazil, was impacted by iron ore tailings from the Fundão Dam rupture (November 2015). The deposition of tailings on the riverbed has changed the hydrogeomorphological characteristics of the GNR, resulting in a decrease in the diversity of physical habitats and ecological biodiversity. As part of the process of restoration and management of this damaged ecosystem, the river restoration project ReNaturalize was implemented to restructure the geomorphological characteristics and the physical habitat and to enhance the reestablishment of biota, mainly for macroinvertebrates and fishes. For this goal, 203 wooden structures, such as tree trunks, branches, and grass were installed in two sections of GNR (T6R and T7R), totaling 1.8 km long. The effectiveness of the project was evaluated by an assessment that followed a before and after and control and impacted (BACI) design. Upstream of each Restored reach there is a Control and a Reference reach. Four campaigns were carried out, two before and two after the restoration process. After 14 months of the woody installation, an increase in hydraulic retention in the restored reaches was observed (T6R-20.2%; T7R-63.5%), when compared with the Control reaches, which favored the accumulation of sediments (T6R-388 metric tons; T7R-396 metric tons). This enhanced the formation of natural tailings barriers and promoted the enrichment of substrate types (T6R-39.2%; T7R-43%). The benthic macroinvertebrate community showed an increase in the total abundance (T6-110%), including the most sensitive groups (T6R-124%; T7R-124%). For fish, the increase was up to 81.38% with hand nets capture, indicating the recruitment of juveniles, and the abundance and the biomass of some species were also higher (up to 100%) than the Control reaches. The results indicated that the Restored reach is already qualitatively and quantitatively better than the Control reach and similar to the Reference reach, indicating the success of the study. Integr Environ Assess Manag 2023;19:648-662. © 2022 SETAC.

Assuntos

RESUMO

Abstract Coral reefs harbor one of the largest fish biodiversity on earth; yet information on reef fishes is still absent for many regions. We analyzed reef fish richness, distribution, and conservation on the largest Brazilian multiple use coastal MPA; which cover a large extent of coral reefs at the SWA. A total of 325 fish species have been listed for MPA Costa dos Corais, including Chondrichthyes (28 species) and Actinopterygii (297). Fish species were represented by 81 families and the most representative families were Carangidae (23 species), Labridae (21) and Gobiidae (15). The MPA fish richness represented 44% of all recorded fish species of the Southwestern Atlantic Ocean (SWA) highlighting the large-scale importance of this MPA. A total of 40 species (12%) are registered at Near Threatened (NT), Vulnerable (VU), Endangered (EN) or Critically Endangered (CR). This study reinforces the importance of MPA Costa dos Corais on reef fish biodiversity and conservation and emphasize the urgent need of conservation strategies.

Resumo Os recifes de coral abrigam uma das maiores biodiversidades de peixes do planeta; no entanto, as informações sobre peixes de recife ainda estão ausentes em muitas regiões. Analisamos a riqueza, distribuição e a conservação de peixes recifais na maior Área de Proteção Ambiental (APA) costeira de uso múltiplo do Brasil; área que possui grande extensão de recifes de corais no SWA. Um total de 325 espécies de peixes foram listadas para APA Costa dos Corais, incluindo Chondrichthyes (28 espécies) e Actinopterygii (297). As espécies de peixes foram representadas por 81 famílias e as famílias mais representativas foram Carangidae (23 espécies), Labridae (21) e Gobiidae (15). A riqueza de peixes da APA representou 44% de todas as espécies de peixes registradas no Oceano Atlântico Sudoeste (SWA), destacando a importância em grande escala desta APA. Um total de 40 espécies (12%) estão registradas como Quase Ameaçada (NT), Vulnerável (VU), Em Perigo (EN) ou Criticamente Em Perigo (CR). Este estudo reforça a importância da APA Costa dos Corais na biodiversidade e conservação dos peixes recifais e enfatiza a necessidade urgente de estratégias de conservação.

RESUMO

Abstract The large estuaries can present long narrow branches called subestuaries or tidal creeks. These types of subsystems are distributed along the Uruguayan coast of the Río de la Plata estuary and are very important as nursery and refuge areas for fish. For the first time, the seasonal composition and abundance of the fish community of the Solís Chico subestuary was studied by using beach and gill nets. Fourteen species, mainly euryhaline (86%) presented a significant representation of juvenile stages. The fish community was dominated by Odontesthes argentinensis, Platanichthys platana, Mugil liza, Brevoortia aurea, Micropogonias furnieri and Paralichthys orbignyanus, similar to adjacent subestuaries. While Micropogonias furnieri and B. aurea were the most abundant species, some other species were rarely caught. A seasonal variation of the fish assemblage abundance was detected, with higher values in autumn showing a positive correlation with temperature. Species that complete their life cycle in the Río de la Plata estuary, some of which are relevant to fisheries (64% of the analyzed species) were captured in the Solís Chico subestuary. The importance of this environment as a transitional system for some estuarine fish species is advised.

Resumo Os grandes estuários podem apresentar longos ramos estreitos chamados subestuários e riachos de maré. Estes subsistemas estão distribuídos ao longo da costa uruguaia no estuário do Río de la Plata e são muito importantes como áreas de reprodução e refúgio para os peixes. Pela primeira vez, a composição sazonal e abundância da comunidade de peixes do subestuário Solís Chico foi estudada usando redes de arrasto de praia e rede de emalhar. Quatorze espécies com predominância das eurialinas foram capturadas, havendo uma representação significativa das fases juvenis e espécies alvo para a pesca. A comunidade de peixes foi dominada por Odontesthes argentinensis, Platanichthys platana, Mugil liza, Brevoortia aurea, Micropogonias furnieri e Paralichthys orbignyanus, semelhante aos subestuários adjacentes. Enquanto, M. furnieri e B. aurea foram as espécies com maior número de individuos. Solís Chico apresentou espécies exclusivas com baixa abundância e ocorrência. Foi verificada uma variação sazonal da abundância de peixes, com valores maiores no outono, mostrando uma correlação positiva com a temperatura. Algumas espécies relevantes para a pesca que completam seu ciclo de vida no estuário do Río de la Plata foram capturadas (64% das espécies estudadas) no subestuário Solís Chico, indicando a importância deste ambiente como um sistema transitório para algumas espécies estuarinas de peixes.

Assuntos

RESUMO

This study examined the fish communities of Peri Lagoon in southern Brazil to aid in the development of an effective management plan because the area is under threat from human activities. Sampling of fish fauna, ichthyoplankton and limnological data were compared between sites, differing by habitat type and characteristics such as depth, substratum composition and vegetation type. Results were significantly related to site, with the highest diversity and abundance recorded at shallow vegetated sites. A total of 14 fish species were recorded throughout the lagoon, with the most abundant being Hyphessobrycon luetkenii. Of the 14 species, half were sampled at their larval stage, suggesting a healthy and protected system. Significantly more larvae and eggs were collected during colder months (autumn to winter) and at sites closer to stream flow, possibly owing to increased food sources and habitat protection. This study highlights the importance of Peri Lagoon as a nursery ground for a wide range of fish species, providing essential information for incorporation into the future protection of fish stocks throughout Brazil.

Assuntos

RESUMO

Abstract The large estuaries can present long narrow branches called subestuaries or tidal creeks. These types of subsystems are distributed along the Uruguayan coast of the Río de la Plata estuary and are very important as nursery and refuge areas for fish. For the first time, the seasonal composition and abundance of the fish community of the Solís Chico subestuary was studied by using beach and gill nets. Fourteen species, mainly euryhaline (86%) presented a significant representation of juvenile stages. The fish community was dominated by Odontesthes argentinensis, Platanichthys platana, Mugil liza, Brevoortia aurea, Micropogonias furnieri and Paralichthys orbignyanus, similar to adjacent subestuaries. While Micropogonias furnieri and B. aurea were the most abundant species, some other species were rarely caught. A seasonal variation of the fish assemblage abundance was detected, with higher values in autumn showing a positive correlation with temperature. Species that complete their life cycle in the Río de la Plata estuary, some of which are relevant to fisheries (64% of the analyzed species) were captured in the Solís Chico subestuary. The importance of this environment as a transitional system for some estuarine fish species is advised.

Resumo Os grandes estuários podem apresentar longos ramos estreitos chamados subestuários e riachos de maré. Estes subsistemas estão distribuídos ao longo da costa uruguaia no estuário do Río de la Plata e são muito importantes como áreas de reprodução e refúgio para os peixes. Pela primeira vez, a composição sazonal e abundância da comunidade de peixes do subestuário Solís Chico foi estudada usando redes de arrasto de praia e rede de emalhar. Quatorze espécies com predominância das eurialinas foram capturadas, havendo uma representação significativa das fases juvenis e espécies alvo para a pesca. A comunidade de peixes foi dominada por Odontesthes argentinensis, Platanichthys platana, Mugil liza, Brevoortia aurea, Micropogonias furnieri e Paralichthys orbignyanus, semelhante aos subestuários adjacentes. Enquanto, M. furnieri e B. aurea foram as espécies com maior número de individuos. Solís Chico apresentou espécies exclusivas com baixa abundância e ocorrência. Foi verificada uma variação sazonal da abundância de peixes, com valores maiores no outono, mostrando uma correlação positiva com a temperatura. Algumas espécies relevantes para a pesca que completam seu ciclo de vida no estuário do Río de la Plata foram capturadas (64% das espécies estudadas) no subestuário Solís Chico, indicando a importância deste ambiente como um sistema transitório para algumas espécies estuarinas de peixes.

RESUMO

Abstract We assessed the fish assemblage structure and composition of Nova Ponte Reservoir (Araguari River, Upper Paraná Basin, Brazil). We observed significant differences in abundance (p = 0.0003), richness (p = 0.0005) and diversity (p = 0.02) between lacustrine and riverine zones of the reservoir. Nine species were significantly more abundant in the riverine region: Astyanax altiparanae, Astyanax gr. fasciatus, Galeocharax knerii, Hoplias intermedius, Hypostomus sp., Leporinus friderici, Leporinus obtusidens, Pimelodus maculatus and Schizodon nasutus. The results indicated a longitudinal gradient in the composition and abundance of fishes in Nova Ponte Reservoir, reinforcing the importance of freely flowing riverine reaches for conserving native neotropical ichthyofauna and reflecting the strong adaptation of these species to riverine systems.

Resumo Este estudo avaliou a assembléia de peixes do reservatório de Nova Ponte (rio Araguari, bacia do Alto Paraná, Brasil), em termos de estrutura e composição. Foram observadas diferenças significativas na abundância (p = 0.0003), riqueza (p = 0.0005) e diversidade (p = 0.02) entre as zonas lacustres e fluviais do reservatório. Nove espécies foram mais abundantes na região fluvial: Astyanax altiparanae, Astyanax gr. fasciatus, Galeocharax knerii, Hoplias intermedius, Hypostomus sp., Leporinus friderici, Leporinus obtusidens, Pimelodus maculatus and Schizodon nasutus. Os resultados indicaram a existência de um gradiente longitudinal na composição e abundância de peixes no reservatório de Nova Ponte. Estes padrões reforçam a importância de trechos fluviais livres de barramentos para a conservação da ictiofauna neotropical nativa e refletem a forte adaptação dessas espécies aos sistemas fluviais.

Assuntos

RESUMO

Abstract We assessed the fish assemblage structure and composition of Nova Ponte Reservoir (Araguari River, Upper Paraná Basin, Brazil). We observed significant differences in abundance (p = 0.0003), richness (p = 0.0005) and diversity (p = 0.02) between lacustrine and riverine zones of the reservoir. Nine species were significantly more abundant in the riverine region: Astyanax altiparanae, Astyanax gr. fasciatus, Galeocharax knerii, Hoplias intermedius, Hypostomus sp., Leporinus friderici, Leporinus obtusidens, Pimelodus maculatus and Schizodon nasutus. The results indicated a longitudinal gradient in the composition and abundance of fishes in Nova Ponte Reservoir, reinforcing the importance of freely flowing riverine reaches for conserving native neotropical ichthyofauna and reflecting the strong adaptation of these species to riverine systems.(AU)

Resumo Este estudo avaliou a assembléia de peixes do reservatório de Nova Ponte (rio Araguari, bacia do Alto Paraná, Brasil), em termos de estrutura e composição. Foram observadas diferenças significativas na abundância (p = 0.0003), riqueza (p = 0.0005) e diversidade (p = 0.02) entre as zonas lacustres e fluviais do reservatório. Nove espécies foram mais abundantes na região fluvial: Astyanax altiparanae, Astyanax gr. fasciatus, Galeocharax knerii, Hoplias intermedius, Hypostomus sp., Leporinus friderici, Leporinus obtusidens, Pimelodus maculatus and Schizodon nasutus. Os resultados indicaram a existência de um gradiente longitudinal na composição e abundância de peixes no reservatório de Nova Ponte. Estes padrões reforçam a importância de trechos fluviais livres de barramentos para a conservação da ictiofauna neotropical nativa e refletem a forte adaptação dessas espécies aos sistemas fluviais.(AU)

Assuntos

RESUMO

Abstract We assessed the fish assemblage structure and composition of Nova Ponte Reservoir (Araguari River, Upper Paraná Basin, Brazil). We observed significant differences in abundance (p = 0.0003), richness (p = 0.0005) and diversity (p = 0.02) between lacustrine and riverine zones of the reservoir. Nine species were significantly more abundant in the riverine region: Astyanax altiparanae, Astyanax gr. fasciatus, Galeocharax knerii, Hoplias intermedius, Hypostomus sp., Leporinus friderici, Leporinus obtusidens, Pimelodus maculatus and Schizodon nasutus. The results indicated a longitudinal gradient in the composition and abundance of fishes in Nova Ponte Reservoir, reinforcing the importance of freely flowing riverine reaches for conserving native neotropical ichthyofauna and reflecting the strong adaptation of these species to riverine systems.

Resumo Este estudo avaliou a assembléia de peixes do reservatório de Nova Ponte (rio Araguari, bacia do Alto Paraná, Brasil), em termos de estrutura e composição. Foram observadas diferenças significativas na abundância (p = 0.0003), riqueza (p = 0.0005) e diversidade (p = 0.02) entre as zonas lacustres e fluviais do reservatório. Nove espécies foram mais abundantes na região fluvial: Astyanax altiparanae, Astyanax gr. fasciatus, Galeocharax knerii, Hoplias intermedius, Hypostomus sp., Leporinus friderici, Leporinus obtusidens, Pimelodus maculatus and Schizodon nasutus. Os resultados indicaram a existência de um gradiente longitudinal na composição e abundância de peixes no reservatório de Nova Ponte. Estes padrões reforçam a importância de trechos fluviais livres de barramentos para a conservação da ictiofauna neotropical nativa e refletem a forte adaptação dessas espécies aos sistemas fluviais.

RESUMO

Resumen Los arrecifes rocosos proveen una alta diversidad de organismos. Se presentaron cambios en la estructura de la comunidad íctica a lo largo de la estación climática y la acción del oleaje. Este estudio evaluó la diversidad y la abundancia de los peces del arrecife rocoso La Viuda, Golfo Dulce, Costa Rica (8°37'33" N - 83°14'08" W). Los peces fueron estudiados con el método de Bohnsack y Bannerot comparando las estaciones seca y lluviosa, las zonas protegidas y expuestas al oleaje usando índices ecológicos. El total de especies fue 28, las familias más abundantes fueron Pomacentridae y Labridae. La diversidad de Shannon-Wiener resultó entre 1,1 y 1,73 nits/ ind. El índice de Pielou en La Viuda fue 0.43. Se encontró mayor diversidad de especies en la época seca y en la zona protegida al oleaje.

Abstract Rocky reefs maintain a high diversity of organisms. Differences in fish community could be expected by seasonal events and wave action on rocky reefs. I studied "La Viuda" rocky islet, Golfo Dulce, CostA Rica (8°37'33" N - 83°14'08" W) with Bohnsack and Bannerot visual census methods four times between February and December 2002. I identified 28 species and the most abundant families were Pomacentridae and Labridae. Shannon-Wiener diversity was between 1.1 and 1.73 nits/ind., and Pielou 0.43. There is a higher diversity in the dry season and in areas protected from wave action. Rev. Biol. Trop. 63 (Suppl. 1): 329-338. Epub 2015 April 01.

Assuntos

RESUMO

Ichthyofauna from 29 tidepools in Jericoacoara National Park (Ceará State, Brazil) was sampled. A total of 733 fishes, comprising 16 species belonging to 12 families, was collected. The three most abundant species were the frillfin goby Bathygobius soporator, the sergeant-majorAbudefduf saxatilis and the molly miller Scartella cristata. An invasive species from the Indo-Pacific, the Muzzled blenny Omobranchus punctatus, was also recorded. The known geographic distribution of the blenny Hypleurochilus fissicornis was extended approximately 2,500 km northward. These findings highlight the lack of knowledge of the rocky intertidal ecosystems along the Brazilian coast, an area that needs more sampling effort and ecological data.

Um total de 733 espécimes de peixes, pertencentes a 16 espécies (12 famílias), foi capturado em 29 poças de maré no Parque Nacional de Jericoacoara (Ceará, Brasil). As espécies mais numericamente abundantes foram o amboré Bathygobius soporator, o sargentinho Abudefduf saxatilis e o macaco-verdeScartella cristata. Uma espécie invasora originária do Indo-Pacífico, Omobranchus punctatus, foi registrada para a área. A ocorrência de Hypleurochilus fissicornis permitiu expandir sua distribuição geográfica em cerca de 2.500 km ao norte. Esses resultados demostram que diversos aspectos relacionados a ictiofauna do ecossistema entremarés em substrato consolidado ainda permanecem pouco estudados no Brasil, e portanto, mais levantamentos da biodiversidade e dados ecológicos são necessários.

RESUMO

Ecological impacts of military bombing activities in Puerto Rico have often been described as minimal, with recurrent allegations of confounding effects by hurricanes, coral diseases and local anthropogenic stressors. Reef craters, though isolated, are associated with major colony fragmentation and framework pulverization, with a net permanent loss of reef bio-construction. In contrast, adjacent non-bombarded reef sections have significantly higher benthic spatial relief and biodiversity. We compared benthic communities on 35-50 year-old bomb-cratered coral reefs at Culebra and Vieques Islands, with adjacent non-impacted sites; 2) coral recruit density and fish community structure within and outside craters; and 3) early effects of a rehabilitation effort using low-tech Staghorn coral Acropora cervicornis farming. Reef craters ranged in size from approximately 50 to 400m² and were largely dominated by heavily fragmented, flattened benthos, with coral cover usually below 2% and dominance by non-reef building taxa (i.e., filamentous algal turfs, macroalgae). Benthic spatial heterogeneity was lower within craters which also resulted in a lowered functional value as fish nursery ground. Fish species richness, abundance and biomass, and coral recruit density were lower within craters. Low-tech, community-based approaches to culture, harvest and transplant A. cervicornis into formerly bombarded grounds have proved successful in increasing percent coral cover, benthic spatial heterogeneity, and helping rehabilitate nursery ground functions.

Los impactos ecológicos de las actividades militares de bombardeos en Puerto Rico se han descrito a menudo como mínimos, con recurrentes denuncias al confundir efectos por huracanes, enfermedades de corales y estresores antropogénicos locales. Los cráteres de arrecife, aunque aislados, están relacionados con una alta fragmentación de la colonia y pulverización del contorno, con una pérdida neta permanente de arrecife en bio-construcción. En contraste, secciones adyacentes de arrecife no bombardeado tienen mayor biodiversidad y mayor relieve espacial bentónico. Comparamos las comunidades bentónicas en cráteres-bomba de arrecifes de coral con 35-50 años de antigüedad en las islas de Vieques, Puerto Rico, en comparación con los sitios adyacentes no impactados; 2) la densidad de reclutamiento de coral y estructura de la comunidad de peces dentro y fuera de los cráteres; y 3) impactos preliminares de un esfuerzo de rehabilitación basado en la comunidad arrecifal usando tecnología simple con el cultivo del coral Staghorn Acropora cervicornis. Los cráteres de arrecife se distancian en tamaño de aproximadamente 50 a 400m² y fueron dominados ampliamente por fragmentos de bentos aplanado, con una cubierta de coral generalmente por debajo de 2% y el predominio de taxones no constructores de arrecifes (es decir, tapetes de algas filamentosas, macroalgas). La heterogeneidad espacial bentónica fue significativamente menor dentro de cráteres que también resultaron en un reducido valor funcional como tierra de vivero de peces. La riqueza de especies de peces, abundancia y biomasa y densidad coral recluta fueron significativamente menores dentro de cráteres. Tecnología simple, basada en los enfoques de cultivo de comunidad, la cosecha y transplante de A. cervicornis en terrenos anteriormente bombardeados han demostrado un éxito al aumentar el porcentaje de cobertura de coral, la heterogeneidad espacial bentónica y ayudando a rehabilitar funcionalmente la tierra para vivero.

Assuntos

RESUMO

The coral reefs located off the north coast of the Jamaican mainland are some of the best and most studied reefs in the world. Coral reefs of Pedro Bank, Jamaica were assessed in March, 2012 as part of the KSLOF Global Reef Expedition using a modified Atlantic and Gulf Rapid Reef Assessment (AGRRA) protocol. The main objectives were to: 1) characterize the distribution, structure and health of coral reefs; and 2) evaluate the population status of commercially important reef fishes and invertebrates. This work was conducted to assist in characterizing coral reef habitats within and outside a proposed fishery reserve, and identify other possible conservation zones. Within 20 reefs, live coral cover ranged from 4.9% to 19.2%. Coral communities were dominated by small corals (esp. Agaricia, Porites and Siderastrea) although many sites had high abundances of large colonies of Montastraea annularis and M. faveolata, and these were generally in good condition. A single area, within the proposed fishery reserve, had extensive Acropora cervicornis thickets, and several shallow locations had small, but recovering A. palmata stands. Macroalgal cover at all sites was relatively low, with only three sites having greater than 30% cover; crustose coralline algae (CCA) was high, with eight sites exceeding 20% cover. Fish biomass at all sites near the Cays was low, with a dominance of herbivores (parrotfish and surgeonfish) and a near absence of groupers, snappers and other commercially important species. While parrotfish were the most abundant fish, these were all extremely small (mean size= 12cm; <4% over 29cm), and they were dominated by red band parrotfish (Sparisoma aurofrenatum) followed by striped parrotfish (Scarus iseri). While coral communities remain in better condition than most coastal reefs in Jamaica, intense fishing pressure using fish traps (main target species: surgeonfish) and hookah/spear fishing (main target: parrotfish) is of grave concern to the future persistence of these reefs. The proposed fishery reserve encompasses some of the best coral reef habitat near the Cays, but this MPA should be expanded to encompass other habitats and MPAs should be considered for bank reefs at the northwestern end, as well as Banner Reef and Blowers Rock.

Los arrecifes de coral ubicados en la costa norte de Jamaica son los mejores y mas estudiados corales del mundo. Los corales de arrecife del Banco de Pedro, Jamaica, fueron evaluados en marzo 2012 como parte de la expedición global KSLOF utilizando una modificación del protocolo de estimación rápida de arrecifes para el Atlántico y el Caribe (AGRRA). Los objetivos principales fueron: 1) caracterizar la distribución, estructura y salud de los arrecifes de coral; y 2) evaluar la condición de las poblaciones de peces arrecifales e invertebrados de interés comercial. Este trabajo fue realizado con el propósito de colaborar en la caracterización de hábitats arrecifales, tanto dentro como fuera de un área sugerida como reserva marina, e identificar otras áreas de conservación. Para los 20 arrecifes, la cobertura de coral vivo varió entre 4.9% y 19.2%. Las comunidades de corales son dominadas por corales pequeños (Agaricia, Porites y Siderastrea), aunque en varias localidades se presentó una mayor abundancia de colonias grandes de M. annularis y M. faveolata, y estos se encontraban por lo general en buenas condiciones. Dentro de la reserva pesquera propuesta, una sola área presentó fragmentos de A. cervicornis, y varias localidades someras presentaron pequeños fragmentos de A. palmata, pero en proceso de recuperación. La cobertura de macroalgas en todas las áreas fue relativamente baja, solo tres lugares presentaron más de un 30%; la cobertura de algas coralinas calcárea (CCA) fue alta, ocho lugares excedieron el 20%. La biomasa de peces fue baja en todos los sitios cercanos a los cayos, y hubo dominancia de herbívoros (pez loro y cirujanos), y en general ausencia de chernas, pargos y otras especies de peces de interés comercial. Aunque los peces loro fueron los más abundantes, estos presentaron tamaños extremadamente pequeños (tamaño promedio = 12cm; <4% por encima de 29cm), y estuvieron dominados por el pez loro de banda roja (Sparisoma aurofrenatum), y por el pez loro de rayas (Scarus iseri). Mientras que las comunidades de coral permanecen en mejor condición que muchos de los arrecifes costeros de Jamaica, existe una intensa presión pesquera usando trampas de pesca (principal objetivo: cirujanos) y de compresores de aire (hookah)/ pesca con arpón (principal objetivo: pez loro) es preocupante, y compromete la persistencia y el futuro de estos arrecifes. La reserva marina (MPA) que se sugiere incluye algunos de los mejores hábitats de arrecife coralino cerca de los cayos, pero es recomendable que se amplíe para incluir otros hábitats y que se consideren áreas marinas protegidas en los bancos de arrecife del extremo noroeste, así como el arrecife Banner y Blowers Rock.

RESUMO

The aim of this study was to investigate the influence of spatial variation in river channels and habitats on the distribution of fish communities in the headwater streams of the Jaú River System, a blackwater tributary of the Negro River. Collections and measurements were made in 34 headwater streams during the period of November- December, 1998. Fish were captured with fish traps and hand nets along standard reaches of two meanders. Data on benthic habitat structure, stream depth and width were collected along lateral transects in each sample reach. A total of 66 fish species from 24 families were collected and classified into seven trophic guilds: allocthonous insectivore, autochthonous insectivore, general insectivore, piscivore, detritivorous planktivore, detritivorous insectivore and insectivorous piscivore. Variations in the distribution and diversity of bottom substrates were important factors influencing fish community structures in these systems. Also, variation in stream size explained the observed variability in fish communities.

O objetivo desse estudo foi investigar a influência da variação espacial de características físicas do canal dos igarapés e habitats na distribuição das comunidades de peixes em igarapés de cabeceira no sistema do rio Jaú. O rio Jaú é um tributário de águas pretas do rio Negro. Coletas e medidas foram realizadas em 34 igarapés de cabeceira durante os períodos de novembro a dezembro de 1998. Os peixes foram capturados com armadilhas e puçás ao longo de dois meandros em cada local. Um total de 66 espécies de peixes de 24 famílias foram coletados e classificados em sete guildas tróficas: insetívoro alóctone, insetívoro autóctone, insetívoro em geral, piscívoro, detritívoro algívoro, detritívoro insetívoro e insetívoro piscívoro. Variações na distribuição e diversidade do substrato de fundo foram importantes fatores influenciando a estrutura da comunidade nesses sistemas. Sendo assim, variações no tamanho dos igarapés mostraram reflexos nas comunidades de peixes.

Assuntos

RESUMO

The aim of this study was to investigate the influence of spatial variation in river channels and habitats on the distribution of fish communities in the headwater streams of the Jaú River System, a blackwater tributary of the Negro River. Collections and measurements were made in 34 headwater streams during the period of November- December, 1998. Fish were captured with fish traps and hand nets along standard reaches of two meanders. Data on benthic habitat structure, stream depth and width were collected along lateral transects in each sample reach. A total of 66 fish species from 24 families were collected and classified into seven trophic guilds: allocthonous insectivore, autochthonous insectivore, general insectivore, piscivore, detritivorous planktivore, detritivorous insectivore and insectivorous piscivore. Variations in the distribution and diversity of bottom substrates were important factors influencing fish community structures in these systems. Also, variation in stream size explained the observed variability in fish communities.

O objetivo desse estudo foi investigar a influência da variação espacial de características físicas do canal dos igarapés e habitats na distribuição das comunidades de peixes em igarapés de cabeceira no sistema do rio Jaú. O rio Jaú é um tributário de águas pretas do rio Negro. Coletas e medidas foram realizadas em 34 igarapés de cabeceira durante os períodos de novembro a dezembro de 1998. Os peixes foram capturados com armadilhas e puçás ao longo de dois meandros em cada local. Um total de 66 espécies de peixes de 24 famílias foram coletados e classificados em sete guildas tróficas: insetívoro alóctone, insetívoro autóctone, insetívoro em geral, piscívoro, detritívoro algívoro, detritívoro insetívoro e insetívoro piscívoro. Variações na distribuição e diversidade do substrato de fundo foram importantes fatores influenciando a estrutura da comunidade nesses sistemas. Sendo assim, variações no tamanho dos igarapés mostraram reflexos nas comunidades de peixes.

RESUMO

The aim of this study was to investigate the influence of spatial variation in river channels and habitats on the distribution of fish communities in the headwater streams of the Jaú River System, a blackwater tributary of the Negro River. Collections and measurements were made in 34 headwater streams during the period of November- December, 1998. Fish were captured with fish traps and hand nets along standard reaches of two meanders. Data on benthic habitat structure, stream depth and width were collected along lateral transects in each sample reach. A total of 66 fish species from 24 families were collected and classified into seven trophic guilds: allocthonous insectivore, autochthonous insectivore, general insectivore, piscivore, detritivorous planktivore, detritivorous insectivore and insectivorous piscivore. Variations in the distribution and diversity of bottom substrates were important factors influencing fish community structures in these systems. Also, variation in stream size explained the observed variability in fish communities.(AU)

O objetivo desse estudo foi investigar a influência da variação espacial de características físicas do canal dos igarapés e habitats na distribuição das comunidades de peixes em igarapés de cabeceira no sistema do rio Jaú. O rio Jaú é um tributário de águas pretas do rio Negro. Coletas e medidas foram realizadas em 34 igarapés de cabeceira durante os períodos de novembro a dezembro de 1998. Os peixes foram capturados com armadilhas e puçás ao longo de dois meandros em cada local. Um total de 66 espécies de peixes de 24 famílias foram coletados e classificados em sete guildas tróficas: insetívoro alóctone, insetívoro autóctone, insetívoro em geral, piscívoro, detritívoro algívoro, detritívoro insetívoro e insetívoro piscívoro. Variações na distribuição e diversidade do substrato de fundo foram importantes fatores influenciando a estrutura da comunidade nesses sistemas. Sendo assim, variações no tamanho dos igarapés mostraram reflexos nas comunidades de peixes.(AU)

Assuntos

RESUMO

The construction of reservoirs is considered an important source of impacts on the fish fauna, severely altering the structure of the assemblage. This paper aimed to describe the structure of the fish assemblage of the Goioerê River, determining its longitudinal distribution and patterns of species dominance. The evaluation of its longitudinal variation in the diversity and abundance of the fish assemblage was conducted in July and October 2004 and January and May 2005. The collections were carried out near the headwaters (Gurucaia), middle stretch (Olaria), just above the falls (Paiquerê) and downstream (Foz). Forty-four species were captured. The Gurucaia fish assemblages differed significantly from Olaria, Paiquerê and Foz. The Olaria assemblages differed significantly from the Foz. Gurucaia showed the lowest diversity and abundance of species. Astyanax aff paranae Eigenmann,1914 (78% of the total) was found to be dominant at this site. Almost the same species richness was found at Olaria and Paiquerê, although Olaria had the greatest abundance of individuals. Astyanax aff paranae, Cyphocharax modestus (Fernández-Yépez, 1948) and Astyanax altiparanae Garutti & Britski, 2000 were the top three dominants and comprised over 71% of the total number of fish caught. At Paiquerê, Astyanax altiparanae, Hypostomus aff ancistroides (Ihering, 1911) and Loricariichthys platymetopon Isbrücker & Nijssen, 1979 composed 58% of the catches. Thirty-one species were recorded at Foz, which presented the greatest richness. The most abundant species were Apareiodon affinis (Steindachner, 1879), Galeocharax knerii (Steindachner, 1879) and A.altiparanae, which contributed to 50% of the total catches in this environment.These results record the fish biodiversity and how the community is longitudinally structured in the Goioerê River, and also demonstrate how this type of evaluation is important to understanding the fish community patterns and finding solutions to problems related to the conservation and management of the basin.(AU)

A construção de reservatórios é considerada importante fonte de impactos para a fauna de peixes, levando a alterações significativas na estrutura da assembleia. Considerando isso, esse artigo objetiva descrever a estrutura da assembleia de peixes do rio Goioerê, determinando sua distribuição longitudinal e padrões na dominância das espécies. A avaliação da variação longitudinal na diversidade e abundância da assembleia de peixes neste rio foi conduzida em julho e outubro de 2004 e janeiro e maio de 2005. As coletas foram realizadas próximas as nascentes (Gurucaia), no segmento médio (Olaria), logo acima do salto Paiquerê (Paiquerê) e na foz do rio (Foz). Foram registradas 44 espécies. A assembleia de peixes de Gurucaia diferiu significativamente de Olaria, Paiquerê e Foz. A assembleia de Olaria diferiu significativamente de Foz. Gurucaia apresentou a menor diversidade e abundância de espécies. Astyanax aff. paranae Eigenmann,1914 (78% do total) foi dominante nesta localidade. Em Olaria e Paiquerê foi encontrada grande similaridade na riqueza de espécies, no entanto, em Olaria registrou-se a maior abundância de indivíduos. Astyanax aff. paranae, Cyphocharax modestus (Fernández-Yépez, 1948) and Astyanax altiparanae Garutti & Britski, 2000 foram as três espécies dominantes de topo e compreenderam cerca de 71% do total de peixes capturados. Na localidade Paiquerê, A. altiparanae, Hypostomus aff. ancistroides (Ihering, 1911) and Loricariichthys platymetopon Isbrücker & Nijssen, 1979 compuseram 58% das capturas. Trinta e uma espécies foram registradas na Foz, que apresentou a maior riqueza. As espécies mais abundantes foram Apareiodon affinis (Steindachner, 1879), Galeocharax knerii (Steindachner, 1879) and A. altiparanae, as quais contribuíram com 50% das capturas totais neste ambiente. Estes resultados registram a biodiversidade de peixes e como esta comunidade se estrutura longitudinalmente no rio Goioerê, além de demonstrar a importância desse tipo de avaliação para a compreensão dos padrões das comunidades de peixes e para a busca de soluções para problemas relacionados à conservação e o manejo desta bacia.(AU)

Assuntos

RESUMO

The construction of reservoirs is considered an important source of impacts on the fish fauna, severely altering the structure of the assemblage. This paper aimed to describe the structure of the fish assemblage of the Goioerê River, determining its longitudinal distribution and patterns of species dominance. The evaluation of its longitudinal variation in the diversity and abundance of the fish assemblage was conducted in July and October 2004 and January and May 2005. The collections were carried out near the headwaters (Gurucaia), middle stretch (Olaria), just above the falls (Paiquerê) and downstream (Foz). Forty-four species were captured. The Gurucaia fish assemblages differed significantly from Olaria, Paiquerê and Foz. The Olaria assemblages differed significantly from the Foz. Gurucaia showed the lowest diversity and abundance of species. Astyanax aff paranae Eigenmann,1914 (78% of the total) was found to be dominant at this site. Almost the same species richness was found at Olaria and Paiquerê, although Olaria had the greatest abundance of individuals. Astyanax aff paranae, Cyphocharax modestus (Fernández-Yépez, 1948) and Astyanax altiparanae Garutti & Britski, 2000 were the top three dominants and comprised over 71% of the total number of fish caught. At Paiquerê, Astyanax altiparanae, Hypostomus aff ancistroides (Ihering, 1911) and Loricariichthys platymetopon Isbrücker & Nijssen, 1979 composed 58% of the catches. Thirty-one species were recorded at Foz, which presented the greatest richness. The most abundant species were Apareiodon affinis (Steindachner, 1879), Galeocharax knerii (Steindachner, 1879) and A.altiparanae, which contributed to 50% of the total catches in this environment.These results record the fish biodiversity and how the community is longitudinally structured in the Goioerê River, and also demonstrate how this type of evaluation is important to understanding the fish community patterns and finding solutions to problems related to the conservation and management of the basin.

A construção de reservatórios é considerada importante fonte de impactos para a fauna de peixes, levando a alterações significativas na estrutura da assembleia. Considerando isso, esse artigo objetiva descrever a estrutura da assembleia de peixes do rio Goioerê, determinando sua distribuição longitudinal e padrões na dominância das espécies. A avaliação da variação longitudinal na diversidade e abundância da assembleia de peixes neste rio foi conduzida em julho e outubro de 2004 e janeiro e maio de 2005. As coletas foram realizadas próximas as nascentes (Gurucaia), no segmento médio (Olaria), logo acima do salto Paiquerê (Paiquerê) e na foz do rio (Foz). Foram registradas 44 espécies. A assembleia de peixes de Gurucaia diferiu significativamente de Olaria, Paiquerê e Foz. A assembleia de Olaria diferiu significativamente de Foz. Gurucaia apresentou a menor diversidade e abundância de espécies. Astyanax aff. paranae Eigenmann,1914 (78% do total) foi dominante nesta localidade. Em Olaria e Paiquerê foi encontrada grande similaridade na riqueza de espécies, no entanto, em Olaria registrou-se a maior abundância de indivíduos. Astyanax aff. paranae, Cyphocharax modestus (Fernández-Yépez, 1948) and Astyanax altiparanae Garutti & Britski, 2000 foram as três espécies dominantes de topo e compreenderam cerca de 71% do total de peixes capturados. Na localidade Paiquerê, A. altiparanae, Hypostomus aff. ancistroides (Ihering, 1911) and Loricariichthys platymetopon Isbrücker & Nijssen, 1979 compuseram 58% das capturas. Trinta e uma espécies foram registradas na Foz, que apresentou a maior riqueza. As espécies mais abundantes foram Apareiodon affinis (Steindachner, 1879), Galeocharax knerii (Steindachner, 1879) and A. altiparanae, as quais contribuíram com 50% das capturas totais neste ambiente. Estes resultados registram a biodiversidade de peixes e como esta comunidade se estrutura longitudinalmente no rio Goioerê, além de demonstrar a importância desse tipo de avaliação para a compreensão dos padrões das comunidades de peixes e para a busca de soluções para problemas relacionados à conservação e o manejo desta bacia.

Assuntos

RESUMO

In India, freshwater aquatic resources are suffering from increasing human population, urbanization and shortage of all kind of natural resources like water. To mitigate this, all the major rivers have been planned for a river-interlinking through an interlinking canal system under a huge scheme; yet, the baseline information on ecological conditions of those tropical rivers and their fish communities is lacking at present. In view of that, the present study was undertaken to assess the ecological condition by comparing the trophic metrics of the fish community, conservation status and water chemistry of the two tropical rivers of the Ganga basin, from October 2007 to November 2009. The analysis of trophic niches of the available fish species indicated dominancy of carnivorous (19 species) in river Ken and omnivorous (23 species) in Betwa. The trophic level score of carnivorous species was recorded similar (33.33%) in both rivers, whereas omnivorous species were mostly found in Betwa (36.51%) than Ken (28.07%). Relatively undisturbed sites of Betwa (B1, B2 and B3) and Ken (K2, K3 and K5) were characterized by diverse fish fauna and high richness of threatened species. The higher mean trophic level scores were recorded at B4 of Betwa and K4 of Ken. The Bray-Curtis index for trophic level identified the carnivorous species (>0.32) as an indicator species for pollution. Anthropogenic exposure, reflected in water quality as well as in fish community structure, was found higher especially in the lower stretches of both rivers. Our results suggest the importance of trophic metrics on fish community, for ecological conditions evaluation, which enables predictions on the effect of future morphodynamic changes (in the post-interlinking phases), and provide a framework and reference condition to support restoration efforts of relatively altered fish habitats in tropical rivers of India.

En la India, los recursos acuáticos de agua dulce están sufriendo debido a la creciente población humana, la urbanización y la escasez de todo tipo de recursos naturales como el agua. Para mitigar esto, se ha planificado bajo un amplio esquema que todos los grandes ríos estén interconectados a través de un sistema de canales, sin embargo, la información básica sobre las condiciones ecológicas de los ríos tropicales y sus comunidades de peces es escasa en la actualidad. En vista de ello, el presente estudio se realizó para evaluar el estado ecológico, mediante la comparación de los parámetros tróficos de la comunidad de peces, estado de conservación y el agua de los dos ríos tropicales de la cuenca del Ganges, de octubre 2007 a noviembre 2009. El análisis de los nichos tróficos de las especies de peces disponibles indican dominancia de carnívoros (19 especies) en el río Ken y omnívoros (23 especies) en Betwa. El nivel trófico de las especies carnívoras fue similar en ambos ríos (33.33%), mientras que las especies omnívoras fueron mayores en Betwa (36.51%) que en Ken (28.07%). Sitios relativamente inalterados de Betwa (B1, B2 y B3) y Ken (K2, K3 y K5) se caracterizaron por la alta diversidad y riqueza de especies de peces amenazadas. Los puntajes medios más altos del nivel trófico se registraron en B4 de Betwa y K4 de Ken. El índice de Bray-Curtis para el nivel trófico identificó las especies carnívoras (>0.32) como indicadoras de contaminación. Exposición antropogénica, reflejada en la calidad del agua, así como en la estructura de la comunidad de peces, fue más alta, especialmente en los tramos inferiores de ambos ríos. Nuestros resultados sugieren la importancia de métricas tróficas en la comunidad de peces, para la evaluación de las condiciones ecológicas, lo que permite hacer predicciones sobre el efecto de futuros cambios morfodinámicos (en las fases de post-interconexión), y proporcionar un marco y condición de referencia para apoyar los esfuerzos de restauración de hábitat de peces relativamente alterados en los ríos tropicales de la India.

Assuntos

RESUMO

“Los Petenes” Biosphere Reserve (RBLP) is a critical habitat for many aquatic and terrestrial species. It has the biggest and better conserved seagrass beds, and it represents an important habitat for food, protection and breeding of aquatic organisms, and a temporal refuge for migratory species. The objective of this study was to describe the ichthyofauna diversity in the littoral coastal area of the RBLP, to identify the ecological dominant species, and to analyze the abundance of the fish community and its temporal and spatial changes, and their relationship with some environmental variables. Monthly fish samples were obtained with the aid of trawl nets, from 24 samplings sites distributed along the reserve, between May 2009 and April 2010. The trawl net was operated 288 times and 21 795 individuals with 279.5kg of weight were collected. A total of 46 fish species grouped in 34 genera and 23 families were identified. In a spatial scale, the abundance showed the next ranges: 0.018-0.094ind./m²; 0.249-1.072 g/m² and 9.75-19.32g/ind.; the diversity indexes obtained were: Hn=1.46-2.15, J=0.45-0.71 and D=2.08-3.92. In a temporal scale, the abundance and diversity ranged between: 0.026-0.066ind./m2; 0.342-0.764g/m² and 6.49-22.98g/ind.; Hn=1.76-2.08; J’=0.52-0.64 and D=3.07-4.18. Eleven dominant species were identified with a representation of the 94.39% in number of individuals, and 89.66% in weight of the total catch. From the total, eight species had economic or commercial importance, especially Lagodon rhomboides and Haemulon plumierii. The cluster analyses identified four fish associations; these results are discussed in order to identify relationships between habitat-species. Finally, the canonical correspondence analysis evidenced an association between H. plumierii with salinity and dissolved solids. The RBLP has high habitat diversity and its fish community has developed strategies to use all the spatial and temporal conditions and to satisfy the needs of their life cycles.

La Reserva de la Biósfera Los Petenes constituye un hábitat crítico para una gran diversidad de especies de peces, la zona de pastos marinos es utilizada con fines de alimentación, protección, crianza y refugio temporal. El objetivo es analizar la estructura espacio-temporal de la comunidad de peces y su relación con la variabilidad ambiental e identificar las especies dominantes. Se realizaron 12 muestreos mensuales en 24 sitios a partir de mayo 2009 hasta abril 2010. Se realizaron 288 arrastres, se capturó un total de 21 795 organismos con un peso total de 279.5 kg. Se identificaron 46 especies de peces (34 géneros y 23 familias). Los intervalos de variación espacial de la abundancia fueron: 0.018-0.094ind./m²; 0.249-1.072g/m² y 9.75-19.32g/ind. Los índices de diversidad fueron: Hn=1.46-2.15bits/ind., J=0.45-0.71 y D=2.08-3.92. La variación temporal de la abundancia y diversidad fue de 0.026-0.066ind./m²; 0.342-0.764g/m² y 6.49-22.98g/ind. Hn=1.76-2.08; J=0.52-0.64 y D=3.07-4.18. Se identificaron 11 especies dominantes, que representan el 94.39% en número de individuos y 89.66% en peso de la captura total. El análisis cluster permite identificar cuatro grupos de especies que se asocian a las distintas condiciones de hábitat de la reserva. El análisis de correspondencia canónica destaca la asociación de H. plumierii con la salinidad y los sólidos disueltos. La RBLP cuenta con una alta diversidad de hábitats y la comunidad de peces ha desarrollado estrategias para aprovechar todas las condiciones espaciales y temporales y así satisfacer sus necesidades en el desarrollo de sus ciclos de vida.

Assuntos

RESUMO

Efforts to halt freshwater ecosystem degradation in central Mexico can benefit from using bio-monitoring tools that reflect the condition of their biotic integrity. We analyzed the applicability of two fish-based indices of biotic integrity using data from lotic and lentic systems in the Angulo River subbasin (Lerma-Chapala basin). Both independent data from our own collections during two consecutive years, and existing information detailing the ecological attributes of each species, were used to calculate indices of biological integrity for 16 sites in lotic and lentic habitats. We assessed environmental quality by combining independent evaluations water and habitat quality for each site. We found sites with poor, regular and good biotic integrity. Our study did not find sites with good environmental quality. Fish-based IBI scores were strongly and significantly correlated with scores from independent environmental assessment techniques. IBI scores were adequate at representing environmental conditions in most study sites. These results expand the area where a lotic system fish-based IBI can be used, and constitute an initial validation of a lentic system fish-based IBI. Our results suggest that these bio-monitoring tools can be used in future conservation efforts in freshwater ecosystems in the Middle Lerma Basin.

Las acciones para detener el deterioro de los ecosistemas dulceacuícolas del centro del México requieren herramientas de biomonitoreo que permitan el análisis de su integridad biológica. En este trabajo se analizó la viabilidad del uso de dos índices biológicos de integridad (IBI) con base en las comunidades de peces en ambientes lóticos y lénticos en la subcuenca del Río Angulo (Cuenca del Lerma-Chapala). Utilizando datos provenientes de recolectas independientes durante dos años consecutivos e información sobre los atributos ecológicos para cada una de las especies, se calcularon los valores de dos IBI en 16 sistemas lénticos y lóticos. Se estimó también la calidad ambiental a través de la evaluación de la calidad del agua y del hábitat en cada sitio. Se encontró integridad biótica pobre, regular y buena. El estudio no mostró sitios con buena calidad ambiental. Los valores de los IBI presentaron correlaciones altas y significativas con aquellos derivados de metodologías independientes de evaluación ambiental. Los IBI reflejaron de forma fehaciente las condiciones ambientales en la mayoría de los sitios de estudio. Con este análisis se logró la expansión de área de uso del IBI para ambientes lóticos y una validación inicial del IBI para ambientes lénticos. Estos resultados sugieren que las herramientas pueden ser utilizadas en futuros esfuerzos de conservación en cuerpos dulceacuícolas en la cuenca del Medio Lerma.

Assuntos