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Riparian ecotones and spatial variation of fish assemblages in Portuguese lowland streams

Collares-Pereira, M.J.; Geraldes, Ana Maria; Magalhães, M.F.; Coelho, M.M.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
45.99%
The first results of a long-term study on the role of riparian ecotones on the population and community dynamics of Iberian stream fish are presented and discussed . Riparian and macrophyte cover, bank slope and depth were among the most important variables affecting fish distribution . In general small fish favoured shallow areas with high macrophyte cover, whereas large fish dominated in deep areas with a high riparian cover . Slight spatial changes in terrestrial prey use were found suggesting a minor role for this resource during autumn . Finally, no significant spatial differences were found for linear growth, although some differences were obtained for the condition factor

Larval fish distribution in shallow coastal waters off North Western Iberia (NE Atlantic)

Azeiteiro, Ulisses Miranda; Bacelar-Nicolau, Leonor; Resende, Paula; Gonçalves, Fernando; Pereira, Mário Jorge
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Artigo de Revista Científica Formato: aplication/PDF
ENG
Relevância na Pesquisa
46.08%
Monthly sampling for ichthyoplankton was conducted at three stations very near to the coast (near to shore shallow stations before the surf zone in direction to the shoreline) of Atlantic northwestern Portugal within contrasting localities: rocky shore, in front of a sandy beach receiving an estuary and a fishing port with heavy anthropogenic impact. Sampling was conducted from August 2002 to October 2003, always at full moon, at low tide and high tide in daylight hours, at the water column using a 48 cm diameter plankton net with 335 [mu]m mesh. Analysis of the physico-chemical parameters pointed out the spatial (horizontal) homogeneity of the sampling area. Fish larvae from 41 taxa belonging to 17 families were identified; Blenniidae, Labridae, Ammodytidae, Clupeidae, Gobiidae, Soleidae and Gobiesocidae were the most representative during the study period. Parablennius gattorugine, Ammodytes tobianus, Symphodus melops, Sardina pilchardus, Lipophrys pholis and Coryphoblennius galerita were the most representative species (percentage contribution to total abundance). Peak abundance of fish eggs occurred during May, June and August 2003 and fish larvae occurred during May and July 2003 and August 2002 and 2003; there was a pronounced winter/early spring (March 2003) peak in larval abundance dominated by the small sandeel A. tobianus. This study identifies the occurrence of a conspicuous assemblage of larval fishes at very nearshore shallow environments of a variety of species with different adult habitats: the fish larvae assemblage was dominated by intertidal species. The present study has shown that temporal and spatial variations in the larval fish assemblage are related to environmental conditions and biological dynamics: the results suggest that abiotic conditions mediate biotic parameters...

Estudos sobre Variabilidade de Amostragem, Distribui-cao e Abundancia de Larvas de Peixes da Regiao Sudes-te do Brasil; Study on sampling variability, distribution and abundance of fish larvae off the Southeastern Coast of Brazil

Katsuragawa, Mario
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 17/04/1985 PT
Relevância na Pesquisa
36.22%
Utilizando-se materiais coletados durante qua-tro cruzeiros oceanográficos com o N/Oc ."Prof. W. Besnard", na região Sudeste do Brasil, compreendida entre Cabo Frio (RJ) e Florianópolis (SC), de janeiro de 1980 a março de 1982, foram realizados estudos quali quantitativos so-bre ocorrências de larvas de peixes, relacionando-as com fatores abióticos. Problemas concernentes aos processos de amostragem tambem foram verificadas. Realizaram-se dois tipos de arrastos: arrasto oblíquo com a rede Bongo usando-se malhagens de 0,333 mm (fina) e de 0,505 mm (regular), e arrasto horizontal de superfície com a rede de Neuston, de 0,333 mm de malhagem. Em cada estação oceanográfica, alem das amostras biologicas, efetuaram-se as medições de temperatura e coleta de água para determinação de salinidade. Um total de 35.090 larvas foram analisadas, incluíndo as coletas das redes fina e regular da Bongo e a rede de Neuston. Dentre estas, 61 grupos diferentes foram separados, chegando a níveis específicos em alguns casos.- Dois gêneros e quatro especies foram identificados pela primeira vez na região: Saurida spp, Hygophum spp, Trachinocephalus myops, Synodus foetens Bregmaceros can-tori e Maurolicus muelleri. As famílias predominantes foram Clupeidae...

Environmental influences on fish assemblage distribution of an estuarine coastal lagoon, Ria de Aveiro (Portugal)

Pombo, L.; Elliott, M.; Rebelo, J. E.
Fonte: Consejo Superior de Investigaciones Científicas Publicador: Consejo Superior de Investigaciones Científicas
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.23%
Fish assemblage was examined for patterns in spatial and seasonal structure within an estuarine coastal lagoon, Ria de Aveiro. Two years of variation in abiotic conditions were recorded to identify factors responsible for maintaining the structure of fish assemblages. Nine sites were sampled monthly with a traditional “chincha” beach-seine net between November 1998 and October 2000. Fish abundance and biomass changed significantly between sites. Temperature was found to be the most important abiotic factor affecting the abundance (number of fish) distribution of fish assemblage, which is more related to seasonal migrations than to spatial migrations. Salinity was the most important abiotic factor affecting the fish biomass, with temperature also having a major influence. The other abiotic parameters analysed also showed some influence on the distribution of fish, although, isolated from the other controlled and/or uncontrolled factors, they could not fully explain all the differences between assemblages. Feeding analysis indicates that fish assemblage is mostly dependent on small benthic and pelagic crustaceans and/or detritus, although they can feed opportunistically on other prey. The low spatial segregation of fish in relation to feeding preference indicates that...

Fish-based groups for ecological assessment in rivers: the importance of environmental drivers on taxonomic and functional traits of fish Assemblages

Matono, Paula; Bernardo, João Manuel; Ferreira, Maria Teresa; Formigo, Nuno; Raposo Almeida, Pedro; Ilhéu, Maria
Fonte: Knowledge and Management of Aquatic Ecosystems Publicador: Knowledge and Management of Aquatic Ecosystems
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.16%
The use of river-types is of practical value, serving as groups for which assessment procedures can be developed and applied. An abiotic typology was set by the Portuguese Water Agency, mainly based on 6 major morphoclimatic regions. However, to be biologically meaningful, this typology should fit the distribution patterns of the biological quality elements communities proposed in Water Framework Directive under the lowest possible human pressure. This study aimed to identify and characterize fish-based geographical groups for continental Portugal and their environmental and geographical discriptors, using taxonomic and functional traits. Sampling took place between 2004 and 2006 during Spring. Fish fauna from 155 reference sites was analysed using a multivariate approach. Cluster Analysis on fish composition identified 10 fish-groups, expressing a clear correspondence to the river basin level, due to the restrict basin distribution of many species. Groups showed a wider aggregation in 4 regions with a larger geographical correspondence, statistically supported by Similarity Analysis, both on fish composition and mostly on fish metrics/guilds. Principal Components Analysis revealed major environmental drivers associated to fish-groups and fish-regions. Fish-groups were hierarchically grouped over major and local regions...

Fish distribution and abundance in mediterranean streams:the role of habitat quality, spatial context, and movement patterns

Pires, Daniel Filipe Carvalho Miranda, 1977-
Fonte: Universidade de Lisboa Publicador: Universidade de Lisboa
Tipo: Tese de Doutorado
Publicado em //2012 ENG
Relevância na Pesquisa
46.22%
Tese de doutoramento, Biologia (Ecologia), Universidade de Lisboa, Faculdade de Ciências, 2012; Patterns of fish distribution and abundance in streams are currently thought of as a product of multi-scale factors. Local habitats, spatial relationships and movement are increasingly emerging as drivers of population and assemblage dynamics, though the way in which these factors may interplay remains poorly addressed, particularly in temporary streams. This dissertation addressed the role of multiple environmental and spatial factors and movement on patterns of fish distribution and abundance in dry and wet-season habitats in seasonally-drying mediterranean streams, at the segment scale. Overall, we found that assemblage structure of fish was more consistently associated with local habitat characteristics than spatial context. Specifically, species richness in dry-season pools was primarily associated with pool morphology, whereas abundance was mostly determined by physicochemical factors. During the wet-season, species richness, abundance and occurrence was consistently associated with habitat quality, whereas connectivity to dryseason refugia and neighbouring effects were episodically important. There was considerable variation in fish–habitat relationships among species and size classes...

Early life stages of fish and the relationships with zooplankton in a tropical Brazilian reservoir: Lake Monte Alegre

MESCHIATTI,A. J.; ARCIFA,M. S.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2002 EN
Relevância na Pesquisa
45.99%
For evaluating the trophic relationship between early life stages of fish and zooplankton in Lake Monte Alegre, fish distribution and feeding habits have been studied in areas with and without macrophytes. In the first of these areas, 356 specimens belonging to 8 species, mostly juveniles, were caught by a sieve. Another 35 specimens, belonging to 4 species, were caught by gill nets and seine in areas lacking macrophytes. Their diets were composed of aquatic insects, microcrustaceans, rotifers, detritus, and other aquatic invertebrates. Microcrustacean prey were mainly littoral or benthic dwellers, found in the highest proportion in specimens of 7-20 mm SL. Most fish species have parental care, which could explain the absence of planktonic larvae. Early life stages of fish do not exert a predation pressure on the lake zooplankton.

Distribution pattern of two fish species in a coastal stream in Southeast Brazil

MAZZONI,R.; IGLESIAS-RIOS,R.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2002 EN
Relevância na Pesquisa
45.98%
Longitudinal distribution of Mimagoniates microlepis and Hoplias malabaricus was analyzed in a coastal stream system in Southeast Brazil. Six sites were sampled by electrofishing in seven months, from July 94 to July 95. Densities of M. microlepis, and H. malabaricus and its prey (Poecilia vivipara, Deuterodon sp. and Astyanax janeiroensis) were estimated by the Zippin method; environmental variables of: (i) kind of substratum; (ii) percentage of pools, runs, riffles, instream vegetation, and canopy were registered for each site in each sampling month. The relative importance of each biotic and abiotic variable was tested through simple correlation analyses. We verified that M. microlepis occurrence correlates with canopy; H. malabaricus is correlated with instream vegetation, pools, clay substratum, and P. vivipara densities; and P. vivipara correlates with pools and clay substratum. Our results suggest that environmental variables, and food and shelter availability are the main factors in determining M. microlepis and H. malabaricus distribution.

Spatial and temporal distribution patterns of ichthyoplankton in a region affected by water regulation by dams

Gogola,Tatiane M; Daga,Vanessa S; Silva,Pedro R. L. da; Sanches,Paulo V; Gubiani,Éder A; Baumgartner,Gilmar; Delariva,Rosilene L
Fonte: Sociedade Brasileira de Ictiologia Publicador: Sociedade Brasileira de Ictiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 EN
Relevância na Pesquisa
46.08%
The aim of this work was to study the occurrence of ichthyoplankton in a region affected by water regulation by dams. The study area was located in the region of Ilha Grande National Park, upper Paraná River floodplain. Specifically, we examined the temporal and spatial distribution of Ichthyoplankton, identified spawning areas and established the relationships between the abundances of fish eggs and larvae and some limnological and hydrological variables. Samples were taken monthly between October and March from 2001 to 2005 at 24 sampling sites. For analytical purposes, the sampling sites were grouped into upper, middle and lower areas. The upper area of the National Park had the highest egg density and should be considered the primary spawning area. The middle area should be considered a drift area, and the lower area likely functions as a growth and feeding habitat. Statistical analyses showed that the spawning was influenced by water temperature, pH, fluviometric level and rainfall, and that larval density was influenced by pH, conductivity, dissolved oxygen and rainfall. The results also revealed that the tributaries apparently are used as migratory routes by fish, and and this shows the need to protect these sites.

Patterns of distribution and abundance of larval phosichthyidae (actinopterygii, stomiiformes) in southeastern Brazilian waters

Goçalo,Cássia Gôngora; Katsuragawa,Mario; Silveira,Ilson Carlos Almeida da
Fonte: Universidade de São Paulo, Instituto Oceanográfico Publicador: Universidade de São Paulo, Instituto Oceanográfico
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2011 EN
Relevância na Pesquisa
45.83%
Horizontal and vertical distribution patterns and abundance of larval phosichthyids were investigated from oblique and depth-stratified towns off Southeastern brazilian waters, from São Tomé cape (41ºW.; 22ºS.) to São Sebastião island (45ºW.; 24ºS.). The sampling was performed during two cruises (January/2002 -summer; August/2002 -winter). Overall 538 larvae of Phosichthyidae were collected during summer and 158 in the winter. Three species, Pollichthys mauli, Vinciguerria nimbaria and Ichthyioccoccus sp. occurred in the area, but Ichthyioccoccus sp. was extremely rare represented by only one specimen, caught in the oceanic region during the summer. Geographically, larval were concentrated in the oceanic region, and vertically distributed mainly between the surface and 80 m depth in the summer and winter. Larvae were more abundant during the night, performing a diel vertical migration in the water column. The results suggest that the meandering and eddies of Brazil Current play important role on the transport and distribution patterns of larval phosichthyids over the oceanic and neritic area in the Southeastern Brazil.

Fish abundance and distribution patterns related to environmental factors in a choked temperate coastal lagoon (Argentina)

Bruno,Daniel Osvaldo; Barbini,Santiago Aldo; Díaz de Astarloa,Juan Martín; Martos,Patricia
Fonte: Universidade de São Paulo, Instituto Oceanográfico Publicador: Universidade de São Paulo, Instituto Oceanográfico
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2013 EN
Relevância na Pesquisa
56.13%
The aim of this study was to assess the influence of environmental factors on the fish distribution and abundance in Mar Chiquita coastal lagoon. Seasonal fish sampling stations were distributed along the lagoon and grouped in three zones from a mixo-oligohaline waters zone with high contribution of freshwater to a mixo-eurihaline waters zone with high marine water influence. A mixo-mesohaline waters zone characterized the middle part of the lagoon. The results showed that the fish composition was dominated by marine estuarine dependent (ED) species in all three zones and in all seasons: Odontesthes argentinensis, Brevoortia aurea, Mugil liza and Micropogonias furnieri were the most representative species. The following important ecological category was freshwater fishes (FW), with Platanichthys platana and Jenynsia multidentata being the most representative species. According to the best model selected, by fitting generalized linear models, abundance of ED increased as water temperature increased during summer and autumn in all three zones. The highest abundance was recorded in the mixo-eurihaline waters zone. On the other hand, FW abundance increased with high rainfall and also when easterly winds blew. In conclusion, a differential habitat use by the species that occur in the Mar Chiquita coastal lagoon was observed. A few ED species dominated the fish composition but FW species also made use of the lagoon during periods of heavy rainfall.

Influence of local and landscape characteristics on the distribution and diversity of fish assemblages of streams in the Ivinhema River basin, Upper Paraná River

Lemke,Ana Paula; Súarez,Yzel Rondon
Fonte: Associação Brasileira de Limnologia Publicador: Associação Brasileira de Limnologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 EN
Relevância na Pesquisa
36.2%
OBJECTIVES: Among the most relevant issues in community ecology is the influence of different ways of addressing the pattern of diversity and distribution of species, and based on this, the present study sought to evaluate the influence of landscape and local characteristics on the richness and composition of fish assemblages in the Ivinhema River basin. METHOD: In the present study, we used data of distribution of fish species in 25 stretches of streams of the Ivinhema River basin, Upper Paraná River, aiming to know the role of local characteristics and land use on fish assemblages. RESULTS: We identified 113 fish species, and those sampled in a greater number of sites were: Astyanax altiparanae and Serrapinnus notomelas. The richness varied between 4 and 65 species. The regression tree allowed explaining 89.3% of richness variation, and permitted to identify that altitude is the main predictor of richness. According to the canonical correspondence analysis, variables that most influenced the species distribution were: altitude, depth, width, velocity, conductivity and percentage of built-up areas. CONCLUSIONS: Our results suggested that factors that most influenced fish assemblages in the Ivinhema River basin were physiographic and limnological characteristics...

The Relationship between the Distribution of Common Carp and Their Environmental DNA in a Small Lake

Eichmiller, Jessica J.; Bajer, Przemyslaw G.; Sorensen, Peter W.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 10/11/2014 EN
Relevância na Pesquisa
36.17%
Although environmental DNA (eDNA) has been used to infer the presence of rare aquatic species, many facets of this technique remain unresolved. In particular, the relationship between eDNA and fish distribution is not known. We examined the relationship between the distribution of fish and their eDNA (detection rate and concentration) in a lake. A quantitative PCR (qPCR) assay for a region within the cytochrome b gene of the common carp (Cyprinus carpio or ‘carp’), an ubiquitous invasive fish, was developed and used to measure eDNA in Lake Staring (MN, USA), in which both the density of carp and their distribution have been closely monitored for several years. Surface water, sub-surface water, and sediment were sampled from 22 locations in the lake, including areas frequently used by carp. In water, areas of high carp use had a higher rate of detection and concentration of eDNA, but there was no effect of fish use on sediment eDNA. The detection rate and concentration of eDNA in surface and sub-surface water were not significantly different (p≥0.5), indicating that eDNA did not accumulate in surface water. The detection rate followed the trend: high-use water > low-use water > sediment. The concentration of eDNA in sediment samples that were above the limit of detection were several orders of magnitude greater than water on a per mass basis...

Controls on fish distribution and abundance in temporary wetlands

Baber, Mathew J.; Childers, Daniel L.; Babbitt, Kimberly J.; Anderson, D. H.
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
46.08%
Our main goal was to determine if fish distribution and adundance in temporary wetlands were shaped primarily by large-scale (landscape) or small-scale (local) characteristics and to investigate the influence of cattle ranching on fish assemblages. A total of 24 temporary ponds were selected at the Kissimmee Prairie Sanctuary and the Mac- Arthur Agro-Ecology Research Center. Each wetland was sampled for fish using throw traps and dip nets during 1999. Landscape processes (connectivity to permanent water bodies) predominately influenced fish assemblages, although local processes (depth–hydroperiod) were also important. Furthermore, no colonizing species went locally extinct before wetlands began to dry. Our findings suggest that large-scale processes that influence colonization dynamics are of more importance than small-scale processes that influence extinction dynamics. Finally, hydrological changes (ditching) associated with agriculture (cattle ranching) have adversely affected temporary wetland fish assemblages by reducing wetland hydroperiods and connectivity.

Patterns of distribution and abundance of larval phosichthyidae (actinopterygii, stomiiformes) in southeastern Brazilian waters

GOÇALO, Cássia Gôngora; KATSURAGAWA, Mario; SILVEIRA, Ilson Carlos Almeida da
Fonte: Universidade de São Paulo, Instituto Oceanográfico Publicador: Universidade de São Paulo, Instituto Oceanográfico
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
45.83%
Horizontal and vertical distribution patterns and abundance of larval phosichthyids were investigated from oblique and depth-stratified towns off Southeastern brazilian waters, from São Tomé cape (41ºW.; 22ºS.) to São Sebastião island (45ºW.; 24ºS.). The sampling was performed during two cruises (January/2002 -summer; August/2002 -winter). Overall 538 larvae of Phosichthyidae were collected during summer and 158 in the winter. Three species, Pollichthys mauli, Vinciguerria nimbaria and Ichthyioccoccus sp. occurred in the area, but Ichthyioccoccus sp. was extremely rare represented by only one specimen, caught in the oceanic region during the summer. Geographically, larval were concentrated in the oceanic region, and vertically distributed mainly between the surface and 80 m depth in the summer and winter. Larvae were more abundant during the night, performing a diel vertical migration in the water column. The results suggest that the meandering and eddies of Brazil Current play important role on the transport and distribution patterns of larval phosichthyids over the oceanic and neritic area in the Southeastern Brazil.; Padrões de distribuição horizontal e vertical e abundância de larvas de peixes de Phosichthyidae foram examinados a partir de arrastos oblíquos e estratificados em águas do Sudeste Brasileiro...

Environmental influences on zooplankton and micronekton distribution in the Bransfield Strait and adjacent waters

Catalán, Ignacio Alberto; Morales-Nin, Beatriz; Company, Joan B.; Rotllant, Guiomar; Palomera, Isabel; Emelianov, Mikhail
Fonte: Springer Publicador: Springer
Tipo: Artículo Formato: 131118 bytes; application/pdf
ENG
Relevância na Pesquisa
46.16%
17 pages, 12 figures, 4 tables.-- Printed version published May 2008.-- Full-text version available Open Access at: http://www.icm.csic.es/files/oce/almacen/papers/AR-2008-02.pdf; The spatial distribution, biomass and size structure of key mesozooplankton species and micronekton in the Bransfield Strait (Antarctica) are described in relation to environmental variables during the austral summer 2001. Stratified (BIONESS) biological sampling at five depth-ranges and CTD casts were performed at 40 stations, including a cross-Strait transect. Six families, 11 genera and 16 species composed the total catch of larval and juvenile fish, which were more abundant in the upper 75 m. Trematomus scotti was the most abundant fish and large individuals dominated at depths >75 m. The fish distribution patterns were associated with the main water masses in the area and with bottom depth. Spatial segregation in density and biomass of krill (Euphausia superba) and salps (Salpa thompsoni) was observed at a relatively small scale, in relation to the main water masses. Also, size-related spatial segregation was found in krill. The present study suggests that the spatial distribution of krill, salps and early life stages of fish, are influenced by the main water masses in the Strait...

Patterns of distribution and abundance of larval phosichthyidae (actinopterygii, stomiiformes) in southeastern Brazilian waters

Goçalo, Cássia Gôngora; Katsuragawa, Mario; Silveira, Ilson Carlos Almeida da
Fonte: Universidade de São Paulo. Instituto Oceanográfico Publicador: Universidade de São Paulo. Instituto Oceanográfico
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 01/09/2011 ENG
Relevância na Pesquisa
45.83%
Horizontal and vertical distribution patterns and abundance of larval phosichthyids were investigated from oblique and depth-stratified towns off Southeastern brazilian waters, from São Tomé cape (41ºW.; 22ºS.) to São Sebastião island (45ºW.; 24ºS.). The sampling was performed during two cruises (January/2002 -summer; August/2002 -winter). Overall 538 larvae of Phosichthyidae were collected during summer and 158 in the winter. Three species, Pollichthys mauli, Vinciguerria nimbaria and Ichthyioccoccus sp. occurred in the area, but Ichthyioccoccus sp. was extremely rare represented by only one specimen, caught in the oceanic region during the summer. Geographically, larval were concentrated in the oceanic region, and vertically distributed mainly between the surface and 80 m depth in the summer and winter. Larvae were more abundant during the night, performing a diel vertical migration in the water column. The results suggest that the meandering and eddies of Brazil Current play important role on the transport and distribution patterns of larval phosichthyids over the oceanic and neritic area in the Southeastern Brazil.; Padrões de distribuição horizontal e vertical e abundância de larvas de peixes de Phosichthyidae foram examinados a partir de arrastos oblíquos e estratificados em águas do Sudeste Brasileiro...

Fish abundance and distribution patterns related to environmental factors in a choked temperate coastal lagoon (Argentina)

Bruno, Daniel Osvaldo; Barbini, Santiago Aldo; Díaz de Astarloa, Juan Martín; Martos, Patricia
Fonte: Universidade de São Paulo. Instituto Oceanográfico Publicador: Universidade de São Paulo. Instituto Oceanográfico
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 01/03/2013 ENG
Relevância na Pesquisa
56.13%
O objetivo deste estudo foi avaliar a influência de fatores ambientais sobre a distribuição e abundância de peixes na lagoa costeira Mar Chiquita. Estações sazonais de amostragem de peixes foram distribuídas ao longo da lagoa e agrupadas em três zonas de uma zona de águas Mixo-oligohalino com elevado aporte de água doce para uma zona de águas Mixo-eurihaline com alta influência da água do mar. Uma zona de águas Mixo-mesohalino caracteriza a parte do meio da lagoa. Os resultados mostraram que a composição dos peixes foi dominada por espécies marinhos estuarinos dependentes (ED) em todas as três zonas e em todas as estações: Odontesthes argentinensis, Brevoortia aurea, Mugil liza e Micropogonias furnieri foram as espécies mais representativas. A categoria seguinte mais importante foi peixes de água doce (FW), com Platanichthys platana e Jenynsia multidentata sendo as espécies mais representativas. De acordo com o melhor modelo selecionado pelo ajuste de modelos lineares generalizados, a abundância de ED aumentou de acordo com a temperatura da água durante o verão e outono, em todas as três zonas. A maior abundância foi registrada na zona de águas mixo-eurihalinas. Por outro lado, a abundância de FW aumentou com o aumento da pluviosidade e também quando os ventos de direção leste sopraram. Em conclusão...

Top Predator Distribution and Foraging Ecology in Florida Bay, Florida

Torres, Leigh Gabriela
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação Formato: 4905562 bytes; application/pdf
Publicado em 14/11/2007 EN_US
Relevância na Pesquisa
36.17%
The heterogeneous landscape of Florida Bay provides habitats for a variety of predators and prey. This dissertation examined the bottom-up transfer of affects from environmental variability through prey composition up to competition and predation affects on top predator distribution and foraging ecology in Florida Bay. Line transect surveys for bottlenose dolphins and seabirds were conducted in Florida Bay during the summer months of 2002 - 2005. Photo-identification techniques were implemented to identify individual dolphins. Synoptic with this survey effort, habitat characteristics (temperature, salinity, dissolved oxygen, turbidity, chlorophyll a, depth and bottom type) and prey composition (bottom trawl or gillnet) were sampled. Comparison of envelope maps from generalized additive models determined that predictive capacity of dolphin habitat did not improve by incorporating fish distribution data. However, models of dolphin distribution based solely on environmental proxies of fish distribution resulted in high predictive capacity. During the 2005 summer, shark distribution was sampled using a longline. The abundance of sharks was only correlated to fish catch from trawls on a regional scale. Larger sharks, of species that may threaten dolphins...

Distribution of fish in seagrass, mangroves and coral reefs: life-stage dependent habitat use in Honduras

Jaxion-Harm,Jessica; Saunders,James; Speight,Martin R
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2012 EN
Relevância na Pesquisa
46.16%
Many coral reef fish exhibit habitat partitioning throughout their lifetimes. Such patterns are evident in the Caribbean where research has been predominantly conducted in the Eastern region. This work addressed the paucity of data regarding Honduran reef fish distribution in three habitat types (seagrass, mangroves, and coral reefs), by surveying fish on the islands of Utila and Cayos Cochinos off the coast of Honduras (part of the Mesoamerican barrier reef). During July 2nd - Aug 27th 2007 and June 22nd - Aug 17th, 2008, visual surveys (SCUBA and snorkel) were performed in belt transects in different areas: eleven coral reef, six seagrass beds, and six mangroves sites. Juvenile densities and total habitat surface area were used to calculate nursery value of seagrass and mangroves. A total of 113 fish species from 32 families were found during underwater surveys. Multi-dimensional analyses revealed distinct clusters of fish communities in each habitat type by separating fish associated with seagrass beds, mangroves, and coral reefs. Coral reefs showed the highest mean fish species richness and were dominated by adult fish, while juvenile fish characterized seagrass beds and mangrove sites. Habitat use differed widely at the fish species level. Scarus iseri (Striped Parrotfish)...