Estuary

Aquatic coastal systems are affected by high fluctuations in salinity and the zooplankton may rely on dispersal or dormancy to recolonise these environments. Here, we analysed the long-term dynamics of the zooplankton community over 6 years during large salinity fluctuations in a coastal lagoon (Garças Lagoon, Brazil) and the effect of salinity on the hatching patterns of the resting egg bank. We hypothesised that salinity is the main driving factor of the zooplankton community structure, and that increases in salinity reduce the species richness and the abundance of hatchlings. Multiple regression analysis showed that salinity was associated negatively with species richness in the open water, whereas total phosphorus and chlorophyll-a concentrations were negatively and positively related to abundance respectively. Redundancy analysis demonstrated that temporally structured environmental variables (total phosphorus and salinity) were important for zooplankton composition. Periods of...

This study investigated the behaviour of Pomacea bridgesii, describing the daily activity, substrate selection and the influence of the flood regime in the Amazon, the species’ native habitat. The present study described the daily activity and substrate selection, and evaluated the activity adaptations of the gastropods in a simulated flood-pulse regime. Gastropods were collected in Amazonas, Brazil, in June 2013. Assessments of the daily behaviour, substrate selection, and flood-pulse simulation were made in experimental water tanks. The snails were observed hourly for 48h, and their behaviour recorded on an ethogram. The snails were more active during the night, when up to 80% of them moved about. In general, during both day and night, the gastropods used the pebble substrate most often. Comparing the day periods, a significant proportion of the individuals that were using the pebbles moved to other substrates (t=5; d.f.=2; P=0.03). The interaction of the behaviour of P. bridgesii...

Identifying the respective role of environmental, landscape and management factors in explaining the patterns in community composition is an important goal in ecology. Using a set of 32 temporary ponds in northern Morocco we studied the respective importance of local (within the pond) and regional (density of ponds in landscape) factors and the impacts of different land uses on the plant species assemblages, separating pond and terrestrial species. The main hypotheses tested were that (1) species assemblages respond to both local and regional environmental factors, (2) anthropogenic pressure has a negative influence on the number of pond species, and that (3) human activities differ in their impact on pond biodiversity. The results showed that (1) local factors explain most of the variation in plant community composition, and (2) land use impacts the communities through changing local environmental conditions, leading to a loss of typical pond species. Aside from recreation, all oth...

Parasites constitute the majority of coral reef animal diversity and are believed to contribute significantly to host, community and trophic dynamics. Anilocra spp. are large conspicuous ectoparasitic isopods, making them ideal models for host–parasite studies. In the tropical western Atlantic and Caribbean, Anilocra haemuli infects the ecologically important French grunt (Haemulon flavolineatum). French grunt are trophic connectors between reef and seagrass environments, and how A. haemuli infection influences connectivity is unknown. As a first step in understanding the French grunt–A. haemuli association, we conducted reef surveys during three consecutive years to quantify the abundance and prevalence of infected fish on reef sites in the north-eastern Caribbean. We examined their correlations with fish population and aggregation size, and social affiliation. Annual infected fish abundance and prevalence per site ranged from 0–24 fish and 0–66%. Prevalence: (1) appeared autocorre...

Resource limitation controls the base of food webs in many aquatic ecosystems. In coastal ecosystems, nitrogen (N) has been found to be the predominant limiting factor for primary producers. Due to the important role nitrogen plays in determining ecosystem function, understanding the processes that modulate its availability is critical. Shallow-water estuarine systems are highly heterogeneous. In temperate estuaries, multiple habitat types can exist in close proximity to one another, their distribution controlled primarily by physical energy, tidal elevation and geomorphology. Distinctions between these habitats such as rates of primary productivity and sediment characteristics likely affect material processing. We used membrane inlet mass spectrometry to measure changes in N 2 flux (referred to here as denitrification) in multiple shallow-water estuarine habitats through an annual cycle. We found significantly higher rates of denitrification (DNF) in structured habitats such as sub...

The analysis of age structure of fisher women showed that 35-55 years age groups are mainly engaged in various
fishery related activities (50%) in average of total population. The average family size is 6, and 51.5% being the illiterate
group. About 15% of the population are migrant having immigration from Bangladesh. Undernutrition and malnutrition
are quite prevalent among the fisherwomen. The fisher women earn more than fifty percent (58%) of their livelihood
from fisheries and related activities. Mass media exposure and extension contact of the fisher women both in freshwater
and marine stretch was very low. Most of the fisherwomen perceive (81%) that lack of credit facilities from the Banks,
Co-operatives etc is the major constraint. In most of the cases fisherwomen are not aware of the facilities offered by the
State and Central Governments. Launching of mass literacy campaigns particularly for fisherwomen are much needed.
Formation of SHGs, Mahila Mandal to upgrade their knowledge and skill is suggested.

Trends of annual sea level records of four tidal observatories of the Hugli estuary—Sagar, Gangra, Haldia, and Diamond Harbour—are analysed from the records of Permanent Service for Mean Sea Level (PSMSL). The rates of sea level changes for the stations are found to be –3.82, +0.89, +2.43 and +4.85 mm yr^–1 respectively, connoting a significant positive relation between landward distances of the stations and the rates of sea level rise. This seems to be mainly controlled by disequilibrium in the morphological state of the landward-narrowing estuary with some contribution from sediment autocompaction. Sea level trends of the Hugli have no apparent relation with erosion and accretion of its tidal islands.

Estuaria merupakan wilayah pesisir semi tertutup yang mempunyai hubungan bebas dengan laut terbuka dan menerima masukan air tawar dari daratan. Sebagian besar estuaria didominasi oleh substrat berlumpur yang merupakan endapan yang dibawa oleh air tawar dan air laut. Daerah perairan yang termasuk dalam estuaria ini adalah muara sungai, teluk dan rawa pasang surut. Estuaria daratan pesisir merupakan tipe estuaria yang paling umum dijumpai (Kamal, 2004)

The Barren Measures Formation (middle Permian, ~271e260 Ma), the non-coaliferous lithounit sandwitched
between two major coal-bearing formations in the Indian Lower Gondwana succession, was
earlier interpreted as continental fluvio-lacustrine deposits. The present contribution documents sedimentary
attributes of marginal marine tideewave interference from the Barren Measures Formation of
eastern peninsular India, exposed along the Bokaro River section, West Bokaro Coalfield, Jharkhand.
Tidalites, including various tidal bundle sequences with frequent reactivation surfaces (velocity asymmetry)
and single/double mud drapes (pause planes), systematic arrangement of tidal beddings (flaser,
wavy, lenticular) and tidal rhythmites with alternate sand-dominated and mud-dominated planelaminated
units, manifest sedimentation by open marine springeneapespring tidal cycles under diurnal
inequalities in a semi-diurnal tidal system. The architecture of tidalites attests to sedimentation in
shallow subtidal to intertidal flat facies, affected by intermittent strong to week reworking by open
marine waves/storms. Wave reworking is manifested by wave ripples, combined-flow ripples and wavegenerated
tidal bundles. Their coexistence and gradation with tidalites indicate low-energy wave/storm
interference with tidal currents in a sheltered, tide-dominated estuary, especially on tidal flats along
estuary channel banks. Overall fining-up facies sequence, upward increase of prodeltaic mud over tide
ewave led sediments, signify a sustained transgressive phase onlaping the estuary system in eastern
peninsular India during middle Permian (Guadalupian).

Plankton plays an important role in a body of water as the primary producers and the beginning of the chain in the food web (food chain) causes the plankton used as a measure of fertility an ecosystem scale. This study aims to analyze the diversity and community structure of plankton in order to describe the condition of waters in the estuary Perancak, Bali.. This research was conducted by field surveys in September 2015 (transitional season II), consisting of three location , namely data collection Loloan River (north), Dermaga Perancak (middle) and Muara Perancak (south). Based on the results, both plankton abundance of phytoplankton and zooplankton ranged between 300-20100 ind/m3 and 300-28500 ind/m3. An abundance of plankton in the Estuary Perancak influenced by the water quality, especially the concentration of nutrients (phosphate, silicate and nitrate). Ecological index showed that species diversity of phytoplankton in the Estuary Perancak was categorized as low diversity (0,98≤H'≤ 1.38) and no species of phytoplankton dominating (0,55≤E≤0,77) with uniformity kind of approaching a stable and tend evenly (0,32≤ D≤0,48). While the index showed that diverisity index of zooplankton is low (1,06≤H'≤1,29), with the distribution species are fairly uniform and relatively similar (0,54≤E≤1), and dominant species is not present (0,33≤D≤0,51). These results indicate that Perancak Estuary is moderate levels of water pollution. It is known from the low diversity index of phytoplankton and zooplankton in the waters of  Perancak Estuary.
Keywords: plankton community structure, Perancak Estuary, abundance, diversity, dominance index.

Pada saat muson tenggara perairan selatan Jawa, Bali dan Nusa Tenggara mengalami upwelling yang berpengaruh ke perairan selat Bali disebut sebagai in-direct upwelling. Pengaruh upwelling ini bisa dilihat dari perubahan parameter fisika, kimia dan biologi perairan seperti suhu, klorofil-a dan nutrien. Penelitian ini bertujuan untuk mengetahui pengaruh terjadinya upwelling terhadap distribusi suhu, klorofil-a dan nutrien terutama nitrat,
fosfat, dan silika di Selat Bali dari hasil observasi bulan Juni-September 2012. Lokasi penelitian di koordinat 8,4 LS – 8,85 LS dan 114,40 BT – 115,5 BT. Metode yang digunakan adalah observasi lapangan saat terjadinya upwelling. Pengukuran parameter suhu dan klorofil-a menggunakan Conductivity Temperature Depth (CTD). Sampel nutrien
diambil tiap layer kedalaman dari permukaan sampai 100 m dibagi menjadi 3 zona mewakili karaketristik perairan utara (Laut Bali), tengah (Selat Bali) dan selatan (Samudera Hindia). Hasil penelitian menunjukkan terjadi peningkatan konsentrasi nutrien yang terlihat dari peningkatan konsentrasi nitrat, fosfat, silikat dan klorofil-a serta penurunan suhu. Konsentrasi klorofil-a maksimum di kedalaman 20 m zona selatan yang berhubungan langsung dengan Samudera Hindia dan terjadi kenaikan massa air dingin dikedalaman 70 m serta peningkatan konsentrasi fosfat di kedalaman 60 m, hal ini memperkuat bahwa pada bulan Juni-September perairan selat Bali mendapatkan pengaruh upwelling kuat dari Samudera Hindia.
Kata kunci : in-direct upwelling, suhu, klorofil-a, nutrien

Antonio Pantojas revela la historia de una geografía en San Juan hasta ahora poco explorada, la del transformismo. El término significa aquí el trabajo de hombres o mujeres que deciden cruzar las fronteras de las vestimentas relacionadas a su género para ofrecer espectáculos artísticos en lugares como barras, salones y discotecas.

El actor y transformista puertorriqueño forma parte de una generación que durante la década de los setenta articuló circuitos homoeróticos en San Juan bien definidos y con unos ejes urbanos distintivos. Nuestros principales ejes urbanos gay son el Viejo San Juan, Santurce, el Condado y Río Piedras, todos unidos por las principales vías de tránsito sanjuaneras y hogar de múltiples complejos de edificios multipisos, donde es posible mantener cierto anonimato. En la posguerra y los cincuenta todavía ese circuito era oculto, en los sesenta se comienza a formar, con la apertura de barras transformistas en el Viejo San Juan, y a finales de los noventa era ya visible y presente, con manifestaciones como la Parada de orgullo LGBTT.

La cultura gay de Puerto Rico se desarrolla paralela con la puesta en marcha del discurso de modernización del país. Esto, pesar de tener un movimiento conservador y fundamentalista organizado en su contra. El tránsito masivo de puertorriqueños desde y hacia las grandes ciudades de Estados Unidos formó una parte clave del proceso. Muchas de las personas que influenciaron a Pantojas, desde Myrta Silva, compositora y artista que tenía programas televisivos de farándula en Nueva York y San Juan, hasta el dramaturgo Pablo Cabrera, que fue profesor del Hostos Community College de CUNY, mantenían lazos estrechos con Nueva York y otras ciudades estadounidenses.

... phytoplankton and zooplankton have been established in estuarine systems ([Sautour et al., 1996], [Perissinotto et al., 2000] and [Tan et al ... Maximum number of microzooplankton species (seven) observed was at stations 1 and 6 only, but species like Tintinnidium incertum and ...

... Perillo, GME, 1995. Definitions and geomorphologic classifications of estuaries. In: Perillo, GME (Ed.), Geomorphology and Sedimentology of Estuaries. Developments in Sedimentology, 53. ... De. Galaxia Vigo. pp. 237–250. Varela, M., Prego, R., Canle, M. and Lorenzo, J., 1994. ...

The freshwater fish, Rhadinocentrus ornatus Regan, 1914, has a patchy distribution through coastal drainages of Queensland and New South Wales, eastern Australia. Isolated populations of R. ornatus are found on several islands, as well as in a disjunct northern population 350 km from its nearest conspecific population. Deoxyribonucleic acid was extracted and sequenced for the mitochondrial ATPase gene to describe the geographic and genetic subdivision within the species. Four major clades were identified. These clades diverged between two and seven million years ago and so represent long-term divisions and possible units of conservation. There are conservation implications in that the narrow and localised distribution of R. ornatus overlaps with an area of large-scale land clearing, high human population and threats from introduced exotic fish. A particularly high centre of Rhadinocentrus diversity in the Tin Can Bay area of Queensland presents some interesting questions about the e...

Systematic study of charts, maps and satellite images pertaining to 1967-68, 1975, 1992, 1997, 2000, 2003, 2006, 2009 and 2012, indicate that the Balari Bar steadily increased, choking up the northern portion of the Haldia Channel, on the west of the Hugli Estuary. Its rapid growth, from 0.29 km^2 in 1997 to 3.83 km^2 in 2012, started to threaten the Haldia Dock Complex (HDC). Eight superimposed profiles across the 15 km Balari Reach of the estuary show gradual deterioration of the western Haldia Channel and the improvement of the eastern Rangafalla Channel resulting in the concentration of the tidal flows in the latter. The decrease in the overall capacity of the reach has been 8.13% from 2000 to 2012. The result of this is reflected on the performance of the HDC as some of its share of cargo is diverted to the other sea ports in the vicinity.

In this study we investigate for the first time the zooplankton assemblages in a relatively small tidal channel called Bahía del Medio, situated in the middle-outer area of the Bahía Blanca Estuary, South of the Main channel. We focused the study on micro- and mesozooplankton assemblages with emphasis on tintinnids, copepods and meroplankton along the annual cycle 1997-1998. Fifteen species of tintinnids belonging to 6 genera were observed in the study area, the mean total tintinnid abundance fluctuating between 3.4 x 106 ind. m-3 and 5.1 x 106 ind m-3. The mesozooplankton comprised 11 taxa, total abundance fluctuating between 449 ind m-3 in March 1997 and only 1 ind m-3 in October 1997. The channel proved to be spatially homogeneous in its physical and biochemical features. Micro- and mesozooplankton abundance displayed a high degree of spatial homogeneity, though the seasonal variation in both environment and zooplankton was significant. Comparison with the zooplankton observed at a station in the Main channel of the estuary showed differences in number of taxa represented, a general lower abundance of both assemblages and the presence of some rare species, a fact which is discussed.

Most of the estuarine and ocean bottoms are covered with sediments making this the largest habitat on our planet. Grain size data of the estuarine sediments are of great importance in differentiating various depositional microenvironments and also useful for assessing the textural characteristics of the habitat in benthic ecological studies. Here we use grain size analysis of the intertidal surface sediments along the Brunei estuary (Borneo, South East Asia) and the result reveals the dominance of sand fractions, and the percentage of dominance follows the order of sand > clay > silt. The sand size fraction was higher at seaward stations, which were poor in organic matter (<4 %), in contrast to the low-energy landward stations, which comprised a higher proportion of fine-grained (clay and silt) sediments and were rich in organic matter (> 5%). This pattern suggests that the intertidal sediments of the estuary derive from a mixed origin, including continental/marine and terrestrial sources, which vary in degree along the estuarine gradient in relation to hydrodynamic wave/current energy (generally low to high in a seaward direction along the estuary). There was strong negative correlation between the sand fraction and the other sediment variables (silt, clay and organic matter), whereas a positive correlation was observed between organic matter and silt/clay. Univariate (ANOVA) and multivariate (PCA) techniques clearly showed significant spatial differences in the sediment variables among the stations investigated, confirming differential energy conditions at different locations. Cluster analysis and PCA helped to discriminate the station groups along the estuary according to their sediment textural properties. This study also revealed that sediment grain size is a key factor influencing the organic matter accumulation in surface sediments. The organic matter observed in different stations is quite in agreement with the widely accepted view of other researchers from the tropical region that fine grained sediments generally have higher amounts of organic matter than the coarse grained one. The high organic matter at landward stations was found to reflect natural (mangroves) and anthropogenic (pollution) organic input.