Potential phenotypic plasticity within Simulium nigrimanum Macquart, 1838 (Diptera: Simuliidae) larvae

Black fly larvae (Diptera: Simuliidae) are suspension filter-feeders which strongly depend on water velocity for proper feeding. Black fly species feature different microhabitat preferences. Studies of Holarctic black fly larvae revealed their phenotypic plasticity in response to water current velocity variation, but such studies have been rarely undertaken with Neotropical black flies. The current work presents results on the phenotypic plasticity of the black fly species Simulium nigrimanum Macquart. Twelve last instar larvae, sampled from the Brazilian Cerrado, were photographed under a stereoscopic microscope and measured using the CMEIAS Image tool software. Linear regressions with water velocity as the independent variable were performed, indicating that while body size and anal disk diameter correlated positively with water velocity, labral fan length correlated negatively. The observed relationships between water velocity and labral fan length and anal disk diameter were consistent with the literature, while the pattern of body size variation partially corroborated previous studies. The present work results suggest that potential phenotypic plasticity can be observed in black fly larvae within one population distributed in different microhabitats of the same stream section, as opposed toprevious reports implying that such variation is only found among population from different streams.

Diatoms Flora from a Shallow Reservoir in Ivory Coast

The diatoms flora of Adzopé Reservoir in Côte d’Ivoire was investigated from January to December 2005. The species composition of the assemblage was compiled, accompanied by illustrations. Firty-one taxa were identified in the temporal survey. Five taxa (16.3%) were new for Côte d’Ivoire. Eleven common species, 9 occasional taxa and 11 rare taxa were also recorded. No spatial variations in the taxonomic composition of the populations of diatoms were found. Variations were encountered in the seasonal analysis. Variation in the dimensions of some identified taxa have been observed. The species richness of Diatoms in the Adzopé Reservoir was in relation with water current velocity.

Hydrodynamic characterization of a meso-tidal estuary: Inhambane Bay (Mozambique)

<p>This contribution analyze “in-situ” data obtained in the unexplored estuary of Inhambane Bay (Mozambique). Inhambane Bay is a bar-built estuary with a length of 30.5 km and an extension of 288 km<sup>2</sup>. Synchronous measurements of sea-level, temperature/salinity and water current velocity were obtained during two intensive field campaigns covering dry and wet climatological seasons. Additional Sea Surface Temperature (SST) obtained from GHRSST project were used to charcterize the estuary. The first results reveal a meso-tidal estuary with water currents of 1.0 m/s. The water velocity profiles show an homogeneous profile in the ADCP measurements. The hydrographic surveys and GHRSST product confirms a remarkable seasonal variability. The largest SST are observed from November to May, coinciding with the warm and rainy season. Salinity profiles are almost vertical and the variability follows the direction of the tidal phase (lower salinity values are observed during low tide). In consequence, the estuary is well-mixed with salinity increasing values downward the estuary. The flushing time is estimated between 1 -3 days in function of the neap/spring tide using the Tidal Prism method.</p><p>Acknowledgments:</p><p> ECOSISTEMA project (CTM2017-84275-R)</p>

KESESUAIAN LAHAN PANTAI UNTUK WISATA DAN BERENANG DI KABUPATEN LOMBOK TIMUR

East Lombok Regency has different beach variations from the north, middle, and south in terms of its constituentmaterial. The beauty of the beach in East Lombok District has not been well managed and developed so that it is lessdeveloped than the other beaches in Lombok Regency. Therefore, a preliminary study is needed in the developmentof coastal tourism in East Lombok Regency. The initial study that needs to be done is the land suitability of coastalfor tourism and swimming in East Lombok Regency. Parameters used for land suitabiliy coastal for swimmingconsist of 10 parameters, coastal typology, beach width, depth of water, bottom of water, current velocity, beachslope, water brightness, land cover, hazardous biota, the depth material of the waters, and availability of fresh water.Parameters for land suitability of coastal for tourism consisting of 8 parameters, the depth of the waters, the type ofbeach, the width of the beach, the depth material of the waters, current velocity, brightness of the waters, dangerousbiota and availability of freshwater. The land suitability class is divided into four classifications, namely highlysuitable (S1), moderately suitable (S2), marginally suitable (S3), and not suitable (N). The beaches studied areLabuan Haji, Pink, Gili Kondo, Gili Petagan, Gili Kapal, Surga, Rambang, Lampu, and Gili Bidara. The results of thestudy of coastal land suitability for tourism and swimming are expected to be the basis for the development ofcoastal tourism in East Lombok Regency. The results of land suitability for tourism in Labuan Haji Beach areincluded in S1, Rambang Beach S2, Pink Beach S1, Lampu Beach S1, Surga Beach S2, Gili Petagan S2, Gili Bidara S1,Gili Kapal S2, and Gili Kondo S1. The land suitability for swimming in Labuan Haji Beach includes S1, Rambang BeachN, Pink Beach S1, Lampu Beach S1, Surga Beach N, Gili Petagan S2, Gili Bidara S1, Gili Kapal S2, and Gili Kondo S1.

Spatial changes in zooplankton communities in a strong human-mediated river ecosystem

River damming causes a decrease in water current velocity which leads to an increase in richness and abundance of organisms atypical for running waters. Zooplankton is a representative example of such organisms. The influx of zooplankton from carp ponds is an additional factor that increases richness and abundance of zooplankton in rivers. We hypothesized that zooplankton dispersing from the carp ponds colonize the impoundments in river and the richness of zooplankton increase in impoundments by development of new species, not observed in the upstream. The zooplankton was collected monthly from April to September of 2013 and 2014. Sampling sites were located in the Barycz river (in the lotic sections and in the dam impoundments), as well as in its tributaries, which are the outlets of carp ponds. The most changes in zooplankton richness and abundance were observed at sites located within the dam impoundments, especially in relation to the lower values of the current velocity. Since the abundance of pelagic rotifers, cladocerans and copepods in the carp pond outlets was similar to that at lower sites in the Barycz, the influence of the carp pond outlets on the abundance in the dam and lotic sections was significant. The river itself in its impounded sections provides advantageous conditions for retention and colonization by a high abundance of zooplankton dispersing from the carp ponds, and for the development of species not occurred in the upstream, which, in turn, increases richness.

Modelling the factors influencing ontogenetic dietary shifts in stream-dwelling brown trout (Salmo trutta)

Biotic and abiotic variables shape ontogenetic trajectories of animals. This study modelled (i) the body length related timing of the ontogenetic switch from aquatic to surface prey and (ii) the impacts of habitat characteristics, prey availability, and fish densities on the relative contribution of surface prey to the overall diet of native brown trout (Salmo trutta). We used individual-based models of dietary data for 170 fish (length range 48–343 mm). There was a high degree of individual variation in the use of surface prey, but logistic regression suggested that the shift from aquatic to surface prey was established at a body length of 81 mm (range 36–127 mm). Results of linear mixed-effects models highlighted the importance of fish length, benthic invertebrates, brown trout density, and water current velocity to the switch to surface prey by riverine brown trout, with fish length being the most influential variable. Our study provides evidence of the importance of ontogeny (intrinsic features of individuals linked to fish length) and individual differences in feeding behaviour to understand water-column use for feeding by stream-dwelling salmonids.

THE PHYSICAL ENVIRONMENT IN CORAL REEFS OF THE TAYRONA NATIONAL NATURAL PARK (COLOMBIAN CARIBBEAN) IN RESPONSE TO SEASONAL UPWELLING

Coral reefs are subjected to physical changes in their surroundings including wind velocity, water temperature, and water currents that can affect ecological processes on different spatial and temporal scales. However, the dynamics of these physical variables in coral reef ecosystems are poorly understood. In this context, Tayrona National Natural Park (TNNP) in the Colombian Caribbean is an ideal study location because it contains coral reefs and is exposed to seasonal upwelling that strongly changes all key physical factors mentioned above. This study therefore investigated wind velocity and water temperature over two years, as well as water current velocity and direction for representative months of each season at a windand wave-exposed and a sheltered coral reef site in one exemplary bay of TNNP using meteorological data, temperature loggers, and an Acoustic Doppler Current Profiler (ADCP) in order to describe the spatiotemporal variations of the physical environment. Findings revealed that water temperatures (28.7 ± 0.8 °C and maximal 30.3 °C during non-upwelling; 25.1 ± 1.7 °C and minimal 20.3 °C during upwelling) exhibited no significant differences between sites and were negatively correlated with wind velocities (0.4 ± 0.3 m s-1 during non-upwelling and 1.8 ± 1.0 m s-1 with a maximum of 4.1 m s-1 during upwelling). Water current velocity was significantly higher at the exposed compared to the sheltered site during non-upwelling periods at a water depth of 8-10 m. During upwelling, water current velocities were also higher at the exposed site (6.4 cm s-1 exposed and 5.9 cm s-1 sheltered), but when wind speed surpassed 1.7 m s-1, no spatial differences occurred. Water currents showed a clockwise circulation during upwelling following the wind fields, but no clear circulation pattern during non-upwelling. Significant positive correlation between wind and water current velocity was detected at the sheltered, but not at the exposed site. Wind-stress at the exposed site affected water currents throughout the entire water column (at least 10 m deep) during both seasons, but reached only until 3-4 m water depth at the sheltered site during non-upwelling and down to 10 m during upwelling. Consequently, organisms at the exposed site experience constantly high water current exposure throughout the year. This may explain the pronounced site-specific reef community composition differences as water current velocity and circulation control distribution of invertebrate larvae and supply with plankton and essential nutrients.

A STUDY OF CHANNEL WATER CURRENT VELOCITY METER WITH HORIZONTAL AND VERTICAL AXIS PROPELLER TYPE

Current meter adalah salah satu alat ukur kecepatan air. Pada umumnya current meter yang ada di pasaran dibuat oleh pabrik-pabrik di luar negeri dan dalam negeri. Pada rancang bangun ini dibuat alat ukur kecepatan air di saluran dengan tipe propeller poros horisontal dan vertikal terbuat dari bahan resin yang diperkuat dengan bahan fiberglass, sensor putaran menggunakan read switch, pencatat putaran (counter) menggunakan panel meter dengan 7 segmen yang menampilkan 4 angka dan dilengkapi dengan pewaktu yaitu berupa timer switch dengan durasi maksimum 5 menit. Berdasarkan hasil yang didapat dengan penerapan berbagai bahan dan modul yang digunakan dalam rancang bangun ini dapat terintegrasi dengan baik. Current meter tipe propeller poros horisontal dapat beroperasi pada kisaran kecepatan 0,040 – 2,500 m/s dan tipe propeller poros vertikal dapat beroperasi pada kisaran kecepatan 0,100 – 1,250 m/s.