Evaluation of Melanotaenia duboulayi (Atheriniformes : Melanotaeniidae), Hypseleotris galii (Perciformes : Eleotridae), and larvicide Vectolex (R) WG (Bacillus sphaericus) for integrated control of Culex annulirostris

Australian freshwater fish species Melanotaenia duboulayi and Hypseleotris galii were selected for a small plot field evaluation of an integrated pest management strategy using native fish and VectoLex® WG (Bacillus sphaericus) for the control of Culex annulirostris Skuse, the principal freshwater vector of arbovirus Ross River virus in Australia. When tested alone, the level of control afforded by M. duboulayi and H. galii was highly dependent on the prerelease density of mosquito larvae; and even when stocking rates as high as 10 g per pond (>30 kg/ha) were used, larval abundance was too high to attain adequate control from fish alone. In contrast, treatment with VectoLex WG at 500 g/ha resulted in 100% mortality of Cx. annulirostris immatures, but no residual activity was evident. The delayed reduction of Cx. annulirostris immatures in ponds stocked with fish alone, and the recolonization by Cx. annulirostris in ponds after treatment with B. sphaericus, did not occur when both treatments were combined.

Recent developments on a nearshore, terrigenous-influenced reef: Low Isles Reef, Australia

Low Isles Reef is the most southerly located of 46 coral reef platforms unique to the inner shelf of the northern Great Barrier Reef Province, Australia, which support both sea grass and mangrove growth. Such reefs develop in areas that are influenced by river flood plumes and where interreef sediments are dominated by terrigenous mud. Low Isles Reef has long been a popular tourist destination. Informal reports of decreasing visibility, a decline in scleractinian corals, and increases in soft coral and macroalgae have sparked speculation that agricultural activities in coastal catchments are affecting the reef. Comparison of the modern surface of Low Isles Reef with historical surveys and photographs dating back to 1928 allows quantification of modern sedimentary processes, rates of change, and factors influencing reef development. Results indicate that changes on Low Isles Reef are related to remobilization of coarse sediment during storm events and gradual shoreline retreat associated with rising sea level. Retreat of shingle ramparts and elongate ridges of coral debris toward the reef interior has led to the infilling of subtidal ponds on the reef top, which supported hard coral colonies in 1928. The gradual development of a composite shingle rampart along the windward margin has promoted an increase (;150%) in the area of the reef top covered by mangroves. On the leeward margin, a decrease in hard corals since 1950 may reflect a rising contribution of organic debris from the expanding mangrove swamp. Results suggest that recent changes on Low Isles Reef can be explained in the context of natural processes. Further study is needed before the effects of agricultural activities in coastal catchments on reef health can be confirmed.

Aquatic invertebrates in final void water bodies at an open-cut coal mine in central Queensland

We describe the diversity of aquatic invertebrates colonising water-filled final voids produced by an open-cut coal mine near Moura, central Queensland. Ten disused pits that had been filled with water from < 1 year to 22 years prior to the survey and three nearby 'natural' water bodies were sampled in December 1998 and again in March 1999. All invertebrates collected were identified to family with the exception of oligochaetes, cladocerans, ostracods and copepods, which were identified to these coarser taxonomic levels. Sixty-two taxa were recorded from > 20 000 individuals. The greatest familial richness was displayed by the Insecta (33 families) followed by the mites (Acari) with 12 families. While natural water bodies held the greatest diversity, several mine pits were almost as rich in families. Classification analyses showed that natural sites tended to cluster together, but the groupings did not clearly exclude pit sites. Mining pits that supported higher diversity tended to be older and had lower salinity (< 2000 mu S/cm); however, salinity in all water bodies varied with rainfall conditions. We conclude that ponds formed in final voids at this mine have the potential to provide habitat for many invertebrate taxa typical of lentic inland water bodies in central Queensland.

Treefrogs in Forested Swamps at the La Selva Biological Station: Assemblage Variation through Space and Time

Swamp-breeding treefrogs form conspicuous components of many tropical forest sites, yet remain largely understudied. The La Selva Biological Station, a rainforest reserve in Costa Rica, harbors a rich swamp-breeding treefrog fauna that has been studied in only one of the many swamps found at the site. To understand if the species composition of treefrogs at La Selva varies over space or time, frogs were censused in 1982-83, 1994-95, 2005 and 2011 at two ponds located in the reserve. Data on treefrog habitat utilization were also collected. Species composition varied spatially only in 2011. Temporal variation was observed at both ponds for all groups tested. Habitat use varied among species and between swamps. The pattern of variation suggests that temporally dynamic systems such as temporary Neotropical forest swamps will converge and diverge in species composition over time.

Controls on fish distribution and abundance in temporary wetlands

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.

Hydrological Conditions Control P Loading and Aquatic Metabolism in an Oligotrophic, Subtropical Estuary

Using high-resolution measures of aquatic ecosystem metabolism and water quality, we investigated the importance of hydrological inputs of phosphorus (P) on ecosystem dynamics in the oligotrophic, P-limited coastal Everglades. Due to low nutrient status and relatively large inputs of terrestrial organic matter, we hypothesized that the ponds in this region would be strongly net heterotrophic and that pond gross primary production (GPP) and respiration (R) would be the greatest during the “dry,” euhaline estuarine season that coincides with increased P availability. Results indicated that metabolism rates were consistently associated with elevated upstream total phosphorus and salinity concentrations. Pulses in aquatic metabolism rates were coupled to the timing of P supply from groundwater upwelling as well as a potential suite of hydrobiogeochemical interactions. We provide evidence that freshwater discharge has observable impacts on aquatic ecosystem function in the oligotrophic estuaries of the Florida Everglades by controlling the availability of P to the ecosystem. Future water management decisions in South Florida must include the impact of changes in water delivery on downstream estuaries.

Disturbance regime and limits on benefits of refuge use for fishes in a fluctuating hydroscape

Refuge habitats increase survival rate and recovery time of populations experiencing environmental disturbance, but limits on the ability of refuges to buffer communities are poorly understood. We hypothesized that importance of refuges in preventing population declines and alteration in community structure has a non-linear relationship with severity of disturbance. In the Florida Everglades, alligator ponds are used as refuge habitat by fishes during seasonal drying of marsh habitats. Using an 11-year record of hydrological conditions and fish abundance in 10 marshes and 34 alligator ponds from two regions of the Everglades, we sought to characterize patterns of refuge use and temporal dynamics of fish abundance and community structure across changing intensity, duration, and frequency of drought disturbance. Abundance in alligator ponds was positively related to refuge size, distance from alternative refugia (e.g. canals), and abundance in surrounding marsh prior to hydrologic disturbance. Variables negatively related to abundance in alligator ponds included water level in surrounding marsh and abundance of disturbance-tolerant species. Refuge community structure did not differ between regions because the same subset of species in both regions used alligator ponds during droughts. When time between disturbances was short, fish abundance declined in marshes, and in the region with the most spatially extensive pattern of disturbance, community structure was altered in both marshes and alligator ponds because of an increased proportion of species more resistant to disturbance. These changes in community structure were associated with increases in both duration and frequency of hydrologic disturbance. Use of refuge habitat had a modal relationship with severity of disturbance regime. Spatial patterns of response suggest that decline in refuge use was because of decreased effectiveness of refuge habitat in reducing mortality and providing sufficient time for recovery for fish communities experiencing reduced time between disturbance events.

Examining Seasonally Pulsed Detrital Transport in the Coastal Everglades Using a Sediment Tracing Technique

The Comprehensive Everglades Restoration includes plans to restore freshwater delivery to Taylor Slough, a shallow drainage basin in the Southern Everglades, ultimately resulting in increased freshwater flow to the downstream Taylor River estuary. The effect of altered hydrologic regime on the transport dynamics of flocculent, estuarine detritus is not well understood. We utilized a paramagnetic sediment tracer to examine detrital transport in three Taylor River pond/creek pairs during early wet versus late wet transition season estuarine flow conditions. Flux of floc tracer was greatest in the downstream direction during all observations, and was most pronounced during the early wet season, coincident with shallower water depth and faster discharge from northern Taylor River. Floc tracer was more likely to move upriver during the late wet/dry season. We observed a floc tracer transport velocity of approximately 1.74 to 1.78 m/day across both seasonal hydrologic conditions. Tracer dynamics were also surprisingly site-dependent, which may highlight the importance of channel geomorphology in regulating hydrologic and sediment transport conditions. Our data suggest that restoration of surface water delivery to Taylor River will influence downstream loading of detritus material into riverine ponds. These detrital inputs have the potential to enhance ecosystem primary productivity and/or secondary productivity.

Trajectories of Vegetation Response to Water Management in Taylor Slough, Everglades National Park, Florida

Ecosystem management practices that modify the major drivers and stressors of an ecosystem often lead to changes in plant community composition. This paper examines how closely the trajectory of vegetation change in seasonally-flooded wetlands tracks management-induced alterations in hydrology and soil characteristics. We used trajectory analysis, a multivariate method designed to test hypotheses about rates and directions of community change, to examine vegetation shifts in response to changes in water management practices within the Taylor Slough basin of Everglades National Park. We summarized vegetation data by non-metric multidimensional scaling ordination, and examined the time trajectory of each site along environmental vectors representing hydrology and soil phosphorus gradients. In the Taylor Slough basin, vegetation change trajectories closely followed the hydrologic changes caused by the operation of water pumps and detention ponds adjacent to the canals. We also observed a shift in vegetation composition along a vector of increasing soil phosphorus, which suggests the need for implementing measures to avoid P-enrichment in southern Everglades marl prairies. This study indicates that shifts in vegetation composition in response to changes in hydrologic conditions and associated parameters may be detected through trajectory analysis, thereby providing feedback for adaptive management of wetland ecosystems.

Water for the Wayuu: Procurement and maximization of a limited resource among indigenous pastoralists on the Guajira Peninsula of northern Colombia

For the Wayuu of the Guajira Peninsula of northern Colombia, water procurement has historically been challenging. The ancestral territory of this indigenous pastoral society is windy and arid, with low rainfall, high temperatures and an absence of perennial rivers or streams. In the past, the Wayuu adapted to these environmental conditions by practicing transhumance during the prolonged dry seasons, digging spring wells and artificial ponds and by following guiding principles for water usage. Since the 1930s, the government has made efforts to build additional wind-powered wells and ponds for a growing native population. Notwithstanding, these water solutions have only partly met the necessities; public water sources are limited or unreliable and few attempts are made to generate safe drinking water. Furthermore, the ubiquitous practice of animal husbandry places added pressure on existing sources; livestock consume more water than the human populations in the areas visited. Rapid assessments in four Wayuu areas on the peninsula were conducted by the author and an interdisciplinary team working for the Cerrejón Foundation for Water in La Guajira from 2010 to 2013. The assessments were part of a larger pilot project to design and implement a sustainability plan for reservoir-based water supply systems in the region. This study brings cultural practices and local knowledge to the forefront as key elements for the success of water works and other development projects carried out in Wayuu territory.

Radiocarbon dates of peatland initiation across the northern high latitudes

A compilation of basal dates of peatland initiation across the northern high latitudes, associated metadata including location, age, raw and calibrated radiocarbon ages, and associated references. Includes previously published datasets from sources below as well as 365 new data points.

Ground-based electromagnetic (EM) and drill-hole ice and snow thickness and melt pond depth measurements during Polarstern cruise ARK-IX/4, ARK-XI/1, and ARK-XII

Drillhole-determined sea-ice thickness was compared with values derived remotely using a portable small-offset loop-loop steady state electromagnetic (EM) induction device during expeditions to Fram Strait and the Siberian Arctic, under typical winter and summer conditions. Simple empirical transformation equations are derived to convert measured apparent conductivity into ice thickness. Despite the extreme seasonal differences in sea-ice properties as revealed by ice core analysis, the transformation equations vary little for winter and summer. Thus, the EM induction technique operated on the ice surface in the horizontal dipole mode yields accurate results within 5 to 10% of the drillhole determined thickness over level ice in both seasons. The robustness of the induction method with respect to seasonal extremes is attributed to the low salinity of brine or meltwater filling the extensive pore space in summer. Thus, the average bulk ice conductivity for summer multiyear sea ice derived according to Archie's law amounts to 23 mS/m compared to 3 mS/m for winter conditions. These mean conductivities cause only minor differences in the EM response, as is shown by means of 1-D modeling. However, under summer conditions the range of ice conductivities is wider. Along with the widespread occurrence of surface melt ponds and freshwater lenses underneath the ice, this causes greater scatter in the apparent conductivity/ice thickness relation. This can result in higher deviations between EM-derived and drillhole determined thicknesses in summer than in winter.

Evolução espaço-temporal da ocupação urbana sobre áreas naturais no município de Natal-RN

In this work the landscape morphodynamics was used to check the strength and importance of the changes carried out by man on the environment over time, in Natal-RN municipality. The occupation of partially preserved natural areas was analyzed, but environmentally fragile, such as riparian forests, vegetation on the banks of waterways, which play regulatory role of the water flow, and the dunes, which guarantee the rapid recharge of aquifers. The impacts of urban sprawl in Natal Southern and West zones Were identified and characterized, through a detailed mapping in the period between 1969 and 2013 the main Permanent Preservation Areas - PPA (banks of rivers and lagoons, and dunes remaining) and their temporal changes. For this were used aerial photographs and satellite imagery, altimetry data, and pre-existing information, which allowed the creation of a spatial database, and evolution of maps of impervious areas, evolution of the use and occupation and Digital Terrain Model (DTM) from contour lines with contour interval of 1 meter. Based on this study presents a diagnosis of the environmental situation and the state of conservation of natural areas, over the last 44 years, compared to human pressures. In general, it was found that the urban settlement has advanced about 60% of studied natural areas. This advance was growing by the year 2006, when there was a slowdown in the process, except for the Environmental Protection Zone (EPZ) 03, where the river Pitimbú and your PPA, which experienced a more significant loss area. The urban occupation affected the natural drainage and contributed to the contamination of groundwater Natal, due to increased sealed area, the release of liquid and solid waste, as well as the removal of riparian vegetation. Changed irreversibly the natural landscape, and reduced the quality and quantity of water resources necessary for the population. Thus, it is necessary to stimulate the adoption of use and protection of PPA planning measures, to the preservation of the San Valley Region inserted into the EPZ 01, and integrate more remaining dunes, in good condition, this EPZ, due to the importance of those remaining on the environment and the maintenance of quality of life. It is suggested, also, protection of catchment areas, such as PPA ponds and Pitimbú River. Finally, it is expected that this study can assist the managers in making decisions in urban and environmental planning of the municipality

Caracterização de água de lavagem de filtros em estações de tratamento de água de filtração direta

The water supply and treatment is considered as a great benefit considering that, if done efficiently, provides public health. However, considering the WTP (Water Treatment Plant) is an industry, with its inputs and waste generation, they must be constantly evaluated and monitored to verify the best and most appropriate way to process and dispose their waste, minimizing therefore the potential impacts to the environment. By volume, the most significant waste is the rapid filter backwash water. It is very common the disposal of this waste without treatment in water sources, which are used, for the most part, as a water supply source of a downstream population. This study evaluated quantitative and qualitative parameters in filter backwash water in three WTP - Itaitinga, Maranguape and Pacatuba, located in Ceará State, northeast of Brazil. It was found that the Maranguape WTP, in terms of treatment capacity, is the larger. The Itaitinga WTP is the one that consumes more water during filters washing. The Pacatuba WTP exhibited higher concentration of total suspended and settleable solids, COD and aluminum in the filters backwash water. It is noteworthy that the settleable solids and total suspended solids in all three WTP are above the effluent discharge standard recommended by Resolution 154/2002 of SEMACE (State Superintendent of Environment of Ceará). It was concluded that the filter backwash water from the study WTP exceeded the allowed values for legislation to be disposed directly into surface water bodies. It is suggested as an alternative to treat and recycle the filter backwashing water the construction of sludge settling ponds.

Avaliação de sistemas de lagoas de estabilização em série no Rio Grande do Norte

Stabilization ponds are biological treatment systems in that stabilization of organic matter is performed by the bacterial oxidation and / or reduction of photosynthetic algae. This study aimed to monitor and evaluate the efficiency of stabilization ponds in the Rio Grande do Norte State. Collections were made of the treated effluent, made directly in the output boxes of facultative lagoons and maturation (M1 and M2) and raw sewage (EB) that arrived at the stations. The variables analyzed were: pH, temperature, dissolved oxygen, total suspended solids, chlorophyll "a", apparent color, total phosphorus, organic nitrogen, ammonia nitrogen, Kjeldahl nitrogen, turbidity, cyanobacteria density and concentrations of microcystin. Variance analysis (ANOVA one way) observing the premises using the Tukey test, so as to check differences between treatments. The evaluate the stations found to COD removals in the bands of 48,8% (Pipa) to 75,8% (Caiçara Rio do Vento) and 57,5% (Pipa) to 83,0% (Santo Antônio), respectively. The mean concentrations of cyanobacteria varied from LFs density of 62,545 cels.mL-1 (Pedro Velho Roça) cels.mL-1 to 2,669,048 (Ponta Negra), while the final effluent showed range between 9,072 Cels.mL- 1 (Pedro Velho Roça) to 1,899,981 cels.mL-1 (Macau – Ilha de Santana) and the average concentrations of microcystin the final effluent ranged from 0.02 μg.L-1 (Ponta Negra) to 0.15 μg.L-1 (Macau – Ilha de Santana) at the studied the stations.