Permanent Pools Research Articles

Aquatic invertebrate diversity in isolated and permanent pools along an urban ephemeral stream in Central Texas

Aquatic invertebrate diversity in isolated and permanent pools along an urban ephemeral stream in Central Texas

Spatio-temporal usage of water sources by Black-cheeked Lovebirds Agapornis nigrigenis: implications for conservation planning

Summary The Black-cheeked Lovebird Agapornis nigrigenis has a highly restricted range in dry south-western Zambia, where its distribution is clumped and localised in association with mopane Colophospermum mopane woodland and permanent water pools. Fieldwork and monitoring over 30 months between December 2018 and October 2021 established that the lovebirds’ usage of pools for drinking was higher towards the centre of the bird’s distribution and influenced by the pools’ proximity to mopane woodlands, surrounding tree cover, and level of human activity. Of the four pool types available for use by lovebirds (i.e. mopane, grassland, river, and artificial), mopane and grassland pools were disproportionally susceptible to drying out in the dry season, hence showed greater variation in numbers of visiting birds compared with the other two types. Lovebirds showed a preference for pools with a perimeter of <50 m and tended to avoid those with a perimeter >100 m, consistent with a positive association between pool size and human activity. Convergence between humans and lovebirds in dependence on water resources and mopane woodland points to the need to find ways to overcome potential conflicts. Such ways include creating small, shallow-sided, undisturbed pools in or near mopane woodland, extending water retention in existing mopane pools, and enhancing the capacity of artificial pools to meet the needs of the lovebirds.

From shady ditches to artificial pools – Does mire restoration benefit aquatic invertebrates?

To combat the loss of wetlands and the services they provide, many are now being restored. Rewetting, usually by ditch blocking, is a common approach to restore drained wetlands, where it can create a supply of permanent artificial pools. We studied how aquatic macroinvertebrate abundance, species richness and communities respond to ditch blocking, and how the new lentic waterbodies contribute to the habitat value of these ‘restored’ ecosystems. The study system was a large before-after-control-impact (BACI) experiment along forested mixotrophic bog edges, where we sampled macroinvertebrates prior to and after the restoration that had created a total of 308 individual pools along former ditch channels. The mean abundance and taxon richness increased similarly in drain-blocked and control ditches between 2015 and 2021 but blocked and control ditches started to host distinct communities. Most pronounced changes were the decrease in the numbers of bivalves and plecopterans and the appearance of vagile species, such as odonatans, hemipterans and certain beetles and flies to blocked ditches, including several characteristic species. Overall, the restoration provided new habitats for aquatic macroinvertebrates, but the convergence of these communities toward natural transitional mire communities remains to be studied.

Modelling the removal of nitrogen and sediment by a constructed wetland system in north Queensland, Australia

This study of a multi-component 2.5 ha constructed wetland system near Mackay, north Queensland was established to determine the efficacy of these types of wetlands for improving water quality entering the Great Barrier Reef lagoon. To do this a water balance model was developed using water depth measurements made in the wetland inlet basin, between 25 December 2018 and 30 September 2020. The water balance model allowed daily values of run-in and drainage to be calculated, which were combined with a nitrogen balance model to derive a value for the amount of total nitrogen (TN) removed by the wetland of 83 kg ha−1 year−1, or 37% of the nitrogen input to the wetland. The nitrogen balance model used a mean inflow TN concentration of 5060 (± 1734) μg L−1 derived from TN concentration measurements (automatic and grab) made during four high flow events. The largest losses of nitrogen where via drainage with 49% leaving as outflow and 14% as groundwater seepage. Outflow carried 38% of the sediment and particulate nitrogen (PN) out of the wetland, which means that 62% settled to the bottom of the wetland. Dissolved nitrogen (DN) removal in Bakers Creek is mainly (89%) due to the relatively long residence time of water in its biodiversity pond component, the largest and deepest part of this wetland system which always contained water, even during the dry season. This illustrates the value of large, permanent deep pools in a wetland system, whether they are constructed or natural. Wetlands constructed downstream of areas generating sediments and nutrients should therefore be able to improve the quality of water entering the Great Barrier Reef lagoon. However, to do this they need to retain water for significant amounts of time, which they may do in comparatively low rainfall areas. In higher rainfall areas open, flow through wetlands may not be able to do this, so wetlands constructed in these regions need to be designed to retain water in order to have significant N removal capacity. Proper monitoring of future constructed wetlands is vital in order to derive robust design criteria for systems that can remove significant nitrogen from agricultural run-off water.

Ekonomi Kreatif Dengan Program Warung Keluarga Melalui Budidaya Ikan Dalam Ember

Budikdamber or known as Fish Cultivation in a Bucket is a form of creative economy business that can be done in a family in order to fulfill some basic needs. This research is a Research and Development, which is to continue and modify various findings and problems in the implementation of Warung Keluarga through Budikdamber. The discussion and report models use a qualitative approach. This research was conducted in several places in Boyolali in 2020, 2021, and early 2022. The results show that the Warung Keluarga program through Budikdamber can be done easily, does not require a large space, large capital, and is side-by-side. However, it will result in a significant economic increase in meeting the basic needs of the family, and can be used as a business opportunity if taken seriously. The Budikdamber program can be developed through the media of drums, Pengaron, Plastic Sheeting, and Permanent Pools. Catfish harvest success rate 75% - 95%. The success for the types of catfish and gourami can reach 90% - 98%.

First Report of Culicoides Biting Midges (Diptera: Ceratopogonidae) Attacking People in Italy, With the Description of Extreme Larval Breeding Sites and Diurnal Activity of Culicoides riethi.

Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) play a paramount role in medical and veterinary entomology worldwide, particularly as vectors of pathogens which cause animal diseases. Biting midges are also infamous for the nuisance they provoke to people involved in outdoor activities. Nonetheless, attacks to man by midges from any Culicoides species have not been reported in Italy. An entomological investigation was performed following repeated attacks to man in a nature park near Rome (central Italy). The study area is a natural degassing zone, characterized by widespread hazardous gas emissions of CO2 and H2S, with several water bodies including permanent lakes, ponds, and pools. The biting midge C. riethi Kieffer, 1914 was very active during daytime in the period April–June. The species has been identified as responsible for attacks on people in the area. An in-depth analysis of the extreme environmental conditions revealed the ability of larvae to thrive in several water bodies, characterized by an extremely low pH and a high concentration of sulfates.

Plant species associations with alkaline environments associated with artesian spring wetlands

To describe the physico-chemical environment of artesian spring wetlands and surrounding scalds; to identify the association of plant species with these factors; and to assess the tolerance of a wetland species to an alkalinity gradient. Surface soils were sampled for chemical attributes and water depth in spring wetlands and associated scalds. Plant species were recorded in quadrats and their distribution in relation to physico-chemical attributes assessed. Comprehensive analyses of salt composition and mineralogy were conducted at scald sites. An experiment was conducted to assess the tolerance of theartesian spring wetland species Eriocaulon carsonii. The wetlands of artesian springs have circumneutral pH with low salinity. The environment around the wetlands has extremely high pH, dominated by sodium bicarbonate minerals, but have variable salinity. The plant species, many of which are endemic, have clear associations with individual habitats including the permanent pools, the fringing scalds and the terrestrial scalds without sub-surface groundwater. Eriocaulon carsonii is tolerant of neutral and alkaline waters but not highly acidic water. The permanent pools supported by artesian springs have low salinity and neutral pH. The scalded areas around springs are extremely alkaline and can have high salinity values. The chemistry of the springs described here are of the Na-carbonate type and typical of the Great Artesian Basin. The evolution of endemic wetland species may have resulted from the permanence of the pools rather than distinctive chemistry. By contrast the species of the scalds are specialised to an extreme chemical environment.

Water quality parameters and population characteristics for the Flinders Ranges Gudgeon

ABSTRACT The Flinders Ranges Gudgeon (Mogurnda clivicola) in South Australia, is restricted to permanent spring-fed pools of two creeks in the Northern Flinders Ranges. Consequently, the fish is classified as critically endangered. Regular monitoring of selected water chemistry and fish population characteristics has been conducted since 2018 by a “Friends of Parks” group in an ongoing project contributing to the conservation management for this endangered species. Mogurnda clivicola were abundant and healthy in Weetootla and Nepouie springs, with six or fewer fish displaying any skin lesions on each of the four sampling occasions of May and August 2019 and June and August 2020. Hence the fish populations were not adversely affected by the exceptionally low rainfall years of 2018 and 2019. Fish of less than 2 cm total length were present at each sampling time point, indicating that breeding can occur on an opportunistic basis rather than during a breeding season. Following a substantial flood during February 2020, a substantial breeding event resulted in large numbers of small fish and at Nepouie Spring. For pools that contained fish, the water quality parameters measured and their ranges were: conductivity 1141–13 800 µS/cm; dissolved oxygen concentration 1.9–12.0 mg/L; temperature 11.4–29°C; pH 7.1–8.8; [Ca++] 36–213 mg/L; [NO3-] 0.2–17.7 mg/L.

New information on site occupancy and detection rate of Mixophyes iteratus and implications for management

Mixophyes iteratus (giant barred frog) is listed as Endangered in state and federal legislation, but there have been only two previous studies in scientific literature that have focused on habitat preferences of this species. This study aimed to shed light on habitat selection of M. iteratus by conducting surveys during the 2019–2020 breeding season within the Tweed Valley, northern New South Wales, Australia. Detection rate was also quantified, which is a first for the species. A nested survey method was used in conjunction with a conditional survey design. There were 118 detections of M. iteratus over 31 habitat sites, all beside permanent stream pools >10m in length. Occupancy modelling suggested that frogs were more likely found in sites with ≥12m of undercut bank. Over three survey rounds, detection rate was 0.54–0.65. Surveys at historical sites showed that the species can survive severe drought, which was experienced through 2018 and 2019. Findings suggest that at least two surveys for M. iteratus should be conducted at favourable sites or when targeting the species, especially if land management at the site is proposed to change. Riparian management that retains undercut banks and pools is encouraged for the conservation of this species.

Too little but not too late? Biology of a recently discovered and imperilled freshwater fish in a drying temperate region and comparison with sympatric fishes

Abstract Small‐bodied freshwater fishes are commonly overlooked in threatened species management despite being highly imperilled. Before this study, the newly described little pygmy perch (Nannoperca pygmaea) was known from only 0.06 km2 of habitat in a single catchment in south‐western Australia and a lack of knowledge prevented an understanding of its conservation status and priority actions. The present study determined the distribution, biology, and movement patterns of N. pygmaea and compared these with other small, sympatric percihthyids to assess its conservation status and likely resilience to threatening processes. The current ‘extent of occurrence' of N. pygmaea was determined to be 3,420 km2 and the ‘area of occupancy' was 10 km2. Nannoperca pygmaea inhabited permanent refuge pools in the main stem of an ephemeral, secondarily salinized catchment where salinities remained <6 ppt during summer. During winter N. pygmaea undertook a short upstream migration into a seasonally flowing freshwater tributary to serially spawn. The timing of reproduction was partitioned among three sympatric pygmy perches within the austral winter/spring period. The species qualifies as ‘Endangered' under the IUCN Red List assessment criteria. Its restriction to freshwater refugia within salinized rivers suggests that N. pygmaea may have a limited salinity tolerance similar to the sympatric, threatened Nannatherina balstoni, and that the species is susceptible to prolonged drought, drying of critical baseflow refuges, increasing salinization, and introductions of alien species. The study serves as an example that small‐bodied freshwater fishes need greater research attention to understand the biological and environmental mechanisms underpinning their decline.

Patterns of Distribution of Bivalve Populations in a Mediterranean Temporary River

In the south of the Iberian Peninsula, many rivers are intermittent, a state most likely to be exacerbated by climate change, strongly affecting river biota. An additional challenge for native biota in this area is the arrival of new species, frequently aided by humans, and bivalves are particularly at risk. Here we assessed whether the native (Unio delphinus) and invasive (Corbicula fluminea) bivalves differed in habitat use. To address this question, we sampled populations of both species in six isolated permanent pools in the same river during summer in three consecutive years. U. delphinus occurred in all pools, while C. fluminea occurred only in the two most downstream pools. U. delphinus, but not C. fluminea, was found preferentially in patches under riparian vegetation cover. Both species were found in similar sediment types (coarse and fine gravel respectively). Although U. delphinus was present in all pools, recruitment was detected only in 2016, in one pool. We concluded that both species have the potential to compete for space, but a well-developed riparian vegetation cover may provide U. delphinus some advantage against C. fluminea.

Influence of fishes on macroinvertebrate communities and insect emergence production in intermittent stream refuges

Abstract Drying intermittent stream networks often have permanent water refuges that are important for recolonisation. These habitats may be hotspots for interactions between fishes and invertebrates as they become isolated, but densities and diversity of fishes in these refuges can be highly variable across time and space. Insect emergence from streams provides energy and nutrient subsidies to riparian habitats. The magnitude of such subsidies may be influenced by in‐stream predators such as fishes. We examined whether benthic macroinvertebrate communities, emerging adult insects, and algal biomass in permanent grassland stream pools differed among sites with naturally varying densities of fishes. We also manipulated fish densities in a mesocosm experiment to address how fishes might affect colonisation during recovery from hydrologic disturbance. Fish biomass had a negative impact on invertebrate abundance, but not biomass or taxa richness, in natural pools. Total fish biomass was not correlated with total insect emergence in natural pools, but orangethroat darter (Etheostoma spectabile) biomass was inversely correlated with emerging Chironomidae biomass and individual midge body size. The interaction in our models between predatory fish biomass and date suggested that fishes may also delay insect emergence from natural pools, altering the timing of aquatic–terrestrial subsidies. There was an increase over time in algal biomass (chlorophyll‐a) in mesocosms, but this did not differ among fish density treatments. Regardless, fish presence in mesocosms reduced the abundance of colonising insects and total invertebrate biomass. Mesocosm invertebrate communities in treatments without fishes were characterised by more Chironomidae, Culicidae, and Corduliidae. Results suggest that fishes influence invertebrates in habitats that represent important refuges during hydrologic disturbance, hot spots for subsidy exports to riparian food webs, and source areas for colonists during recovery from hydrologic disturbance. Fish effects in these systems include decreasing invertebrate abundance, shifting community structure, and altering patterns of invertebrate emergence and colonisation.

Traps and netting, better together than alone: an innovative approach to improve Procambarus clarkii management

The red swamp crayfish Procambarus clarkii is the most widespread invasive crayfish in Europe, and responsible for a plethora of negative impacts on aquatic ecosystems. Most capture methods used for controlling crayfish populations have a bias towards the capture of adults, however, the removal of the young-of-the-year crayfish (YOY) may be essential for achieving effective control of invasive populations. This paper analysed the crayfish caught during a management campaign carried out in five permanent stream pools from southern Spain. We compared size structure, CPUE and sex-ratio obtained with two control methods: cylindrical traps (a method commonly used in crayfish management) and horizontal hauls using a fine-mesh net (inspired by zooplankton sampling techniques). Horizontal hauls showed a higher selectivity for catching YOY and higher efficiency (eight-fold) than traps. The combined use of both gears increased total catch by 46%. Our results suggest that YOY may be sharply underestimated if only cylindrical traps are used. The YOY cohort represented 60% of the total catch during the management campaign. Therefore, active netting with a fine mesh may be a complementary method to the use of traps in order to manage invasive populations of P. clarkii and may provide a better understanding of the structure and dynamics of invasive crayfish populations.

Brook lamprey survival in the dry riverbed of an intermittent stream

Intermittent streams account for approximately one half of the global river network, and are especially common in arid and semi-arid regions. These systems are inhabited by several fish species that are adapted to their natural flow intermittency. While many fish species rely on permanent pools or perennial reaches to survive during the dry season, our knowledge regarding fish survival strategies in dry reaches is incomplete. Our observations revealed that ammocoetes (i.e. lamprey larvae) of a non-parasitic brook lamprey (Lampetra sp.) survived in the hyporheic zone of an intermittent stream in the absence of surface water for at least 22 days. This is the first reported observation of ammocoetes persisting in the hyporheic water after loss of surface water, a behavior that has been previously reported for just a few fish species.

Habitat associations of zoophagic bat ensembles in north-western Australia

North-western Australia comprises the Kimberley Craton and parts of three adjacent sedimentary basins. It has a tropical climate and habitats that range from semiarid plains supporting grasslands to mesic uplands supporting woodlands as well as narrow riparian forests and patches of rainforest; mangrove forests occur along the coast. Its bat fauna comprises three obligate phytophages and 27 obligate zoophages. Analysis of zoophagic bats at 171 sites scattered throughout this study area revealed two compositionally distinct ensembles. One, comprising 19 species, occupies mangrove forest and includes three species known only to occupy mangroves in Western Australia. The other, comprising 20 species, occupies landward habitats and includes four species that are found only in landward ecosystems. Both ensembles are structured in terms of resource allocation, but nestedness observed in assemblage composition can be explained by environmental factors, implying the influence of environmental controls. Sixteen species belong to both ensembles, but seven of these require cave roosts and occur only near cavernous country while three others are confined to rocky riparian habitats. The richest assemblages were recorded in rugged cavernous landscapes in complex vegetation structures near permanent freshwater pools in the most mesic areas.

Corrigendum to: Habitat associations of zoophagic bat ensembles in north-western Australia

North-western Australia comprises the Kimberley Craton and parts of three adjacent sedimentary basins. It has a tropical climate and habitats that range from semiarid plains supporting grasslands to mesic uplands supporting woodlands as well as narrow riparian forests and patches of rainforest; mangrove forests occur along the coast. Its bat fauna comprises three obligate phytophages and 27 obligate zoophages. Analysis of zoophagic bats at 171 sites scattered throughout this study area revealed two compositionally distinct ensembles. One, comprising 19 species, occupies mangrove forest and includes three species known only to occupy mangroves in Western Australia. The other, comprising 20 species, occupies landward habitats and includes four species that are found only in landward ecosystems. Both ensembles are structured in terms of resource allocation, but nestedness observed in assemblage composition can be explained by environmental factors, implying the influence of environmental controls. Sixteen species belong to both ensembles, but seven of these require cave roosts and occur only near cavernous country while three others are confined to rocky riparian habitats. The richest assemblages were recorded in rugged cavernous landscapes in complex vegetation structures near permanent freshwater pools in the most mesic areas.

Impacts of Rainfall and Temperatures on Socioeconomic and Environmental Sectors in the Communes of Tondikiwindi and Ouallam, Department of Ouallam, Region of Tillaberi, Niger Republic

The communes of Tondikiwindi and Ouallam in Niger experience changes in rainfall and temperatures like the whole of ahel. This paper focuses on understanding the impacts of these climate parameters on socio-economic and environmental sectors. The methodology is based on calculations of various indices (Lamb, 1982; Tabony, 1977; FAO / UNESCO, 1979) and determination of temperatures within maxima and minima values. With regard to the rainfall evolution, three periods were noted including a long dry period (1968-1989), a relatively wet period (1990-1998), and a period of great variability with an alternation of wet and dry years (1999 -2015). A trend in the South has been noticed in the start and at the end of the rainy season, with a slight decrease in the rainy days. For the temperatures, an increase was registered from 1968 up to date with some slight changes. This is due to the occurrence of the phenomena related to the El Nino or ENSO Southern Oscillation. In terms of impacts, there were several food crises and population migration both inside and outside of the country. On the other hand, the return to a relatively humid phase has led to a change in the Northern limit of cultures, whose corollary is the exacerbation of conflicts between shared natural resources users. This return to an increase in rainfall has also led to major floods that have favored the creation of new permanent or semipermanent pools. Hence, it is necessary to develop a new model of sustainable development for this geographical entity.

Null models for explaining inland water crustacean zooplankton communities in Chile

Abstract Inland water crustaceans in Chile are characterized by their low species number and marked endemism; this is due to the marked oligotrophy of water bodies and the geographical properties of Chilean territory, which consists of mountains and glaciers. The aim of the present study is to typify the inland water crustaceans in the northern Aysen region (44-46°S), which is branded by the presence of mountains, ice fields and inland seas, with different kinds of water bodies such as large lakes, permanent and ephemeral pools, rivers and streams. The results revealed low species numbers, but the species associations are random, because in many sites the same species frequently reoccur. Nevertheless, there are marked differences in species associations. The present results tend to agree with similar results for the Magallanes region in southern Patagonia and Argentinean Patagonia.

Physiological mechanisms of adaptive developmental plasticity in Rana temporaria island populations

BackgroundAdaptive plasticity is essential for many species to cope with environmental heterogeneity. In particular, developmental plasticity allows organisms with complex life cycles to adaptively adjust the timing of ontogenetic switch points. Size at and time to metamorphosis are reliable fitness indicators in organisms with complex cycles. The physiological machinery of developmental plasticity commonly involves the activation of alternative neuroendocrine pathways, causing metabolic alterations. Nevertheless, we have still incomplete knowledge about how these mechanisms evolve under environments that select for differences in adaptive plasticity. In this study, we investigate the physiological mechanisms underlying divergent degrees of developmental plasticity across Rana temporaria island populations inhabiting different types of pools in northern Sweden.MethodsIn a laboratory experiment we estimated developmental plasticity of amphibian larvae from six populations coming from three different island habitats: islands with only permanent pools, islands with only ephemeral pools, and islands with a mixture of both types of pools. We exposed larvae of each population to either constant water level or simulated pool drying, and estimated their physiological responses in terms of corticosterone levels, oxidative stress, and telomere length.ResultsWe found that populations from islands with only temporary pools had a higher degree of developmental plasticity than those from the other two types of habitats. All populations increased their corticosterone levels to a similar extent when subjected to simulated pool drying, and therefore variation in secretion of this hormone does not explain the observed differences among populations. However, tadpoles from islands with temporary pools showed lower constitutive activities of catalase and glutathione reductase, and also showed overall shorter telomeres.ConclusionsThe observed differences are indicative of physiological costs of increased developmental plasticity, suggesting that the potential for plasticity is constrained by its costs. Thus, high levels of responsiveness in the developmental rate of tadpoles have evolved in islands with pools at high but variable risk of desiccation. Moreover, the physiological alterations observed may have important consequences for both short-term odds of survival and long term effects on lifespan.

The role of environmental filtering in the functional structure of fish communities in tropical wetlands

AbstractUnderstanding the mechanisms that structure communities has been a major challenge in ecological theory. In wetlands with a clear seasonal hydroperiod (wet and dry seasons), such as Sian Ka'an Biosphere Reserve (SKBR), Mexico, fish communities experience successive habitat contraction/expansion, with a high mortality rate during the dry season. In this study, we tested the role of environmental filtering in structuring fish communities along an environmental gradient in permanent pools, during three consecutive stages of the dry season. We analysed fish communities using a functional dispersion index weighted by the relative abundance compared against a null model. While the concentration of dissolved oxygen remained low throughout the season, depth and temperature showed a gradient as the season progressed. Independently of their starting composition, at the end of the dry season the communities were dominated by a combination of the same three species. For the key function of locomotion, the functional dispersion was significantly lower at the end of the season in three of the five pools. For food acquisition, no significant differences were found. When the overall functional variation was considered, at the beginning of the dry season no single community differed significantly compared to the random models. However, as the season progressed, significant differences were recorded in four of the five pools. Our study supports the hypothesis that environmental filters have a major role in community structure in severe environmental conditions. Furthermore, our results show that the role of environmental filters gain importance as the dry season progresses.