Use Of Artificial Substrates Research Articles

A field study on using artificial substrate for nesting of introduced pumpkinseed sunfish, Lepomis gibbosus (Linnaeus, 1758)

We experimentally tested the potential use of artificial substrate – plastic bottles for egg deposition of non-native pumpkinseed sunfish,Lepomis gibbosusL. in a former sand-pit lake in western Bulgaria. The lake is situated close to an urban area, and is characterised by high pumpkinseed abundance. The study was carried out for a period of 105 days during the active pumpkinseed breeding season (from May to August). Five sites along the littoral area of the lake, with different habitat characteristics were selected. Each site was divided into two sections – an experimental and a control section. The plastic bottles (cut into two) were fixed to the lake bottom in the area of the experimental sections. Pumpkinseeds actively used the artificial substrate for nesting and the average use of each bottle was 2.3 times. Simultaneously, on the natural substrate of the experimental sections a total of 372 nests were built. The results showed that the choice of artificial substrate was neither associated with the type of bottom substrate, nor the remaining environmental traits that were studied. However, the use of artificial substrate has made a significant contribution to the total number of nests only on sites with “unsuitable” habitat parameters. These results show that waste products can seriously facilitate pumpkinseed’s abundance.

Effects of artificial substrate and night-time aeration on the water quality inMacrobrachium amazonicum(Heller 1862) pond culture

The effects of artificial substrate and night-time aeration on the culture of Macrobrachium amazonicum were evaluated in 12 ponds stocked with 45 prawns m−2. A completely randomized design in 2 × 2 factorial scheme with three replicates was used. The combination of factors resulted in four treatments: with substrate and aeration (SA), with substrate and without aeration (SWA), without substrate and with aeration (WSA) and without substrate and aeration (WSWA). The presence of substrate in SA and SWA treatments reduced suspended particles (seston) by ~17.3% and P-orthophosphate by ~50%. The use of aerator (WSA and SA treatments) significantly (P < 0.05) increased the concentration of dissolved oxygen, suspended particles and nutrients in the pond water. These results indicate that the effect of substrate on turbidity and total suspended solids (TSS) values is opposite to the effect of the aerator. The aerators in semi-intensive grow-out M. amazonicum farming lower water quality because they increased the amount of detritus and nutrients in the pond water. On the other hand, the use of artificial substrate reduces turbidity values, chlorophyll a, TSS and P-orthophosphate concentrations. Therefore, the combination of substrate addition and night-time aeration is not interesting because they have opposite effects.

Use of artificial substrates in the culture of Litopenaeus vannamei (Biofloc System) at different stocking densities: Effects on microbial activity, water quality and production rates

Although the use of artificial substrates can favor shrimp culture, some studies indicate that their presence in growth tanks does not improve water quality or the performance of the animals. One objective of this study was to evaluate whether the presence of artificial substrates modifies the microbial activity and the water quality of the culture of Litopenaeus vannamei with bioflocs. The substrate effects on the shrimp performance and the relationship between these effects and the stocking density/biomass of shrimp were also evaluated. The experiment consisted of four treatments: D238: 238shrimpm−3; D238+S: 238shrimpm−3+substrates; D473: 473shrimpm−3; D473+S: 473shrimpm−3+substrates. Twelve experimental units of 850L were stocked with juvenile L. vannamei (2.6g) that were grown for 34 days. The substrates did not appear to affect water quality since the concentrations of orthophosphate, ammonia and nitrite were not significantly different in tanks with or without substrates. The periphyton biomass was low and the biological activity on the substrates was not significant, indicating that the water quality variables were mainly controlled by the microbial community associated with the suspended bioflocs. The shrimp grown in the presence of the substrate exhibited greater weight gain (D238+S=1.40±0.05 and D473+S=1.20±0.04gweek−1) than those grown without substrates (D238=0.73±0.04 and D473=0.44±0.13gweek−1). The final biomass was 314% greater in the tanks with substrates. The shrimp survival was significantly higher in the tanks with substrates (93.9±2.4%) than in the tanks without substrates (42.5±35.9%). The results indicate that the substrates served to increase the surface area of the tank and to reduce the relative stocking density, which appears to reduce the stress levels of shrimp, indicated by higher shrimp performance. In tanks with higher biomass, where the negative effects of intensification were most severe, the presence of the substrates had a positive effect on the production indices.

Detection of introduced sessile species on the near shore continental shelf in southern Brazil

Invasion by marine species, often considered a grave threat to marine ecosystems, occurs throughout the world as a consequence of many anthropogenic activities. In coastal Paraná, many factors including shipping, aquaculture and the use of artificial substrates provide suitable environments for the establishment and rapid spread of introduced marine species. To better understand this process, the encrusting community was studied on polyethylene plates (n = 120, 10 x 10 cm) that were placed seasonally at fixed locations on the inner continental shelf to detect non-native species. Of the 62 taxa found, 40 were identified to species, 14 of which were native, 9 introduced and 17 cryptogenic. We found a new introduction while most introduced species were previously reported at a nearby estuary with an international port. Possible complementary explanations for these detections are 1) estuaries influence ecological processes on the inner continental shelf, 2) the study area is near the route of cargo and other ships entering the port, 3) other local vectors, such as hulls of fishing and recreational boats, and artificial reefs link the estuary to the offshore areas. Thus, not only are estuaries invaded by exotic species, but also non-indigenous marine species may be present in the open sea where they are likely to colonize artificial substrates.

Initial data on settlement and recruitment of macrobenthic organisms on artificial substrates located over Posidonia oceanica meadows

The present paper presents initial data about settlement and recruitment of macrobenthic organisms through the use of artificial substrates placed over Posidonia oceanica (L.) Delile meadows in the Western Mediterranean. Three settlement frames were submerged in the Marine Protected Area (MPA) of Palma Bay (Balearic Islands, Western Mediterranean). A total of seven macrobenthic species from five phyla were recorded. Assemblages were dominated by the bivalve Anomia ephippium with the largest percentage of surface covered being 43.5% (±4.96). This study provides information on massive primary settlement of A. ephippium. Moreover, this species generated an optimal recruitment substrate for the settlement of two species of polychaete (Serpula vermicularis and Hydroides elegans) and the barnacle Balanus amphitrite. An interspecific relation was observed between B. amphitrite and A. ephippium, since 99.9% of this cirriped recruited directly over A. ephippium. Additionally, this study demonstrated that there is a substantial larval pool available ready to colonize suitable substrates for benthic organisms such as the bryozoan Calpensia nobilis and the ascidian Botryllus schlosseri associated with Posidonia oceanica. Our study is the first approach to gain knowledge of the complex process regarding settlement and recruitment, as well as the application of artificial structures in order to investigate the larval pool over P. oceanica meadows.

Enzyme analysis for Pompe disease in leukocytes; superior results with natural substrate compared with artificial substrates

Enzyme analysis for Pompe disease in leukocytes has been greatly improved by the introduction of acarbose, a powerful inhibitor of interfering alpha-glucosidases, which are present in granulocytes but not in lymphocytes. Here we show that the application of acarbose in the enzymatic assay employing the artificial substrate 4-methylumbelliferyl-alpha-D: -glucoside (MU-alphaGlc) is insufficient to clearly distinguish patients from healthy individuals in all cases. Also, the ratios of the activities without/with acarbose only marginally discriminated Pompe patients and healthy individuals. By contrast, when the natural substrate glycogen is used, the activity in leukocytes from patients (n = 82) with Pompe disease is at most 17% of the lowest control value. The use of artificial substrate in an assay with isolated lymphocytes instead of total leukocytes is a poor alternative as blood samples older than one day invariably yield lymphocyte preparations that are contaminated with granulocytes. To diagnose Pompe disease in leukocytes we recommend the use of glycogen as substrate in the presence of acarbose. This assay unequivocally excludes Pompe disease. To also exclude pseudo-deficiency of acid alpha-glucosidase caused by the sequence change c.271G>A (p.D91N or GAA2; homozygosity in approximately 1:1000 caucasians), a second assay employing MU-alphaGlc substrate plus acarbose or DNA analysis is required.

Nursery of the pink shrimp Farfantepenaeus paulensis in cages with artificial substrates: Biofilm composition and shrimp performance

The use of artificial substrates (polyethylene screens) was investigated during the nursery rearing of the pink shrimp Farfantepenaeus paulensis cultured in fixed cages installed in a shallow estuarine inlet of the Patos Lagoon, southern Brazil. High water renewal rates during the experimental period kept water quality in the suitable range for penaeid shrimp culture. Although shrimp were fed a high quality artificial diet (40% protein) throughout the experiment, they were observed to occupy the substrates and actively graze on the biofilm. The bulk of the biofilm was composed of diatoms, filamentous cyanobacteria, protozoa and nematodes. Biofilm chlorophyll a concentration was significantly affected by shrimp grazing pressure and the composition of the diatom community suffered significant changes after shrimp introduction to the cages. At the end of the trial shrimp reared in the presence of artificial substrates achieved significant higher survival, growth and total biomass ( p < 0.05). Biofilm was likely an additional source of food for the reared animals.

Towards a representative periphytic diatom sample

Abstract. The need to acquire a representative periphytic diatom sample for river water quality monitoring has been recognised in the development of existing diatom indices, important in the development and employment of diatom monitoring tools for the Water Framework Directive. In this study, a nested design with replication is employed to investigate the magnitude of variation in diatom biomass, composition and Trophic Diatom Index at varying scales within a small chalk river. The study shows that the use of artificial substrates may not result in diatom communities that are typical of the surrounding natural substrates. Periphytic diatom biomass and composition varies between artificial and natural substrates, riffles and glides and between two stretches of the river channel. The study also highlights the existence of high variation in diatom frustule frequency and biovolume at the individual replicate scale which may have implications for the use of diatoms in routine monitoring.

Recruitment of Serpuloidea (Annelida: Polychaeta) in a marine cave of the Ionian Sea (Italy, Central Mediterranean)

This paper is the first attempt to study the recruitment of Serpuloideans in a Mediterranean marine cave through the use of artificial substrates placed in three different positions, from the entrance to the interior of the cave. This study provides qualitative and quantitative data concerning Serpuloidea recruitment on panels removed successively after one, three, six and 12 months of permanence in the cave. A homogeneous distribution of juveniles Spirorbidae throughout the cave axis had already been detected after one month of panel immersion. Spirorbids were recorded also on panels removed after three months as well as serpulids, which began to be detected during this sampling time, even though represented by just one species. A significantly different pattern of distribution throughout the cave axis was observed after only six months, while other serpulids were detected for the first time. The pattern of species distribution seemed to reflect the biotic and environmental conditions of the cave. The highest serpuloidean species abundance and diversity was found on panels placed in the intermediate position within the cave. After only one year of panel immersion, a total of 20 taxa (11 Serpulidae and 9 Spirorbidae) was recorded, including five species listed for the first time in the marine caves of the Salento Peninsula.

Biological viability of producing white shrimp Litopenaeus vannamei in seawater floating cages

In the last few years, in an attempt to foment the controlled culture of penaeid shrimp by artisanal fishermen communities, an innovative culture technology using floating cages have been developed in Brazil. In this work, we assessed the biological viability of culturing the Pacific white shrimp Litopenaeus vannamei in floating cages at different stocking densities in Santa María's Bay, México. Additionally, the influence of artificial substrates on growth performance of the shrimp was analyzed. Cages made of PVC-coated polyester mesh supported by wooden poles and PVC tubes were used for this study. Post larvae (PL) were stocked in four nursery cages at 700 PL per m 2. After 30 days of nursery culture, shrimp had reached an average weight of 0.5 g and were then transferred to grow out cages at densities of 100, 150, and 200 shrimp per m 2, with and without the addition of artificial substrates. Survival rate was neither affected by stocking density nor by the presence of added artificial substrates. In contrast, final shrimp weight was higher for those reared at low densities (100 shrimp per m 2) and the use of artificial substrates showed a positive effect on final shrimp weight. After 2 months of culture survival rate was above 90%, the shrimp weight ranged from 6.94 ± 1.51 g to 9.33 ± 1.48 g and yields varying from 818 to 1297 g/m 2 were recorded. The high shrimp production in floating cages was probably due to optimum environmental and rearing conditions provided to the shrimp. The present results confirmed the deleterious effect of high stocking density on shrimp growth, demonstrated the benefits of adding artificial food substrates to the cages, and proved the biological viability of culturing L. vannamei in seawater floating cages in México.

Monitoring Changes in Freshwater Macroinvertebrate Communities Along a Salinity Gradient Using Artificial Substrates

Scientists strive to develop efficient sampling protocols, reducing both the number of samples and processing time required, which can be adapted for use in a broad range of ecosystems. We investigated the accuracy and usefulness of artificial substrates in monitoring the impact of rising salinity on freshwater macroinvertebrate communities. We sampled seven sites along a salinity gradient (from 0.2gL(-1) to 2.6gL(-1)) over a 19-km stretch of the Meurthe River, in northeastern France. All other parameters remained stable in this section of the river. Artificial substrate samples, each consisting of six liters of pebbles, were removed from the river at one-month intervals and examined. Results obtained indicated the same qualitative impairments as those found in samples collected using a Surber net. The use of artificial substrates was found to be a viable alternative method for assessing biological changes in river quality due to increasing salinity disturbance when Surber sampling cannot be performed.

Benthic Responses to Wet-Weather Discharges in Urban Streams in Southern Ontario

Abstract Urban stormwater and combined sewer overflow (CSO) discharges are important sources of sediment and contaminants (trace metals, PAHs, nutrients and road salts), and cause changes in flow, sediment, chemical and thermal regimes of receiving waters. Over the past several years, benthic conditions of streams representing a range of exposure environments were assessed in Hamilton, Toronto, Oshawa and Kingston, Ontario. Studies progressed from initial surveys of sediment contaminant levels, sediment toxicity and benthic invertebrate community structure to more spatially intensive sampling and experimental approaches that included the use of artificial substrates, in situ water toxicity tests and measurements of contaminant bioaccumulation. Results showed that while sediments and some biota at sites exposed to wet-weather discharges were often contaminated with metals and PAHs and enriched with nutrients, significant biological degradation measured by sediment toxicity or depauperated benthic communities was not evident. Exposure to stormwater discharges at sites below outfalls could alter the composition of benthic communities, but these effects were not strongly related to contaminant concentrations in sediment or invertebrate tissue. No outfall-associated toxicity was observed for caged amphipods held in the water column. Effects of wet-weather discharges on benthic communities at the urban stream sites studied appear to be small, and their detection was limited by several inherent conditions, including natural heterogeneity in the distribution of benthic invertebrates, episodic (intermittent) exposure to discharges and contaminant fluxes allowing some recovery, “background” levels of disturbance, poorly delineated changes in communities caused by physical effects such as flow and sediment transport, and community response dynamics. Detection of stormwater discharge effects should be improved by sampling on smaller temporal and multiple spatial scales to better quantify stressor exposure and invertebrate responses.

Meiofaunal colonisation on artificial substrates: a tool for biomonitoring the environmental quality on coastal marine systems

The use of artificial substrates for monitoring environmental quality and contaminant impact has been repeatedly suggested, but little information is yet available on the applicability and the sensitivity of this approach. One of the crucial points to be addressed for using artificial substrates, as tools mirroring actual benthic community state, is assessing whether, and how, they reflect in situ conditions characterising natural sediments. In this study we investigated short-term dynamics of meiofaunal colonisation on artificial substrates (bottle brushes) deployed in impacted and ”pristine” (control) sites. Meiofaunal colonisation reached a threshold level after 4–6 days in both impacted and control sites but with significantly higher densities in artificial substrates deployed in the control site. Meiofaunal parameters in artificial substrates reflected those of meiofaunal assemblages inhabiting natural sediments where artificial substrates were deployed. Colonised artificial substrates were then transplanted from impacted to control sites. This caused a significant increase of meiofaunal abundance, which after 5 days reached values indistinguishable from the non-impacted control. Given the rapid colonisation time, meiofaunal sensitivity to changing environmental conditions, it can be concluded that artificial substrates can represent an useful tool to be further developed for routine and low-cost monitoring studies aiming at integrating biological indicators of environmental quality.

Facile variation of reagent concentrations in rapid quench enzymology

Detailed enzymological investigations are essential in elucidating the reaction pathway of an enzyme, including the identification of reaction intermediates, the quantitative determination of the rate-determining step(s), and the nature of the transition state. The information derived from these enzymological studies is especially important in the development of specific inhibitors that can find application in both research applications and as potential drugs. Many enzymological studies are performed using steady-state kinetics, as, for example, in determining relative affinities in high-throughput screens, determining the order of substrate binding and product release, and structure-activity relationships (SAR) [1]. However, steady-state kinetics are limited in that they only provide the kcat and Km parameters that are potentially complex functions of all the individual rate constants in the enzymatic reaction pathway. Therefore, transient state kinetics have been developed to elucidate both presteady-state and one-turnover reactions allowing for a more complete description of the individual reaction steps [2]. When possible, enzymologists attempt to develop enzyme assays that use an absorbance or fluorescent signal allowing for continuous measurement of product formation (or substrate depletion). The number of enzyme reactions that can be monitored directly using native substrates is extremely limited and has led to the use of artificial substrates that incorporate elements with detectable extinction coefficients or fluorescent properties or coupled assays. However, artificial substrates and coupling enzymes do not adequately address the needs of enzymology. First, full characterization of an enzyme requires work with native substrates and most native substrates do not have useful absorbance or fluorescent properties. Second, coupled assays are not useful in transient state kinetics where the lag time in observation of product formation through the coupling enzymes would mask the reaction of interest. Because of these limitations, enzymologists have for many years relied on rapid quench flow. In this technique, individual time points are collected along the reaction course and then analyzed by a suitable technique, often using radioactive labeling and separation of products from substrates. In order to perform these experiments rapidly enough to measure reaction kinetics on the millisecond time scale, a number of rapid quench apparatus have been developed. A rapid quench flow experiment generally involves three syringes. A number of manufacturers have specialized in making high-quality instruments capable of performing rapid quench flow on a microvolume basis, sufficiently small in volume to be useful for the enzymologist. These companies include Hi-Tech Scientific, Bio-Logic, and KinTek. One of the most common experiments performed by an enzymologist is the variation of substrate and/or enzyme concentration to determine dependencies of reaction rates on these two key variables. In many experiments, a wide-ranging substrate and/or enzyme concentration-dependence determination is not needed. For example, in a so-called single-turnover experiment, one may only be interested in determining whether one is working under conditions of limiting association between enzyme and substrate or limiting rate of reaction on the enzyme (i.e., actual chemistry) [2]. This can easily be determined by doubling the enzyme and Analytical Biochemistry 312 (2003) 80–83

Preliminary study on the use of synthetic substrate for juvenile stage production of the yabby, Cherax destructor (Clark) (Decapoda: Parastacidae)

Juvenile Cherax destructor (commonly called the yabby) (mean weight 48.3 mg) were cultured intensively (stocking density 360/m2) under controlled conditions for 48 days. The animals were provided with a combination of food (high protein pellets and/or natural feed organisms attached to a conditioned synthetic substrate) and refuge. Fastest growth and highest yield was recorded when both pellets and the conditioned synthetic material were provided. Although the yabbies sheltered in the synthetic substrate, it did not increase survival. Juvenile yabbies (< 200 mg) were able to graze on small organisms attached to the synthetic material but this ability appeared to decline as the yabbies grew to a larger size. The use of artificial substrates in the intensive nursery phase production of juvenile freshwater crayfish is discussed.

A ten years survey of longitudinal zonation and temporal changes of macrobenthic communities in the Rhône River, downstream from lake Geneva (Switzerland)

The macrobenthic fauna of the Rhone River below Lake Geneva was studied between 1983 and 1993 to describe patterns of longitudinal and temporal community changes. Sampling was based upon the use of artificial substrates in 11 stations. The confluence with the Arve (an alpine tributary) is the first source of faunal discontinuity, both in terms of species and feeding group composition. The Verbois hydropower plant is the second longitudinal disruption. From a temporal point of view, the construction of the Seujet hydropower plant was a major source of faunal fluctuation. After this event, and until the end of the study, lenitophilous taxa increased to the detriment of rheophilous taxa.

The Seasonal Succession of Macroinvertebrates, in Particular the Zebra Mussel (Dreissena polymorpha), in the River Rhine and Two Neighbouring Gravel-Pit Lakes Monitored Using Artificial Substrates

Artificial substrate samplers were used to study the seasonal succession of macroinvertebrates in the River Rhine and two neighbouring gravel-pit lakes. In two experimental series nearly all epilithic macroinvertebrates normally found at each site settled on the artificial substrates. The analysis of the results showed that the use of artificial substrates is an adequate tool for studying (1) different aspects of the life cycles of species which frequently settle on the plates (e.g. Bryozoa, Corophium curvispinum), (2) seasonal successions of macroinvertebrate communities, and (3) aspects of competition and support within a macroinvertebrate community. The total biomass of macroinvertebrates, in particular the growth of juvenile Dreissena polymorpha, accurately reflected the productivity of the different waters, with highest values for the lake connected to the river, somewhat lower ones for the Rhine, and very low production values for the isolated lake. In other words, a few easily-made measurements of the productivity of primary consumers may be very useful for biological monitoring studies of the floodplains of rivers.

Use of artificial substrates to enhance production of freshwater herbivorous fish in pond culture

Two trials were conducted in mud-bottomed concrete tanks to assess the potential of using artificial substrates to enhance fish production in ponds. Three substrate types were tested: bamboo poles, PVC pipes and sugarcane bagasse bundles. In one trial, periphyton was grown on the substrates in the absence of fish. In the second trial, masheer (Tor khudree Sykes) fingerlings were stocked at three densities. Results showed a significant effect of substrate type on fish growth (P≤ 0.001) and on net fish production (P≤ 0.05), with best growth in the tanks using the bamboo substrate. In the bagasse treatment, 100% fish mortality occurred. Highest extrapolated periphyton-based gross fish yield (i.e. without feed inputs) was 450 kg ha−1 90 d−1 with PVC and 491 kg ha−1 90 d−1 with bamboo substrate. The best periphyton growth occurred on bamboo, followed by bagasse and PVC. Without fish, mean periphyton biomass during the culture period was 0.56–1.20 mg cm−2 on bamboo [ash-free dry matter (DM)], against 0.09–0.36 mg cm−2 on PVC and 0.20–0.59 mg cm–2 on bagasse. No clear effect of fish density or water depth on periphyton biomass could be seen. Only on bamboo, fish density seemed to have a negative effect on periphyton ash-free dry matter and a positive effect on pigment content (chlorophyll-a and phaeophytin). Periphyton from bamboo had a lower ash content (38–47% of DM) than from PVC (54–55% of DM) or bagasse (51–58% of DM). It is concluded that substrate type has a strong effect on periphyton productivity and composition, and on fish productivity. Good fish production was achieved without feed inputs. More research is needed to study the economic viability of periphyton-based systems in the context of Indian aquaculture.

Use of artificial substrates for biological monitoring in the Guandu and Paraiba do Sul Rivers, Rio de Janeiro State, Brazil

Use of artificial substrates for biological monitoring in the Guandu and Paraiba do Sul Rivers, Rio de Janeiro State, Brazil

Artificial Substrate for Egg Laying and Embryonic Development by the Predatory BugMacrolophus caliginosus(Heteroptera: Miridae)

Macrolophus caliginosusWagner is released in greenhouses mainly for controlling whiteflies, aphids, and thrips. Mass rearing ofM. caliginosusoccurs on tobacco plants and induces a high cost. The use of artificial substrates that allow egg laying and embryonic development of the bug is proposed. The number of eggs laid byM. caliginosusand the percentage of survival from egg to adult were compared on artificial substrates and natural host plants. A dental cotton roll wrapped in stretched Parafilm and wetted with water gave promising results as an artificial oviposition substrate. Its hardness was similar to that of the softest part of tobacco plant, and it received a mean of 1.2 eggs laid per day per female, with a 36.4% yield of larvae and 15% yield of adults (related to laid eggs). Meanwhile, under the same conditions, oviposition averaged 3 eggs/day/female on host plants. Spraying a substrate with ethanol leaf extract ofInula viscosaincreased egg laying byM. caliginosusto a mean of 1.6 eggs/day/female. Egg laying and subsequent development to the adult stage were possible on an artificial substrate. However, greater efficiency must be obtained for economical mass rearing ofM. caliginosus.