Effects of fisheries management on fish communities in the floodplain lakes of a Brazilian Amazonian Reserve

Abstract –  We compared fish abundance, diversity and species composition between lakes open (fished) and closed (no-take) to fishing activities in Mamirauá Sustainable Development Reserve in the Central Brazilian Amazon, in order to investigate potential influences of the common-based management. We sampled 1483 fishes from 70 species through gillnet fishing during the low-water season, in seven fished and seven no-take lakes. Contrary to expected, the mean values for abundance, size, diversity and species-richness of fish did not differ between fished and no-take lakes. There was no difference between fished and no-take lakes considering only the abundance of the 14 fish species more intensely targeted by fishermen. However, the abundance of an important commercial fish, the tambaqui ( Colossoma macropomum ) was higher in no-take lakes. Such data from a rapid assessment may be useful to monitor this and other fishery co-management schemes.     

Assessing conservation priorities of endemic freshwater fishes in the Tropical Andes region

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The Galápagos giant tortoises (Geochelone elephantopus) Part II: Conservation methods

Eight of the 11 surviving races of Galápagos tortoises are threatened due to decreased population sizes and predation and/or competition by introduced mammals. Systematic hunting has been effective for controlling and even eliminating goats on the less elevated, more sparsely vegetated, smaller islands and for controlling pigs, even on some of the larger islands. However, the method has been ineffective against dogs and cats and it is doubtful that it could be used to eliminate goats or pigs on the more elevated, larger islands which have a diversity of vegetation zones. Alternative control or extermination methods are being sought and tested for these feral mammals and black rats. In an attempt to increase yearly recruitment of hatchlings, lava corrals have been constructed around nests, resulting in almost 100 per cent success in preventing nest destruction by pigs; but the method was ineffective against dogs. While other control methods are being sought, young of the endangered races are being hatched and raised in captivity for restocking of endemic populations. During the past seven years, improved and highly successful techniques have been found for (1) establishment of breeding colonies and construction of artificial nesting sites, (2) transport of eggs from wild nests, (3) incubation of eggs, and (4) raising of young in captivity. By August 1972, 231 young of six races were being raised, and 71 4·5–6·5 year old captive raised tortoises released on Pinzón in 1970 and 1971 were in good condition and growing rapidly. The advantages of conducting the breeding/raising programme in the Galápagos rather than foreign locations are discussed.     

The Galápagos giant tortoises (Geochelone elephantopus) Part I: Status of the surviving populations

Eleven of the original 15 races of Galápagos tortoises are known to survive. The populations of three of these may be self-replacing. The other eight are threatened with extinction, each by one or more of the following: (1) greatly decreased population size, (2) predation on nests and/or young by introduced pigs, dogs, cats, or black rats, and (3) competition for food resources with feral populations of goats or donkeys. Human exploitation of the tortoise populations has become relatively unimportant in the past few years for a number of reasons, including more wide-spread acceptance of protective laws and the increasing activity of the Servicio del Parque Nacional Galápagos and the Charles Darwin Research Station. Data on population sizes and sex structures, reproductive potential, and natural mortality rates suggest that all but two of the endangered populations could remain stable or even increase in size if the effects of introduced mammals were eliminated or greatly lessened.     

Contributions of ethnobiology to the conservation of tropical rivers and streams

• 1. This study aimed to link basic ethnobiological research on local ecological knowledge (LEK) to the conservation of Brazilian streams, based on two case studies: original data on LEK of fishermen about freshwater fish in the Negro River, Amazon, and previously published data about LEK of farmers on the ecological relationship between forest and streams in the Macabuzinho catchment, Atlantic Forest.
• 2. Information was obtained from fishermen through interviews using standard questionnaires containing open-ended questions. Informants for interview were selected either following some defined criteria or applying the ‘snowball’ method.
• 3. Fishermen's LEK about the diets and habitats of 14 fish species in the Negro River provided new biological information on plant species that are eaten by fish, in addition to confirming some ecological patterns from the biological literature, such as dependence of fish on forests as food sources.
• 4. In the Atlantic Forest, a comparison between farmers' LEK and a rapid stream assessment in the farmers' properties indicated that farmers tended to overestimate the ecological integrity of their streams. Farmers recognized at least 11 forest attributes that correspond to the scientific concept of ecosystem services. Such information may be useful to promote or enhance dialogue among farmers, scientists and managers.
• 5. These results may contribute to the devising of ecosystem management measures in the Negro River, aimed to conserve both rivers and their associated floodplain forests, involving local fishermen. In the Atlantic Forest, we proposed some initiatives, such as to allow direct economic use of their forests to conciliate conflicting perceptions of farmers about ecological benefits versus economic losses from reforestation. Despite their cultural, environmental and geographical differences, the two study cases are complementary and cost-effective and promising approaches to including LEK in the design of ecological research.

Copyright © 2007 John Wiley & Sons, Ltd.     

Hydrocortisone levels in the urine and blood of horses treated with ACTH.

An investigation was undertaken to demonstrate whether therapeutic treatment with ACTH raises hydrocortisone (cortisol) levels in horse urine above the limit (1000 ng/ml) established by the International Conference of Racing Authorities with the aim of controlling the abuse of cortisol and ACTH in equine sports. ACTH (200 iu) was administered i.m. to 3 Thoroughbred horses; urine and blood samples were collected at intervals afterwards and analysed by an immunoenzymatic system (ELISA) and HPLC-MS. To ascertain post exercise cortisol levels in untreated horses, 101 urine and 103 serum samples were taken from horses immediately after racing and analysed by ELISA. The peak urine level of cortisol, detected 8 h after ACTH administration, was around 600 ng/ml using either ELISA or HPLC-MS. The peak serum cortisol concentration was found to be around 250 ng/ml by ELISA, but consistently less by HPLC-MS. Mean cortisol levels in post race horses were 135.1+/-72.1 ng/ml in urine and 90.1+/-41.7 ng/ml in serum. High levels of the metabolite 20beta-dihydrocortisol in urine and the cortisol precursor 11beta-desoxycortisol in serum were found. The latter showed high cross-reactivity with cortisol on ELISA. In our experiment, treatment with ACTH 200 iu i.m. did not raise urinary cortisol levels above the 1000 ng/ml threshold proposed by the ICRA.     

Considerations on endopolygalacturonase activity and determination of comparison ratios with emphasis on the influence of the degree of substrate esterification

A study on the determination and standardization of endopolygalacturonase (EPG) activity is reported, with emphasis on the influence of the degree of substrate esterification using pure yeast EPG. Differences in the results, depending on how the EPG activity unit was defined, are described and discussed. From a theoretical analysis of the expressions established, a general equation for expressing EPG activity in standard international units was obtained, together with the proportional coefficient for each of the substrates studied. It was observed that for a wide range of enzyme concentrations good linear correlations were obtained. Analysis of the comparison ratio (CR) values calculated revealed that these do not differ significantly, except for low-methoxyl apple pectin, confirming the validity of the general expression obtained for pectins with different degrees of esterification. The anomalous CR value found for low-methoxyl (LM) apple pectin is discussed.     

POPs in Mountain Soils from the Alps and Andes: Suggestions for a ‘Precipitation Effect’ on Altitudinal Gradients

POPs are still a priority environmental problem, but can be used as a scientific tool for understanding the distribution phenomena. Both high mountains and polar areas are seen as priority zones for contamination studies. In this context, two altitudinal series of soil samples were analysed for several classes of Persistent Organic Pollutants (PCBs, DDTs, HCHs, HCB and chlordane). Two transects were carried out – one in the Peruvian Andes (Cordillera Blanca) and the other in the Italian Alps (Mount Legnone). In these two areas, POP composition and levels both gave different results, linked to regional emission history. The Italian samples were characterized by high levels of industrial type compounds, and by surprisingly high DDT contamination, due to a defined consistent local source in Northern Italy. The Peruvian samples, on the other hand, were characterized by generally low POP levels with relatively high DDT contamination. The concentration increase in line with elevation was evident only in the Italian transect, where higher precipitation intensities and an increasingly higher precipitation gradient in accordance with altitude was found present. Precipitations are considered a key factor for enhancing the condensation effect at high altitudes and for reducing summer revolatilisation, as they lower soil temperature. In the Italian altitudinal gradient, evidence of fractionation processes, with a shift of the PCB composition towards less chlorinated congeners, and a vegetation effect with a mean woodland/grassland enrichment factor between 2 and 4 were also observed.     

Pharmacokinetics and Effects of Alkalization after Intravenous Administration of Eltenac in Horses

Eltenac (ELT) [4-(2,6-dichlorophenyl)amino-3-thiophene] is a non-steroidal anti-inflammatory drug (NSAID) that was developed for veterinary use in horses and cattle. The pharmacokinetics of ELT was evaluated in horses at 0.5 mg/kg body weight (BW) after single IV injection after 5 days of repeated IV administration and after a single IV injection in horses previously subjected to 250 mg/kg BW of sodium bicarbonate (NaHCO₃) as an alkalization treatment. The aim was to determine whether blood and subsequent urinary alkalization could modify the pharmacokinetics of ELT. Drug quantification was performed with serum and urine using high performance liquid chromatography with UV-visible detection. The results were also integrated with cyclo-oxygenase-inhibition literature data to review the dosage scheme of ELT in horses. After a single intravenous administration, ELT was characterized by rapid distribution (mean t½_λ1 = 0.18 ± 0.07 hour) and a short elimination half-life (mean t½_λ2 = 2.9 ± 0.68 hour). The volume of distribution was small (V_dss = 253.51 ± 47.55 mL/kg), which is likely because of the high percentage of drug protein binding (approximately 97%). The AUC_0-∞ and Cl_B were 6.92 ± 0.84 h*μg/mL and 73.2 ± 10 mL/h/kg, respectively. Repeated administration did not cause either accumulation or modification of the pharmacokinetic profile. The in vitro effective concentrations were maintained for a 6-hour period. The alkalization procedure appeared to accelerate drug elimination, as ELT was quantifiable only for 6 hours; however, the drug clearance was not significantly modified. Thus, the administration of alkaline compounds to accelerate the elimination of ELT is not completely confirmed.