populations in differentially-fished areas of the Peruvian
Amazon.
C. L. Gerstner, H. Ortega, H. Sanchez and D. L. Graham
Journal of Fish Biology (2006) 68, 862–875
Я думаю большинство знакомы или слышали историю о Hypancistrus zebra, находящегося на грани исчезновения из-за вылова для аквариумистов.
В Перу вылов рыб из речек производится варварским способом, после которого в местах вылова на несколько лет исчезают многие виды.
На этот раз авторы расматривают влияние вылова рыб для продажи на популяцию рыб в Перу.
Abstract.
Base-line data were collected to examine the possible effects of the aquarium trade on Amazon fish populations in differentially-fished locations in the Departmento of Loreto, Peru. Fish abundance, species diversity (richness) and biomass were quantified at three locations with differential fishing pressure, including the Rio Nanay (high pressure), Rio Apayacu and Rio Arambassa (medium) and Rio Yanayacu –Pacaya Samiria National Reserve (low). Seining results indicated that the location with the highest fishing pressure had reduced fish abundance, species diversity and biomass compared to the other locations. A similar trend was seen using minnow traps. There was no significant difference in abundance, diversity and biomass between the medium and low fishing pressure locations. Habitat differences (pH and conductivity) among the three locations accounted for <13% of the observed variation, and thus it seemed possible that some of the decline in the Rio Nanay location could be tentatively attributed to increased fishing pressure. Although effects of pollution and habitat alteration could not be ruled out, this is one of the first studies to provide quantitative data on the effect of the freshwater aquarium trade on wild fish populations. While results suggest success in the protection of fishes for the aquarium trade in Pacaya-Samiria National Reserve, it also may be sustainable to establish limited levels of fishing, as was found in the medium fishing pressure locations, in order to promote economic opportunities and incentives for habitat preservation for indigenous communities.
2006 The Fisheries Society of the British Isles
INTRODUCTION
The aquarium fish trade has expanded rapidly over the past 50 years, with many millions of hobbyists worldwide (Davenport, 1996). The popularity of fish keeping is evidenced by the estimated 10% of U.S.A. and 13% of U.K. households which keep fishes as pets (Davenport, 1996). The FAO statistics from 1990 show that major importers of home aquarium fishes are Europe, North America and Asia, with, for example, >1000 species of tropical marine and freshwater fishes imported into the U.K. annually (Davenport, 1996).
Considerable attention has been given to the impact of the trade on coral reef fishes (Kolm & Berglund, 2003; Tissot & Hallacher, 2003) since most marine fishes are ‘wild-caught’ (Tissot & Hallacher, 2003) and because of high impact collecting methods such as blast fishing and cyanide use. In contrast, little attention has been paid to the freshwater trade, although the exceptions include Crampton (1999), Chao (2001) and unpubl. data, since a majority of freshwater aquarium fishes (>90%) are raised in captivity (Andrews, 1990). Estimates from customs records in the U.K., however, indicate that only 6,2% (by value) of live fish imports were tropical marine (Davenport, 1996). Similarly only 4% by volume of aquarium fishes imported into the U.S.A. were marine (c. 8 million fishes) (Basleer, 1994).
Export estimates from Peru indicate that 11 million freshwater aquarium fishes were exported in 1992 (J. Soregui Vargas & V.H. Montreuil Frias, unpubl. data), and Peru is not even in the top 10 list of source countries (by value) exporting fishes to the European Union (Davenport, 1996). Estimates of annual Brazilian freshwater fish exports range from 165 to 22 million (Andrews, 1990; Leite & Zuanon, 1993). These exports represent wild-caught fishes, since there is no commercial cultivation of aquarium fishes in the Amazon (Crampton, 1999).
Although statistics for the aquarium trade are often non-existent or incomplete, it is probable that numbers of wild-caught freshwater fishes in the trade far exceeds wild-caught marine fishes. The ecological impacts of the freshwater fish trade in the Amazon thus warrants closer examination.
The majority of wild-caught aquarium fishes from the Amazon basin are exported from Brazil, Colombia and Peru. Most of these fishes, such as the popular neon tetra Paracheirodon innesi (Myers), arahuana [i Osteoglossum bicirrhosum[/i] (Cuvier), corydoras catfishes Corydoras spp., suckermouth catfishes Hypostomus spp., hatchet fishes Carnegiella spp. and cichlids Apistogramma spp. are purchased by home-hobbyists. The study focused on the species-diverse aquarium fish trade in Peru, where c. 60% of the trade is comprised of 10 species, with no single species comprising >15% of the annual trade (Hanek, 1982; Tello & Canepa, 1991). Well over 300 species are probably exported from the Peruvian Amazon, a single Iquitos exporter listed >270 fish species in stock in April 2005 (Acuario Panduro, 2005). In contrast, the Brazilian trade centred in Manaus is comprised of c. 80% cardinal tetra Paracheirodon axelrodi (Schultz) (Chao, 2001). The centre of aquarium fish export in Peru is Iquitos, where the trade has been active since the 1950s when there were 13 registered commercial aquarium dealers which increased to 32 by 1996 (Tello & Canepa, 1991; J. Soregui Vargas & V.H. Montreuil Frias, unpubl. data). Estimates of fishes exported between 1988 and 1997 range from a low of 64 million in 1990 to a high of 17,9 million in 1994 (V.H. Soregui Vargas & V.H. Montreuil Frias, unpubl. data). While the economic impact of the trade on local communities has yet to be determined, it is estimated that some 3000 families make a living from and 100000 persons benefit economically from the trade, often in villages where few other economic opportunities may be available.
Wild-caught aquarium fishes are potentially one of the few sustainable resources in the Amazon basin. Theoretically, life-history traits such as short life span and high egg production, plus low-impact collecting methods and seasonal extremes in rainfall may limit the exploitation of this resource (Andrews, 1990). Claims that the Amazon aquarium fishery is sustainable (Chao, 2001), however, have not been supported by standardized ecological sampling, and anecdotal reports from fishers in the Peruvian Amazon indicate that the number of species caught is declining and fishers have to travel further to catch the same numbers of fishes (S. Tello, pers. comm.). Some populations of the high-value discus Symphysodon aequifasciatus Pellegrin in Brazil have apparently collapsed due to over-collection (Crampton, 1999) and data from a recent study on the Rio Nanay in Peru indicates that areas sampled closer to Iquitos have reduced abundance and species diversity compared to areas further upstream on the same river (unpubl. data). While collections have been made of Amazonian fishes for taxonomic studies, there are few standardized, quantitative datasets on the abundance and distribution of Amazonian aquarium fish species and the ecological impact of the fishery is largely unknown (Bayley & Petrere, 1989). The purpose of this study was to establish base-line data on fish populations and to evaluate potential impacts of the Amazon aquarium fish trade in three differentially-fished areas of Peru. It was predicted that heavy fishing pressure locations on the Rio Nanay would have reduced fish abundance and species diversity (richness) compared to a location in Pacaya-Samiria National Reserve, where fishing is strictly limited, and to Amazon tributaries downriver of Iquitos where only a few families are known to fish for the aquarium trade.