No abstract

Neotropical freshwater fishes are the most diverse on the planet (>5,500 species), although nations in Latin America have been negligent regarding their conservation. National policies have historically encouraged unsustainable practices, and recent decades have witnessed a sharp increase in harmful activities. Our aim with this review was to expose this situation and illustrate how national policies constitute the main threat to freshwater fish biodiversity. We explain that the most devastating, pervasive and systemic threats are rooted in official policies, particularly unsustainable activities (e.g. hydropower, water diversion, mining, aquaculture, agriculture and fishing), poor management/conservation (e.g. fish stocking and passages) and harmful legislation (e.g. poor licensing, non‐native species). We provide a broad portrait of the Neotropical scenario, where unsustainable policies have caused considerable damage to freshwater ecosystems, and focus on major examples from Brazil, where development projects have caused large‐scale losses to fish biodiversity. Such modus operandi of human development is incompatible with the persistence of biodiversity, and no simple solution is available to correct or minimize its effects. The current situation demands a profound behavioural shift towards better practices and policies, or these multiple high‐impact activities will continue eroding freshwater fish biodiversity and impairing essential ecosystem services.

Brazil has a variety of aquatic ecosystems and rich freshwater biodiversity, but these components have been constantly damaged by the expansion of unsustainable activities. An array of different conservation strategies is needed, especially the creation of protected areas (PAs, hereafter). However, Brazil's PAs are biased towards terrestrial ecosystems and we argue that current PAs have limited efficacy in the protection of freshwater biodiversity. New PAs should better consider aquatic environments, covering entire basins, rivers and other freshwater habitats. We recommend ways to implement these PAs and provide guidance to avoid social impacts. Freshwater systems in Brazil provide essential goods and services but these ecosystems are being rapidly degraded and will be lost if not adequately protected.

No abstract

The executive and legislative branches of Brazilian government have either proposed or taken a variety of initiatives that threaten biodiversity and ecosystems. Opposition by the scientific community has largely been ignored by decision-makers. In this short essay, we present recent examples of harmful policies that have great potential to erode biodiversity, and we suggest ways to communicate scientific knowledge to decision-Communicated by David Hawksworth.

Informal sales of large-bodied non-native aquarium fishes (known as "tankbusters") is increasing among Brazilian hobbyists. In this study, we surveyed this non-regulated trade on Facebook ® from May 2012 to September 2016, systematically collecting information about the fishes available for trading: species, family, common/scientific names, native range, juvenile length, behavior, number of specimens available in five geographical regions from Brazil. We also assessed the invasion risk of the most frequently sold species using the Fish Invasiveness Screening Test (FIST). We found 93 taxa belonging to 35 families. Cichlidae was the dominant family, and most species were native to South America. All species are sold at very small sizes (< 10.0 cm), and most display aggressive behavior. The hybrid Amphilophus trimaculatus × Amphilophus citrinellus, Astronotus ocellatus, Uaru amphiacanthoides, Osteoglossum bicirrhosum, Cichla piquiti, Pangasianodon hypophthalmus, Datnioides microlepis and Cichla kelberi were the main species available. The southeast region showed the greatest trading activity. Based on biological traits, the FIST indicated that Arapaima gigas, C. kelberi and C. temensis are high-risk species in terms of biological invasions via aquarium dumping. We suggest management strategies such as trade regulations, monitoring, euthanasia and educational programs to prevent further introductions via aquarium dumping.Keywords: Aquarium releases, Aquarium trade, Biological invasions, Invasiveness, Propagule pressure.A venda de juvenis de peixes não-nativos de grandes dimensões, chamados de "peixes jumbo", está aumentando entre aquaristas no Brasil. Neste trabalho, pesquisou-se este comércio informal pelo Facebook ® de maio/2012 a setembro/2016, coletando-se informações sobre espécies, família, nomes vulgares/científicos, origem, tamanho juvenil, comportamento e número/frequência de exemplares disponíveis nas cinco regiões geográficas do Brasil. Também avaliou-se o risco de invasão das espécies mais vendidas usando o protocolo Fish Invasiveness Screening Test (FIST). Foram encontradas 93 espécies pertencentes a 35 famílias. Cichlidae foi a família dominante, e a maioria das espécies é nativa da América do Sul. Todas as espécies foram vendidas como juvenis (< 10.0 cm), e a maioria exibe comportamento agressivo. O híbrido Amphilophus trimaculatus × Amphilophus citrinellus, Astronotus ocellatus, Uaru amphiacanthoides, Osteoglossum bicirrhosum, Cichla piquiti, Pangasianodon hypophthalmus, Datnioides microlepis e Cichla kelberi foram as espécies mais comercializadas. A região sudeste apresentou a maior porcentagem de vendas, e o FIST mostrou que Arapaima gigas, C. kelberi e C. temensis foram consideradas de alto risco para desencadear invasões biológicas mediadas por descarte de aquários. Recomendações como a regulação do comércio, monitoramento, sacrifício das espécies e campanhas educacionais para os aquaristas são sugeridas para evitar futuras introduções de peixes via descarte de aquários. Palavras-chave:Comércio o...

Freshwater ecosystems in Brazil, arguably the most diverse on the planet, have been disturbed by several threats in the past years, particularly competition for water and subsequent water abstraction, urbanization, severe drought, dam construction/water diversion, pollution from different sources, commercial exploitation, and the introduction of non-native species (Agostinho et al. 2005; Vitule et al. 2015; Lima et al. 2015; Winemiller et al. 2016). A worrying example is the federal law 5989/2009 that intends to naturalize non-native fish species by decree in Brazil, some of which have a high invasion potential, such as the carps Aristichthys nobilis, Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix and tilapias Oreochromis spp. (Lima et al. 2012; Vitule Communicated by David Hawksworth.

Cage aquaculture has been developed in many countries, including Brazil. This form of production, although economically productive, may cause several impacts to the environment. Considering the historical relationship between aquaculture and species introduction, our study investigated the potential of cage aquaculture in spreading non-native species into hydroelectric reservoirs. We interviewed 19 fish farmers in Furnas Reservoir, Grande River basin. All producers have grown exclusively Nile tilapia (Oreochromis niloticus), an African fish, and all producers reported the occurrence of fish escapes. Releases were mainly accidental, but highly frequent during some management procedures, such as length classification, fish capture and juvenile stocking. Escapes were also reported due to cage damage and deliberate releases. These results indicate that, in cage aquaculture facilities, fish are frequently released to the external environment. When raising non-native species (e.g. Furnas Reservoir), these facilities constitute an important vector for fish introductions.A aquicultura em tanques-rede é destaque em diversos países, inclusive no Brasil, por se tratar de uma prática produtiva. No entanto, esta forma de cultivo também apresenta pontos negativos, entre eles a possível introdução de espécies. Em vista disso, o presente trabalho investigou o potencial da aquicultura em tanques-rede na disseminação de espécies não-nativas. Para isso, foram entrevistados 19 aquicultores do reservatório de Furnas, bacia do rio Grande. Todos os produtores consultados cultivam exclusivamente Tilápia-do-Nilo (Oreochromis niloticus), espécie de origem africana, e todos relataram a ocorrência de escapes de indivíduos dessa espécie. Os escapes foram principalmente acidentais, com elevada frequência durante o manejo de classificação, a despesca e a estocagem de juvenis. Aquicultores também relataram fugas decorrentes do rompimento dos tanques, além de solturas deliberadas. Os resultados indicam, portanto, que a perda de peixes para o meio externo é frequente em sistemas de tanque-rede. Ao lidar com espécies não-nativas, esses sistemas (tanques-rede) constituem importante vetor para a introdução de peixes.