José Amorim Reis-Filho

Estuarine ichthyofauna of the Paraguaçu River, Todos os Santos Bay, Bahia, Brazil

Estuarios sao areas de reconhecida importância no desenvolvimento e refugio dos peixes e tambem grande fonte de recursos pesqueiros. Este artigo apresenta um inventario dos peixes do estuario do Rio Paraguacu, Baia de Todos os Santos, Bahia, Brasil. 28 pontos constituindo as tres secoes salinas que pode haver em um estuario tropical foram amostradas trimestralmente de marco de 2009 a fevereiro de 2010 com auxilio de redes de espera de fundo, de superficie, redes de arrasto manual e tarrafas. Um total de 4.097 individuos foram capturados, pertencendo a 7 especies de Chondrichthyes e 117 especies de Actinopterygii (83 generos e 49 familias). A maioria da extensao territorial do estuario foi amostrada para acessar maior variabilidade espacial na estrutura da assembleia de peixes. A curva de acumulacao de especies (rarefacao) apresentou estabilizacao com ½ das amostras. A estrutura geral da assembleia e descrita e comentada atraves de evidencias para uma nova organizacao espacial da fauna de peixes devido a efeitos de barragem a montante do estuario.

In situ effects of human disturbances on coral reef-fish assemblage structure: temporary and persisting changes are reflected as a result of intensive tourism

Non-lethal human disturbances are often drivers of change in animal population and community structure. To gauge their severity, short-term behaviour (e.g. avoidance and habituation) has been argued to be a sensitive measure. However, many of these behavioural changes may occur only if disturbance-free habitat is readily accessible. In coral-reef fish, we tested whether human disturbances from intensive (i.e. loud music, swimming, snorkelling, splashing and fish feeding by numerous visitors) tourist visitations resulted in assemblage structure shifts led by short-term behaviour. We monitored fish assemblage before, during and after tourist visitations to monitor changes associated with behaviour. Additionally, we monitored two adjacent reefs not visited by tourists because of difficult approach by boat. We posited that if short-term benefits of relocating to disturbance-free habitat outweigh the costs of tolerating disturbances, fish assemblage structure should shift along with tourist visitation levels. By contrast, if sensitive species are unable or unwilling to relocate, we predicted greater levels of assemblage heterogeneity between the visited and control reefs. Our results showed that in situ human visitations led to significant shifts in assemblage structure, resulting from short-term behavioural changes. Additionally, we showed significant between-reefs differences, whereby control reefs were characterised by higher species richness, larger fish sizes and variations in relative trophic guild prevalence. Our results suggest that short-term relocations to adjacent disturbance-free reefs may not mitigate the effects of human disturbances.

Reef fishes captured by recreational spearfishing on reefs of Bahia State, northeast Brazil

Although recreational spearfishing is a growing activity, its impacts are poorly understood. This paper aims to present data on reef fishes captured by recreational spearfishing in the Bahia State, Northeastern Brazil. We analyzed 168 photos of spearfishing conducted in the reefs of this region between 2006 and 2008. A total of 1.121 fish belonging to 48 species were captured in three sub-regions of the Bahia coastline: Litoral Norte (LN), Salvador (SSA) and Baixo Sul (BS). The main species caught were: Scomberomorus brasiliensis (n = 191), Sphyraena barracuda (n = 153), Lutjanus jocu (n = 150) and Caranx bartholomaei (n = 141); these four species represented 56.5% of total captures. Over the sampling period, the highest values of catch rates per day were observed at BS, followed by SSA and LN. There were significant between-sites differences in the number of fish in the number of species caught. However, there were no significant between-years differences in the number of fish and numbers of species caught. The trophic classification of fish showed that carnivores (n = 623) were more frequently captured, followed by piscivores (n = 371), herbivores (n = 101) and invertivores (n = 26). The results showed that high sized, top predatory fishes, were the main targets, although other trophic levels were also captured.

Baited remote underwater video as a promising nondestructive tool to assess fish assemblages in clearwater Amazonian rivers: testing the effect of bait and habitat type

Baited remote underwater video (BRUV) systems are being used in marine ecosystems as a nonextractive, cost-effective method of assessing the fish fauna with minimal species bias. This technique has had limited applications in freshwater ecosystems. Rheophilic fish assemblages of the Xingu River, a clearwater Amazonian river in Northern Brazil, were sampled with BRUV systems. Two-hour video recordings were collected using five different bait treatments (sardine, croaker, cat food, sweet corn, and no bait) in two lotic habitat categories (rocky and sandy bottoms). A total of 2460 fish from 56 taxa and 13 families were recorded from the 80 BRUV deployments. Significantly different fish assemblages, species richness, and abundance were detected between habitat types and among treatments. Our results suggest that the use of crushed sardines as a standardized bait optimizes the sampling recording the highest species richness, relative abundance, and number of exclusive species of rheophilic fish in clearwater Amazonian rivers. The data also highlight the unique fish diversity of the Xingu River prior to the expected large-scale environmental degradation resulting from the forthcoming operation of the Belo Monte hydroelectric power plant.

Community structure of shallow rocky shore fish in a tropical bay of the southwestern Atlantic

Southwestern Atlantic Ocean rocky shores sustain important reef fish communities. However, those communities in tropical regions are not well understood, especially in Brazil. In this present article we assess community parameters of reef fishes such as composition, trophic organization and their relationships with physical and biological factors on four tropical rocky shores in Todos os Santos Bay, southwestern Atlantic. During six months, a total of 80 visual censuses were performed, in which 3,582 fish belonging to 76 species were recorded. Territorial herbivorous fish and turf algae were dominant at all the sites. The spatial variability of fish community structure was related to the benthic cover composition and depth. The high abundance of territorial herbivores and mobile invertebrate feeders could be associated with high levels of turf cover, low wave exposure and shallow waters. Moreover, this fact could be a consequence of the low density of roving herbivores and large carnivores probably due to the pressure of intense fishing activity. Thus complementary studies are needed to evaluate the actual conservation status of these rocky shore reefs, singularly located habitats connecting inner and outer reefs in Todos os Santos Bay.

Gobioides broussonnetii Lacepède, 1800 (Pisces: Gobiidae): First record of the violet goby in the state of Bahia (central coast of Brazil) and evidence of the effect of increased salinity on its local distribution

New recordings of Gobioides broussonnetii Lacepede, 1800 and the distribution of which extends for approximately 1,000 km both to the North and South along the coast of Brazil are reported in the Paraguacu river estuary (Todos os Santos Bay). Preliminary data regarding the impact of increasing salinity on violet goby populations are shown and discussed.

Fringe on the brink: Intertidal reefs at risk

The rocky areas between low and high tide, known as intertidal reef habitats, are one of the most at-risk marine ecosystems ([ 1 ][1], [ 2 ][2]) as a result of coastal urbanization, sewage, and fisheries ([ 2 ][2]). Although they provide essential ecological services to society, such as shoreline

Rediscovery of bonnethead shark Sphyrna tiburo after more than two decades of non-record on central coast of Brazil

We report the sighting of bonnethead shark Sphyrna tiburo juveniles L T ) after more than two decades of apparent absence in Todos os Santos Bay (Brazilian eastern coast). A total of 8 specimens were collected on the Paraguacu estuary during a Long Term Fish Monitoring Programme. The L T , total body mass and stomach contents are reported. Relevance for nursery areas to this threatened species is also discussed.

Cryptobenthic fish as clients of french angelfish Pomacanthus paru (Pomacanthidae) during cleaning behaviour

The French angelfish Pomacanthus paru (Pomacanthidae) is recognised as an important cleaner in tropical reef environments, yet its clients remain relatively undescribed in the literature. Here, we report observations of their cleaning behaviour when interacting with different species of cryptobenthic fish clients. The study was conducted in Bahia state, northeast Brazil. In this region, French angelfish were seen cleaning four different species of cryptobenthic species, respectively, Coryphopterus glaucofraenum, Scorpaena plumieri, Labrisomus cricota, and Scartella cristata. These records show the broad spectra of clients that cleaners interact with in coral reef systems, as well as give important insights into the poorly known cryptobenthic fishes habits and ecology.

Endemic fish species structuring oceanic intertidal reef assemblages

Intertidal reef environments are facing a global crisis as climate changes are causing sea-level rise. Synergistically, other human-induced impacts (e.g., sewage, habitat loss) caused by concentration of human populations near the coast increase the natural vulnerability of intertidal ecosystems. However, the effect of these threats have long been neglected due, in part, to a limited knowledge of some aspects of intertidal fish ecology. We tested what are the main differences and drivers in fish assemblages structure between tidepools in three oceanic and three continental shelf (coastal) sites of the tropical southwestern Atlantic (Brazilian Province) using standardized sampling methods. Oceanic and coastal fish assemblages were distinctly structured at the trophic and composition levels. The noteworthy endemism species rate (38–44%) and high densities in oceanic sites are supported by resident species restricted to mid and high-shore tidepools where herbivores were the major trophic group. The coastal sites, on the other hand, were dominated by widely distributed and carnivore species. Physical (substrate type, pool height, subtidal distance and rock coverage), biological (sessile animal coverage) and chemical (salinity) parameters act as the driving forces influencing fish spatial occupancy. Here, clear evidences of high fish endemism and importance of endemics structuring oceanic communities may act as the last straw in favor of the conservation of oceanic intertidal reefs.