Check List 10(4): 795–807, 2014 © 2014 Check List and Authors Chec List ISSN 1809-127X (available at www.checklist.org.br) Journal of species lists and distribution Inventory of the marine soft bottom macrofauna of São PECIES S Sebastião Channel, southeastern Brazilian continental OF shelf ISTS L Ana Maria S. Pires-Vanin 1*, Pablo Muniz 2 and Sandra Bromberg 1 * 1 CorrUniversidadeesponding de author. São Paulo, E-mail: Instituto [email protected] Oceanográfico, Praça do Oceanográfico 191, Cidade Universitária, 05508-120, São Paulo, SP, Brasil. 2 Universidad de la República, Facultad de Ciencias, Oceanografía y Ecología Marina, Iguá 4225, Montevideo 11400, Uruguay. Abstract: Sebastião Channel at depths ranging from 2 to 45 m yielded 431 species from a total of 38,630 individuals. The present contribution Analysis gives a oflist macrofauna of the species from found 91 quantitative in the area soft-bottom and their depthsamples distribution (from five andsurveys) sedimentary obtained preferences in the São invertebrate soft-bottom fauna of the São Sebastião Channel, a peculiar marine area under crescent human impact. (granulometric characteristics of the sites where they occurred). This is the first complete inventory of the subtidal DOI: 10.15560/10.4.795 Introduction as barrier for the adjacent open sea. The channel itself is Ecological studies are deeply entangled with the about 25 km long with two relatively large openings (6-7 biodiversity knowledge of a given region or system. The km wide) and a narrow central part of nearly 2 km in São Sebastião Channel (SSC) is a conspicuous area located width. It presents fan-like features in the south and a well in the southeastern Brazilian shelf, submitted to a complex sorted sand barrier in the north. Also, its northern region oceanographic regime (Castro and Miranda, 1998) and multiple human impacts (Zanardi et al. 1999; Arasaki et al. 2004; da Silva and Bícego, 2010). The channel harbors the thehas continentala counter-clockwise margin, an vortex,area of whichlow hydrodynamics. transports fine In main maritime oil terminal in Brazil (Dutos e Terminais thegrains central to the deepest south, causingparts of deposition the channel of nofine-sediment deposition ofat sediments occurs, probably due to the increase in current speed caused by narrowing (Furtado 1995; Furtado et al. thatCentro contributes Sul — DTCS), with thelarge commercial amount of sewageSão Sebastião to the area. Port, 2008). withIn intenseorder tofishery describe activity, the speciesand the composition São Sebastião of citythe Although marine currents in Southern Brazilian unconsolidated bottom in the SSC, the present study shelf are variable in space and time, they mainly move reports macrofauna species found along the channel during towards the NE in the SSC (Castro Filho 1990), except in summer (Fontes 1995), when a two-layer opposite water projects. The “Oceanography of São Sebastião Channel” (OPISSfive surveys Project, performed Pires-Vanin as part2008) of andtwo theinterdisciplinary “Assessment of benthic fauna and organic contamination in critical flow establishes, the superficial flow directed to the SW areas of São Sebastião Channel” (CONCASS Project), and the deep flow towards the NE. The bottom current both supported by Fundação de Amparo à Pesquisa do is notcharacterized influenced by by low wind temperature but may be (<18°C) associated and withhigh Estado de São Paulo (FAPESP). The depth range of each salinitythe South (>36). Atlantic For the Central rest of Water the year (SACW) the prevailing intrusion water and species and the dominant sediment type of the sampling stations where they occurred were reported as means of than 20°C and salinity lower than 34.5 (Castro Filho et al. 1987).mass is For the detailed Coastal physical Water (CW) and biological with temperature characterization higher of the SSC and of the main processes responsible ofdistinguish soft-bottom and definemacrofauna their ecological at São Sebastiãopreferences. Channel. This is by the maintenance of the populations see Pires-Vanin Inthe order first comprehensiveto create an initial inventory scenario of the for subtidal future work species in (2008). ecology, monitoring and management it is important to The São Sebastião Channel is also affected by multiple know actual diversity of the area. human activities. It harbours one of the largest oil terminals in Brazil (Dutos e Terminais Centro Sul, DTCS), a Material and Methods commercial port and it is also an important tourist place. The São Sebastião Channel is located on the northern Given the frequent oil spills, dredge activities and sewage discharge from both the “Araçá” pipe and the neighbor cities, SSC is subjected to great environmental stress (da thecoast continent of São Paulo from State the São(23°41′–23°53.5′ Sebastião Island S, 45°19′–45°30′ and functions Silva and Bícego, 2010). W), Brazil (Figure 1). It lays parallel to the coast, separate 795 Pires-Vanin et al. | Macrofauna from São Sebastião A total of 431 species of invertebrates were found, out in the framework of the two interdisciplinary projects being Polychaeta the dominant group with 181 species mentionedThe present before. data For are OPISS the result four seasonalof five surveys surveys carried at 15 belonging to 42 families. Among these, 6 families were oceanographic stations were performed (two replicates, distinguished for their higher species richness: Spionidae (12 species); Orbiniidae (11 species); Onuphidae and perpendicular to the axis of the channel (Figure 1a), and Eunicidae (10 species each); Syllidae and Paraonidae (9 were120 samples).carried out They in November were distributed 1993, February, in five April radials and species each) (Table 3). August 1994 on board of the boats “Veliger II” and “Albacora” Mollusca presented 119 species, from which 75 were from the Oceanographic Institute of the University of São bivalves found in mixed sand substrates, especially in Paulo. For the CONCASS project one survey was carried out represented by 57 species of Peracarida and 42 species of replicates, 93 samples). Stations were positioned with GPS Decapoda.very fine grains. Amphipoda Another characterizes diversified grouphalf of wasthe PeracaridaCrustacea, (Globalin June Positioning2002 at 31 System)stations andaccording depths to were figure measured 1b (three by species, whereas Brachyura did the same for the Decapoda. Sampling was carried out The last diverse group was Ophiuroidea, encompassing 18 using a van Veen grab of 0.1 m2. The sediment was washed species from a total of 24 found for echinoderms. All the onsounding board withthrough “Fish 0.5 – mmFinder”. mesh sieves and the material species reported here are from southern Brazilian inner retained was preserved in 70% ethanol. In the laboratory, shelf, area under temperatures between 18 and 25°C most sediments were elutriated (Santos et al. 1996) before of the year (Soares-Gomes and Pires-Vanin 2005; Pires- Vanin 2008). For detailed studies about structure of benthic SB,sorting Polychaeta; and identification AMSPV, Crustacea)under stereoscopic and by microscope.some other communities in the SSC see Muniz and Pires (1999; specialistsSpecies (Ewere Schelenz, identified University by the of authorsSão Paulo (PM - USP,and 2000), Pires-Vanin (2008); for functional ecology data see Anthozoa; SA Vanin, USP, Mollusca; AMG Monteiro, UNESP, Arasaki et al. (2004) and Pires-Vanin et al. (2013) and for Botucatu, Echinodermata; EF Nonato, USP, Polychaeta). ecosystem functioning Venturini et al. (2011; 2012). database (Rosenberg 2009) was used for checking up the Discussion taxonomicWoRMS (WoRMS status ofEditorial the polychaete Board 2014) and mollusk and Malacolog species, Our present results showed that despite the relative respectively. The material is deposited at the “Biological small study area, the channel presented high number of Collection Prof. Edmundo F. Nonato” (ColBio) of the species, similar to that found in the adjacent São Sebastião shelf (Pires-Vanin 2008). However, comparison of diversity results with others reported in the current literature may ResultsInstituto Oceanográfico USP. be done with caution since the sampling methods, units Table 1 and 2 present geographical coordinates, depth and scales are often different, and moreover the diversity and sediment type of the sampling stations. Depth varied of habitats in tropical and subtropical ecosystems are high between 2 and 45 m with the deeper places situated in the (Chardy and Clavier 1988; Alongi 1990). From the high middle of the channel axis. Sand sediment composed by number of species reported (431) nearly 25% cannot many classes of grain sizes was patchy distributed along the bottom, except in the channel’s central part where case of mollusks, or were new species, as in the case of muddy sites occur. crustaceansbe identified, Isopoda or because and Cumacea. they were However, juveniles, that as number in the Figure 1. São Sebastião Channel, Southeastern Brazilian shelf, showing the sampling stations. 796 Pires-Vanin et al. | Macrofauna from São Sebastião Table 1. Environmental variables studied at the 15 stations in the four surveys carried out in São Sebastião Channel (OPISS Project). CS = coarse sand; MS = medium sand; FS = fine sand;STATIONS VFS = very fine sand;LATITUDE SC = coarse (S) silt;LONGITUDE SM = medium (W) silt; SFDEPTH = fine (m)silt. SEDIMENT TYPE Spring (November/93) 1 15 FS 2 26 SF 3 23°50′24″ 45°29′42″ 10 CS 4 23°52′42″ 45°27′30″ 10 VFS 5 23°53′00″ 45°27′06″