Marine Invertebrates

INFORMATION ABOUT THE MARINE INVERTEBRATES IN CERRO VERDE

2007: CARRANZA, A. Pilot programme of ecosystem monitoring in Cerro Verde (Uruguay): two years of malacological assessment.Tentacle.The

Newsletter of the IUCN/SSC Mollusc Specialist Group, 15: 22-23. http://alvar.carranza.googlepages.com/Tentacle15.pdf

Pilot programme of ecosystem monitoring in Cerro Verde (Uruguay): two years of malacological assessment By A. Carranza Coastal development, land based chemical and nutrient pollution and shipping practices combine to alter the structure and functioning of marine and coastal ecosystems globally. Implementation of marine protected areas (MPAs) is a critical issue for the protection of marine life and their habitats. These areas may provide multiple benefits, including protection of habitat, conservation of biodiversity, insurance against environmental uncertainty and sites for scientific investigation, baseline information, education and recreation. Cerro Verde (Uruguay) is being implemented as the first marine protected area in the country, covering over 510 km2 of a marine-coastal ecosystem. Endangered molluscs potentially contained within the reserve include the gastropods Olivancillaria contortuplicata, O. teaguei and Olivella formicacorsii (Mansur et al., 2003, Scarabino, 2004). However, data on molluscs and other marine invertebrates in the area are scarce, mostly qualitative and scattered in the literature (Scarabino et al., 2006a, b). In the first step of this project, we gather extensive quantitative data on species abundance, distribution, and temporal variation on intertidal and subtidal rocky platforms. This allowed us to obtain the first complete faunal inventory for this environment and to explore the ecological factors controlling local biodiversity. The first results will bepublished in a peer-reviewed international journal in 2007 (Borthagaray & Carranza, in press).

The molluscan assemblage of the intertidal and shallow subtidal rocky platforms is dominated by the mussel Brachidontes rodriguezi, followed in percent cover by Perna perna. The former is able to develop monocultures, principally in the higher intertidal. Scattered, small specimens of Mytilus edulis platensis are occasionally found, together with the mytilid Modiulus carvalhoi. The mussel beds and algae provide spatial heterogeneity for the development of a complex assemblage. At least two more bivalve species (Sphaenia fragilis and Entodesma patagonicum) thrive among the mussel beds.

Gastropods are represented in the upper shore by Echinolittorina lineolata and the limpets Lottia subrugosa and Siphonaria lessonii, the latter species also extending into the low intertidal and shallow subtidal. Costoanachis sertulariarum is commonly found associated with mussel beds in the lower and mid intertidal, where the larger whelk Stramonita haemastoma feeds on mussels. Another predator, the whelk Hanetia hanetti, is found in the low intertidal. With the chiton Chaetopleura sp., a total of 13 mollusc species occurr in the Cerro Verde rocky intertidal. This two-year study has thus provided a qualitative and quantitative baseline for the evaluation of environmental impacts within the MPA.

In order to complete the faunal inventory, we now aim to explore the soft-bottom invertebrate fauna within the reserve by means of benthic surveys onboard the artisanal fleet, using appropriate sampling devices such as epibenthic dredges, shrimp trawl nets and Van Veen dredges. This will allow us to obtain information on benthic invertebrate diversity in the entire area, improving the scientific information needed to effectively manage the MPA.

Borthagaray, A.I. & Carranza, A. in press. Mussels as ecosystem engineers: their contribution to species richness in rocky littoral community. Acta Oecologica. Mansur, M.C.D., Heydrich, I., Pereira, D., Richinitti, L.M.Z., Tarasconi, J.C. & de C. Rios, E. 2003. Moluscos. In: Livro vermelho da fauna ameaçada de extinção no Rio Grande do Sul (eds Fontana, C.S., Bencke, G.A. & Reis, R.E.), p. 49-71. EDIPUCRS, Porto Alegre. Scarabino, F. 2004. Conservación de la malacofauna uruguaya. Comunicaciones de la Sociedad Malacológica del Uruguay 8(8283): 267-273. Scarabino, F., Zaffaroni, J.C., Carranza, A., Clavijo, C. & Nin, M. 2006a. Gasterópodos marinos y estuarinos de la costa uruguaya: faunística, distribución, taxonomía y conservación. In: Bases para la conservación y el manejo de la costa uruguaya (eds Menafra, R., Rodríguez-Gallego, L., Scarabino, F. & Conde, D.), p. 143-

156. Vida Silvestre (Sociedad Uruguaya para la Conservación de la Naturaleza), Montevideo. Scarabino, F., Zaffaroni, J.C., Clavijo, C., Carranza, A. & Nin, M. 2006b. Bivalvos marinos y estuarinos de la costa uruguaya: faunística, distribución, taxonomía y conservación. In: Bases para la conservación y el manejo de la costa uruguaya (eds Menafra, R., Rodríguez-Gallego, L., Scarabino, F. & Conde, D.), p. 157170. Vida Silvestre (Sociedad Uruguaya para la Conservación de la Naturaleza), Montevideo. ___________________________________________________

2008: SEGURA, A., DELGADO, E., CARRANZA, A. The red shrimp fishery in Punta Del Diablo (Uruguay): a first approach. Pan American Journal of Aquatic Sciences,3(3):232-236. http://alvar.carranza.googlepages.com/PanamJAS_33_232-236.pdf

The red shrimp Pleoticus mulleri is captured along most of its distribution range. In Uruguay, it is targeted by the artisanal fleet operating in the Atlantic coast, although a description of the fishery is lacking for this area. The highest fishing effort is located in Punta del Diablo, where the fishing season lasts from September-October to December. This fishery is operated by 7 small vessels (7-9 m) in journeys lasting from 8 to 12 h. The total shrimp-catch per fishing season is ca. 12 tons. By-catch consisted in 27 fish species (21 bony fishes and 6 Condrictians), 11 mollusks species, 9 crustacean species, 2 echinodermatan and one polychaete. We registered interactions with the South American sea lion Otaria flavescens that resulted in gear damage. Larus dominicanus was the most abundant avian species feeding on discarded organisms. During fieldwork, we experienced an important cooperation from the artisanal fishing community, which needs to be linked to scientific knowledge towards a co-management experience.

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2008: CARRANZA, A & BORTHAGARAY, AI. The brown mussel Perna perna in the native mussel beds of Cerro Verde (Uruguay).JMBA2 - Biodiversity Records, Publicado online. http://alvar.carranza.googlepages.com/6000Carranza.pdf

Uruguayan mussel beds are located along the estuarine gradient caused by the interaction of the Rio de la Plata runoff and the Atlantic Ocean, changing in species composition across this gradient. In the oceanic portion of the gradient, the exotic Perna perna showed a sequence of local extinction-colonization episodes since at least the second half of 20th Century, thus altering the dominance relationships within the mussel beds. Owing to its larger size, this species may have caused profound effects on the spatial structure of the mussel beds and consequently on its associated macrofauna. In this vein, we analyzed patterns in zonation, abundance and dominance of mussel species in a mussel bed located in the oceanic portion of the Uruguayan coast in relation to tidal and exposure level. We also evaluated if these factors could

affect the dominance patterns between mussel species. The main results showed that the dominance of the native mussel Brachidontes rodriguezii was consistent across all tidal levels in all sites in terms of absolute and relative abundance, with the exception of the shallow subtidal at the intermediate site, where P. perna dominated over this species in terms of relative abundance. This suggests that the effect of an invasive mussel is highly dependent on the receptive assemblage, and that the outcome of interespecifc competition can also be modulated by small-scale factors. ___________________________________________________

2007. Carranza, A. INVESTIGACIÓN, MONITOREO Y CONSERVACIÓN: INVERTEBRADOS BENTÓNICOS DEL AREA MARINA PROTEGIDA DE CERRO VERDE (ROCHA, URUGUAY). 5° Encuentro de Ecoturismo y Turismo Rural y IV Congreso Nacional de Áreas Naturales Protegidas. Trinidad, Flores, Uruguay, 25 – 28 de Abril de 2007. Pág. 45 La implementación de áreas marinas protegidas (AMPs) es considerada una medida indispensable para la conservación in situ de la diversidad biológica. Sin embargo, para la detección de posibles fenómenos de erosión de la biodiversidad y de especies introducidas es indispensable disponer de un inventario taxonómico preciso y actualizado. Esto resulta particularmente relevante para el caso de los invertebrados bentónicos, el cual constituye el grupo zoológico más importante en términos de número de especies. En Uruguay, el área de Cerro Verde (Rocha), fue designada como la primera área marina protegida dentro del Sistema Nacional de Áreas Protegidas. Sin embargo, la escasa información previa dificulta la cuantificación y detección de impactos ambientales y limita la capacidad de manejo del AMP. En tal sentido, en el marco del proyecto “Pilot programme for ecosystemic monitoring in Cerro Verde (Uruguay): benthic invertebrates as a tool for conservation”, se está realizando un monitoreo de la diversidad y abundancia de la comunidad bentónica. La primera fase del proyecto (2005-06) se centró en el estudio de los invertebrados del intermareal rocoso y permitió identificar hasta el momento tres especies nuevas para Uruguay. En la segunda fase (2007), se están realizando muestreos sistemáticos a bordo de embarcaciones artesanales, empleando los artes de pesca utilizados comúnmente por los pescadores locales (i.e. red camaronera) así como mediante el empleo de rastras epibentónicas. En el muestreo piloto realizado en Enero de 2007 se colectaron 13 taxa de macroinvertebrados bentónicos, siendo dominantes los crustáceos Loxopagurus loxochelis y Libinia espinosa (45,31 y 26,56% de los individuos colectados). Otros grupos bien representados fueron los moluscos (Pachycymbiola brasiliana, Buccinanops cochlidium y B. duartei), los cnidarios (Antholoba achates) y los equinodermos (Mellita quinquiesperforata). Además, se colectaron dos especies de decápodos, Hepatus pudibundus y Araneus cribarius y varias especies de peracáridos aun no identificados. La información obtenida durante este proyecto permitirá conocer en profundidad la diversidad de invertebrados bentónicos en el área y su variabilidad espacial y temporal, proveyendo una herramienta útil para el monitoreo y manejo del AMP. ___________________________________________________

2007: BORTHAGARAY, A. I. & CARRANZA, A. Mussels as ecosystem engineers: Their contribution to species richness in rocky littoral community. Acta Oecologica 31: 243-250. http://alvar.carranza.googlepages.com/BorthagarayCarranza.pdf

Mussels are important ecosystem engineers in marine benthic systems because they agregate into beds, thus modifying the nature and complexity of the substrate. In this study,we evaluated the contribution of mussels (Brachidontes rodriguezii, Mytilus edulis platensis,and Perna perna) to the benthic species richness of intertidal and shallow subtidal communities at Cerro Verde (Uruguay). We compared the richness of macrobenthic species between mussel-engineered patches and patches without mussels but dominated by algae or barnacles at a landscape scale (all samples), between tidal levels, and between sites distributed along a wave exposition gradient. Overall, we found a net increase in species richness in samples with mussels (35 species), in contrast to samples where mussels were naturally absent or scarce (27 species). The positive trend of the effect did not depend upon tidal level or wave exposition, but its magnitude varied between sites. Within sites, a significant positive effect was detected only at the protected site. Within the mussel engineered patches, the richness of all macro-faunal groups (total, sessile and mobile) was positively correlated with mussel abundance. This evidence indicates that the mussel beds studied here were important in maintaining species richness at the landscape-level, and highlights that beds of shelled bivalves should not be neglected as conservation targets in marine benthic environments. ___________________________________________________

2007: CARRANZA, A, BORGES, M, RODRÍGUEZ, M & BORTHAGARAY, AI. Ophiuroidea (Echinodermata) from La Coronilla-Cerro Verde (Uruguay): a new record for the Uruguayan coast. Biota Neotropica, 7(3). http://www.biotaneotropica.org.br/v7n3/pt/fullpaper?bn01607032007+en

La Coronilla-Cerro verde has been proposed as the frst marine protected area in Uruguay. As part of a detailed benthic biodiversity assessment at the reserve, we analyzed the ophiuroid fauna collected in the intertidal and shallow subtidal during 2005 and 2006. Three species of ophiuroids were identifed: Amphioplus lucyae, Amphipholis squamata and Amphiodia sp. Only two species belonging to the genus Amphiodia (A. pulchella and A. planispina) have been previously mentioned for Uruguayan waters, indicating that the unidentifed species found in this study constitutes a previously unreported species. ___________________________________________________

2007: CARRANZA, A., BORTHAGARAY, A. I. & GENZANO, G. N. Two new records of pycnogonids on the Uruguayan coast. Brazilian Journal of Biology, 67 (2):373-375. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S151969842007000200026&lng=&nrm=iso&tlng=

The Pycnogonida from Uruguayan waters are scarcely known, and their reports are markedly discontinuous. In this paper, several individuals of two previously unrecorded Pycnogonids at the shallow rocky subtidal and lower intertidal fringes of Cerro Verde (Rocha, Uruguay) are reported. The specimens were assigned to Pycnogonum pamphorum Marcus, 1940 and Anoplodactylus petiolatus (Kroyer, 1844). This is the first record of these species on the Uruguayan coast and the southernmost record of P. pamphorum, previously recorded only in Santos, Brazil (type locality). ___________________________________________________

Fabrizio Scarabino. TWO GASTROPODS ASSOCIATED WITH FLOATING OBJECTS FROM THE URUGUAYAN COAST. Comunicaciones de la Sociedad Malacológica del Uruguay. 8 (82–83): 275–277. 2004 www.smdu.org.uy/82-83/8283-275.PDF

The gastropods Litiopa melanostoma Rang, 1829 (Caenogastropoda: Litiopidae) and Fiona pinnata (Eschscholtz, 1831) (Nudibranchia: Fionidae) are recorded for the first time from Uruguayan waters based in material collected on the coast of Rocha. This is the southernmost record for these species in the Western Atlantic Ocean, and the first one of F. pinnata from the Atlantic South American coast.