Macroinfaunal Distribution at an Organic-Enriched Estuarine Harbour: Quequén Grande River Inlet, Argentina

GRAVEL ISSN 1678-5975 Dezembro - 2011 V. 9 – nº 1 57-67 Porto Alegre

Godoy, C.E.1; Isla, F.2 & Elías, R.1

1 Departamento de Ciencias Marinas, Universidad Nacional de Mar del Plata. Funes 3350, Mar del Plata, Argentina ([email protected]). 2 Instituto de Geología de Costas y del Cuaternario, Universidad Nacional de Mar del Plata. Casilla de correo 722, Mar del Plata, Argentina.

ABSTRACT

Estuarine benthic assemblages are highly sensitive to pollution. At the same time, they are sensitive to chemical and/or physical changes induced by tides or floods. The estuary of the Quequén Grande River is occupied by a harbour with a constant trading of cereals. Benthic communities are best environmental indicators. In order to evaluate the health of the harbour, a limited sampling of infaunal benthic community was carried out. Nematodes and Capitella "capitata" sp. were the most common species. As the harbour is enriched in organic matter derived from the cities of both margins and the jetties inhibit wave or wind action on the bottom, anoxic conditions prevail almost all year. Therefore, the disposal of the anoxic muds dredged is matter of concern in relation to resort beaches. Peak discharges of the river, constant dredging and the enrichment with organic matter are explaining the present distribution and abundance of these communities.

Palavras chave: macrobenthos, Quequén Harbour, multivariate analyses.

58 Macroinfaunal Distribution at an Organic-Enriched Estuarine Harbour: Quequén Grande River Inlet, Argentina

INTRODUCTION De Ferrera, 1998; Cortizo & Isla, 2000; Perillo et al., 2004). The area was also of concern in Benthos is particularly sensitive to any type relation to urban sewage disposals (Polizzi, of substrate (Elías et al., 2004), but in coastal 2006). To the headlands of the harbour there are areas and estuaries the salinity becomes the most recreational activities related to nautical sports important conditioning factor. Pollution can be and fishing facilities. The watershed is another significant variable affecting highly asymmetric receiving water from the left populated and industrialized areas (Estacio et margin. River discharge usually increases during al., 1997), increasing in low-energy sectors. summer months between a minimum of 6 to a Organic matter derived from domestic wastes is maximum of 167 m3/s (Teruggi et al., 2005). a common pollutant in highly populated areas In this paper, the distribution of subtidal (Méndez, 2002); the increase in nutrients leads macrobenthic community from a harbour to euthrophication. Marine benthic communities, located at the outer marine sector of the especially the macrobenthic infauna (>0.5 mm Quequén estuary was analyzed. Its distribution in body length), have been widely regarded as is related to environmental variables of water bioindicator for monitoring coastal pollution. (salinity, temperature, pH, turbidity) and Sessile infauna is sensitive to environmental sediment (grain size and organic-matter changes such as nutrient and oxygen content). concentration. The principal effects of organic wastes when is incorporated to the sediments are MATERIALS AND METHODS hypoxia (low content in oxygen), anoxia (lack of oxygen) and alteration of the benthic structure Study area (composition, diversity, abundance). The communities become qualitative and structurally The Quequén Grande River is located to the simpler, been the opportunistic k-strategic south of Buenos Aires Province (38º40'S; species replaced by the r-strategic species. 58º45'W), flows to the south of the Tandilia Benthos respond quickly to environmental Range. In its meandering reaches the width is changes, frequently showing an ecological slightly variable between 150 and 200 m and succession. Such changes are within the depth fluctuates between 2 and 4 m (Piccolo & community rather than between communities Perillo, 1997). The construction of the Quequén (Pearson & Rosenberg, 1978). Sensitive species Harbour sued, in addition to the construction of disappear, and only few species can tolerate it jetties, the dredging of the last 2 km of the and eventually proliferate. In an extreme estuary (Fig. 1). Accordingly, in harbour the situation the macrobenthos community can depth reaches 10 – 12 m and the circulation is disappear. Benthic organisms are also of special very low. Sea water dominates at the bottom concern to analyse the results of dredging during common tides; however this pattern may activities, involving not only grain-size be completely altered after peak discharges variations but also total organic carbon (TOC) (Perillo et al., 2004). The magnitude of flooding effects (US Army Corps of Engineers, 1996). is important because they are significant and Harbours from the Southern Hemisphere are fairly frequent. One of the largest occurred in poorly known in terms of their infaunal 1980 with peaks of 200 m3/s that destroyed the communities. There are only some rapid three major bridges of the estuarine area (Perillo characterisation of the sewage outlets at the et al., 2004). The major sources of ports of Montevideo (Danulat et al., 2002; contamination are the urban outfalls of Muñiz et al., 2004) and Mar del Plata (Rivero et Necochea and Quequén that discharge their al., 2005). Dealing with the Quequén Harbour, wastes directly into the system (Polizzi, 2006). foraminifera, gastropods and bivalves At the harbour, there are also illegal sewer distributions were related to the salinity regime disposals. Necochea has a Combined Sewer (Boltovskoy & Boltovskoy, 1968; Wright, 1968; Outfall (CSO) to the estuary for storm events. Lopez-Gappa et al., 1990; De Francesco & Isla, Quequén harbour is subject to common 2003; Adami et al., 2004). The physics of the accidental dumping of cereal grains (Perillo et estuary is clearly related to the tidal and fluvial al., 2004) and, the Power Plant discharges water effects (Piccolo & Perillo, 1997; 1999; Campo 5-7ºC higher than the estuary (Wright, 1968).

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Figure 1. Location map and of sampling stations.

Sampling was performed on 15 May, 2007 Multivariate analyses were performed by with a Pomar type grab (0.025 m2). Sampling means of the PRIMER program (Plymouth design include 10 sites within the harbour, and Marine Laboratory, UK) analyzing changes in four outside sites (as reference). However only 5 abundance and species composition. The stations could be sampled, with three replicates ordination was carried out with the each (2 in station 5). Station 1 was located in the multidimensional scaling (MDS) on the inner harbour, called “Broken Bridge”, adjacent untransformed abundance of all benthic species to a discharge of an outfall of Necochea (CSO). and the similarity percentage analysis (SIMPER) The subsequent sampling sites were located to discriminate the species that most contributed towards the inlet: stations 2 and 4 in the vicinity to differentiate stations. The average of the of the docks and, station 3 in the centre of the species richness (S), the mean abundance (A), port. Station 2 was front of Silos (cereals the Shannon diversity index (Shannon & deposits). Station 5 is almost in front of the Weaver, 1963) and the evenness index (Pielu, discharge of the cooling waters of the 1969), were calculated for each station. A one- Thermoelectric Power Plant. way ANOVA test was carried out with these Environmental variables in the water column parameters in order to establish differences (salinity, temperature, pH, turbidity and depth) among stations (Zar, 1984). were measured in situ using a water-quality checker Horiba U-10. Sediment samples in each RESULTS station were obtained for grain size analysis and organic matter content. The cereal seeds find A total of 2,137 individuals representing 15 into the sediment were also counted. The taxa were determined (Tab. 1). More than 97% samples were sieved through a 0.5 mm mesh, of the total abundance corresponded to only 4 and the retain organisms fixed with 5% taxa: Nematods, Capitella "capitata" sp., Alitta neutralized formaldehyde on board. In succinea and Onuphis dorsalis. laboratory the material was transferred to alcohol 70% after the identification and Multivariate analysis quantification of specimens under stereoscopic microscope. Sediment samples were also sieved The multidimensional scaling analysis through a mesh of 0.0625 mm to separate sand (MDS) of the average abundance (stress= 0) did from mud (silt and clay). The titration method of not clearly discriminate groups, although Walkley & Black (1970) was used to quantify represent almost exactly the spatial sampling the organic matter content in sediments, and pattern (Fig. 2). expressed in percent of mud and sand.

GRAVEL 60 Macroinfaunal Distribution at an Organic-Enriched Estuarine Harbour: Quequén Grande River Inlet, Argentina

Table 1. Abundance of specimens collected in all simples. Taxa Abundance (%) Nematods 74,400 Capitella "capitata" sp. 20,960 Alitta succinea 1,450 Onuphis dorsalis 0,840 Laeonereis culveri 0,560 Paraonidae indet. 0,470 Polychaete indet. 0,420 Pelecypod indet. 0,280 Syndesmia sp. 0,190 Glycera americana 0,140 Cyrtograpsus angulatus 0,046 Parandalia tricuspis 0,046 Lumbrineris tetraura 0,046 Tellina sp. 0,046 Nucula puelcha? 0,046

(CSO), dominated exclusively by Nematods;

b) Stations 2 and 4, located in the docks, dominated by Nematods and Capitella "capitata" sp., accompanied by Alitta succinea;

c) Stations 3 and 5, in the middle of the estuary and along the port, with Capitella "capitata" sp., but accompanied by Nematods, Onuphis

dorsalis and Laeonereis culveri. Figure 2. Multidimensional scaling of untransformed biological data. Nematods and Capitella "capitata" sp. was The SIMPER analysis (Tab. 2) showed three dominant and frequent in the macroinfauna groups: Quequén Grande harbour. Two MDS were performed, one for each dominant species, in the modality that shows the relationship between a) the station 1, close to the Broken Bridge and the combined sewer outflow stations abundances for species (Fig. 3).

Capitella “capitata” sp. Nematods Figure 3. Abundance of the dominant species at different stations.

GRAVEL Godoy et al. 61

Table 2. Similarity percentage Analysis (SIMPER) showing the species that most contributed to the differences among samples.

Species 1 2 3 4 5

Nematods 335,33 62,67 12 117,33 2

Capitella "capitata" sp. 77,67 13,33 54 8,5

Alitta succinea 10,33

Onuphis dorsalis 2 1.33 4

Laeonereis culveri 4

Univariate analysis dominance; group II, with high abundance and by the dominance of a few species, and group The stations grouped have also a very similar III, more diversified (annelids) and very low quantitative structure, especially in richness, abundance (Fig. 4). Differences between stations abundance and evenness. Station I, was were significant for all parameters (Tab. 3). characterised by higher abundance and

Abundance (A) Richness (S)

Diversity of Shannon and Weaver (H') Evenness (J') Figure 4. Population parameters at different stations of Quequén Harbour.

GRAVEL 62 Macroinfaunal Distribution at an Organic-Enriched Estuarine Harbour: Quequén Grande River Inlet, Argentina

Table 3. One-way ANOVA of average community parameters: Richness (S), Abundance (A), Evenness (J´) and Diversity (H´).

SUM OF DF ERROR F P SQUARES S 4 16,84 3,31 5,08 0,020238* N 4 46771,8 7637,1 6,12 0,011591* J´ 4 0,19 0,04 4,19 0,047913* H´ 4 1,33 0,35 3,80 0,044506*

Bottom salinity (40 PSU) and temperature a higher content of organic matter and less (14ºC) were constant, except close to the power turbid waters with lower pH. The greatest plant where water was diluted (25 ups) and number of seeds is located on the docks, warmer (15ºC). The bottom is composed of mud especially in the deepest station, in front of the and fine sand, varying in relation to depth and (Silos Station 2) (Fig. 5). distance from the sea. Stations 2, 3, 4 and 5 have

Organic matter pH

5 8,8

4 8,6 8,4 3 8,2 2 8 7,8 1 7,6 0 7,4 1 2 3 4 5 1 2 3 4 5 Stations Stations

Mud (%) Depth(m)

100 16 80 14 12 60 10 40 8 6 20 4 0 2 0 1 2 3 4 5 1 2 3 4 5 Stations Stations

Seeds Turbidity

250

120 200 100 150 80 100 60

40 50

20 0

0 1 2 3 4 5 1 2 3 4 5 Stations Stations

Figure 5. Main environmental variables measured at stations.

DISCUSSION Blanca port complexes (Piccolo & Perillo, 1999). As the harbour is subject to significant The Quequén harbour is the third important change in its dynamics (one of the jetties was harbour in the Buenos Aires Province, extended), it becomes necessary to analyze the subordinate only to the Rio de la Plata and Bahía macrobenthos distribution in order to recognise

GRAVEL Godoy et al. 63 impacts or long-term changes. Engineering feeding behaviour and survival of benthic improvements at the Seine estuary, for example, organisms (US Army Corps of Engineers, 1996). provoked significant changes in the dynamics, Polychaetes selected in response to different sediment concentration and benthic distribution grain sizes (Gaston, 1987), organic carbon on both margins (Desprez & Dupont, 1986). content, the presence of other polychaetes The bottom of the harbour is a marine (Kristensen, 1988), specific textures and specific environment; we don’t observed effect of the gravity (Self & Jumars, 1978). Previous studies river during the sampling. The saltwater stated that the distribution of Capitella intrusion was recorded and the salinity was "capitata" sp. depends on the larval habitat identical to that of the adjacent sea. We think selection, as they tend to settle in places rich in that may be due to a malfunction of the Horiba organic matter (Thiyagajan et al., 2005), feed U-10. The seabed is composed of a mixture of preferentially in muddy sediments (Grassle et mud and very fine sand. The deeper parts are al., 1992). In Quequén harbour, the grain size muddy (Stations 2, 3), but sandy toward the does not seem to be determinant factor in the mouth of the estuary (Station 5). Bottom water distribution of Capitella "capitata" sp. For has a basic pH, as caliche crusts dominate at the example, although it is very abundant in Station watershed. These values are consistent with 2 with muddy bottom, the polychaete was those previously reported (De Francesco & Isla, almost absent in Station 3 (with similar 2003) and measured at the Mar del Plata conditions as Station 2). On other hand, the harbour, located 120 km NE (Rivero et al., organic matter is distributed homogeneously 2005). while polychaetes did not. The greater This first characterization of the abundance coincided with large amounts of macrobenthos of the Quequén Grande harbour cereal grains (not reflected in organic-matter revealed a benthic infaunal community largely content and pH). In Hong Kong, capitellid dominated by Nematods and Capitella larvae tend to choose sediments with low "capitata" sp. The Nematods, although belong to carbohydrate/protein ratio (Thiyagajan et al., meiobenthic category, were retained into the 2005). In Quequén, the composition of the sieve due to their large size, reaching large organic matter could play an important role for abundances. Similar results were found the Mar the preferences of larvae (Li & Lee, 1996 in del Plata harbour (120 km northeast) where Thiyagajan et al., 2005). The composition of large Nematods (Viscosia sp.) were retained in organic matter and the hydrocarbon content the sieve, and together with Capitella “capitata” could represent a significant clue for future sp. were also highly dominant (Rivero et al., benthic studies. 2005). Capitellids are restricted to sediments The Quequén Grande River is particularly with higher content in organic matter, low pH subject to episodic floods, some, in coincidence and high turbidity (stations 2, 3, 4 and 5). with ENSO events (Fig. 6; Isla, 2008). Capitella "capitata" sp. becomes dominant Samplings conducted during the Spring 2002 where there was abundance of seeds on a muddy recorded a bed-load transport of 2.4 tons/day bottom. Nematods were located near sewages, and a suspended load of 0.24 g/l (Teruggi et al., dominantly in shallow sandy mud. 2005). The magnitude of sediment deposited Variables such as organic matter, pH and could have multiple biological consequences. turbidity divided the harbour into two benthic High-turbidity levels could persist during many environments: the “Broken Bridge” (Station 1), days and can cause the clogging of some and the dredged area (2, 3, 4 and 5). It is species, particularly those with less mobility assumed that in this latter sector the (Farinati et al., 1991). Studies in Petacalco Bay, decomposition of organic matter occurs under Mexico, revealed that the benthos respond to anoxic conditions, product of increased environmental variability caused by El Niño. sedimentation and lack of renewal of bottom The weather event caused the breaking of the water (see Perillo et al. (2004). Capitella stratification and the turn-over of the water "capitata" sp. was in the dredged sector, which column. Fluctuations in abundance and number agrees with their habitat. Several laboratory and of benthic polychaete species was due to the field studies confirmed that grain size and total reduction in oxygen concentration (Rodriguez- organic carbon (TOC) affect habitat selection, Valencia, 2004). The mud could affect the gill

GRAVEL 64 Macroinfaunal Distribution at an Organic-Enriched Estuarine Harbour: Quequén Grande River Inlet, Argentina filters and disadvantage the suspense-feeders suspended particles (Abarnou et al., 1987). So, (Pearson & Rosemberg, 1978). In the Quequén regardless of the dredging, each peak download Grande estuary, the dominance of sediment it can mean the resuspension of pollutants feeders over the filters-feeders community could (hydrocarbons, heavy metals) sequestered in the be related to the high sedimentation discharges sediment. Other estuaries, as the Lagoa dos rates, fine particles dominance and the high Patos, are particularly stressed by these ENSO- content in organic matter. delivered floods (Martins et al., 2003). The field High discharges of the Seine induce the sampling was conducted some days after one of dispersion of pollutants content in fine these events (approx. 20 days before).

Figure 6. Monthly discharges of the Quequén Grande River.

Benthic communities show symptoms of opportunist by excellence (Pearson & organic pollution. It is interesting to specify Rosemberg, 1978). These zones are some aspects due to the environmental comparable and matched with an area known implications: as “opportunistic peak” in the SAB curves of Pearson & Rosenberg (1978). a) The content of organic matter is low c) Trophic structure. The impact of organic (between 0.5 and 5% is considered waste resulting in trophic structure are well contamination without; Méndez, 2002), but known. In the port of Todos Santos Bay, his values are similar to some places that, on Mexico, the waste caused the replacement of the basis of studies benthonic and / or species and decline of trophic groups for physicochemical, are admitted like enriched. other resistant, all-deposit feeders such as In this case it is possible to exemplify with Capitella "capitata" sp. (Encalada-Fleites & the Urias estuary (Mexico), with 3.66 to Millán-Núñez, 1990). The effects of 10.95% (Méndez, 2002), the Algeciras anthropogenic sources from both cities are Harbour (Spain) between 2.9 and 6.8% evident: the deposit-feeders are virtually the (Estacio et al., 1997) and the port of Mar del only feeding guild present. Plata, between 1.72 and 12% (Rivero et al., d) The polychaetes have a high level of 2005). tolerance to adverse effects – both to b) Macrobenthos. Structure qualitative and pollution and natural perturbation (Burd & quantitative simplicity and indicator Brinkhurst, 1990). Quequén Harbour is species, is compatible with organically riched in polychaetes but scarce in enriched sites. At the Broken Bridge and oligochaetes, crustacean and bivalves. An docks the benthos is characterized by increase of polychaetes in relation to predominance of a few species: Nematodes oligochaetes can be caused by dredging and Capitella "capitata" sp. The polychaete activities in ports with organic enrichment. is considered universal indicator of pollution For example, the channels excavated in the (Pocklington & Wells Pocklington, 1992; Seine estuary caused the decline of Méndez, 2005) and their enrichment populations of some oligochaetes (Tubifex

GRAVEL Godoy et al. 65

costatus) and growth of communities of activities and by the flushing effects induced by Nephtys hombergii (Despres & Dupont, rapid floods at the watershed. 1986). In the same sense, Crustaceans are highly sensitive to organic pollution (Estacio ACKNOWLEDGMENTS et al., 1997). e) Water quality. High levels of faecal Dr. D. Martinez provided discharge coliforms and faecal streptococci, indicate information of the Quequén Grande River. This organic contamination due to the high manuscript has been presented as master thesis number illegal sewer connections to the of the Facultad de Ciencias Exactas y Naturales, storm-water system (Polizzi, 2006). University of Mar del Plata, by one of the authors (CEG). The impact of the chlorinated water drained by the Thermoelectric Power Plant is reflected REFERENCES in the benthos community at stations 5. Only one specimen was sampled near the discharge to ABARNOU, A.; AVOINE, J.; DUPONT, J.P.; 39 in the sample collected furthest. Reductions LAFITE, R. & SIMON, S. 1987. Role of in salinity and dissolved oxygen are common suspended sediments on the distribution of effects of cooling systems operated with fresh PCB in the Seine estuary (France). water (Rodriguez-Valencia, 2004). Continental Shelf Research 7 (11-12): 1345- The lengthening of the western jetty will 1350. reduce the effects of wind and swell that ADAMI, M.L.; TABLADO, A. & LÓPEZ- noticeably affect port activities (Perillo et al., GAPPA, J. 2004. Spatial and temporal 2004). But the decrease in water energy implies variability in intertidal assemblages an increase in the reducing conditions at the dominated by the mussel Brachidontes bottom (perceptible by smell). This type of rodriguezii. Hydrobiology 520: p. 49-59. situation should be avoided as much as possible BOLTOVSKOY, E. & BOLTOVSKOY, A. if it is desired to maintain water quality at the 1968. Foraminíferos y tecamebas de la harbour. In this sense, a reduce in the load of parte inferior del río Quequén Grande. organic matter seems unavoidable. The plan is to Hidrobiología 2: 127-164. remove some sewers and increase the system BURD, B.J. & BRINKHUST, R.O. 1990. capacity towards a new outfall planned at Punta Vancouver Harbour and Burrard Inlet Carballido. Benthic Infaunal Sampling Program, This study has served to not only know the October 1987. Canadian Technical Report structure of the quali-quantitative macrobenthos of Hydrography and Ocean Sciences 122. p. of the place, but has also laid foundations for 49. future disease control programs in the estuary. CAMPO DE FERRERA, A.M. 1998. Organic enrichment in areas with reduced Hidrografía del río de Quequén Grande. hydrodynamics may have more significant than Unpublished doctoral thesis, Departamento in other areas of higher energy (Estacio et al., de Geografía, Universidad Nacional del Sur, 1997). Given the characteristics and importance Bahia Blanca, 141 p. of the estuary a monitoring program is firmly CORTIZO, L.C. & ISLA, F.I. 2000. Land- recommended in order to preserve sanitary cover change and cliff retreat along the conditions in regard to tourism and commercial coasts of Necochea and Lobería, interests. Argentina. Memorias, IX Simposio Latinoamericano de Teledetección, CONCLUSION Universidad Nacional de Luján, Sociedad de Especialistas Latinoamericanos en Regarding the macrofauna distribution and Percepción Remota, Cataratas del Iguazú, 6- abundance, the Quequén Grande River inlet has 10 de noviembre de 2000, 525-533. very high values of organic pollution induced by DANULAT, E.; MUÑIZ, P.; GARCÍA– the handling of cereals at the harbour area. ALONSO, J. & YANNICELLI, B. 2002. These values change significantly with dredging First assessment of the highly contaminated harbour of Montevideo,

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Uruguay. Marine Pollution Bulletin 44: experiments in still water and flume flows. 554.565. Journal of Marine Research 50: 717-743. DE FRANCESCO, C.G. & ISLA, F.I. 2003. ISLA, F.I. 2008. ENSO-dominated estuaries of Distribution and abundance of hydroiid Buenos Aires: The interannual transfer of snails in a mixed estuary and a coastal water from Western to Eastern South lagoon, Argentina. Estuarine, Coastal and America. Global and Planetary Change, 64, Shelf Science 62: 790-797. 1-2: 69-75. DESPREZ, M. & DUPONT, J.P. 1986. Impact KRISTENSEN, E. 1988. Factors influencing biosedimentologique d´amenagements the distribution of nereid polychaetes in portuaries en estuarie de Seine. La Baie de Danish coastal waters. Ophelia 29:127-140. Seine (GRECO-MANCHE). Université de LÓPEZ-GAPPA J.J.; TABLADO A. & Caen, 1985, IFREMER, Actes de colloques MAGALDI, N.H. 1990. Influence of 4: 449-458. sewage pollution on a rocky intertidal DILLON, T.M.; MOORE, D.W. & GIBSON, community dominated by the Mytilid A.B. 1993. Development of chronic Brachidontes rodriguezi. Marine Ecology sublethal bioassay fro evaluating Progress Series, 63: 163-175. contaminated sediment with the marine MARTINS, L.R.; MARTINS, I.R & polychaete worm Nereis (Neanthes) TABAJARA, L.L. 2003. Ocorrência de arenaceodentata. Environmental Toxicology fragmentos de lama na praia do Cassino, and Chemistry 12: 589-605. RS, Brasil. Gravel, 1, 47-53. ELÍAS, R.; IRIBARNE, O.; BREMEC, C.S. & MENDEZ, N. 2002. Annelid assemblages in MARTÍNEZ, D.E. 2004. Comunidades soft bottoms subjected to human impact in Bentónicas de Fondos Blandos. In Piccolo, the Urías estuary. Oceanologica Acta 25: M. C. y Hoffmeyer, M. S. (eds.), Ecosistema 139- 147. del Estuario de Bahía Blanca. Instituto MUÑIZ, P.; DANULAT, E.; YANNICELLI, B.; Argentino de Oceanografía (IADO), Bahía GARCÍA-ALONSO, J.; MEDINA, G. & Blanca, Argentina: 179-190. BÍCEGO, M.C. 2004. Assessment of ENCALADA-FLEITES, R.R. & MILLÁN- contamination by heavy metals and NÚÑEZ, E. 1990. Impact of industrial and petroleum hydrocarbons in sediments of domestic wasre waters on the benthic Montevideo Harbour (Uruguay). communities of Todos Santos Bay, Baja Environment International 29: 1019– 1028. California, Mexico. Ciencias Marinas. 16 PICCOLO, M.C. & PERILLO, G.M.E. 1997. (4): 121-139. Geomorfología e hidrografía de los ESTACIO, F.J.; GARCÍA-ADIEGO, E.M.; FA, estuarios. In Boschi, E. E. (ed.), El Mar y D.A.; GARCÍA-GÓMEZ, J.C.; DAZA, J.L.; sus recursos pesqueros I. Antecedentes HORTAS, F. & GÓMEZ- ARIZA, J.L. históricos de las exploraciones en el mar y 1997. Ecological Analysis in a polluted las características ambientales. Publicación area of Algeciras Bay (Southern Spain): del INIDEP, Mar del Plata, Argentina, 131- external “versus” internal outfalls and 133. environmental implications. Marine PEARSON, T.H. & ROSENBERG, R. 1978. Pollution Bulletin 34: 780-793. Macrobenthic sucesión in relation to FARINATI, E.A., ALIOTTA, S. & organic enrichment and pollution of the GINSBERG, S.S. 1991. Mass mortality of a marine enviroment. Oceanography Marine Holocene Tagelus plebeius (Mollusca Biology Annual Review 16: 229-311. bivalvia) population in the Bahía Blanca PERILLO, G.M.E.; PÉREZ, D.E.; PICCOLO, estuary, Argentina. Marine Geology 106: M.C.; PALMA, E.D. & CUADRADO, D.G. 301-308. 2004. Geomorphologic and physical GASTON, G.R. 1987. Benthic polychaete of characteristics of a human impacted the Middle Atlantic Bight: Feeding and estuary: Quequén Grande River Estuary, distribution. Marine Ecology 36: 251-262. Argentina. Estuarine, Coastal and Shelf GRASSLE, J.P.; BUTMAN, C.A. & MILLS, Science 62:127-164. S.W. 1992. Active habitat selection by PICCOLO, M.C. & PERILLO, G.M.E. 1999. Capitella sp. I lavae; II. Multiple-choice Estuaries of Argentina: a review. In:

GRAVEL Godoy et al. 67

Perillo, G. M. E., Piccolo, M. C., Pino TERUGGI, L.B.; MARTÍNEZ, G.A.; BILLI, P. Quivira, M (eds.), Estueries of South & PRECISO, E. 2005. Geomorphic units America: Their Geomorphology and and sediment transport in a very low relief Dynamics, Environmental Sciences Series. basin: Río Quequén Grande, Argentina. In Springer-Verlag, Berlín: 101-132. Geomorphologic processes and human PIELU, E.U. 1969. An introduction to impacts in river basins. Proceedings mathematical ecology. Wiley, New York. International Conference, IAHS Publ. POCKLINGTON, P. & WELLS, P.G. 1992. 299:154-160. Polychaetes. Key taxa for marine THIYAGARAJAN, V.; SOO, L. & QUIAN, P. environmental quality monitoring. Marine 2005. The role of sediment organic matter Pollution Bulletin 24: 593-598. composition in larval habitat selection by POLIZZI, P. 2006. Calidad bacteriológica de the polychaete Capitella sp I. Journal of aguas recreacionales, Quequén, Provincia Experimental Marine Biology and Ecology de Buenos Aires. Seminario de Licenciatura, 323: 70-83. Departamento de Biología, FCEN, US ARMY CORPS OF ENGINEERS, 1996. Universidad Nacional de Mar del Plata, Grain size and Total Organic Carbon Argentina, 41 p. effects on benthic organisms. RIVERO M.S.; ELÍAS, R. & VALLARINO, Environmental effects of dredging, Technical E.A. 2005. First survey of macroinfauna in notes, EEDP-01-37, 10 pp. the Mar del Plata harbour (Argentine), WALKEY A & BLACK, C.A. 1965. Methods and the use of polichaetes as pollution of soil analysis. American Society of indicators. Revista de Biología Marina y Agronomy, Madison, Wisconsin, USA. Oceanografía 40:101-108. WHITLATCH, R.B. & WEINBERG, J.R. 1982. RODRIGUEZ-VALENCIA, J.A. 2004. Factors influencing particle selection and Response of benthic polychaetes to feeding rate in polychaete Cistenis environmental variability and El Niño (Pectinaria) gouldii. Marine Biology conditions at Petacalco Bay (Mexico). 71:174-179. Ciencias Marinas. 30(4): 515-526. WRIGHT, R. 1968. Miliolidae (Foraminíferos) SELF, R.F.L. & JUMARS, P.A. 1978. New recientes del estuario del río Quequén resource axes for deposit feeders. Journal Grande (Provincia de Buenos Aires). of Marine Research 36(4): 627-641. Hidrobiologia 2: 225-256. SNELGROVE, P.V.R. & BUTMAN, C.A. ZAR, J.H. 1984. Biostatistical analysis. 1994. Animal-sediment relationships Prentice-Hall, Englewood Cliffs, 130 p. revisited: casue versus effect. Oceanography and Marine Biology: an annual review 32, 111-177.

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