Susana Pinedo

Seasonal dynamics of macroinfaunal key species inhabiting shallow soft-bottoms in the Bay of Blanes (NW Mediterranean)

Abstract Within the frame of a wider research project on the littoral ecosystem of the Bay of Blanes (NW Mediterranean), the dynamics of shallow soft-bottom macroinfaunal assemblages of medium-to-fine-sand sediment communities of Spisula subtruncata have been followed since March 1992. These assemblages exhibited a very predictive annual cycle. Abundance and biomass rose sharply during spring, followed by a striking drop through summer showing lower values during autumn and winter. These cycles were consistent with the temporal variation of key macroinfaunal species in these shallow habitats: Spisula subtruncata, Owenia fusiformis, Ditrupa arietina, Lucinella divaricata, Echinocardium mediterraneum, Spio decoratus, Chone infundibuliformis, Paradoneis armata, Mediomastus fragilis, Protodorvillea kefersteini, Branchiostoma lanceolatum, Glycera cf. capitata and Callista chione. These species were included in ecological groups based on the trends observed during the 4 years of seasonal dynamics which are presented.

Distribution patterns and trophic structure of soft-bottom polychaete assemblages in a North-Western Mediterranean shallow-water bay

Abstract This study describes the spatial distribution and trophic structure of the polychaetes inhabiting the soft-bottoms of Alfacs Bay, a semi-enclosed, shallow-water area (Ebro Delta, north-western Mediterranean). The hydrographic regime is basically marine, with a combination of sea-water renewal and continental runoff causing permanent stratification. The Bay was affected by anthropogenic activities (viz. influx of irrigation waters, large-scale aquaculture, and periodical dredging at the mouth). 41 samples were taken during summer (July 1987 and September 101 polychaete species were identified, with an average density and biomass of 6370(650-23700) ind.m-2 and 7.52(0.87-66) DWgm-2, respectively. Nine assemblages were identified: shelf (stressed, confined, typical), boundary, deep central basin (inner, typical, seaward) and marine (typical, navigation channel). The trophic structure was dominated by deposit-feeding polychaetes (mainly Pseudomastus deltaicus, Heteromastus filiformis, Notomastus latericeus, Mastobranchus trinchesii, Eudymene oerstedii, Clymenura clypeata, Streblospio shrubsolii, Monticellina heterochaeta and Ampharete acutifrons). An increase in the ecological weight of carnivorous polychaetes (mostly Lumbrineris latreilli) from the shelf towards the marine assemblages was also noticed. The analysis of the polychaete taxo-coenosis provides key items to understand the functioning of the semi-enclosed, shallow-water system under study.

Long-term changes in sublittoral macroalgal assemblages related to water quality improvement

Abstract Sampling of sublittoral macroalgal assemblages was carried out in 1982 and 1999 along the coast of Catalonia (Northwestern Mediterranean, Spain) in order to study long-term changes in species composition. Ordination analysis revealed significant differences in species composition and abundance between the two study periods. The number of stations with indicators of eutrophication, such as species of Chaetomorpha, Cladophora, and Ulva, decreased from 1982 to 1999. This decrease was not balanced by an increase in species typical of pristine environments, such as large perennial brown algae (in particular, Cystoseira mediterranea), but rather by an increase of stress-resistant species such as Corallina elongata. The observed shifts seem to be driven by the decrease in nutrient loadings in the water column, resulting from the progressive implementation of sewage treatment management in the study region since the mid-1970s.

Relationships Between Heavy Metals Contamination in Shallow Marine Sediments with Industrial and Urban Development in Catalonia (Northwestern Mediterranean Sea)

A total of 179 surface sediment samples from shallow waters have been collected in Catalonia (Northwestern Mediterranean) from 2002 to 2010 to analyze heavy metals (Al, Cd, Cu, Hg, Pb, V, and Zn) concentrations, organic matter content, and sediment size in order (i) to find baseline values, (ii) to investigate metal contamination trends, and (iii) to identify its spatial and temporal distribution. Highest metals concentrations were registered in the Barcelona metropolitan area and in the mouth of Besòs and Llobregat Rivers for Zn, Cu, Pb, and Cd. Mercury was also abundant in these areas but the highest record was found close to Tarragona. The concentrations agree with those reported in other studies performed in big river’s mouths and industrialized areas. The absence of large industrial activity and urbanization outside Barcelona and Tarragona explains the low metal contents found at the other sampling sites. Based on enrichment factor (EF), Pb was the most enriched metal. Results will provide a useful aid for sustainable marine management in Catalonia.

Environmental Quality of Catalan Coastal Waters Based on Macroalgae: The Interannual Variability of CARLIT Index and Its Ability to Detect Changes in Anthropogenic Pressures over Time

CARLIT is a Water Framework Directive-compliant methodology permitting a rapid assessment of water quality using rocky-shore macroalgae as biological quality elements. Here we present the water quality assessment of 32 coastal water bodies of Catalonia (Northwestern Mediterranean) during a period of 14 years (1999–2012) applying CARLIT. The averaged ecological status of the water bodies ranges between high and poor and the Ecological Quality Ratio shows a significant negative relationship with a modified LUSI index, thus providing further evidence on the utility of CARLIT to detect anthropogenic pressures. The lowest interannual variability in water quality was found in water bodies having most of their shore covered by natural rocks, while the highest variability was observed in water bodies situated in semi-confined environments or located close to freshwater discharges. In spite of the multiple advantages of CARLIT as a monitoring methodology, it can show strong disagreements in water quality assessment with other methodologies using other biological quality elements (i.e., macroinvertebrates). These discrepancies mainly occur in water bodies with reduced extension of rocky shores, questioning the use of CARLIT in these situations.

Using MEDOCC (MEDiterranean OCCidental) Index to Evaluate the Ecological Status of Catalan Coastal Waters (Northwestern Mediterranean Sea) Over Time and Depths

The Ecological Status (ES) of littoral coastal waters from Catalonia (Northwestern Mediterranean Sea) has been evaluated between 2002 and 2010 using MEDOCC (MEDiterranean OCCidental) index. Macroinvertebrate assemblages inhabiting both littoral fine sands (<20 m depth) and littoral sandy muds (25–35 m depth) have been sampled. The relative abundance of four Ecological Groups (e.g., sensitive, indifferent, tolerant, and opportunistic taxa) has been studied along a disturbance gradient. Sensitive taxa are often present in disturbed situations, and tolerant species are usually associated with the presence of opportunistic taxa, both in fine sands and muddy sediments. Sensitive species dominate in sandy habitats, while tolerant species dominate in muddy bottoms. The ES of Catalan coastal waters measured with the samples collected in littoral fine sands has improved since 2002, and all locations rated above a good ES in 2010. The ES measured with the samples collected in littoral sandy muds was above a good ES although the Ecological Quality Ratio (EQR) was always lower than in littoral fine sands. Consequently, the ES of all water bodies was rated as good or high ES in 2010, and no water body was at risk of noncompliance of Water Framework Directive (WFD) requirements.

First Report on the Distribution and Impact of Marine Alien Species in Coastal Benthic Assemblages Along the Catalan Coast

The Mediterranean Sea is especially prone to the introduction of alien species due to an intense marine traffic, the connection with the Red Sea through the Suez Canal and intensive aquaculture. Catalonia, a region in the Northwestern Mediterranean, began an extensive study on the presence, distribution and impact of invasive macroalgae in 1992, which was extended to all macrobenthic alien species by 2007. Gathering all presence and abundance data of introduced species from the monitoring, we also calculated a Biopollution Level (BPL) index to assess the magnitude of the effects of introduced species on the marine biota at a local level (water body) as required by Marine Strategy Framework Directive (MSFD). Seventeen alien species have been identified although only three can be considered so far as threatening in non-modified environments: the green alga Caulerpa cylindracea and the red algae Womersleyella setacea and Asparagopsis armata. These species show an uneven distribution along the coast but sometimes coexist in the same water body. The impact of alien species on native communities was never severe as shown by the low values obtained using the BPL. The only species triggering a moderate to strong impact was Caulerpa cylindracea but it only affected a single water body. However, C. cylindracea exhibited a great temporal variability on its abundance, with sudden collapses of its populations, which also caused a great variability in the BPL. Future monitoring of the coasts of Catalonia is advised as there is an increase in the number of water bodies affected by alien species and an increase in their abundances from 2007 to 2012.

Assessing the Environmental Quality in Heavily Modified Transitional Waters: The Application of MEDOCC (MEDiterranean OCCidental) Index in Ebre Delta Bays

The assessment of ecological quality in the frame of the Water Framework Directive has been performed in Ebre Delta bays (Alfacs and Fangar) using MEDOCC (MEDiterranean OCCidental) index. Results demonstrate the applicability of the index in heavily modified transitional water bodies and its response to pressures (mainly agricultural activities) affecting macroinvertebrate assemblages inhabiting soft bottoms. According to previous studies and the organic matter enrichment and heavy metal gradients inside the bays, three different Transitional Waters (TW) have been distinguished, but only two of them are assigned to Heavily Modified Water Bodies (HMWB). Two different reference conditions have been considered depending on the acting pressures: a Maximum Ecological Potential (MEP) for the areas highly affected by the pressures (i.e., HMWB) and a Reference Condition (RC) for non-modified waters from the southern shelf of Alfacs Bay where the effect of agricultural activity is scarce. A good Ecological Potential/Status (EP/ES) was always achieved in the surveys.