The relationship between EU's public procurement policies and energy efficiency of ferries in the EU

The European ferry sector is the largest ferry sector globally and one of the key environmental issues facing the sector is the mitigation of greenhouse gas emissions. This paper provides an analysis of how the EU ferry procurement policies lead to lack of implementation of energy efficiency measures, contrary to the EU's key objective of reducing CO₂ emissions in ferries within the EU region. This paper is the first analysis to examine the public–private sector interaction in transport and how this leads to a lack of implementation of energy efficiency measures. Analysing the sector using agency theory suggests that split incentives are pervasive and can stymie attempts to improve the energy efficiency of ferry services in the procurement of ferries. The findings suggest that there is a need to review current ferry procurement policies with a view to devising procurement policies that can address the split incentives, as well as other policies, that are outside the scope of procurement policies, which can be used to minimise the split incentives.     

Submerged vegetation complexity modifies benthic infauna communities: the hidden role of the belowground system

Marine plants provide a variety of functions with high economic and ecological values in ecosystems. The above‐ (AG) and below‐ground (BG) systems increase the structural complexity of plants, which also enhance faunal abundance and diversity. The ecological role of the AG compartment in structuring inter‐tidal macrobenthic communities has been widely studied; however, this is not the case for the BG compartment. This study addressed the effects of variation in vegetation complexity (in both AG and BG systems) on associated macrobenthic infauna with respect to abundance, species richness, composition, weight and body type. To achieve this aim, a field experiment using artificial vegetation mimics was carried out using replicated treatments with different AG‐BG complexity ratios. We found a significant increase in the density and the number of taxa of macrobenthic infaunal species in plots with vegetation mimics compared with unvegetated areas, regardless of either AG or BG complexity. This effect was found even when AG parts were not present (i.e. when only BG parts were used). Furthermore, a positive relationship between structural complexity and diversity was recorded. Variation in one or both plant compartments was strongly related to diversity changes in the associated macrobenthic infauna. In conclusion, our experimental set‐up provides the first evidence that the BG compartment is at least as important as the AG compartment in controlling diversity in inter‐tidal vegetated areas because it was able to strongly affect community structure even when the AG system was totally absent.     

Spartina anglica eradication experiment and in situ monitoring assess structuring strength of habitat complexity on marine macrofauna at high tidal level

The cordgrass Spartina anglica is an introduced species that tends to invade sheltered sand and mudflats, at the upper low marsh level. In Arcachon Bay, a lagoon in South West of France, the cordgrass can also replace Zostera noltii beds. The consequence of cordgrass presence on macrobenthic fauna was estimated and compared to adjacent habitats (bare sands, Z. noltii sea grass beds) during one year. The communities of the three habitats were characterised by low species richness, low abundance and biomass (when Hydrobia ulvae, 90% of abundance, is not considered) and high seasonal stability. The infaunal assemblages were particularly homogeneous between habitats without any characteristic species.Cordgrass eradication experiments were performed and zoobenthic recolonisation was observed the following year. Modifications in benthic fauna were observed on epifauna only.These results highlight the limited structuring effect of habitat heterogeneity at high tidal levels and in soft-bottom sediments where desiccation becomes the dominant factor determining infauna community structure.     

Macrobenthic infaunal communities associated with deep‐sea hydrocarbon seeps in the northern Gulf of Mexico

There are thousands of seeps in the deep ocean worldwide; however, many questions remain about their contributions to global biodiversity and the surrounding deep‐sea environment. In addition to being globally distributed, seeps provide several benefits to humans such as unique habitats, organisms with novel genes, and carbon regulation. The purpose of this study is to determine whether there are unique seep macrobenthic assemblages, by comparing seep and nonseep environments, different seep habitats, and seeps at different depths and locations. Infaunal community composition, diversity, and abundance were examined between seep and nonseep background environments and among three seep habitats (i.e., microbial mats, tubeworms, and soft‐bottom seeps). Abundances were higher at seep sites compared to background areas. Abundance and diversity also differed among microbial mat, tubeworm, and soft‐bottom seep habitats. Although seeps contained different macrobenthic assemblages than nonseep areas, infaunal communities were also generally unique for each seep. Variability was 75% greater within communities near seeps compared to communities in background areas. Thus, high variability in community structure characterized seep communities rather than specific taxa. The lack of similarity among seep sites supports the idea that there are no specific infauna that can be used as indicators of seepage throughout the northern Gulf of Mexico, at least at higher taxonomic levels.     

Circalittoral Macrobenthic Assemblages of Strymonikos Gulf (North Aegean Sea)

Abstract. Six macrobenthic assemblages of the circalittoral zone found in Strymonikos Gulf, North Aegean Sea, are described and compared with the corresponding ones from other Mediterranean and Atlantic areas. For the delimination of these assemblages and the evaluation of the major environmental gradients governing their distribution, several numerical techniques were used.     

Enhancement of the benthic communities around an isolated island in the Antarctic Ocean

Insular marine biotas are often richer in faunal diversity than those from the open sea in the same geographical region. The existence of particular island effects were tested under polar conditions by comparing infaunal benthic assemblages on Peter I Island with those of similar latitudes in the open ocean at the Bellingshausen Sea and also from the coast of the Antarctic Peninsula. Sampling was carried out aboard the R/V Hespérides during the expedition named BENTART-2003 from 24 January to 3 March 2003. Benthic samples were collected at 18 stations ranging from 90 to 2 044 m depth, using an USNEL-type box corer (BC) dredge. Representatives of 32 higher taxa of invertebrates were found. Univariate and multivariate analyses revealed various patterns in the data. First, significant differences in polychaete abundance were detected between the stations located in the open sea and the remaining sites (island plus mainland sites). Bivalve abundances were also distinct between island and mainland sampling sites. Sediment columns taken from the island seafloor exhibited the highest rate of bioturbation by the infauna. These findings confirm the model that islands develop distinct assemblages characterized by the enhancement of the benthic communities even in cold waters. Several abiotic factors were measured simultaneously at the seafloor and along the water column to investigate faunal distribution patterns. Significant correlations were found between the benthic assemblages and a combination of two environmental variables: "island effect" (measured as a categorical variable) and the redox state of sediments. Richer and more complex benthic assemblages were found in Peter I Island’s sea bottom, whereas the more depauperate bottoms remained in the open sea.     

胶州湾大沽河口小型底栖动物分布的季节变动

Sediment samples were collected in the intertidal zone of the Dagu River Estuary, Jiaozhou Bay, China in April,July and October 2010 and February 2011 for examining seasonal dynamics of meiofaunal distribution and their relationship with environmental variables. A total of ten meiofaunal taxa were identified, including free-living marine nematodes, benthic copepods, polychaetes, oligochaetes, bivalves, ostracods, cnidarians, turbellarians,tardigrades and other animals. Free-living marine nematodes were the most dominant group in both abundance and biomass. The abundances of marine nematodes were higher in winter and spring than those in summer and autumn. Most of the meiofauna distributed in the 0–2 cm sediment layer. The abundance of meiofauna in hightidal zone was lower than those in low-tidal and mid-tidal zones. Results of correlation analysis showed that Chlorophyll a was the most important factor to influence the seasonal dynamics of the abundance, biomass of meiofauna and abundances of nematodes and copepods. CLUSTER analysis divided the meiofaunal assemblages into three groups and BIOENV results indicated that salinity, concentration of organic matter, sediment sorting coefficient and sediment median diameter were the main environmental factors influencing the meiofaunal assemblages.     

Polychaete assemblage as surrogate for prey availability in assessing southeastern Bering Sea flatfish habitat

The flatfish yellowfin sole (Limanda aspera), northern rock sole (Lepidopsetta polyxystra), and Alaska plaice (Pleuronectes quadrituberculatus) in the southeastern Bering Sea prey mainly on infauna. Spatial correspondence between their stomach contents and infauna assemblages across habitat types was examined to identify indices of prey availability for flatfish habitat characterization and quality assessment. Benthic samples and flatfish stomachs were collected in 2009 near the Alaska Peninsula in the southeastern Bering Sea. Polychaetes and bivalves were the most dominant infauna groups, each comprising 35–60% by weight in each infauna sample. These two were also the only prey groups that frequently averaged > 50% of stomach content by weight. Bivalves dominated the infauna biomass on the relatively sandy inner shelf (0–50 m depth). The muddier middle shelf (50–100 m) had the highest infauna biomass, which was dominated by polychaetes. Diet compositions of the flatfish varied spatially in correspondence with the infauna assemblage. Polychaetes were prevalent in all flatfish diets on the middle shelf, even yellowfin sole whose typical primary prey are amphipods and bivalves. Polychaete-rich habitats are potentially prime for flatfish as polychaetes are readily utilized where available and generally have high nutritional value. Flatfish did not select for specific polychaete taxa, so an index of habitat quality could be based on the biomass of aggregate polychaetes or on dominant polychaete families of the region. Under normal environmental conditions, the three flatfish have slightly-offset spatial distributions, enabling each to utilize different infauna assemblages across the shelf. However, during cold phases in the Bering Sea ecosystem, as when this study was conducted, a cold pool of < 2 °C bottom water from the spring ice melt extends over the middle shelf in summer. This physiological barrier displaces all three flatfish to the inner shelf, intensifying competition for prey resources.     

Local habitat drivers of macrobenthos in the northern,central and southern KwaZulu-Natal Bight,South Africa

The relatively wide KwaZulu-Natal Bight between St Lucia and Durban on the north-east shelf of South Africa is characterised by several circulation features driven by the Agulhas Current, wind and coastal inputs. A large multidisciplinary programme investigated the sources and relative influences of nutrients on the shelf. Within this, and to address a critical knowledge gap, this study describes macrobenthic (<1 mm) composition and frequency from 16 stations, assigned amongst four oceanographic focus areas. The areas were predetermined across the disciplines to represent upwelling, outwelling and a semi-persistent eddy, with nutrients and primary productivity being measured at each. Environmental variables such as sediment distribution, sediment TOC and bottom water physico-chemistry were determined at a significantly larger spatial scale. Our study postulated that oceanographic focus areas support significantly different macrobenthic assemblages, and that composition and relative distribution is due to measurable habitat attributes at each. Macrofauna were relatively abundant and particularly rich at >1 000 taxa. Annelida, Arthropoda, Mollusca, Echinodermata, Sipuncula and Cnidaria (>50 taxa each) were the dominant macrobenthic groups in the bight. Annelida were dominated by the polychaete families Spionidae, Terrebelidae and Cirratullidae, which were generally associated with outwelling and a mud depocentre off the Thukela River. Two unique and distinctive assemblages were found, one in the Thukela Mouth focus area and another on the midshelf between Thukela and Durban. The latter is influenced by poorly sorted, coarse sand and with probable influences from the Durban Eddy. There assemblages were abundant, rich and specific to this habitat. Correlation, PERMANOVA and CAP analyses showed assemblage fidelity to the focus areas. Medium sand, fine sand, mud and the variance of overall sediment type were the habitat drivers underlying macrofaunal abundance distributions.     

Variance estimate and taxonomic resolution: An analysis of macrobenthic spatial patterns at different scales in a Western Mediterranean coastal lagoon

The effects of taxonomic resolution on the variance estimates of macrobenthic assemblages were studied at four spatial scales in a Mediterranean coastal lagoon. The assemblages exhibited significant differences at all the investigated scales; however, spatial variability was mainly associated with the smallest and the largest scales. The decrease of taxonomic resolution (from species to family) was not related to a decrease of the overall variability and similar estimates of variance components were obtained using species and family resolution levels. The ordination models derived from species and family abundances were very similar both in terms of location and dispersion effect, while further aggregation to the class level began to alter the observed spatial patterns. In future studies aimed at assessing changes in the lagoon, resources derived from the cost reductions achieved using family level could be employed to plan more frequent surveys and/or to adopt complex spatial sampling designs with a high number of replicates.     

Midlittoral Soft Substratum Macrofaunal Assemblages in the North Aegean Sea

Abstract. The soft substratum macrobenthic assemblages of the midlittoral zone, along the atidal shores of the upper Thermaikos (polluted) and Strymonikos (unpolluted) Gulfs in the North Aegean Sea, arc qualitatively and quantitatively described. The composition of each of the seven assemblages found (four in Thermaikos and three in Strymonikos Gulf) is statistically tested and discussed in relation to abiotic factors. One of the four Thermaikos Gulf assemblages is located on a silt to fine sand substrate in brackish waters and is characterized by the dominance of the polychactc Hedisie diversicolor and the amphipod Corophium orientate. The other three assemblages arc located on coarse substrates and characterized by the very high dominance of the bivalve Donacillu corneu and the polychactc Ophelia bicornis (both of which are exclusive inhabitants of the midlittoral zone); the First is additionally characterized by the very high dominance of the polychactc Nerine cirratulus , both the second and the third by the dominance of turbellarians due to the pollution of the Gulf (stations located near sewage discharge, high organic carbon, low oxygen). In Strymonikos Gulf, one of the three assemblages is dominated by H. diversicolor and C. orientate; it is similar to the corresponding assemblage found in Thermaikos Gulf, although located on a relatively coarSér sediment. The second is dominated by D. cornea and O. bicornis and is also similar to that of Thermaikos Gulf. The third assemblage does not have a corresponding one in Thermaikos Gulf, is located on a substrate consisting of granules to pebbles, arid is characterized by the high dominance of the amphipods Allorchestes aquilinus and Echinogammarus olivii and the isopod Sphaeroma Sérratum. The corresponding assemblages of the two gulfs are compared. The results of the data analysis are discussed and compared with the literature.     

Recovery of the macrobenthic community in the Valli di Comacchio,northern Adriatic Sea,Italy

The macrobenthic community structure of the Valli di Comacchio (northern Italy) was described in order to assess the ecological conditions of the main basins through 2001. In addition, the biotic data set gathered in 1997–1998 was compared to achieve an estimation of the eventual recovery of the lagoonal benthic assemblages. Four permanent sites (P1, M4, M5 and M6), located along a gradient of sediment texture and confinement, and representing four different areas of the lagoon, were sampled quarterly in 2001 for macrofauna and sedimentary variables (organic content, phytobenthic chlorophyll-a, depth of the redox potential discontinuity layer), and fortnightly for water variables (temperature, salinity, dissolved oxygen and planktonic chlorophyll-a). Water and sedimentary variables were typical of eutrophic areas. A total of 52 macrobenthic taxa were identified and, on the basis of the species collected, differences in faunal distribution among the four areas were recognized, although less marked than in previous studies. Sediment trophic status and its seasonal dynamics in the Valli were crucial in determining species distribution among the different areas. The comparison between 1997–1998 and 2001 biotic data indicated that conditions in the lagoon had improved, especially in the formerly most impaired, central area. In the Valli di Comacchio, the recovery of benthic communities after severe disturbance will probably take longer, even if sewage discharges have been removed 11 years ago. Secondary disturbance due to scarce water circulation, sharp temperature and salinity fluctuations, release of toxic substances from sediments influenced animal assemblages along spatial and temporal scales. The interplay of these variables probably caused deviations from the expected improvement in benthic conditions. Nevertheless, clear signs of amelioration, particularly at the previously most impaired area, were detectable.     

Polychaete Assemblages in the San José Gulf (Chubut, Argentina), in Relation to Abiotic and Biotic Factors

Abstract. The composition and distribution of the polychaete assemblages of the San José Gulf (Chubut, Argentina) are described in relation to environmental variables using indicator species (TWINSPAN) and canonical correspondence analysis (CCA). The polychaetes were collected during a benthic cruise in October 1984. Sediments were collected at 110 sampling sites using a 0.25 m² van Veen bottom grab or by divers in near-shore areas and sieved with 1 mm mesh. A total of 73 polychaete taxa were collected and identified. Both analyses revealed the presence of four main assemblages distributed according to depth as well as bivalve and seaweed abundance gradients: ' Syllis-Eunice ' and ' Harmothoe-Eunice ' assemblages occurred at the same depths (0 –­ 185 m) and substrata (poorly sorted rock and coarse sand), but were separated by bivalve and seaweed abundance, wherby the highest abundances of bivalves and the minimum abundances of seaweeds corresponded to the ' Syllis-Eunice ' association. The ' Ninoe-Glycera ' and ' Aglaophamus- Fabriciinae indet. 6' assemblages also occurred at similar depths (0 – 60 m) and substrata (very well-sorted medium-fine sand), but differed in their composition of bivalves and seaweed abundances; the ' Aglaophamus- Fabriciinae indet. 6' association corresponded with minimum bivalve and maximum seaweed abundances.     

Field observations of waves generated by passing ships: A note

This short contribution reports the results of a field study on the nearshore characteristics of waves generated by both conventional and high speed passenger ferries. The field observations took place in the late summer of 2005, at a beach close to the port of Mytilene (Island of Lesbos, Greece), and involved the visual observation of ship waves, using digital video recordings and image processing techniques. The results showed that passage of the fast ferry was associated with a longer, more complex and energetic nearshore event; this event not only did include higher nearshore waves (up to 0.74 m) and was organised in different wave packets, but it was also an order of magnitude longer (∼ 680 s) than the conventional ferry event. Regarding the effects on beach sediment dynamics, the fast ferry waves were estimated to be very efficient in mobilising the nearshore sediments in contrast to those of the conventional ferry. The fast ferry service appears to generate daily prolonged nearshore events, which contain waves with higher energy than those expected from the normal summer wind wave regime of the area; these events also include some high and very steep waves, which can be particularly erosive. Therefore, fast ferry wakes may have considerable impacts on the seasonal beach sediment dynamics/morphodynamics and the nearshore benthic ecology, as well as they may pose significant risks to bathers, affecting the recreational use of the beaches exposed to fast ferry traffic. Finally, the study has shown that satisfactory field observations of the nearshore characteristics of ship-generated (and wind) waves can be obtained using inshore deployments of calibrated poles, digital video cameras and appropriate image processing algorithms.     

Material type and roughness influence structure of inter‐tidal communities on coastal defenses

On a global scale, urbanization has resulted in substantial proportions of coasts being replaced by artificial structures such as marinas, breakwaters and seawalls. There is broad consensus that coastal defense structures are poor surrogates of the natural habitats that they replace. Here we investigated the effects of the type and roughness of materials used for the construction of artificial structures on the surrounding biota by comparing abundances and distribution of key inter‐tidal taxa between natural shores and coastal defenses. Lower abundances of gastropods and barnacles were found on artificial coastal defense structures (regardless of the material type). At small spatial scales, abundances of key taxa increased with increasing roughness. Our results suggest that the choice of materials used for the construction of coastal defense structures has little effect on community structure per se, but that enhanced roughness could make coastal defenses better surrogates of natural habitats by supporting assemblages that are more similar to those found on natural shores.     

Combining echo sounding,sediment and biological data to map benthic habitats in a coastal area of the Persian Gulf

Mapping surveys of coastal benthic habitat in Qeshm Island Geopark, Persian Gulf, were conducted using a combination of biological, sedimentological and echo‐sounding data. The survey area covered approximately 233 km² in a depth range of 5–25 m, and the data were acquired from a single beam echo sounder, grab, video and still photography. Sediment and macrofauna samples were collected by grab at 76 stations and subjected to classification and ordination analyses. Two acoustic classes were identified differentiating along the near/offshore axis. Sediment texture was dominated by fine grain sizes, with five distinct sub‐sediment types. In total, 214 macrobenthic taxa were identified, of which polychaetes accounted for 60%. Other dominant groups included young sponges, nematodes, malacostracan crustacean, bivalves, ostracods and ophiuroids. Underwater videos and still photos integrated the macrofaunal and sedimentary data and revealed a range of biogenic sedimentary features such as burrows and tubes. The biological data identified six main biological assemblages showing an inshore/offshore pattern. The macrobenthic abundance did not demonstrate a significant difference with depth, although polychaetes were positively correlated with depth. The highest abundance and species richness were observed at median depths. Species distribution and diversity did not show any correlation with sediment type. A preliminary habitat mapping of the south coast of the Qeshm Island Geopark has been carried out, integrating acoustic, sediment and biological data.     

The influence of troughs and crests of ripple marks on the structure of subtidal benthic assemblages around rocky reefs

This study tested the hypothesis that the small-scale topography caused by ripples in sediment would affect benthic macrofaunal assemblages. Ripple marks were measured and macrofauna and sediments were sampled near to and far from subtidal rocky reefs at two sites. Ripples were significantly wider and taller close to than far from reefs. Sediment grain-size was significantly different between crests and troughs. Microtopography clearly influenced the structure of the benthic macrofaunal assemblages in three of the four locations (and 8 of the 12 sites) examined. Numbers of taxa of the benthic macrofaunal assemblages and almost all individual taxa analysed showed significant greater abundances in troughs than in crests. The results strongly support the model that benthic macrofauna are affected by locally varying hydrodynamic environments produced by ripple-beds. These, in turn, were influenced by their proximity to a reef. Models about passive transport of the macrofauna by water-movement and active movements of the fauna are discussed. Furthermore, it appeared that there was a relationship between spatial variability of the macrofaunal assemblages and size of ripples. It is suggested that microtopography should be considered in experimental designs when patterns of distribution of benthic organisms are being evaluated.     

Epizooic metazoan meiobenthos associated with tubeworm and mussel aggregations from cold seeps of the northern Gulf of Mexico

The abundance and higher taxonomic composition of epizooic metazoan meiobenthic communities associated with mussel and tubeworm aggregations of hydrocarbon seeps at Green Canyon, Atwater Valley, and Alaminos Canyon in depths between 1400 and 2800?m were studied and compared to the infaunal community of non-seep sediments nearby. Epizooic meiofaunal abundances of associated meiobenthos living in tubeworm bushes and mussel beds at seeps were extremely low (usually <100?ind. 10?cm(-2)), similar to epizooic meiofauna at deep-sea hydrothermal vents, and the communities were composed primarily of nematodes, copepods, ostracods, and halacarids. In contrast, epizooic meiobenthic abundance is lower than previous studies have reported for infauna from seep sediments. Interestingly, non-seep sediments contained higher abundances and higher taxonomic diversity than epizooic seep communities, although in situ primary production is restricted to seeps.     

Beta diversity of tropical marine benthic assemblages in the Spermonde Archipelago, Indonesia

In order to preserve diversity it is essential to understand how assemblages change across space. Despite this fact, we still know very little about how marine diversity is spatially distributed, especially among lesser‐studied invertebrate taxa. In the present study beta‐diversity patterns of sea urchins, sponges, mushroom corals and larger foraminifera were assessed in the Spermonde Archipelago (Indonesia). Using ordinations we showed that the inshore zone (<5 km offshore), midshore zone (5 < x < 30 km offshore) and distance offshore zone (>30 km offshore) all contained distinct assemblages of sponges and corals, while only foraminifera assemblages from the inshore (<5 km offshore) zone were distinct. There was a significant spatial pattern of community similarity for all taxa surveyed, but this pattern proved to be wholly related to environmental variables for sponges and foraminifera, and primarily for mushroom corals and sea urchins. The lack of a pure spatial component suggests that these taxa may not be dispersal limited within the spatial scales of this study (c. 1600 km²). The analyses of the corals and foraminifera were additionally tested at two spatial scales of sampling. Both taxa were primarily associated with local‐scale environmental variables at the local scale and larger‐scale variables at the larger scale. Mean inter‐plot similarity was also higher and variation lower at the larger scale. The results suggest that substantial variation in similarity can be predicted using simple locally assessed environmental variables combined with remotely sensed parameters.     

Factors structuring temporal and spatial dynamics of macrobenthic communities in a eutrophic coastal lagoon (Óbidos lagoon, Portugal)

The present work aimed to identify the main environmental drivers shaping temporal and spatial dynamics of macrobenthic communities within a eutrophic coastal lagoon. Sediments in the óbidos lagoon showed a gradient of increasing metal contamination from the inlet area to inner branches. The mid-lower lagoon area exhibited an intermediate contaminated condition between the inlet and upstream areas, suggesting that the effects of the organic loadings into the lagoon may be reflected until this area. This transitional feature was corroborated by biological data, with macrobenthic assemblages displaying characteristics of down- and upstream areas. Macrobenthic abundance peaked in winter, which was associated with a higher nutrient availability (mainly ammonium) and the proliferation of green macroalgae in mid-lower and inner lagoon areas. However, massive macroalgae growth resulted in a sharp decrease of macrobenthic diversity and abundance in spring, particularly where the higher amounts of decaying algae were detected. Higher dissimilarities between assemblages were detected during winter (and spring, for trophic composition), while in summer, differences were highly attenuated. The least contaminated area (close to the sea inlet) experienced smaller temporal variations for environmental variables, as well as the lowest temporal biological variability. This area was dominated by carnivores, which were related with increased salinity. Deposit-feeders were numerically dominant in the lagoon, being generally spread within organically enriched sandy and muddy areas. The high concentration of chlorophyll a and suspended particulate matter in water was reflected in the abundance of deposit-feeders/suspension-feeders, taking benefit of the high primary productivity. On the other hand, deposit-feeders/herbivores responded to the decay of macroalgae mats in the sediment. Biological associations varied with the biological data used (taxonomic versus trophic group composition; abundance versus biomass), highlighting the relevance of the combination of different data analysis' approaches. In general, BIOENV analysis indicated total phosphorus, biomass of Ulva, metals and organic carbon and nitrogen as being significantly influencing benthic patterns. On the other hand, discrepancies in ecological behaviours of some taxa were also detected in the present study stressing the need for additional studies on the relationships between macrobenthic communities and environmental variables. Implications of the present results for monitoring studies are discussed.