Extending over warmer environments in the Brazilian waters, the exotic vermetid Eualetes tulipa was first recorded from Ceará State (3°S) in 2005. In 2009, it was reported in cold-water environments in Rio de Janeiro State (22°S). Seven years later, E. tulipa was recorded from Rio Grande do Norte State (6°S) on rocky pools in sandstone reefs. In the present study, E. tulipa is for the first time recorded from Bahia State (12°S), associated with a biofouling community in the Todos-os-Santos Bay, co-occurring with exotic dendrophylliid corals (Tubastraea). The vermetid community recorded from Bahia State shows a great diversity of epibionts, mostly bivalves, cirripeds and sponges. The co-occurrence of Eualetes and Tubastraea corals must be monitored, once these exotic species are co-occurring in a protected environmental area, bringing concern on possible impacts on native benthic fauna.

The shallow-water hydrothermal system of Punta Mita in Banderas Bay is located on the fault called Fisura de las Coronas off Punta Pantoque beach. In this area, three sites with hydrothermal vents were studied at a depth of 9 m. This study aimed to characterize the structure of the benthic infauna communities that coexist in this hydrothermal system; therefore, physicochemical parameters were measured and the organisms found in the sediment samples were identified up to the class taxonomic level. The highest temperatures (89°C) were recorded within the hydrothermal influence area, which was reflected in an inverse relationship with pH, conductivity and salinity. Sediment temperature profiles increased at greater depth. A total of 371 individuals were found and these were grouped into eight classes: Malacostraca, Maxillopoda, Gastropoda, Bivalvia, Scaphopoda, Polychaeta, Leptocardii and Stenolaemata. The Malacostraca class was the most abundant with 240 individuals, while the Scaphopoda was the lowest with 3. The organic matter contents in the sediments were higher in the areas adjacent to the hydrothermal activity. The high temperature of the hydrothermal discharges structures the benthic community since it was the factor that differed most significantly in the study sites, causing lower abundances in the area of hydrothermal influence compared with the more distant areas. Despite the above, it is concluded that the benthic community of the area with hydrothermal activity is part of the community adjacent to this influence, only in lower numbers.

Recruitment is related to the occupation of the substrate by fouling organisms. It plays an important role in the maintenance and distribution of benthic populations, being under the influence of biotic and abiotic factors. In the present work, the recruitment of calcareous sponges was monitored over two years in a marina at Todos os Santos Bay, a large bay in the tropical portion of the Brazilian coast. Artificial plates were immersed, being replaced bimonthly and the potential influence of the seawater temperature, photoperiod and precipitation on the number of sponge recruits was tested. The results showed that the number of calcareous sponge recruits had significant temporal variation. Nevertheless, different species showed different patterns over time. Significant differences were observed for Sycon avus, Sycon sp. and Leucandra serrata, and the periods with the highest number of recruits were different amongst them. Sycon bellum, Paraleucilla incomposita, Leucilla sp. and Heteropia glomerosa did not show significant variation in the number of recruits over time. None of the three tested environmental factors were correlated with the number of recruits, but results indicated S. avus recruitment might be driven by seawater temperature. Our results contribute to improve the current knowledge on the dynamics of each species found on the plates and reinforce the general view that the pattern of recruitment varies greatly in Calcarea, even amongst sympatric species.

Understanding the distribution, abundance and habitat preferences of species in the Southern Ocean provides a foundation for assessing the impacts of environmental change and anthropogenic disturbance on Antarctic ecosystems. In near-shore waters at Casey and Davis Stations, photoquadrat surveys were used to determine sea anemone distribution and abundance, habitat preferences, associations with other species and the impact of human disturbance on sea anemone distribution. Two distinct sea anemone morphotypes were found in this study: large sea anemones that require hard substrate for attachment and small, burrowing sea anemones found in muddy sediment. The large sea anemones were found in rocky habitats, with the exception of some sedimentary habitats where other biota were used as substrate. The large sea anemones were associated with a diverse community of epibenthic species found in rocky habitats. The burrowing sea anemones were associated with a less diverse assemblage of sediment-dwelling epibenthos. At Casey Station, sea anemones were more abundant in habitats adjacent to a former waste disposal site than at control sites. The reason for this is not yet known, but may be due to high organic matter inputs or, alternatively, a longer sea ice duration providing protection from ice scour.

Coral reefs have experienced extensive degradation across the world over the last 50 years as a result of a variety of stressors operating at a range of spatial and temporal scales. In order to assess whether declines are continuing, or if reefs are recovering, detailed baseline information is required from across wide spatial scales. Unfortunately, for some regions this information is not readily available, making future reef trajectories difficult to determine. Here we characterized the current benthic community state for coral reefs in the Wakatobi region of Indonesia, one of the most biodiverse marine regions in the world. We surveyed 10 reef sites (5, 10 and 15 m depth) to explore spatial variation in coral reef benthic communities and provide a detailed baseline. Previous data (2002–2011) were available for coral, sponges, algae and soft coral at six of our study sites. Using this information, we determined if any changes had occurred in dominance of these benthic groups. We found that benthic assemblage composition differed significantly over relatively small spatial scales (2–10 km) and hard coral cover was highly variable, ranging from 7–48% (average 19.5% ± 1.5 SE). While coral cover appears to have declined at all sites where data were available since 2002, we found little evidence for widespread increases in other benthic groups or regime shifts. Our study provides a comprehensive baseline dataset for the region that can be used in the future to determine rates of change in benthic communities.

Benthic communities, critical to the health and function of marine ecosystems, are under increasing pressure from anthropogenic impacts such as pollution, eutrophication and climate change. In order to refine predictions of likely future changes in benthic communities resulting from these impacts, we must first better constrain their responses to natural seasonality in environmental conditions. Epibenthic time series data (July 2008–May 2014) have been collected from Station L4, situated 7.25 nautical miles south of Plymouth in the Western English Channel. These data were analysed to establish patterns in community abundance, wet biomass and composition, and to link any observed patterns to environmental variables. A clear response to the input of organic material from phytoplankton blooms was detected, with sediment surface living deposit feeders showing an immediate increase in abundance, while predators and scavengers responded later, with an increase in biomass. We suggest that this response is a result of two factors. The low organic content of the L4 sediment results in food limitation of the community, and the mild winter/early spring bottom water temperatures allow the benthos to take immediate advantage of bloom sedimentation. An inter-annual change in community composition was also detected, as the community shifted from one dominated by the anomuran Anapagurus laevis to one dominated by the gastropod Turitella communis. This appeared to be related to a period of high larval recruitment for T. communis in 2013/2014, suggesting that changes in the recruitment success of one species can affect the structure of an entire community.

The cyanobacteriosponge Terpios hoshinota is expanding its range across the Indo-Pacific. This species can have massive outbreaks on coral reefs, actively kill corals it overgrows and affect the entire benthic community. Although it has received much attention on the post-outbreak follow-up, little is known about its ecology, habitat preferences, and the possible environmental triggers that cause its outbreaks. We present a baseline study in the Spermonde Archipelago, Indonesia, where T. hoshinota was first observed in 2012. We surveyed 27 reefs and recorded patches between 14 and 217 cm2, at four reef sites (~15% cover). The sponge was found on both mid-shelf and outer shelf reefs but not close to the coast and the city of Makassar. Differences in benthic community structure, as well as spatial variables relating to the on-to-offshore gradient in the Spermonde archipelago, neither constrained nor promoted its expansion. Patches of the sponge were mostly overgrowing branching corals, belonging to Acroporidae species. Genetic variation within T. hoshinota was studied by sequencing partitions of the mitochondrial CO1 and nuclear ribosomal 28S gene. Two haplotypes were found within the Spermonde archipelago, which differed from the CO1 sequence in GenBank. The present study provides an indication of habitat preferences of T. hoshinota in non-outbreak conditions, although it is still unclear which environmental conditions may lead to the onset of its outbreaks.

We examined the benthic macroinfauna at three strata during two seasons (winter and summer) on two sandy beaches (dissipative and reflective) in south-eastern Brazil. The hypothesis raised is that effects of morphodynamics and zonation determine the structure of macroinfauna, with dissipative beaches having comparatively higher species richness and density than the reflective beaches. Flamengo beach (dissipative) had higher species richness but lower density compared to Grumari beach (reflective). A high dissimilarity in assemblage structure (91.75%) was detected between the two beaches. Zonation in the occurrence of macroinfauna was detected for the two beaches in the two examined seasons. At Grumari beach, Emerita brasiliensis occurred mainly in stratum 1 (intertidal swept zone) while Saccocirus sp. occurred in stratum 2 (infralittoral at 0.5 m depth), whereas at Flamengo beach E. brasiliensis and Enoploides sp. had the highest density in stratum 1 (intertidal swept zone) whereas Scolelepis goodbodyi and Donax uncinata dominated in stratum 3 (infralittoral at 1.0 m depth). Scolelepis goodbodyi, Dispio uncinata, Enoploides sp., Nematoda and Trileptium sp. were associated with higher a Dean parameter and content of organic matter at Flamengo beach. In contrast, Hastula sp., Donax sp., Pisionidens indica, Hemipodus californiensis, Saccocirus sp. and Phyllodocidae were associated with the higher wave period and grain size of Grumari beach. The hypothesis that macroinfauna structure differs between the beaches and strata was confirmed, with the dissipative beaches having comparatively higher richness but lower density than the reflective beaches.

The soft-bottom zoobenthic community structure of Izmir Bay was examined seasonally at eight stations (depth-range: 19–67 m) in 2009. A total of 427 species were found. Polychaeta had the highest number of species (50% of total species) and individuals (75%), whereas Echinodermata possessed the highest biomass (47%). The number of species varied from 3 to 79 (0.1 m−2), the density from 60 to 5360 ind.m−2, and the biomass from 1 to 530 g.m−2. The most numerically dominant species were the polychaetes Aricidea claudiae, Streblospio gynobranchiata, Levinsenia demiri and Sternaspis scutata. The distribution of zoobenthos was strongly related to spatial differences in total organic carbon, sediment texture and depth among different regions of the bay rather than temporal differences among seasons. However, significant seasonal variability in community structure (mainly differences in the relative abundance of species) was present. The inner region of the bay can be classified as ‘poor’ or ‘bad’ based on the results of biotic indices (H′, AMBI, m-AMBI and BENTIX). Among biotic indices, only H′ and m-AMBI appeared to be capable of explaining the bay's benthic quality status. Thirteen alien species were also found. Streblospio gynobranchiata, Prionospio pulchra, Pseudopolydora paucibranchiata and Polydora cornuta formed dense populations in the inner most polluted part of the bay and are considered to be new pollution indicator species in the eastern Mediterranean Sea.

The invasion of marine species is a threat to local and global biodiversity and can have many ecological, economic and social impacts. The bivalve Isognomon bicolor has invaded the rocky shores of Brazil and spread along the coast, occurring from Rio Grande do Norte to the Santa Catarina State. The present study evaluated the distribution of I. bicolor on different rocky shores of Arvoredo Island (Santa Catarina State) and its relationship with other taxa. A high density of I. bicolor was found on the exposed shore, which was associated with the occurrence of articulated calcareous macroalgae. In addition, I. bicolor was also found in empty shells of the barnacles Tetraclita stalactifera and Megabalanus spp. The physical structure of these habitats probably plays an important role in the success of I. bicolor invasion. For these reasons, I. bicolor evidences an alteration on the benthic community of the rocky shores and its potential consequences become a threat to local species.

The benthic succession was evaluated in the Inferior (0.6 to 1.4 m) and Superior (1.4 to 2.2 m) Eulittoral fringes of a rocky intertidal zone on the northern coast of Rio de Janeiro after an experimental disturbance of all benthic organisms in December 2007. Eight removal and control quadrats were marked along eight vertical profiles in each fringe and sampled bimonthly by a photo-quadrat method. In the Inferior Eulittoral fringe, in both treatments, Ulva fasciata and Perna perna were initially predominant and replaced by Phragmatopoma lapidosa in the sixth month. In this successional period, the species presence prior to the disturbance effect reinforced the similarity of >75% between treatments. In the Superior Eulittoral fringe, Chthamalus spp. predominated throughout all the months and bare space represented up to 30%. In the removal treatment the substrate remained 75% empty until the sixth month, mainly occupied by Collisella subrugosa. The control and removal quadrats showed a high dissimilarity in all succession periods and suggest the permanence of an early succession stage, while in the Inferior Eulittoral fringe, with less stressful environmental conditions, the local benthic community showed a stability tendency on a time scale less than six months. Such information is essential for the understanding of the community structure and the recovery time in relation to a given disturbance and should be applied routinely on areas with potential disturbance events such as the studied one, which has several oil platforms.

Since the early part of the 20th Century the impact of a range of anthropogenic activities in our coastal seas has steadily increased. The effect of such activities is a major cause for concern but in the benthic environment few studies exist that date back more than a few decades. Hence understanding long term changes is a challenge. Within this study we utilized a historic benthic dataset and resurveyed an area west of Eddystone reef in the English Channel previously investigated 112 years ago. The aim of the present work was to describe the current benthic community structure and investigate potential differences between 1895 and 2007. For each of the four major phyla investigated (Polychaeta, Crustacea, Mollusca and Echinodermata), multivariate community analysis showed significant differences between the historic and contemporary surveys. Echinoderm diversity showed a clear reduction between 1895 and 2007. The sea urchins Echinus esculentus, Spatangus purpureus, and Psammechinus miliaris and large star-fish Marthasterias glacialis showed reductions in abundance, in some cases being entirely absent from the survey area in 2007. Polychaetes showed a shift from tubiculous species to small errant and predatory species such as Glycera, Nephtys, and Lumbrineris spp. Within the group Mollusca large species such as Pecten maximus and Laevicardium crassum decreased in abundance while small species increased. Crustaceans in 1895 were dominated by crab species which were present in similar abundances in 2007, but, the order Amphipoda appeared to show a significant increase. While some of the differences observed could stem from differences in methodologies between the surveys, in particular increases of small cryptic species, the loss of large conspicuous species was judged to be genuine. The study area is an important beam trawling and scallop dredging ground; the differences observed are concomitant with changes generally associated with disturbance from demersal fishing activities such as these.

A study of the benthic leaf litter community of the Tarumazinho, a central Amazonian stream (03° S, 60° W) is presented. This small tributary of the Rio Negro is of the blackwater type with a very low nutrient content. The sampling stations were towards the mouth of the tributary where it flowed through annually inundated forest and the work was carried out during the low water season. Previous studies concluded that these acid waters were of very low productivity and held impoverished faunas. However, this study showed that leaf litter banks held a diverse aquatic community of unexpectedly high biomass. This was because the banks supplied food and shelter and were available during the low water period when other habitats had dried out. The macrofauna was dominated by fish and shrimps. From an examination of gut contents a food web was produced. Primary consumers were found to take mainly detritus and fungi and it was concluded that allochthonous inputs were the main source of energy and nutrients. No feeding specialists were found and all the predators took prey from more than one trophic level.

Barnacles are the common fouling organisms encountered in coastal waters around the world. In the present study, breeding biology of the intertidal barnacle Amphibalanus amphitrite (=Balanus amphitrite) was studied for a period of two years (July 2003 to June 2005) in the Kudankulam coastal waters. Results showed that A. amphitrite breeds throughout the year in the study area. A high percentage of individuals with free nauplii in the mantle cavity was observed during March 2004 (47.6%) and May 2004 (41.7%). Barnacles with fertilized eggs in the ovary were high during November 2004 (56%), March 2005 (46.7%) and April 2005 (42.8%). Overall, a peak breeding activity was observed during the March–May period. The breeding activity showed a significant positive correlation with surface water temperature and phytoplankton abundance.

This paper is a contribution to the Latitudinal Gradient Project. It describes macro and epifaunal assemblages and habitats at three shallow water locations at the southern end of the western Ross Sea coast, and investigates relationships between faunal composition and environmental characteristics. Many variables (e.g. substrate type, sediment composition, depth, latitude, longitude) contributed to explaining the differences in community composition between locations, with latitude (a likely surrogate for broader scale factors, e.g. ice cover) one of the most important. The percentage explained by environmental characteristics was strongly scale dependent, decreasing with increasing scale of observation. As much as 66% and 75% of the variability in macrofaunal and epifaunal assemblages, respectively, was explained at the smallest scale (i.e. between transects within a location), compared to 9–18% and 11–32%, respectively, at the scale of the entire study. This relationship was also true for species richness and total abundance. This suggests that while small-scale habitat variability will not confound our ability to detect latitudinal gradients in future studies, adequately quantifying the environmental factors important in structuring these communities at larger (latitudinal) spatial scales will be important. Finally, large differences in habitat structure did not translate into large differences in the diversity of fauna, illustrating the difficulty of predicting faunal composition in the Ross Sea based on seafloor topography alone.

Manila clams, Tapes philippinarum (Adams and Reeve) are cultivated beneath plastic netting, to protect them from excessive predation, and harvested after approximately two years. Both the on-growing and harvesting process have the potential to alter benthic communities. In order to study these effects, we surveyed a clam lay and uncultivated areas at a site of commercial clam cultivation in south-east England. Surveys were undertaken at the end of the growing stage, immediately after harvesting by suction dredge and seven months later. Infaunal abundance was greatest within a net covered clam lay than in proximate and distant control areas, but the total number of species encountered was similar in all areas (20–22). These differences were not attributable to variation in sediment structure or environmental variables between the areas sampled. Tube-building polychaetes, such as Lanice conchilega and Euclymene lumbricoides, were particularly abundant within the cultivated area as was the errant polychaete, Syllis gracilis. Harvesting by suction dredge altered sediment composition by removing the larger sand fractions down to the underlying clay substratum, consequently there was a large reduction in the density of all individuals and the total number of species. Seven months later, no significant difference was found between the infaunal community in the harvested clam lay or either of the control areas and sedimentation had nearly restored the sediment structure. These observations indicate that the practice of clam cultivation does not have long-term effects on the environment or benthic community at this site.