Long-term changes in a benthic assemblage associated with artificial reefs

The aim of the study was to evaluate the long-term development of a hard bottom benthic assemblage over a period of 20 years in an area off the mouth of a large river. The artificial reef of Fregene was selected because benthic assemblage data were available for the period 1981-1992. This artificial reef is located in the mid Tyrrhenian Sea, 5 nautical miles north of the two mouths of the Tevere River (Latium, Italy) and 1.5 nautical miles offshore from Fregene (Rome, Italy). The artificial reef was deployed in March 1981 for fisheries enhancement in 10-14 m of water on a sandy-silty seabed. The Tevere River carries suspended materials and a heavy load of organics since it transports Rome's effluent, resulting in the eutrophic state of area waters. Benthic sampling was conducted in 2001 by SCUBA diving; two standard surfaces of 400 cm 2 were scraped from the vertical walls of the same uppermost block in four different periods. All organisms were identified and counted. The methodology used is the same as that adopted in the previous periods, so that the 2001 data could be compared with past collected data. The benthic assemblage was analysed by cluster analysis using the Bray-Curtis index and clustered using the group average clustering algorithm. The SIMPER procedure was used to identify those taxa that characterize each station group identified by cluster analysis. Changes in benthic assemblages and hydrological trends of the Tevere River were investigated using the cumulative sum series method. The 20-year development of the benthic community, starting from the new substratum, is composed of different phases characterised by different benthic assemblages. In particular five different phases were distinguished: 1. Pioneer species recruitment (May 1981-June 1981); 2. Mytilus galloprovincialis (mussel) dominance (August 1981-November 1983); 3. M. galloprovincialis regression (July 1984-October 1985); 4. M. galloprovincialis absence (91-92); 5. Bryozoans bioconstruction dominance (2001). The dynamic succession of the observed benthic assemblages exhibited a good relation with the Tevere River flow. The Tevere River flow, and the subsequent sedimentation process, seems to have strongly influenced the benthic assemblage succession of the Fregene artificial reef

Valorization, comparison and characterization of coconuts waste and cactus in a biorefinery context using NaClO2-C2H4O2 and sequential NaClO2-C2H4O2/autohydrolysis pretreatment

The search for new sources of lignocellulosic raw materials for the generation of energy and new compounds encourages the search for locations not well known and with a high potential for biomass availability as is the case of the Northeast Region of Brazil. Thus, the cactus (CAC), green coconut shell (GCS), mature coconut fibre and mature coconut shell were pretreated by NaClO2C2H4O2 and sequential NaClO2C2H4O2/autohydrolysis aiming at the obtention of high added-value compounds in the liquid fraction and solid phase. The yield of the solid phase was between 61.42 and 90.97% and the reduction up to 91.63% of lignin in the materials pretreated by NaClO2C2H4O2. After NaClO2C2H4O2/autohydrolysis pretreatment the obtained solids yield was between 43.57 and 52.08%, with a solubilization of the hemicellulose content up to 81.42%. For both pretreatments the cellulosic content remained almost unchanged. The pretreated solids were characterized by SEM, X-ray and crystallinity indexes showing significant modifications when submitted to pretreatments. These results were further confirmed by the enzymatic conversion yields of 81.6890.03 and 86.9790.36% of the LCMs pretreated by NaClO2C2H4O2 and pretreated by NaClO2C2H4O2/autohydrolysis, respectively. The resulting liquors had a total phenolic compounds content between 0.20 and 3.05 g/L, lignin recovered up to 7.40 g/L (absence of sulphur) and xylooligosaccharides between 16.13 and 20.37 g/L. Thus, these pretreatments showed an efficient fractionation of LCMs, especially in the GCS, being an important requirement for the generation of products and byproducts in the context of the biorefinery.The authors gratefully acknowledge the Brazilian research funding agencies CNPq and CAPES for financial support. Financial support from the Energy Sustainability Fund 2014-05 (CONACYT-SENER), Mexican Centre for Innovation in Bioenergy (CemieBio), Cluster of Bioalcohols (Ref. 249564) is gratefully acknowledged. We also gratefully acknowledge support for this research by the Mexican Science and Technology Council (CONACYT, Mexico) for the infrastructure project - INFR201601 (Ref. 269461) and CB-2015-01 (Ref. 254808).info:eu-repo/semantics/publishedVersio

The polychaete community of the Fregene artificial reef (Tyrrhenian Sea, Italy): a 20-year study (1981-2001).

the fourth is a phase of mud accumulation between dead balanids, with the presence of laminar bryozoans (1991–92), and the last corresponds to a phase dominated by bryozoan bioconstruction (2001). The increased complexity in the benthic assemblage and substratum on the reef is also shown by an increased differentiation and distribution of polychaete functional groups. Increasing environmental heterogeneity on the reef is the basic factor that affected biodiversity by generating new niches that could be occupied by additional species with different ecology. The similarity of the benthic assemblage observed on the reef in 2001 with natural bioconstructions suggest that after two decades the ecological succession has lead to a settlement at a steady-state of equilibrium with the surrounding environment.; the third is a phase characterized by Mytilus galloprovincialis dominance and regression (1983–85); The artificial reef of Fregene, Italy, was built in 1981 as a multipurpose structure with the intent of protecting the coastal environment from illegal trawling and also improving fishery production. It is located at 10–14 m depth on a sandy-silty seabed in the Tyrrhenian Sea, 5 nmi north of the outlet of the Tevere River (Latium, Italy) and 1.5 nmi offshore the town of Fregene (Latium, Italy). The development of the polychaete community on the reef was studied from May 1981 to December 2001 in order to examine long-term community dynamics and verify to what extent changes in polychaete assemblage could depict the development of the benthic assemblage. At each sampling time, two standard surfaces of 400 cm2 were scraped from the vertical walls of the same block. Temporal changes in the development of the polychaete community were detected by univariate (S, N, ExpH', 1/Simpson, J') and multivariate (CLUSTER, nMDS) analysis of the faunal data. Functional structure of the community was also analyzed. Changes in the community structure were shown by an overall increasing trend in the total number of species and individuals. The 20-year development of the polychaete community was divided into five different phases representing different benthic assemblages on the reef: the first two periods correspond to settlement of pioneer species (1981–82

The Humber Regional Environmental Characterisation

The Humber Regional Environmental Characterisation (REC) is a multidisciplinary marine study of the geology, biology and archaeology of an area of 11 000 km2 off the east coast of England. It was funded by the Marine Aggregate Levy Sustainability Fund (MALSF). 2. Within the REC area, there are 12 active aggregate licences with applications submitted for 10 more. Within the region there is also gas production, wind energy development, and intensive shellfish harvesting. Without proper management of the sea bed areas there could be conflict over development of resources in the area. 3. The overall objective of the REC project was to provide integrated broadscale seabed maps in order to support the sustainable management of offshore resources now and into the future. The basis of the maps is a regional assessment of the physical, biological and archaeological environment. Here for the Humber REC area we present the results of each individual project element together with their integration into a holistic overview of the marine environment. 4. In addition to SeaZone single beam bathymetry, data from three geophysical and one sampling survey provided the basis for the interpretation. BGS legacy data supplemented the new data set. In total these data provided a sound basis for reporting on the regional character of the geology, biology and archaeology of the area. 5. The geology of the Humber REC area is characterised by a western gravelly region, a sandy eastern one and a transitional area in between. Outside of large sand banks and areas of sand waves the mobile sediment cover is thin. The terminations of the outer Norfolk Banks are located in the southeast of the area, and a series of low amplitude sinuous and linear banks are found in the southwest and centre. A number of arcuate and linear deeps, with a radial pattern incise the seabed. 6. The morphology and sediment distribution are attributed to a number of episodes; initially the region was glaciated and the Bolders Bank till Formation was laid down. After deglaciation the till was eroded to leave a thin coarse-grained relict deposit. As sea level rose the area was transgressed, the relict deposit winnowed and fine grained sediment was transported into the area from the south. This sediment was reworked into the sand banks and sand waves present today over much of the sea bed. The dominance of gravelly sediment in the nearshore areas is the result of strong currents. 7. The Humber REC area is a region which is rich in archaeology, with finds ranging from the Palaeolithic to World War II. The archaeological material in the Humber REC region can be found both on and beneath the seabed. This archaeological material can be grouped into three main categories, prehistoric, maritime and aviation, all of which are present within the study area. 8. Several locations of archaeo-environmental potential were discovered during the Humber REC which directly relate to the regions prehistoric archaeological potential. Most of this potential is present in major channel systems within the south and east of the study area and dates to the Mesolithic period. 9. The submerged prehistoric resource has been characterised. This has been derived from the spatial mapping for the Mesolithic period. Evidence for earlier periods of prehistory is limited within the study area. The characterisation of the Mesolithic landscape indicates that where suitable preservation conditions exist there may be a large resource of material present. 10. The maritime archaeological resource from the late 19th century onwards can be located across the study area and has also been spatially mapped and characterised. No evidence was found for pre 19th century wrecks, despite documentary evidence indicating their presence. 11. The Humber REC area has also been a focus for aviation activity, particularly during World War II, and correspondingly, wrecked aircraft are likely. As most aircraft break up on impact, the wreckage is not commonly intact and can be hard to locate. As such, the number of aircraft wreck sites known to be present within the study area is assumed to represent only a small proportion of incidents, but are possibly more likely in areas on routes to and from World War II targets such as nearby airbases and Kingston upon Hull. 12. Analysis of the biological data collected across the Humber REC study area revealed four functional biological communities. 13. The most common community ‘infaunal polychaetes with burrowing bivalves and amphipods’ was recorded across much of the mid and eastern sections of the study area in sandy deposits. The second most abundant community was characterised by ‘barnacles, ascidians and tubiculous polychaetes’ and was associated with coarser, mixed sediments with suitable areas for attachment. In some areas where the REC study area was influenced by higher levels of sand this community was replaced by a ‘Sabellaria spinulosa reef’ community. A small number of locations, in both mixed and sandy sediments, were found to support a very sparse biological community. 14. The biological communities were found to correlate strongly with the composition of sediment deposits, but were also influenced by shear bed stress and stratification of the water column. Predicted biotope distributions maps were created for the Humber REC study area utilising the EUNIS habitat classification scheme and habitat suitability modelling. Both methods yielded maps which are suitable for marine management purposes. However, since the EUNIS scheme forces a split on a limited set of environmental variables, which did not correlate strongly with the biological communities, it was felt that this method led to an overly complicated map with many communities occurring in multiple habitats.The EUNIS habitat model and RECHUM functional community model were combined to create a full coverage biotope model equivalent to EUNIS Level 5. 15. A number of rare and alien species were identified across the Humber REC study area including the tiny bivalve Coracuta obliquata This is only the second record of this species from British waters in the last 100 years. The invasive American Slipper limpet was also observed and it is thought that these records may indicate a northwards shift in the range of this species, possibly associated with a warming climate. 16. Potentially important Annex I reef habitats were found in association with the Silver Pit. The reefs were predominantly created by the Ross worm Sabellaria spinulosa although high densities of the blue mussel Mytilus edulis were also identified. It seems likely that there is a cyclical succession occurring between these two reef building species driven by minor changes in environmental conditions and recruitment success