Gianna Fabi

Overview on artificial reefs in Europe

Artificial reefs in Europe have been developed over the last 40 yrs. Most of these reefs have been placed in the Mediterranean Sea, but there is an increasing interest on the part of northern European countries. Fish stock enhancement and fishery management are the main purposes of reef construction in the Mediterranean Sea and on the Atlantic coast of the Iberian Peninsula, while nature conservation/restoration, research, and recreation have been the main purposes served in the other European regions to date. Artificial reef deployment falls under some general regulations concerning the protection of the sea against pollution due to the dumping of unsuitable materials. Specific Regional Plans relating to the use of artificial reefs in the marine environment and Guidelines for reef construction have been derived from these general regulations. In spite of recent developments, national and/or regional programs for the deployment of artificial reefs and/or their inclusion in overall management plans for integrated management of coastal zones are in force only in the majority of Mediterranean countries, while only a few projects have, to date, been undertaken in the other European Regions. Moreover, there is a noteworthy lack of plans, in many countries, for the management of the reefs after their deployment.

Integrated use of biomarkers in the mussel Mytilus galloprovincialis for assessing off-shore gas platforms in the Adriatic Sea: Results of a two-year biomonitoring program

Despite a large number of gas platforms existing in the Adriatic Sea, which is a semi-enclosed basin characterized by a slow turnover rate and increasing industrial as well as other anthropogenic activities, the effects of these structures on the aquatic ecosystem require further investigation. Since 1998, multidisciplinary studies have been performed by CNR-ISMAR to comply with legislation and to support the development of protocols for the monitoring of offshore activities in the Adriatic Sea. The present study was developed to implement a biomonitoring plan to assess the ecotoxicological effects of the extraction activities of an off-shore gas platform. Biomarkers were evaluated in mussels collected from the platform in relation to physiological stress, DNA damage, cellular damage, oxidative stress and exposure effects. Organic contaminants and trace element bioaccumulation were also assessed in the soft body of the mussels to correlate bioaccumulation of pollutants with biomarker responses. The results indicate an absence of platform-related environmental stress.

A multidisciplinary approach to evaluate the environmental impact of offshore gas platforms in the western Adriatic Sea

Detecting the anthropogenic impacts of offshore gas platforms requires reliable tools, because the traditional evaluation based only on chemical analyses is neither appropriate nor sufficiently sensitive. Thus, a 3-year monitoring project was carried out to evaluate the impact of a platform based on a chemical–biological approach. Benthic communities are investigated as they are widely used to monitor the effects of marine impacts because the organisms are mostly sessile and integrate the effects of pollutants over time. Changes in benthic infauna, sediments and water quality, as well as biota bioaccumulation, caused by drilling and platform operations were evaluated experimentally. Furthermore, mussels (Mytilus galloprovincialis) were collected seasonally from the platform legs, both close to and far from the sacrificial anodes and at a control site. Responses of biomarkers of exposure and effect were related to the average levels of polycyclic and aliphatic hydrocarbons, organic matter content and heavy metals in bivalve tissues. Our data suggested that a slight perturbation can be detected only by integrating the results of chemical analyses on water and sediments and those obtained from benthic biological surveys.

Development of an integrated chemical, biological and ecological approach for impact assessment of Mediterranean offshore gas platforms

The pressure for more energy demand is a strong driver for the construction of offshore oil and gas platforms. This also applies to the Adriatic Sea where, since 1960, several gas fields have been commissioned. The continuous expansion of the gas industry may potentially have detrimental effects on marine communities. This may become particularly clear in such a peculiar semi-enclosed basin as the Adriatic Sea, which contains ecosystems that are subject to intensive anthropic pressures, such as unsustainable fishing and inputs of environmental pollutants. To date, still scant information is available on the environmental effects of gas platforms. Thus, to comply with the national Italian legislation and to support the development of protocols for the monitoring of offshore activities, multidisciplinary studies have been conducted and performed by CNR-ISMAR in cooperation with some private and public research institutes. A multidisciplinary approach based on chemical, biological and ecological investigations was performed to evaluate both the water column and the sediment quality near a gas platform. The overall results indicate moderate effects of platform-related environmental stress.

Comparison of growth rates estimated by otolith reading of Scorpaena porcus and Scorpaena notata caught on artificial and natural reefs of the northern Adriatic sea

Despite the high number of studies on fish assemblages associated with artificial reefs and offshore platforms, little information exists on the growth rates of fish living on artificial and natural substrates. Age and growth was determined throughout otolith reading on two commercial scorpionfishes (Scorpaena porcus and Scorpaena notata) caught in the surroundings of artificial structures (artificial reefs and gas platforms) and natural habitats. Von Bertalanffy growth parameters were calculated for each species separately for each site. Age of S. porcus and S. notata ranged from 0 to 8 years and from 0 to 16 years, respectively. Kimura test applied to Von Bertalanffy growth curves indicated that the individuals of both species inhabiting the artificial structures had higher growth parameters than those caught in the natural habitat. The presence of artificial habitats in the northern Adriatic Sea positively affects growth rates and growth performance of both species, likely for the greater prey availability in respect to the natural open sea.

Use of multiple cell and tissue-level biomarkers in mussels collected along two gas fields in the northern Adriatic Sea as a tool for long term environmental monitoring.

As a consequence of the growing global demand of energy supplies, intense oil and gas exploration and exploitation programs have been carried out worldwide especially within the marine environments. The release of oil-derived compounds in the sea from anthropogenic sources both as effluents or accidental spill is perceived as a major environmental concern. An approach based on a combination of biomarkers and the distribution of some classes of environmentally relevant pollutants was used to investigate the occurrence of a stress syndrome in mussels (Mytilus galloprovincialis) collected at three gas platforms placed in two distinct oceanographic districts within the Adriatic Sea. Biological responses were integrated by a ranking algorithm which demonstrated both a range of biological effects reflecting exposure gradients and a temporal related trend in the investigated responses. The overall results demonstrate a moderate to absent pollution from studied gas platforms with low but remarkable biological disturbance in sentinel organisms.

Trophic structure of polychaetes around an offshore gas platform.

The distribution of polychaetes associated with an offshore gas platform built on a muddy-sandy bottom in the northern Adriatic Sea was investigated with emphasis on their feeding structure. Polychaete species were collected at different distances from the rig using a Van Veen grab. Assessment of the polychaete community and trophic groups for impacts related to the presence of the platform demonstrated significantly different abundances at rising distances from the rig. The present findings highlight an effect of the rig on the spatial distribution of polychaete assemblages. Even though the effects of gas platforms on surrounding benthic communities have been investigated in the Adriatic Sea, no studies have addressed the distribution of polychaete trophic groups along a gradient based on distance from the rig.

Multibeam investigation of an artificial reef settlement in the Adriatic sea (Italy) 33 years after its deployment

Artificial reefs (ARs) are becoming a popular biological and management component in shallow water environments characterized by soft seabed, representing both important marine habitats and tools to manage coastal fisheries and resources. Because of the unstable nature of sediments, they require a detailed and systematic investigation that acoustic systems can provide. An AR into the marine environment acts as an open system with exchange of material and energy, altering the physical and biological characteristics of the surrounding area. The AR stability will depend on the balance of scour, settlement, and burial resulting from ocean conditions over time. The acoustic systems are efficient tools in monitoring the environmental evolution around ARs, whereas water turbidity can limit visual dive and ROV inspections. High-frequency multibeam echosounder offers the potential of detecting fine-scale distribution of reef units, providing an unprecedented level of resolution, coverage, and spatial definition. In 2008 the EM3002 multibeam was used to investigate the first scientifically-planned AR in Italy deployed during 1974-75. After 33 years the AR is almost in perfect condition. A considerable scouring around the structures and some vertical/horizontal movements of the single units have occurred. Moreover a deepening of the whole area hosting the AR was observed.

Comparative Effects of Ingested PVC Micro Particles With and Without Adsorbed Benzo(a)pyrene vs. Spiked Sediments on the Cellular and Sub Cellular Processes of the Benthic Organism Hediste diversicolor

The plastic microliter represents an emerging contaminant as well as multiple stress agent in the aquatic environments. Microplastics are found even in the remote areas of the world. Together with their occurrence in all environmental compartments, there is a growing concern about their potential of adsorbing pollutants co-occurring in the environment. Currently, little is known about this source of exposure for aquatic organisms in the benthic environment. Exposure conditions were set up mimicking the contribution of microplastics in different exposure routes. The potential biological effects were investigated in the model organism: the annelid Hediste diversicolor. Cellular effects including alterations of immunological responses, lysosomal compartment, mitochondrial activity, oxyradical production and onset of genotoxicity were assessed in coelomocytes while temporary and permanent effects of oxidative stress were also performed at tissue level. In this study polyvinylchloride (PVC) microplastics were shown to adsorb benzo(a)pyrene with a time and dose-dependent relationship. Results also indicated a marked capability of contaminated microplastics to transfer the model organic chemical to exposed model organism under physiological gut conditions and concentrated in tissues. The elevated bioavailability of the model pollutant after the ingestion induced a clear pattern of biological responses. Toxicity mainly targeted impairment of cellular functioning and genotoxicity in ragworm’s coelomocytes, while permanent effects of oxidative stress were observed at tissue level. Coelomocytes responded faster and with a higher degree of sensitivity to the adverse stimuli when compared with responses observed in whole tissue samples. The results showed that microplastic particles in sediments may play a significant role as vectors for organic pollutants. The highest adverse responses were observed in those ragworms exposed to sediments spiked with PVC particles pre-incubated with B[a]P when compared against sediments spiked with B[a]P and microplastics separately.

Plastic Soles: Microplastic Litter in the Gastrointestinal Tract of Solea solea from the Adriatic Sea

Plastic is widely used in everyday life being one of the more versatile materials ever produced. The rising demand of plastic items to support the societal development has dramatically boosted the annual plastic production from 1.5 in the 1950s to 311 million tonnes in 2014 (PlasticEurope in Plastic-the Facts 2015: an analysis of European plastic production, demand, and waste data, 2014). The dark side of the plastic revolution is the marine pollution, with an estimated amount of 9.5 million tonnes of new plastic waste flowing into the oceans each year (Boucher and Friot in Primary microplastics in the oceans: a global evaluation of sources. IUCN, Gland, p. 43, 2017).