Abstract Among marine ecosystems globally, those in the Mediterranean Sea, are facing many threats. New technologies are crucial for enhancing our understanding of marine habitats and ecosystems, which can be complex and resource-intensive to analyse using traditional techniques. We tested, for the first time, an integrated multi-platform approach for mapping the coastal benthic habitat in the Civitavecchia (northern Latium, Italy) coastal area. This approach includes the use of an Unmanned Surface Vehicle (USV), a Remote Operated Vehicle (ROV), and in situ measurements of ecosystem functionality. The echosounder data allowed us to reconstruct the distribution of bottom types, as well as the canopy height and coverage of the seagrass Posidonia oceanica . Our study further involved assessing the respiration (Rd) and net primary production (NCP) rates of P. oceanica and its associated community through in situ benthic chamber incubation. By combining these findings with the results of USV surveys, we were able to develop a preliminary spatial distribution model for P. oceanica primary production (PP-SDM). The P. oceanica PP-SDM was applied between the depths of 8 and 10 m in the studied area and the obtained results showed similarities with other sites in the Mediterranean Sea. Though in the early stages, our results highlight the significance of multi-platform observation data for a thorough exploration of marine ecosystems, emphasizing their utility in forecasting biogeochemical processes in the marine environment.
Svalbard archipelago is experiencing the effects of climate changes (i.e., glaciers’ thickness reduction and glacier front retreat), but how ice melting affects water biogeochemistry is still unknown. Microbial communities often act as environmental sentinels, modulating their distribution and activity in response to environmental variability. To assess microbial response to climate warming, within the ARctic: present Climatic change and pAst extreme events (ARCA) project, a survey was carried out along a transect in Konsfjorden from off-shore stations towards the Kronebreen glacier. Total bacterial abundance and the fraction of actively respiring cells (labelled by cyanotetrazolium chloride, CTC), cultivable heterotrophic bacterial abundance, and extracellular enzymatic activities (leucine aminopeptidase (LAP), beta-glucosidase (GLU), and alkaline phosphatase (AP)) were measured. In addition, water temperature, salinity, dissolved oxygen, turbidity, total suspended matter (TSM), particulate and chromophoric dissolved organic matter (CDOM), chlorophyll-a (Chl-a), and inorganic compounds were determined, in order to evaluate whether variations in microbial abundance and metabolism were related with changes in environmental variables. Colder waters at surface (3.5–5 m) depths and increased turbidity, TSM, and inorganic compounds found at some hydrological stations close to the glacier were signals of ice melting. CDOM absorption slope values (275–295 nm) varied from 0.0077 to 0.0109 nm−1, and total bacterial cell count and cultivable heterotrophic bacterial abundance were in the order of 106 cells/mL and 103 colony forming units/mL, respectively. Enzymatic rates <1.78, 1.25, and 0.25 nmol/L/h were recorded for AP, LAP, and GLU, respectively. Inorganic compounds, TSM, and turbidity correlated inversely with temperature; AP was significantly related with CDOM absorption spectra and heterotrophic bacteria (r = 0.59, 0.71, p < 0.05); and LAP with Chl-a, Particulate Organic Carbon (POC) and Particulate Organic Nitrogen (PON) (0.97, 0.780, 0.734, p < 0.01), suggesting that fresh material from ice melting stimulated the metabolism of the cultivable fraction.
Chlorophyll and suspended sediments are the main indicators of the marine ecosystem’s bio-optical properties. Chlorophyll is directly connected with primary productivity, while the suspended sediments are associated with water quality; both factors are influenced by climate change. The present research is mainly focused on testing the capability of Sentinel-2 on estimating the Tiber River driven spatial dynamics of chlorophyll and suspended sediment. The present research also aims to identify suitable methods for estimating chlorophyll and suspended sediment levels in the Tyrrhenian coastal ocean and seas. Algorithms including SNAP-bound C2RCC-Nets, C2X-Nets, C2X-COMPLEX-Nets, and ACOLITE-bound OC2, OC3, SPM_Nechad2010 and SPM_Nechad2016 algorithms were applied to estimate the dynamic distribution of chlorophyll and suspended sediment in the Tyrrhenian region. C2RCC-Nets outperformed all other and a statistically significant positive correlation observed with in situ-derived chlorophyll and suspended sediment, with coefficients of 0.903 and 0.966, respectively. Additionally, a positive seasonal spatial correlation was estimated between chlorophyll and suspended sediments, indicating that Tiber River discharge have positive impacts by accelerating the chlorophyll level on the Tyrrhenian coastline compared to the negative trend observed in the Mediterranean region. Keywords: Sentinel-2, C2RCC, chlorophyll, Suspended sediments, Tiber River, Tyrrhenian region.
Oceanographic investigations, traditionally, are both limited and strictly dependent by time and space scales and by sensors technological developments (Dickey & Bidigare, 2005).To observe oceanographic phenomena and processes, several and different methods can be utilized providing different results.Even if some methods still have remained almost unvaried, even if they have been improved and perfectioned (as for example the continuous plankton recorder, CPR), in many cases, technological developments lead us to a noteworthy advancing of the knowledge of processes and phenomena, formerly undetectable and just intuitable.www.intechopen.comOceanography 42 Platforms and sensorsRelating to a defined phenomena, observation has to be carried out with the appropriated method in order to detect processes and trends of such phenomena.To this aim, platforms and sensors have to be choose as in respect to the time and space scale of the phenomena, as taking into account the nature (e.g.chemical, physical or biological) of what we are looking to (Dickey & Bidigare, 2005).The environment (e.g.shallow water, deep sea or coastal areas) is also fundamental to the choice of the adequate sampling sensors and operative methods.Many physical, chemical and biological aspects can be described by means of punctual observations, e.g.stand alone moored instruments or oceanography buoys and multipurpose platforms.Also, dedicated oceanographic surveys can be set up in order to study a particular aspect of a defined marine area.In order to reduce operative costs and to enhance spatial resolution of data for water column characterization, towed vehicles can be utilized to continuous measure of physical, chemical and biological variables, along water column and along horizontal trajectories.Also the use of expendable probes and the ship of opportunity, are fundamental to this aim.From an operative point of view, observation platforms can be divided basically into the following categories: Ships (Research Vessels RV); Mooring; Underwater vehicles and lowered devices (Remote Operated Vehicles ROV; Towed Vehicles; Crewed Deep Submersible Vehicles; Autonomous Underwater Vehicles; Gliders; Lagrangian buoys; Expendable probes; Drifters) Voluntary Observing Ships (VOS); Remote sensing platforms (Airplains and Satellites); ShipsOceanographic research vessels can be considered shipborne platform as they can be utilized to conduct many kind of scientific investigations, such as mapping and charting, marine biology, fishery, geology and geophysics, physical processes, marine meteorology, chemical oceanography, marine acoustics, underwater archaeology, ocean engineering, and related fields (Dinsmore, 2001in Thorpe, 2009).The United Nations International Maritime Organization (IMO) has established a category of Special Purpose Ship which includes ships engaged in research, expeditions, and survey.Scientific personnel are also defined as "persons who are not passengers or members of the crew, who are carried on board in connection with the special purpose" (www.imo.org).The design of a modern Research Vessel can vary significantly in respect to the research activities.Typical caracteristics can be as follow described: a. RV have to be as general as possible in order to allow multidisciplinary studies and researches; b. the size is determined by the requirements, but the length-over-all should not exeed 100 m LOA; c. speed of 15 knots cruising should be sustainable through sea state 4 (1.25-2.5 m) and the seakeeping should be able to maintain science operations in the following speeds and seastates: -15 knots cruising through sea state 4 (1.25-.5 m); -13 knots cruising through sea state 5 (2.5-4 m); -8 knots cruising through sea state 6 (4-6 m);www.intechopen.comNew Technological Developments for Oceanographic Observations 43 -6 knots cruising through sea state 7 (6-9 m).d.Work environment: lab spaces and arrangements should be highly flexible to accommodate large, heavy, and portable equipments.e. Suite of modern cranes, in order to reach all working deck areas and offload vans and heavy equipment, and in order to work close to deck and water surface.f.Oceanographic winches permanently installed should provide a wire monitoring systems with inputs to laboratory panels allowing local and remote data and operational controls.The above general characteristics, can be modulate relating to the particular purpose of the vessels itself.Therefore it is more convenient and appropriate divides RV in the following categories: General Pourpose Vessels Multidiscipline Ships represent the classic oceanographic research vessels and are the dominant class in terms of numbers today.Current and future multidiscipline oceanographic ships are characterized by significant open deck area and laboratory space.Also accommodations for scientific personnel are greater than for single purpose vessels due to the larger science parties carried.Flexibility is an essential feature in a general purpose research vessel. Mapping and Charting VesselsThese group of ships were probably the earliest oceanographic vessels, traditionally involved in exploration voyage.Surveys were carried out using wire sounding, drags, and launches.Survey vessels are also characterized by less deck working space than general purpose vessels.Modern survey vessels, however, are often expected to carry out other scientific disciplines.Winches, cranes and frames can be observed on these ships. Fisheries Research VesselsFisheries research generally includes studies on environment, stock assessment, and gear testing and development.The first of these are carried out by traditional surveys to collect biological, physical, and chemical parameters of sea surface and water column as well as geological informations.These surveys can be accomplished from a general purpose oceanographic research vessel. Geophysical Research VesselsThe purpose of marine geophysical research vessels is to investigate the sea floor and subbottom, oceanic crust, margins, and lithosphere ranging from basic research of the Earth's crust to resources exploration.The highly specialized design requirements for a full-scale marine geophysics ship usually precludes work in other oceanographic disciplines. Polar Research VesselsPolar research vessels are defined by their area of operations.The special requirements defining a polar research vessel include increased endurance, usually set at 90 days, helicopter support, special provisions for cold weather work, such as enclosed winch rooms and heated decks, and icebreaking capability.Support Vessels These include vessels that support submersibles, ROVs, buoys, underwater habitats, and scientific diving.
Coastal areas are characterized by several disturbances due to the presence of numerous anthropic activities that may alter the health status and ecological functioning of Posidonia oceanica meadows. The reduction of seawater transparency and the increase of sedimentation rate are among the main causes of their regression. This work is focused on the northern Latium coast (Central Tyrrhenian Sea), from Marina di Tarquinia to Santa Severa. Over time, alteration of river run-off (change in land use, captation along rivers, etc.) and dredging activities carried out within the Civitavecchia harbour, have led to the dispersion of a large amount of fine materials in the marine environment. In this area, four Sites of Community Importance were identified according to the Habitats Directive (92/43/EEC), due to the presence of P. oceanica beds. Meadows are fragmented and discontinuous also because the high geomorphological heterogeneity. The aim of this work has been to evaluate the effects of the reduction of seawater transparency and the alteration of sedimentation rate on the meadows due to dredging activities. The evaluation of meadows health status from 2002 to 2013 was performed by structural (shoot density and coverage) and functional (leaf biometry) standard descriptors analysis. In the same period, the water transparency and the sedimentation rate have been analysed using numerical models able to distinguish between river and dredging contributions. The simulations of dredged sediments transport have highlighted as the plume is transported mainly to the north, with high concentration values near the shoreline; for this reason the evaluations of shoot density of P. oceanica meadows located near the harbour and far from the coast have not shown a decrease over the years. In the meadow further north, where the concentration of dredged suspended materials is decreasing, the reduction in shoot number is mainly due to the sediment plumes of the Marta and Mignone rivers.
According to the Water Framework Directive, harbours that are classified as heavily modified water bodies must either reach or maintain good ecological potential. Moreover, following the marine spatial planning principles, the effects of port structure changes on water quality must also be considered. To support the sustainable management of harbour waters, we calculated flushing time (FT) through the use of a numerical model within the Civitavecchia port under different scenarios. To assess the effects of the realization of new infrastructure that will significantly alter the port configuration in the coming years, we also developed the flushing efficiency index (FEI). The increase in the harbour basin size due to the embankment extension result in high values of FT, particularly in the inner part of the port, in accordance with the highest values of the enrichment factor of the trace metals found in the sediment. The deterioration of water quality is confirmed by negative FEI values. Otherwise, the index assumes positive values after the realization of a second entrance in the southern part of Civitavecchia port, highlighting a drastic improvement in harbour water renewal. This study provides a low-cost and predictive tool to correctly address environmentally sustainable management of port activities.
This study reports the quantification and analysis of the ecosystem services (ESs) value of Posidonia oceanica (L.) Delile (1813) meadows in Italy (Liguria, Tuscany, Latium, Campania, Calabria, Apulia, Sardinia, and Sicily regions). The ES evaluation method of P. oceanica meadows applied in this study was obtained from a previous study in which the site-specific approach for the definition of the benefits and services was applied. The distribution of P. oceanica and the ESs economic value have been managed through an open-source geographic information system (QGIS), focusing on five essential ESs: carbon sequestration, bioremediation, oxygen production, erosion protection, and food production. The average value of the ESs obtained on the Italian national scale is €21,660.5 ha−1 yr−1, which is comparable with the values reported in the international literature concerning P. oceanica ESs. The results of this study confirm that the economic evaluation of ESs is an essential tool for the management of the coastal marine environment, especially considering the modularity of the applied approach. The value of the total benefits, considering the entire extension of the national P. oceanica meadows, represents significant value with respect to the Italian gross domestic product, and the individual budgets of the considered Italian regions.
