Session 20 - Marine environment and coastal management

[CEST2019_00892] Seasonal variations of water quality and aquatic macrophytes survey based on side scan sonar, in a shallow coastal lagoon (Gialova, SW Peloponnesus, Greece)
by Papakonstantinou M., Papatheodorou G., Christodoulou D. Papastergiadou E.

Gialova lagoon is located in the north-west of Pylos city (Prefecture of Messinia, SW Peloponnesus) and is part of the Ecological Network “Natura 2000”. The aim of the current research is the assessment of the ecological quality of the lagoon using hydroacoustic technique and the monitoring of abiotic and biotic parameters on seasonal basis. Side scan sonar imagery resulted in 6 different lagoon floor acoustic types which correspond to different percentage of vegetation cover. Samplings of aquatic vegetation were carried out from 9 different sampling stations oriented by the results of the hydroacoustic survey. Macrophytes Ruppia cirrhosa and Cymodocea nodosa but also chlorophyte Cladophora glomerata were recorded in the lagoon floor. Key water quality parameters and primary production (Chlorophyll-a) were monitored seasonally at nine stations. Chl-a and TP seems to be the main responsible parameters for the eutrophic ecological status of the lagoon.

Session: 20, Room: B, at Fri, 09/06/2019 - 10:00 to 10:15
Oral presentation in Marine environment and coastal management
[CEST2019_00893] Benthic litter density maps through low-cost underwater towed video camera surveys. An integrated approach.
by Fakiris E., Christodoulou D., Kordella S., Geraga M., Papatheodorou G.

The marine environment is the final recipient and digester of litter. Floating and benthic litter constitute the majority of litter items in the marine environment while both remain quite unexploited due to their demand in high-cost and time-consuming surveys. In this paper we propose an integrated approach for assessing in detail the spatial distribution and composition of benthic litter in coastal environments, through the use of underwater towed cameras. The method is showcased in Syros Island, Cyclades, Greece where benthic litter density maps revealed benthic litter sources and environmental drivers controlling their spatial distribution and general pathways.

Session: 20, Room: B, at Fri, 09/06/2019 - 10:15 to 10:30
Oral presentation in Marine environment and coastal management
[CEST2019_00781] Development of Continuous, Linear Models for Marine Benthic Macrophytes Description
by Tzouvaras N.P.

The European Water Framework Directive has fostered indicator development, pertinent to biological quality elements, for ecological status assessment of coastal waters. For seaweed communities, the CFR index considers composition, abundance and physiological status, through four constituents (Richness, Opportunistic species, Cover, physiological Status) with arithmetically added scores (integers), summing up in [0, 100] and yielding ecological quality ratio (EQR) values in [0, 1]. Quantities C, O and S are expressed as percentages; R as small integer values; each one’s range of values is subdivided into 5 intervals, each attributed a score (integer). Discontinuous (step-wise) score values cause CFR (integer) discontinuities in the ranges [0, 10] and [90, 100], affecting pertinent EQR values and precluding certain ones (e.g. 0.04, 0.93, 0.98). Based on the major contribution of quantities C and O to CFR, the present work transforms their combined, discontinuous variation into a continuous, linear model, employing recently used concepts (PRI approach), applied in developing a continuous, linear, composite model for another benthic macrophytic index. Application to CFR underlines the flexibility of the RPI approach.

Session: 20, Room: B, at Fri, 09/06/2019 - 09:45 to 10:00
Oral presentation in Marine environment and coastal management
[CEST2019_00756] Sustainable musselculture activity in terms of hydrodynamics. The case study of Chalastra basin (NW Gulf of Thessaloniki)
by Savvidis Y., Galinou-Mitsoudi S.

Based on the framework strategic guidelines for marine aquacultures, the musselculture section has to be operated in Areas of Organized Aquaculture Development (AOAD). Chalastra (NW Thessaloniki’s Gulf, Thermaikos) produces the 40% of the national musselculture production using pole and longline systems. Following the legislation, farmers and authorities are in process of reforming the existed units and planning new ones so that the musselculture would remain a sustainable activity in AOAD. The aim of this study is to estimate the appropriate orientation of the mussel units and the lines from which the mussels’ socks are hung, in relation to the sea currents’ directions for the optimum water circulation in AOAD. The hydrodynamics of Chalastra basin is mainly wind driven and affected both by prevailing northern and southern winds during winter and summer respectively. The mussel units and the socks work as “fence” of the sea currents when the production lines are placed perpendicular to them. Consequently, we propose (a) the division of the studied AOAD in three sub-areas for the pole and long-line units respectively and (b) the placement of the shortest possible length of production lines with orientation parallel to the sea currents.

Session: 20, Room: B, at Fri, 09/06/2019 - 09:30 to 09:45
Oral presentation in Marine environment and coastal management
[CEST2019_00713] SeaLoc: A pilot forecasting system providing sea characteristics and other support services on high local resolution
by Kalantzi G., Kotsopoulos S., Panitsidis K., Partozis A., Karystinakis K.

SeaLoc project aims in developing an integrated forecasting system with accompanying services for the Greek seas. Further development, however, can facilitate the whole Mediterranean region. It will provide interaction both with specialists as well as with everyday users through the internet and specialized applications, whose output will be in a format ready to be utilized by relevant target groups. The specialized applications will focus on identified needs of each target group, providing easy-to-comprehend thematic indices alongside the actual forecasts. The system consists of in-house wind and wave predictions as well as other crucial Copernicus Marine products (currents, salinity, SST, nitrate, plankton and dissolved oxygen). The great impact of the project derives from the fact that it combines current forecasting research developments along with available Copernicus Marine data/ services in an effort to bridge the gap between science and end-users. Additionally, the high spatial and temporal resolution in selected areas of marine-dependent financial importance, make SeaLoc a great decision-support tool towards local development and financial growth. Sectors than can benefit from such a tool are: coastal and marine tourism, fishing, aquaculture, shipping, coastal constructions, energy harvesting and others.

Session: 20, Room: B, at Fri, 09/06/2019 - 10:33 to 10:36
Flash presentation in Marine environment and coastal management
[CEST2019_00527] A study of alkali-activated concrete mixes in seawater environments
by Mengasini L., Mavroulidou M., Gunn M.J.

This paper assesses the performance in seawater environment of concrete mixes based on alkali-activated (AA) cements; these are proposed as an alternative to Ordinary Portland Cement (OPC) to address environmental footprint of cement production and to find new uses for waste materials. The proposed AA cements contained an industrial by-product, ground granulated blast furnace slag (GGBS) and a waste material, paper sludge ash (PSA). Mixes were made with fresh water and seawater respectively and were cured either in freshwater or seawater to simulate future exposure environments. The compressive strength at different curing times and a number of durability-related properties of AA mixes in marine environment were investigated and compared to those of OPC systems. The findings indicated that mixing with seawater rather than freshwater enhanced the performance of the AA mixes in terms of compressive strength and durability (resistance to chloride and sulphate attack). In a seawater environment the AA slag concrete mixes with PSA had the lowest porosity, which can be linked to their good durability performance. The study gives promise for the suitability of the tested alkali-activated concrete mixes in seawater environments.

Session: 20, Room: B, at Fri, 09/06/2019 - 09:15 to 09:30
Oral presentation in Marine environment and coastal management
[CEST2019_00490] Plastic Litter Project 2018: exploring the detection of floating plastic litter using drones and satellite images
by Topouzelis K., Papakonstantinou A., Garaba S.P., Doukari M., Chatziantoniou A., Spondilidis S.

Plastic litter has been shown to pose a significant problem in the marine environment and the food chain at all trophic levels. Within the scope of Plastic Project 2018, we investigated the prospective use of imaging technology on airborne and spaceborne platforms in detecting floating plastic litter. Three artificial targets of plastic litter were prepared using PET-1water bottles, LDPE plastic bags and nylon fishing ghost nets. Each target measured 10 m x 10 m fixed by a PVC frame to prevent spillage as well as to make an aggregated target. We evaluated the derived spectral reflectances of these plastic litter targets gathered from the airborne (drone) and spaceborne (Sentinel-2) images. Improved geo-referencing of the high geo-spatial resolution (resampled 10 m) Sentinel-2 images was achieved by utilizing excellent geospatial resolution (<0.03 m) drone images. Further analysis involved determining accurate pixel coverage of each target with future application in quantification efforts. Of the three plastic litter targets, it was noted that the plastic bottles had the highest spectral reflectances that were measured by the Sentinel-2 mission image. The experiment showed that Sentinel-2 satellites could be used to detect marine plastics when they cover a large area. The Sentinel-2 NIR band can significantly contribute to marine litter detection and the water content partly influence the behaviour of spectral values.

Session: 20, Room: B, at Fri, 09/06/2019 - 09:00 to 09:15
Oral presentation in Marine environment and coastal management
[CEST2019_00263] Genetic population structure of scallops going through a rapid population decline in the Eastern Mediterranean
by Metaxatos A., Gazouli M.

Genetic structure of the endemic Pecten jacobaeus of Aegean inferred from mitochondrial 16s DNA sequence analysis was performed. This genetic marker is a powerful tool for measuring genetic variation and gene flow among populations. Valuable scallop stocks were abundant in the past in Euboikos gulf and Aegean but now are severely depleted due to overfishing, pollution and ocean warming. To restock and conserve this bivalve, a better understanding of its genetic variability is essential. DNA was isolated using the nucleospin tissue kit after homogenization of ligament and PCR using genus specific primers. The PCR products were analyzed by sequencing. The genomic comparison was performed by Blast analysis. We studied two hypotheses: 1. Scallops (P. maximus & P. jacobeus) which can be easily distinguished by the shell morphology belong to the same species without a significant genetic variation or not 2. The possibility to extract DNA from dead shells, a good practice for protected or endangered species. We showed that it is possible to extract DNA from ligaments of dead shells exposed for longtime on the seabed. A high similarity (>99%) between our results for P. jacobeus (16s rRNA genome) and P. Jacobeus or P. maximus nucleotide collections was revealed

Session: 20, Room: B, at Fri, 09/06/2019 - 10:30 to 10:33
Flash presentation in Marine environment and coastal management