Mapping Spatial Patterns of Posidonia oceanica Meadows by Means of Daedalus ATM Airborne Sensor in the Coastal Area of Civitavecchia (Central Tyrrhenian Sea, Italy)

Abstract

Abstract:The spatial distribution of sea bed covers and seagrass in coastal waters is of key importance in monitoring and managing Mediterranean shallow water environments often subject to both increasing anthropogenic impacts and climate change effects. In this context we present a methodology for effective monitoring and mapping of Posidonia oceanica (PO) meadows in turbid waters using remote sensing techniques tested by means of LAI (Leaf Area Index) point sea truth measurements. Preliminary results using Daedalus airborne sensor are reported referring to the PO meadows at Civitavecchia site (central Tyrrhenian sea) where vessel traffic due to presence of important harbors and huge power plant represent strong impact factors. This coastal area, 100 km far from Rome 4878(Central Italy), is characterized also by significant hydrodynamic variations and other anthropogenic factors that affect the health of seagrass meadows with frequent turbidity and suspended sediments in the water column. During 2011-2012 years point measurements of several parameters related to PO meadows phenology were acquired on various stations distributed along 20 km of coast between the Civitavecchia and S. Marinella sites. The Daedalus airborne sensor multispectral data were preprocessed with the support of satellite (MERIS) derived water quality parameters to obtain here improved thematic maps of the local PO distribution. Their thematic accuracy was then evaluated as agreement (R 2 ) with the point sea truth measurements and regressive modeling using an on purpose developd method.

A Benthic Zonation System as a Fundamental Tool for Natural Capital Assessment in a Marine Environment: A Case Study in the Northern Tyrrhenian Sea, Italy

“…Based on this information, species lists were determined for every unit area to define the relative biocenosis. Literature data were integrated with original unpublished data obtained through two sampling campaigns of soft substrate benthic biocenosis, performed in 2013 and 2017, and through assessment campaigns for the characterization of P. oceanica meadows, in the study area [14,15]. The aim was to validate the literature information by comparing the characteristic species lists.…”

“…The map is based on Map 1:100,000 from the Military Geographic Institute of Italy (IGM) and on previous studies with particular reference to a compendium of several surveys conducted in the decade 1999-2009, in the study area [18]. Literature data are integrated using unpublished results of two sampling campaigns of soft bottom benthic biocoenoses, carried out in 2013 and 2017, and P. oceanica characterization surveys [14,15].…”

“…Data from the literature [14,15,[34][35][36] were used in this work. P. oceanica is widely distributed in the study area and can be found in most of the littoral zone on, both, rocky and sandy seabeds.…”

Integrated Observing Systems Supporting Civitavecchia Port Development

“…Before and after each dredging operation the health status of P. oceanica meadows in the study area was evaluated through the analysis of the number of shoots per square meter (shoot density) that, together with remote sensing data, allowed to calculate the Leaf Area Index (LAI) [15].…”

The use of remote sensing for monitoring Posidonia oceanica and Marine Protected Areas: A systemic review

“…In the last decades, RS technologies have been improved allowing not only the mapping of P. oceanica (Fornes et al, 2006;Pasqualini et al, 2005) but also the assessment of other variables dealing with the observation of P.oceanica. For example, Borfecchia et al (2013) used multispectral satellite sensors for monitoring P. oceanica ied the use of lightweight autonomous underwater vehicles with the RS payload, showing their high performance in terms of economic cost and time. Poursanidis et al…”