Changes in Genetic Structure of Posidonia oceanica at Monterosso al Mare (Ligurian Sea) and Its Resilience Over a Decade (1998–2009)

Abstract

Genetic differences in the Posidonia oceanica meadow of Monterosso al Mare (NW Mediterranean, Marine Protected Areas (MPAs) "Cinque Terre") were compared in three stations, at an increasing distance from a source of impact (beach nourishment) in the recent decade. Random amplified polymorphic DNA analysis showed a higher genetic variability (>20 %) in the area directly subjected to the stress, increasing with time. Clone integration, confirmed by phenotypic analysis, showed increases both in shoot density and leaf length connected to genetic differences observed in DNA fingerprints of new shoots. Analysis of molecular variance (AMOVA) showed 45 % individual differences within populations and 54 % among the populations. The fixation index (F (ST) = 0.54), of the genetic differentiation, showed a marked difference between the populations at different temporal scales. Over a decade AMOVA indicated genetic variations from 28 % (1998) to 54 % (2009). These results make it clear that in the P. oceanica population examined the environment had, in ten years, selected those clones which were more resistant to the anthropogenic impact, despite being subjected to the effects of the resuspension of fine sediments. These findings could help to explain both the survival of the regressed Mediterranean P. oceanica meadows in areas subjected to moderate impacts and the extreme variability in success of revegetation experiments. Management of the ecological disturbance here described indicates also the timescale in population response to stress and its increased resilience in MPAs.

Ecological Function of Phenolic Compounds from Mediterranean Fucoid Algae and Seagrasses: An Overview on the Genus Cystoseira sensu lato and Posidonia oceanica (L.) Delile

“…Haznedaroglu and Zeybek [14], for instance, found in young leaves a higher quantity of chicoric acid. In the marine realm, the genetic variability and phenotypic plasticity of the species confer an adaptive mechanism to environmental disturbances by producing, for instance, secondary metabolites, which allow for an efficient plant acclimation [16,29,138]. The changes in phenol metabolism could be a result of the adaptation to the marine environment [129].…”

“…Since the changes in phenolic compounds represent a response to environmental stressors, they can be used to screen the P. oceanica health status during the regular monitoring programs carried out for management purposes [16,17,113,116,132,139,140]. Two promising tools (easy, rapid and inexpensive): phenolic compounds in rhizome and Random Amplified Polymorphic DNA (RAPD) markers in leaves, were recently proposed to monitor the health state of P. oceanica meadows [17,116,132].…”

“…Among secondary metabolites, phenolic compounds, carbon-based metabolites ranging from simple molecules, such as free and ester-bound phenolic acid, to more complex polymers such as condensed tannins and lignins, are commonly produced by algae and seagrasses for structural, protective and ecological purposes [4][5][6][12][13][14][15][16][17]. For instance, algae and plants living in saltworks produce and accumulate polyphenols as defense strategies to cope with these extreme environmental conditions [18].…”

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

“…Due to impacts from these different factors PO may exhibit various kind of responses to stress [2], mainly evidenced by extents reduction, fragmentation increase and changes of phenology and morphological parameters of the meadows [3]. In general the extensive analysis of such variability, by means of remote sensing monitoring and advanced laboratory analysis techniques, aims at the detection and better characterization of PO meadows specific biophysical parameters (i.e., LAI) and distribution to assess their health and resilience capability [3] and possibly identify the various environmental stress factors with the perspective to better support their sustatinable management [4].…”

“…In general the extensive analysis of such variability, by means of remote sensing monitoring and advanced laboratory analysis techniques, aims at the detection and better characterization of PO meadows specific biophysical parameters (i.e., LAI) and distribution to assess their health and resilience capability [3] and possibly identify the various environmental stress factors with the perspective to better support their sustatinable management [4]. Although many biological tests have been carried out on PO as good indicator of water quality and status of marine ecosystems [4,5], its accurate spatial patterns mapping is still in progress in various Italian coastal zones affected by high anthropogenic pressure and often characterized by diffused shallow waters turbidity which often makes difficult their extensive detection by means of remote sensing techniques.…”