Variation of structural and functional metrics in macrophyte communities within two habitats of eastern Mediterranean coastal lagoons: natural versus human effects

Abstract

2. The aim was to differentiate metric variation caused by human or natural processes and thereby to (1) select reliable metrics and (2) develop user-friendly protocols for cost-effective monitoring programmes for coastal lagoon water quality.3. Eight different sites dominated by macrophyte communities characterized by two angiosperms (Ruppia cirrhosa and R. maritima), two opportunistic macroalgae (Ulva sp. and Chaetomorpha linum), and Cyanobacteria colonies were quantitatively and destructively sampled twice.4. Structural metrics showed highest heterogeneity at a local site-specific scale, while functional metrics showed highest heterogeneity at the scale of habitat. As a result the structural metrics appeared inappropriate as indicators of lagoon water quality changes. By contrast shifts of habitat dominated by angiosperms to opportunistic macroalgae owing to nutrient excess, especially nitrogen, can be identified by functional metrics, especially with EEI.

Community shifts, alternative stable states, biogeochemical controls and feedbacks in eutrophic coastal lagoons: a brief overview

“…In the Valli di Comacchio lagoon, a clear succession was observed from pristine Ruppia cirrhosa and Lamprothamnium papulosum meadows, to an intermediate macroalgal bloom and, recently, to the development of a mixed community of nanoplanktonic green algae and cyanobacteria (Andreoli et al, 1998;Piccoli, 1998). A similar pattern was observed in degraded sites of the Agiasma lagoon (Greece), where a seasonal alternation between summer Ulva and winter cyanobacteria blooms often occurs (Orfanidis et al, 2008b).…”

“…Among the possible limiting factors, nitrogen rather than phosphorus is becoming the primary control of the shift in benthic vegetation (Ferdie and Fourqurean, 2004;Howarth and Marino, 2006;Orfanidis et al, 2008b). Recent studies have added further evidence that in the latest stage of this succession small-sized cyanobacteria, nano-and picoplankton can prevail, with an increase of the heterotrophs to autotrophs ratio (Coppola et al, 2007).…”

Ecological Evaluation Index continuous formula (EEI-c) application: a step forward for functional groups, the formula and reference condition values

“…Similar sites were sampled again in July 2009. Five destructive random quadrates were sampled in each site using a metallic handheld box corer (17 cm x 17 cm x 15 cm; length x width x height; see ORFANIDIS et al, 2008). They were representative of the 'Brackish coastal lagoons' (EUNIS) (EU Habitats Directive Annex I code 1150).…”

“…In order to implement the WFD in the Mediterranean Sea, different benthic macrophyte ecological quality indices are currently suggested for rocky coastal (GIACCONE & CATRA, 2004), (CARLIT;BALLESTEROS et al, 2007b), (BENTHOS;PINEDO et al, 2007), and sedimentary transitional waters (EXCLAME; DEROLEZ, 2007), (CYMOX;MASCAR et al, 2009), (MAQI;SFRISO et al, 2009), and one of them is applicable for both types (EEI; ORFANIDIS et al, 2001ORFANIDIS et al, , 2003ORFANIDIS et al, , 2008PANAYOTIDIS et al, 2004). Other methodologies applied along Eastern Atlantic rocky coasts include the reduced species list index (RSL) (WELLS et al, 2007), the quality of rocky bottoms index (CFR) and opportunistic algal cover (KRAUSE-JENSEN et al, 2007).…”

Applicability and intercalibration of macrophyte quality indices to characterise the ecological status of Mediterranean transitional waters: the case of the Venice lagoon

“…For the sedimentary TWs of the Mediterranean eco‐region, two benthic macrophyte quality indices have been proposed by Italy and Greece: the Macrophyte Quality Index (MaQI; Sfriso et al. 2007, 2009a; ISPRA 2010) and the Ecological Evaluation Index (EEI; Orfanidis et al. 2001, 2003, 2008, 2011).…”