Effects of point source of untreated sewage waters on seagrass (Zostera marina and Z. noltii) beds in the South-Western Black Sea

Sediment Properties as Important Predictors of Carbon Storage in Zostera marina Meadows: A Comparison of Four European Areas

“…The first survey on Z . marina along the Bulgarian coast was carried out in 1977–78, in which our study sites were reported, and the estimates of biomass were similar to those found in recent years (2010–11) indicating that the seagrass meadows have been stable for many years [35,44]. The sampling in Rio Formosa (Algarve Marine Sciences Centre—Faro) took place in August 2013.…”

“…com), and in Ria Formosa the growth season peak is in June-July [34]. The water temperature in the Sozopol area is between 5 and 29°C [35], while in Ria Formosa the temperature ranges from 12 to 27°C [36]. The sampling on the Swedish west coast was carried out in June 2013 off The Sven Lovén Centre for Marine Sciences—Kristineberg in the Gullmar Fjord (58°20’N, 11°33’E; Table 1).…”

Species-specific response to sulfide intrusion in native and exotic Mediterranean seagrasses under stress

“…Nevertheless, difference in nutrient enrichment from anthropogenic activities was observed across sites, as shown by the significant differentiation of sites with moderate pressure index (Gournes, Chania, Elounda, Souda) from those with low pressure (Lendas, Kouremenos), based on the sediment (TOC, TN) and seagrass (leaf TN, leaf δ 15 N, leaf TS, leaf δ 34 S, leaf-rhizome-root Fsulfide) variables measured during this study. Leaf TN, TS and δ 15 N, all recognized as sensitive physiological indicators of nutrient enrichment in seagrasses (Christianen et al, 2011;Frederiksen et al, 2008;Holmer et al, 2016;Lassauque et al, 2010;Roca et al, 2016;Ruiz et al, 2010;Vizzini et al, 2005) were higher at Gournes, Chania, Elounda and Souda (1.5 -2 % DW, 0.3 -0.4% DW and 1.1 -5.2 ‰, respectively) compared to Lendas and Kouremenos (1.1 -1.4 % DW, 0.2 -16 0.3% DW and 1.5 -2.6 ‰, respectively). Fsulfide reached higher values at sites with higher pressure (17 -29 % in leaves, 16 -% in rhizomes, 20 -44 % in roots) contrary to low pressure sites (18 -26 % in leaves, 25 -29 % in rhizomes, 19 -33 % in roots), suggesting that increasing nutrient availability is related to increasing sulfide intrusion, as observed for other species with similar sulfide intrusion (Holmer et al, 2016;Kilminster et al, 2014).…”

“…Leaf TN, TS and δ 15 N, all recognized as sensitive physiological indicators of nutrient enrichment in seagrasses (Christianen et al, 2011;Frederiksen et al, 2008;Holmer et al, 2016;Lassauque et al, 2010;Roca et al, 2016;Ruiz et al, 2010;Vizzini et al, 2005) were higher at Gournes, Chania, Elounda and Souda (1.5 -2 % DW, 0.3 -0.4% DW and 1.1 -5.2 ‰, respectively) compared to Lendas and Kouremenos (1.1 -1.4 % DW, 0.2 -16 0.3% DW and 1.5 -2.6 ‰, respectively). Fsulfide reached higher values at sites with higher pressure (17 -29 % in leaves, 16 -% in rhizomes, 20 -44 % in roots) contrary to low pressure sites (18 -26 % in leaves, 25 -29 % in rhizomes, 19 -33 % in roots), suggesting that increasing nutrient availability is related to increasing sulfide intrusion, as observed for other species with similar sulfide intrusion (Holmer et al, 2016;Kilminster et al, 2014). This is further supported by the significant positive correlation of TS with TN and TN with δ 15 N in P. oceanica leaves, similarly to the positive relationship between leaf TS and TN shown for Z. marina in enriched conditions (Holmer et al, 2016).…”

Season affects strength and direction of the interactive impacts of ocean warming and biotic stress in a coastal seaweed ecosystem

“…The amplification or buffering of environmental impacts by biotic interactions should be particularly pronounced where foundational, that is, habitat‐forming, species are involved (Doney et al ). Habitat forming macroalgae, for instance, at small spatial scales may act as community “rescuers” (Bulleri et al ) by counteracting the effects of global change factors such as warming (e.g., Silliman et al ), deoxygenation (e.g., Hiddink et al ), acidification (e.g., Hurd ; Wahl et al ), or eutrophication (e.g., Holmer et al ). In consequence, a collapse of habitat‐formers in response to environmental shifts may have severe ramifications to the entire community (Smale and Wernberg ; Bulleri et al ).…”