Measuring restoration in intertidal macrophyte assemblages following sewage treatment upgrade

Successions of phytobenthos species in a Mediterranean transitional water system: the importance of long term observations

“…It is well known that untreated sewage discharged into coastal basins is the cause of severe modifications in benthic communities, due to increases in nutrients, toxic substances, turbidity and silt. Generally, in these conditions, filamentous and sheet-like algae prevail over thick algae, due to their higher uptake efficiency and faster growth (Díez et al 2013). Specifically, in these environments, macrophytes represent an important structuring component.…”

“…Similar occurrences have been observed in other transitional systems. A 22-year study of the recovery of seaweed populations after the installation of a sewerage system was carried out in the Abra de Bilbao (North Spain), a semi-enclosed bay, which for a long time had received urban and industrial effluent through a river (Díez et al 2009(Díez et al , 2013. The increased algal cover at once degraded sites, the rise in the number of species concomitant with the improvement in seawater quality and the increase in similarity amongst stations were the most noteworthy results (Díez et al 2009).…”

Role of environmental factors in affecting macrophyte dominance in transitional environments: The Italian Lagoons as a study case

“…Macrophytes are affected by different anthropogenic pressures that can affect the environmental status. Transitional environments can change from pristine‐natural conditions, with aquatic angiosperms and sensitive macroalgae present (Bermejo, de la Fuente, Ramírez‐Romero, Vergara, & Hernández, ; Littler & Littler, ; Orfanidis et al., ; Sfriso et al., ), into environments either colonized by opportunistic macroalgae, especially Ulvaceae, Cladophoraceae and Gracilariaceae, or completely deprived of vegetation (Bermejo et al., ; Díez, Santolaria, Muguerza, & Gorostiaga, ; Krause‐Jensen, Carstensen, & Dahl, ; Orfanidis et al., ; de Paz, Neto, Marques, & Laborda, ; Scanlan, Foden, Wells, & Best, ; Sfriso et al., ) very rapidly. The Valli di Comacchio in the Emilia‐Romagna Region are perfect examples of basins with bad transitional environmental conditions (Sorokin & Zakuskina, ; Viaroli et al., ), where phytoplankton or cyanobacteria prevail over other primary producers.…”

Restoring rocky intertidal communities: Lessons from a benthic macroalgal ecosystem engineer

“…Discharge of treated sewage effluent (wastewater) into the nearshore marine environment has been shown to have detrimental effects on rocky intertidal and shallow subtidal communities around the world (Brown et al, 1990;Bustamante et al, 2012;Coleman et al, 2008;Cormaci and Furnari, 1999;Díez et al, 2013;Fairweather, 1990;Hirose, 1978;Littler and Murray, 1975;May, 1985). Our understanding of these effects in the intertidal zone is summarised in Fig.…”

“…Thus to be able to set realistic water quality targets for restoration of coastal ecosystems, it is imperative that we also understand the effects of pulses of toxic constituents on the fucoid algae, Reducing the toxicity of sewage effluent discharged into the marine environment alone may not be sufficient to restore fucoid populations. There are multiple factors that might limit the recovery of fucoids and other lost seaweed species into remediated areas (Bellgrove et al, 2010;Díez et al, 2013), highlighting the need to compliment laboratory studies with manipulative field experiments to appropriately predict outcomes of management decisions aimed at restoring communities affected by sewage effluent discharge. Furthermore, the recruitment potential of early-life stages and longterm survival of adults on remediated shores should be investigated in the field to evaluate the effectiveness of wastewater upgrades in achieving a water quality that permits re-establishment and self-perpetuation of fucoid populations.…”