Benthic macrofauna changes in areas of Venice lagoon populated by seagrasses or seaweeds

Author(s): Sfriso A, Birkemeyer T, Ghetti PF

Abstract

Two areas of the Venice lagoon populated by seagrasses (three stations covered by Cymodocea nodosa (Ucria) Asherson, Zostera marina Linnaeus, Zostera noltii Hornemann) or seaweeds (two stations: one covered by Ulva rigida C. Agardh and another at present without seaweed biomass) were monitored by means of six surveys over a year in order to study macrofaunal composition and seasonal changes. The seagrass stations showed a mean species richness (28–30 S m−2), individual abundance (1854–4018 N m−2) and biomass (22.3–37.7 g m−2 ash-free-dry-weight, AFDW) ca. 3–8 times higher than those populated by seaweeds (10–15 S m−2, 494–1395 N m−2 and 5.6–13.7 g m−2 AFDW). Differences among seagrass or seaweed stations were much lower. The Ulva-dominated station showed a macrofauna completely different both from the other stations and the communities recorded ca. 30 years ago, before the prolific growth of Ulva. In this station, frequent biomass decompositions and anoxic crises created critical conditions for life favouring organisms with reduced life cycles, younger individuals and the epifaunal species instead of the infaunal ones. In particular, Ulva grazers and scrapers such as Gammarus aequicauda Stock and Gibbula adriatica Philippi were found to be by far the most abundant species, whereas the taxa characteristic of the associations found in the past, in the presence of seagrasses or seaweeds and typical of low eutrophicated environments, appear strongly reduced. Marked differences in the macrophyte dominance and in the bio-physico-chemical variables which characterise the main environmental conditions of the Venice lagoon support the different distribution and composition of macrofaunal communities. Seaweed stations appear mainly governed by the seasonal cycles of these un-rooted macrophytes which, by alternating periods of production and decomposition, are responsible for the drastic reduction of macrofauna biodiversity and biomass. Conversely, seagrass stations exhibit a better oxidisation of the environment and show conditions more favourable for macrofauna colonisation, especially in the presence of macrophytes which are characterised by very well developed below-ground systems such as Cymodocea nodosa.

Similar Articles

Basic Ecology

Author(s): Odum EP

The estuarine ecosystem

Author(s): Mc Lusky DS

Differences in benthic fauna and sediment among mangrove (Avicennia marina var

Author(s): Morrisey DJ, Skilleter GA, Ellis JI, Burns BR, Kemp CE, et al.

The seagrasses of the world

Author(s): Den Hartog C

World Atlas of Seagrasses

Author(s): Green EP, Short FT

Accelerating loss of seagrasses across the globe threatens coastal ecosystems

Author(s): Waycott M, Duarte CM, Carruthers TJB, Orth RJ, Dennison WC, et al.

Seagrasses: biology, ecology and conservation

Author(s): Larkum AWD, Orth RJ, Duarte CM

Seagrass Ecology

Author(s): Hemminga MA, Duarte CM

Seagrass community ecology: Marine Community Ecology

Author(s): Williams SL, Heck Jr K.L.

The future of seagrass meadows

Author(s): Duarte C.M

Latitudinal gradients as natural laboratories to infer species’ responses to temperature

Author(s): De Frenne P, Graae BJ, Rodríguez-Sanchez F, Kolb A, Chabrerie O, et al.

(2016b) Cockle infection by Himasthla quissetensis - II

Author(s): de Montaudouin X, Blanchet H, Bazairi H, Nazik A, Desclaux-Marchand C, et al

Consequences of climate-driven biodiversity changes for ecosystem functioning of North European rocky shores

Author(s): Hawkins SJ, Sugden HE, Mieszkowska N, Moore PJ, Poloczanska E, et al.

Changes in North Sea macrofauna communities and species distribution between 1986 and 2000

Author(s): Kröncke I, Reiss H, Eggleton JD, Aldridge J, et al.

Sea level variability and tidal resonance in the Gulf of Gabès, Tunisia

Author(s): Sammari C, Koutitonsky VG, Moussa M

Long-term evolution (1988-2008) of Zostera spp

Author(s): Plus M, Sebastien D, Gilles T, Isabelle A, de Montaudouin X, et al.

The Mathematical theory of communication

Author(s): Shannon CE, Weaver W

Diet of Worms Emended: An Update of Polychaete Feeding Guilds

Author(s): Jumars PA, Dorgan KM, Lindsay SM

Polychaete/amphipod ratio revisited

Author(s): Dauvin JC, Ruellet T

PRIMER v6: User Manual/Tutorial

Author(s): Clarke KR, Gorley RN

Infauna from Zostera marina L

Author(s): Fredriksen S, De Backer A, Böstrom C, Christie H

Seagrass colonization: knock-on effects on zoobenthic community, populations and individual health

Author(s): Do VT, de Montaudouin X, Lavesque N, Blanchet H, Guyard H

A Three-Stage Symbiosis Forms the Foundation of Seagrass Ecosystems

Author(s): van der Heide T, Govers LL, de Fouw J, Olff H, van der Geest M, et al.

The biodiversity of the Mediterranean Sea: estimates, patterns, and threats

Author(s): Coll M, Piroddi C, Steenbeek J, Kaschner K, Ben Rais Lasram F, et al.

Differential responses of bacteria, meiofauna and macrofauna in a shelf area (Ligurian Sea, NW Mediterranean): role of food availability

Author(s): Albertelli G, Covazzi-Harriague A, Danovaro R, Fabiano M, Fraschetti S, et al.

Complex interactions in a rapidly changing world: responses of rocky shore communities to recent climate change

Author(s): Hawkins SJ, Moore PJ, Burrows MT, Poloczanska E, Mieszkowska N, et al.

The impacts of climate change in coastal marine systems

Author(s): Harley CDG, Hughes AR, Hultgren KM, Miner BG, Sorte CJB, et al.