Trophic Transfer of Trace Elements in an Isotopically Constructed Food Chain From a Semi-enclosed Marine Coastal Area (Stagnone di Marsala, Sicily, Mediterranean)

Abstract

Trace element accumulation is particularly important in coastal and transitional environments, which act as contaminant buffers between the continental and marine systems. We compared trace element transfer to the biota in two locations with different open-sea exposures in a semi-enclosed marine coastal area (Stagnone di Marsala, Sicily, Italy) using isotopically reconstructed food chains. Samples of sediment, macroalgae, seagrasses, invertebrates, fish, and bird feathers were sampled in July 2006 and analysed for stable carbon and nitrogen isotopes (d 13 [Pb]). Trophic magnification factors were calculated through the relationships between trace elements and d 15 N in consumers. As and Pb were greater in organic matter sources (sediments and primary producers), whereas Cd and THg were greater in bird feathers. At the food chain level, an insignificant trophic transfer was found for all elements, suggesting biodilution rather than biomagnification. Sediments were more contaminated in the location with lower open-sea exposure. Macroalgae and seagrasses overall mirrored the spatial pattern highlighted in sediments, whereas differences between the two locations became further decreased moving toward higher trophic levels, indicating that trophic transfer of sediment and macrophyte-bound trace elements to the coastal lagoon food chain may be of relatively minor importance.

Decomposition rate and invertebrate colonization of seagrass detritus along a hydrodynamic gradient in a Mediterranean coastal basin: The Stagnone di Marsala (Italy) case study

“…Seagrass meadows are recognized as some of the most productive of the Earth's ecosystems (Fourqurean et al, ), but most of the primary production is exploited only through detrital routes (Cebrián & Duarte, ). Accordingly, in the Stagnone di Marsala, the bottom of which is covered by a dense C. nodosa meadow and patchy P. oceanica , there is evidence for the role of seagrass‐derived organic matter for consumers through detrital pathways (Vizzini, Costa, Tramati, Gianguzza, & Mazzola, ).…”

Population dynamics of Cymodocea nodosa under future ocean scenarios.

“…Increased growth (vertical and horizontal elongation) and production (vertical rhizome, horizontal rhizome and leaf) with proximity to CO 2 seeps at all three locations suggests plants were C limited in current conditions in the world oceans (Zimmerman et al, 1997;Invers et al, 2001). Additionally, the Adamas, Paleochori and Vulcano seeps, apart from CO 2 supplies, may also be enriched volcanic inputs such as trace elements, which above certain levels can be toxic (Vizzini et al 2013) and along with low pH and depleted oxygen levels can deteriorate the chemical properties of nearby water and sediment and in turn affect the seagrass productivity negatively.…”

“…1B). Some parts of this bay are well-suited for studies of the effects of increased CO 2 levels (Boatta et al, 2013) despite areas with elevated H 2 S and metals (Vizzini et al, 2013). The main underwater gas seeps are located along southern and western shores of the bay at <1 m depth (Boatta et al, 2013).…”

“…CO 2 seep sites have been used to assess the long-term effects of elevated CO 2 on benthic marine ecosystems and respective underlying mechanisms (Hall-Spencer et al, 2008, Fabricius et al, 2011, Vizzini et al, 2013, Enochs et al, 2015. However, other cofounding factors related to the volcanic seeps, such as the emissions of heavy metals (Dando et al, 1999, Vizzini et al, 2013, Kadar et al, 2013 and sulphide (Dando et al, 1999, Boatta et al,2013 may influence the plants and population responses to elevated CO 2 . These are very variable among seeps (Dekov et al, 2004, Varnavas et al, 2005 whereas the major CO 2 composition of emissions is constant.…”

Characteristics of Marine Environmental Geochemistry From Ha Tinh to Quang Nam (60-100m Water Depth)

“…However, the high development of socio-economic development on the mainland often causes many tent and bioaccumulation in trophic levels of the food chain (Aderinola et al, 2009;Esslemont, 2000;Vizzini et al, 2013). Heavy metals can be released from sediments to seawater and vice versa due to the changing of environmental geochemistry.…”