ABSTRACT
The ecosystem services provided by seagrass meadows, and valued at about a tenth of the total global flow value (Constanza et al. 1997), are central to current advocacies for resource restoration and conservation (Duarte 2002, Orth et al. 2006). Seagrass meadows are coastal ecosystems that often exhibit high primary production (Duarte and Chiscano 1999), which supports diverse floral and faunal assemblages and large marine animals (McConnaughey and McRoy 1979, Lewis and Stoner 1983, Howard et al. 1989, Hily and Bouteille 1999). Bed sediments and the leaf canopies serve as habitat and refugia to benthos and resident and transient fish (Bell and Westoby 1986, Bell and Pollard 1989, Connolly 1994, Loneragan et al. 1997, Sheridan 1997, Heck et al. 2003). Seagrass canopies modify currents and attenuate wave energy, a case of autogenic ecosystem engineering (sensu Jones et al. 1994), thus, trap sediment, seston, and larvae (Grizzle et al. 1996, Duarte et al. 1999, Koch 1999, Terrados and Duarte 2000, Vermaat et al. 2000, Gacia and Duarte 2001, Evrard et al. 2006), affect the storage of primary production within the system (Duarte and Cebrián 1996) or its export (Slim et al. 2006), and contribute to buffering adjacent sensitive habitats against the direct effects of water turbulence (Koch et al. 2006) and riverine siltation (Kenworthy et al. 1982, Cebrián et al. 2000). Belowground, the production of roots and rhizomes is substantial (45% of the meadow’s total biomass; Vermaat et al. 1995), hence, probably fundamental to substrate stability (Duarte et al. 1998).
