A characterization of Patagonian salt marshes

Abstract

We combined literature reviews with an analysis of regional cartography, aerial photographs, and satellite images to identify the locations of heretofore-unknown salt marshes along the Patagonian coastline of Argentina. Subsequent ground surveys confirmed the presence of the marshes. While numerous sites still require verification, our surveys confirmed the existence of 27 large coastal salt marshes, which had estimated areas of between 3 and 2400 ha distributed along ,225 km of coastline. We described the major patterns of landscape physiognomy and community structure at eight of these sites. We classified these marshes as either muddy or rocky marshes, and subdivided them into Spartina and Sarcocornia marshes depending on the dominant vegetation. Muddy marshes were the most common type and showed a clear regional pattern with Spartina-dominated communities in the north (# 42uS) and Sarcocornia-dominated systems in the south ($ 42uS). Plant height and standing crop biomass tended to be lower at higher latitudes, but plant cover showed the opposite trend. Spartina marshes had a more diverse marine macro-invertebrate fauna than Sarcocornia marshes, when the two marsh types occur at similar latitudes. Although the diversity of invertebrates was relatively low along the entire latitudinal range, most marshes supported unique species assemblages.

Faunal assemblages of intertidal hydroids (Hydrozoa, Cnidaria) from Argentinean Patagonia (Southwestern Atlantic Ocean)

“…This is a remarkable novelty for the hydroid literature, never reported before for salt marshes. Even a specific revision of Patagonian salt marsh communities (Bortolus et al, 2009) did not report cnidarians among the marine invertebrates inhabiting these extensive areas. We found only few specimens of microcrustaceans and polychaetes in the studied austral Patagonian pool marshes.…”

“…1, Table 1). A general description of benthic communities inhabiting the sampling sites is found in Bastida et al (2007) and Bortolus et al (2009).…”

“…During low tides, temperature values range seasonally from cold (in summer, with temperatures varying from 12° to 16°C) to near freezing (in winter, with temperatures varying from 6° to 12°C) (Bastida et al, 2007;Bortolus et al, 2009;Schwindt et al, 2014). Fringe bottom is predominantly formed by sand and gravel sediments, but salt marshes and rocky outcrops are also frequent (Bastida et al, 2007;Bortolus et al, 2009), providing colonizable areas for hydroids. However, the lack of studies on the hydroid fauna distributed along ~2,000 km of the Patagonian coast represents a substantial gap in our biodiversity knowledge.…”

Crab Bioturbation and Herbivory May Account for Variability in Carbon Sequestration and Stocks in South West Atlantic Salt Marshes

“…Dominant plant species are the cordgrasses S. densiflora and S. alterniflora and the glasswort Sarcocornia spp. (formerly named Sarcocornia perennis; Costa and Davy, 1992;Isacch et al, 2006;Bortolus et al, 2009). These plant species dominate ∼70% of the SWA salt marshes and their relative abundance is closely related to the input of freshwater in each location.…”

Habitat complexity and community composition: relationships between different ecosystem engineers and the associated macroinvertebrate assemblages

“…The rocky salt marshes of Patagonia were recently described as an environmental intersection between rocky intertidal and salt marsh (Bortolus et al 2009). In this environment, three well-known ecosystem engineers can be found coexisting and characterizing the intertidal: cordgrass, mussels, and non-native barnacle.…”