Interactive effects of grazing and environmental stress on macroalgal biomass in subtropical rocky shores: Modulation of bottom-up inputs by wave action

Trophic cues as possible triggers of mussel larval settlement in southeastern Brazil

“…The aim of this study was primarily to gain insights on bivalve settlement dynamics in a subtropical region, where populations of benthic invertebrates that dominate the upper shores are often subjected to low food supply conditions (Kasten and Flores, 2013;Flores et al, 2015;Kasten et al submitted). Such conditions may impose a challenge for competent planktotrophic larvae and early post-larvae of intertidal bivalves during their search for a suitable benthic habitat, raising the question: what settlement cues might be acting in subtropical oligotrophic regions?…”

Environmental heterogeneity at small spatial scales affects population and community dynamics on intertidal rocky shores of a threatened bay system

“…As the tidal range in this region is about 1 m, changes in the bathymetry of only 30 to 50 cm represent an important variation in the vertical gradient and distance from the supra-littoral zone to the soft bottom region. We can suggest an interactive effect of nutrients and hydrodynamics driven bottom up processes as was shown in rocky shores in the São Sebastião Channel (Flores et al 2015). In this context, pelagic enrichment in nutrients from the soft sediment disturbance during the flood tide increases the food available for the filter feeding animals in the Araçá Bay.…”

“…In the infra-littoral fringe of the middle shore, from our third sampling during the winter of 2013, until the end of the study in the winter of 2014, the area occupied by the macroalgae Ulva lactuca increased, restricting the occurrence of the turfing of algae to small patches underneath. The dynamic of ephemeral algae in the São Sebastião Channel is controlled by nutrient inputs driven by wave exposure and grazing (Flores et al 2015). In the Araçá Bay, during the wet season, riverine inputs from the Mãe Isabel river result in a gradient of nutrients within the bay (Dottori et al 2015) with a proportion of dissolved inorganic nitrogen from the inner to the outer portions of the bay of 6:1 (SABESP 2015, Gorman et al 2017).…”

Monitoring nitrogen pollution in seasonally-pulsed coastal waters requires judicious choice of indicator species

“…While concerns over treated effluent are often subordinate to those related to toxic organic chemicals and heavy metals in shallow marine bays (Martins et al, 2011;Rainbow, 1995), nutrient limitation within the Araçá region (Flores et al, 2015) makes it likely that sewagederived nitrogen may impact local ecosystems. Accumulation of sewage in the western part of the bay, which borders local human communities, may also present a public health concern.…”