Evidence of seasonal changes in community structure for a coastal ecosystem in the central coast of Brazil, south-west Atlantic

Abstract

Wet biomass of principal plankton components and whole plankton standing stock were assessed in waters of the Heron Island ring reef and surrounding deep lagoon. Biomass of phytoplankton ranged between 30 to 120 mg m 23 , without its pronounced depletion over the reef shallows. Picocyanobacteria and prochlorophyte algae contributed over 70% of this biomass. Biomass of bacterioplankton varied between 75 to 340 mg m 23 , with its maximum over the reef flat. Biomass of planktonic protozoa's ciliates and zooflagellates ranged between 20 to 110 mg m 23 . The daytime biomass of zooplankton varied between 490 to 1590 mg m 23 in the deep lagoon in the zone of intense tidal currents. Over the reef shallows, it was 10-20 mg m 23 . At night, it rose there up to 800 to 4000 mg m 23 as the result of emerging demersal zooplankton from the benthic substrates. The time scale of nocturnal emerging by different taxa was also documented. Biomass of whole demersal zooplankton communities hiding by the daytime in bottom substrates at the reef flat was found to be over 100 g m 22 . Problems of nutrition planktivore reef fauna related to the plankton production and abundance are discussed. . (1983) Technique for enumeration of nanoplankton using epifluorescence microscopy. Limnology and Oceanography 33, 1595-1606. Crosbie N.D. and Furnas M.J. (2001) Growth rate of picocyanobacteria and phytoplankton in the central and southern Great Barrier Reef. Aquatic Microbial Ecology 24, 209-224. Yahel R., Yahel G. and Genin A. (2005) Near-bottom depletion of zooplankton over coral reefs: I: diurnal dynamics and size-distribution. Coral Reefs. 24, 75-85.

Fish assemblages in a coastal bay adjacent to a network of marine protected areas in southern Brazil

“…On the southeastern and southern coasts of Brazil, G. genidens, C. chrysurus and P. puncatus are abundant (over 1%) in demersal assemblages (AZEVEDO et al, 2007;QUEIROZ et al, 2007;BARLETTA et al, 2008. However, we registered high abundances of C. spilopterus in North Bay (the most abundant species in this area) and a low occurrence of S. rastrifer, which is not consistent with these fish surveys.…”

“…The high abundance of G. genidens is expected in the demersal assemblages of the southern and southeastern coasts of Brazil (HOSTIM-SILVA et al, 2002;QUEIROZ et al, 2007;BARLETTA et al, 2008;CARTAGENA et al, 2011). In a comparison of the fish fauna of five estuaries along the Brazilian coast, there was a predominance of this species on the southern and southeastern coasts (VILAR et al, 2013).…”

“…With respect to the structure of assemblages, the dominance of a few species of demersal fish has also been registered in other studies on the southeastern and southern coasts of Brazil (ROSSI-WONGTSCHOWSKI;PAES, 1993;ARAÚJO et al, 2002;HOSTIM-SILVA et al, 2002;SCHWARZ JR. et al, 2006;AZEVEDO et al, 2007;QUEIROZ et al, 2007;BARLETTA et al, 2008;PINHEIRO et al, 2009;CARTAGENA et al, 2011). The dominance of a few species seems to be an ecological pattern of demersal assemblages or an effect of the selectivity of the fishing gear.…”

“…Seasonal differences in the abundance of the demersal fish fauna of the southeastern and southern regions are often observed (ROSSI-WONGTSCHOWSKI; PAES, 1993;HOSTIM-SILVA et al, 2002;ARAÚJO et al, 2002;AZEVEDO et al, 2007;QUEIROZ et al, 2007;BARLETTA et al, 2008;PINHEIRO et al, 2009;CARTAGENA et al, 2011), except for the fish fauna of the Pinheiros Bay, located in the Paranaguá estuarine complex (CEP) (SCHWARZ JR. et al, 2006). However, the lack of statistical seasonal differences in fish abundance in the Pinheiros Bay does not seem to be a pattern for CEP, in view of significant temporal differences on the main axis (east-west) of CEP (BARLETTA et al, 2008).…”

“…The reproductive patterns, according to which the main species of the families Sciaenidae and Clupeidae spawn during the spring and summer, while recruiting in shallow areas, but which are still not part of demersal assemblages, might also explain such differences. In autumn and winter, recruited fish have reached maturity and occupy deeper areas of estuaries (PINHEIRO et al, 2009), increasing the probability of capture by trawl.…”