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| Format: | Artículo científico |
| Language: | en |
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Universidad de Costa Rica
2016
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| Online Access: | https://www.redalyc.org/articulo.oa?id=44946472031 https://www.redalyc.org/journal/449/44946472031/ https://www.redalyc.org/journal/449/44946472031/html/ https://www.redalyc.org/journal/449/44946472031/44946472031.epub https://www.redalyc.org/journal/449/44946472031/movil |
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Table of Contents:
- Brachiopods, sipunculans, enteropneusts and metals from two estuarine tidal flats, Pacific, Costa Rica José A. Vargas Jenaro Acuña-González Fiorella Vásquez Jeffrey A. Sibaja-Cordero Biología infauna Glottidia Apionsoma pollution Sipunculus Reports on the abundances and on metal concentrations in intertidal estuarine invertebrates from the Eastern Tropical Pacific are rare. Thus , the objectives of this report are to make accessible data on the abundances (1984-1987, 49 dates; 2013, 12 dates) of sipunculans, brachiopods and hemichordates from a sand-mud flat; and on trace metals (1996, 2000) and abundances (2015, 3 dates) of sipunculans and brachiopods at a sand flat in the Gulf of Nicoya estuary (10 o N-85 o W). Cores (17.7 cm 2 ) were collected at the sand-mud flat, and quadrats (0.2 m 2 ) at the sand flat. The flats contrasted in their sand (65 % vs 90 %) and silt+clay (31.5 % vs 5.6 %) contents. At the sand-mud flat (1984-87: 1.83 m 2 ) the sipunculans were represented by 13 individuals, the brachiopods by 129 and the acorn worms by 185, with estimated maximum densities of: 5.7, 29, and 40 ind./m 2 , respectively. Trace metal (Fe, Mn, Ni, Cr, Cd, Zn, and Pb) analysis (Atomic Absorption Spectrometry) were conducted in specimens of Sipunculus nudus (Sipuncula) and Glottidia audebarti (Brachiopoda). Maximum mean concentrations in S. nudus were: For non-depurated worms, Fe (16.0 mg/g dw) > Mn (165 μg/g dw) > Zn (81 μg/g dw) > Cu (26 μg/g dw) > Cr (11 μg/g dw) > Ni (10.4 μg/g dw) > Pb (9.3 μg/g dw) > Cd (1.2 μg/g dw). For 72 hour depurated worms: Fe (5.0 mg/g dw) > Mn (61 μg/g dw) > Zn (39 μg/g dw) > Cu (24 μg/g dw) > Ni (8.4 μg/g dw) > Pb (2.7 μg/g dw) > Cd (0.62 μg/g dw). For G. audebarti : Fe (1.6 mg/g dw-soft parts) > Zn (123.5 μg/g dw-soft parts) > Cu (31.4 μg/g dw-pedicles) > Pb (21.0 μg/g dw-shells) > Cd (5.2 μg/g dw-soft parts) > Cr (4.7 μg/g dw-shells). For sediments; Fe (46 mg/g dw) > Mn (41.3 μg/g dw) > Zn (63 μg/g dw) > Cu (36.2 μg/g dw) > Cr (31.5 μg/g dw) > Pb (21.1 μg/g dw) > Ni (16.1 μg/g dw) > Cd (1.1 μg/g dw). These concentrations were expected for a non- industrialized estuary. At the sand flat (Area sampled: 10.6 m 2 ) 76 individuals of G. audebarti, 112 of G. albida, and 366 of S. nudus were collected in 2015, with estimated maximum densities of: 7.1, 10.5, and 31 ind./m 2 , respectively. Densities of G. audebarti and G. albida were relatively low, while those of S. nudus were relatively high when compared with other reports. The shell lenght of G. audebarti ranged from 9.0 mm to 38.0 mm and from 6.0 mm to 29.0 mm for G. albida . These ranges were within those found for these lingulides elsewhere. The mean length of S. nudus was 41 mm and the maximum weight was 1.6 g, which are small. No brachiopods were found at the sand-mud flat in 2013, nor enteropneusts at the sand flat in 2015. G. audebarti had a relatively stable presence, while G. albida almost vanished from the samples at the end of 2015. The spatial distributions of the three inverte - brates were found aggregated at both intertidal flats. Strong ENSO warming events during 1983 and 2015, and red tides in 1985 may have in 2016 artículo científico 0034-7744 https://www.redalyc.org/articulo.oa?id=44946472031 https://www.redalyc.org/journal/449/44946472031/ https://www.redalyc.org/journal/449/44946472031/html/ https://www.redalyc.org/journal/449/44946472031/44946472031.epub https://www.redalyc.org/journal/449/44946472031/movil en http://www.redalyc.org/revista.oa?id=449 Revista de Biología Tropical application/pdf Universidad de Costa Rica Revista de Biología Tropical (Costa Rica) Num.3 Vol.64