Macrobenthic zonation caused by the oxygen minimum zone on the shelf and slope off central Chile

Gallardo, V. A.; Palma, Mario; Carrasco, Franklin D.; Gutiérrez, Dimitri; Levin, Lisa A.; Cañete, Juan I.

doi:10.1016/j.dsr2.2004.07.028

Cited by 57 publications

(51 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Similar contrasts in the taxonomic composition of macrofauna have been observed between the Peru (11ºS) and Chilean (36ºS) margins; oligochaetes are abundant in the former but absent in the latter (Levin et al, 2002;Gallardo et al, 2004). In addition to environmental factors, these differences may reflect undersampling, seasonal fluctuations in population sizes or biogeographic patterns.…”

Section: Comparison Of Benthic Faunas On the Pakistan And Oman Marginsmentioning

confidence: 71%

“…At our 300-m site, the sparse macrofauna comprised polychaetes and nemerteans. A polychaete-dominated macrofauna was well developed on the Chilean shelf where oxygen dropped to levels (~0.1 ml l -1 ) comparable to those on the Pakistan margin (Gallardo et al, 2004). Further north off Peru, metazoan macrofauna were most abundant at even lower oxygen concentrations (0.02 ml l -1 ; Station A).…”

Section: Macrofaunamentioning

confidence: 82%

“…Macrofauna typically exhibit low species richness, high dominance and a predominance of polychaetes in OMZ settings (Levin, 2003;Gallardo et al, 2004).…”

Section: Macrofaunamentioning

confidence: 99%

See 2 more Smart Citations

Faunal responses to oxygen gradients on the Pakistan margin: A comparison of foraminiferans, macrofauna and megafauna

Gooday

Levin

Silva

et al. 2009

Deep Sea Research Part II: Topical Studies in Oceanography

Self Cite

142

103

View full text Add to dashboard Cite

The Pakistan margin is characterized by a strong midwater oxygen minimum zone (OMZ) that intercepts the seabed at bathyal depths (150 to 1300 m). We investigated whether faunal abundance and diversity trends were similar among protists (foraminiferans and gromiids), metazoan macrofauna and megafauna along a transect (140-1850 m water depth) across the OMZ during the 2003 intermonsoon (March-May) and late/post monsoon (August-October) seasons. All groups exhibited some drop in abundance in the OMZ core (250-500 m water depth; O 2 : 0.10-0.13 ml l -1 = 4.46-5.80 μM l -1 ) but to differing degrees. Densities of foraminiferans >63 µm were slightly depressed at 300 m, peaked at 738 m, and were much lower at deeper stations. Foraminiferans >300 µm were the overwhelmingly dominant macrofaunal organisms in the OMZ core.Macrofaunal metazoans reached maximum densities at 140 m depth, with additional peaks at 850, 940 and 1850 m where foraminiferans were less abundant. The polychaete Linopherus sp. was responsible for a macrofaunal biomass peak at 950 m. Apart from large swimming animals (fish and natant decapods), metazoan megafauna were absent between 300 and 900 m (O 2 <0.14-0.15 ml l -1 = 6.25-6.69 μM l -1 ) but were represented by a huge, ophiuroid-dominated abundance peak at 1000 m (O 2 ~0.15-0.18 ml l -1 = 6.69-8.03μM l -1 ). Gromiid protists were confined largely to depths below 1150 m (O 2 >0.2 ml l -1 = 8.92 μM l -1 ). The progressively deeper abundance peaks for foraminiferans (>63 µm), Linopherus sp. and ophiuroids probably represent lower OMZ boundary edge effects and suggest a link between body size and tolerance of hypoxia. Macro-and megafaunal organisms collected between 800 and 1100 m were dominated by a succession of different taxa, indicating that the lower part of the OMZ is also a region of rapid faunal change. Species diversity was depressed in all groups in the OMZ core, but this was much more pronounced for macrofauna and megafauna than for foraminiferans. Oxygen levels strongly influenced the taxonomic composition of all faunal groups. Calcareous foraminiferans dominated the seasonally and permanently hypoxic sites (136-300 m); agglutinated foraminiferans were relatively more abundant at deeper stations where oxygen concentrations were >0.13 ml l -1 (= 5.80 μM l -1 ). Polychaetes were the main macrofaunal taxon within the OMZ; calcareous macrofauna and megafauna (decapods, 3 echinoderms) were rare or absent where oxygen levels were lowest. The rarity of larger animals between 300 and 700 m on the Pakistan margin, compared with the abundant macrofauna in the OMZ core off Oman, is the most notable contrast between the two sides of the Arabian Sea. This difference probably reflects the slightly higher oxygen levels and better food quality on the western side.

show abstract

Section: Comparison Of Benthic Faunas On the Pakistan And Oman Marginsmentioning

confidence: 71%

Section: Macrofaunamentioning

confidence: 82%

See 1 more Smart Citation

Faunal responses to oxygen gradients on the Pakistan margin: A comparison of foraminiferans, macrofauna and megafauna

Gooday

Levin

Silva

et al. 2009

Deep Sea Research Part II: Topical Studies in Oceanography

Self Cite

142

103

View full text Add to dashboard Cite

show abstract

“…At greater depths biomass values are negligible due to an extended zone in which the oxygen concentration is equal or lower than 0.5 ml l ¡1 (oxygen minimum zone-OMZ; Ramorino and Muñiz 1970;Levin 2003;Gallardo et al 2004;Escribano et al 2004). The oxygen minimum layer is typically shallow in the coastal area oV northern Chile (Morales et al 1996;Escribano et al 2002Escribano et al , 2004 with an upper boundary, e.g.…”

Section: Introductionmentioning

confidence: 99%

Sublittoral soft bottom communities and diversity of Mejillones Bay in northern Chile (Humboldt Current upwelling system)

et al. 2007

View full text Add to dashboard Cite

The macrozoobenthos of Mejillones Bay (23°S; Humboldt Current) was quantitatively investigated over a 7-year period from austral summer 1995/1996 to winter 2002. About 78 van Veen grab samples taken at six stations (5, 10, 20 m depth) provided the basis for the analysis of the distribution of 60 species and 28 families of benthic invertebrates, as well as of their abundance and biomass. Mean abundance (2,119 individuals m ¡2 ) was in the same order compared to a previous investigation; mean biomass (966 g formalin wet mass m ¡2 ), however, exceeded prior estimations mainly due to the dominance of the bivalve Aulacomya ater. About 43% of the taxa inhabited the complete depth range. Mean taxonomic Shannon diversity (HЈ, Log e) was 1.54 § 0.58 with a maximum at 20 m (1.95 § 0.33); evenness increased with depth. The fauna was numerically dominated by carnivorous gastropods, polychaetes and crustaceans (48%). About 15% of the species were suspensivorous, 13% sedimentivorous, 11% detritivorous, 7% omnivorous and 6% herbivorous. Cluster analyses showed a signiWcant diVerence between the shallow and the deeper stations. Gammarid amphipods and the polychaete family Nephtyidae characterized the 5-mzone, the molluscs Aulacomya ater, Mitrella unifasciata and gammarids the intermediate zone, while the gastropod Nassarius gayi and the polychaete family Nereidae were most prominent at the deeper stations. The communities of the three depth zones did not appear to be limited by hypoxia during non-El Niño conditions. Therefore, no typical change in community structure occurred during El Niño 1997-1998, in contrast to what was observed for deeper faunal assemblages and hypoxic bays elsewhere in the coastal Humboldt Current system.

show abstract

“…However, for terrestrial ecosystems, it has been shown that disturbances could move communities away from this interactive steady state, restarting the assembly processes and causing changes in the species co-occurrence patterns within communities (Badano et al 2005). For macrozoobenthos communities of shallow and deep waters off Chile and Peru, changes in bottom temperatures and oxygen concentration associated to EN represent a strong disturbance (Arntz et al , 1991Arntz and Fahrbach 1996;Tarazona et al 1985Tarazona et al , 1988bTarazona et al , 1996Gallardo 1985;Gutiérrez et al 2000;Gallardo et al 2004). Thus, it could be proposed that EN may restart successional processes of sublittoral communities, which should be reflected in a change in the species co-occurrence patterns.…”

Section: Introductionmentioning

confidence: 99%

Subtidal macrozoobenthos communities from northern Chile during and post El Niño 1997–1998

et al. 2007

View full text Add to dashboard Cite

Despite a large amount of climatic and oceanographic information dealing with the recurring climate phenomenon El Niño (EN) and its well known impact on diversity of marine benthic communities, most published data are rather descriptive and consequently our understanding of the underlying mechanisms and processes that drive community structure during EN are still very scarce. In this study, we address two questions on the effects of EN on macrozoobenthic communities: (1) how does EN affect species diversity of the communities in northern Chile? and (2) is EN a phenomenon that restarts community assembling processes by affecting species interactions in northern Chile? To answer these questions, we compared species diversity and co-occurrence patterns of soft-bottoms macrozoobenthos communities from the continental shelf off northern Chile during (March 1998) and after (September 1998) the strong EN event 1997-1998. The methods used varied from species diversity and species cooccurrence analyses to multivariate ordination methods. Our results indicate that EN positively affects diversity of macrozoobenthos communities in the study area, increasing the species richness and diversity and decreasing the species dominance. EN represents a strong disturbance that affects species interactions that rule the species assembling processes in shallow-water, sea-bottom environments.

show abstract

Macrobenthic zonation caused by the oxygen minimum zone on the shelf and slope off central Chile

Cited by 57 publications

References 51 publications

Faunal responses to oxygen gradients on the Pakistan margin: A comparison of foraminiferans, macrofauna and megafauna

Faunal responses to oxygen gradients on the Pakistan margin: A comparison of foraminiferans, macrofauna and megafauna

Sublittoral soft bottom communities and diversity of Mejillones Bay in northern Chile (Humboldt Current upwelling system)

Subtidal macrozoobenthos communities from northern Chile during and post El Niño 1997–1998

Contact Info

Product

Resources

About