Upwelling of subsurface water into the rim of the Biobı́o submarine canyon as a response to surface winds

Sobarzo, Marcus; Figueroa, Manuel; Djurfeldt, Leif

doi:10.1016/s0278-4343(00)00082-0

Cited by 64 publications

(37 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Ascendance rates (vertical velocities) of 0.02 to 0.03 cm s -1 or 17 to 26 m d -1 for the 11°C isothermal reported for the study zone (Sobarzo et al 2001) imply that it would take 4 d for a water parcel from 80 m to reach the surface. This period should be enough for the prokaryote assemblage to acclimate to surface radiation conditions.…”

Section: Biogeochemical Hcs Implicationsmentioning

confidence: 92%

“…In fact, the values of bacterial secondary production reported for central-southern Chile are among the highest of all marine ecosystems (Cuevas et al 2004). The high productivity of the marine ecosystem off central Chile has been related mostly to physical factors such as upwelling, river runoff, Kelvin waveassociated mixing events, mesoscale structures, and topography (Quiñones & Montes 2001, Sobarzo et al 2001, Cuevas et al 2004. Our study suggests that, in addition to these factors, solar radiation could also play a role in influencing energy and matter fluxes in the HCS because it limits bacterioplankton activity and, accordingly, may modify fluxes within the microbial loop.…”

Section: Biogeochemical Hcs Implicationsmentioning

confidence: 99%

See 1 more Smart Citation

Effects of solar radiation on bacterioplankton production in the upwelling system off central-southern Chile

Hernández¹,

Quiñones²,

Daneri³

et al. 2006

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

The influence of solar radiation on bacterial secondary production (BSP), bacterial growth efficiency (BGE), and growth rates (μ) in upwelling zones of the Humboldt Current System (HCS) is not yet understood. Here we assessed the impact of solar radiation, with special focus on ultraviolet radiation (UVR, 280 to 400 nm) on 2 natural bacterioplankton assemblages with different light history coming from surface waters (0.5 m) and subsurface waters (80 m) off central-southern Chile (36°S). The samples were incubated under ambient irradiance for 4 to 11 h and exposed to 3 spectral radiation treatments: photosynthetically active radiation (PAR, 400 to 700 nm), PAR+UV-A (320 to 700 nm), and PAR+UVR (280, to 700 nm). BSP was estimated by 14 C-leucine (protein synthesis) and [methyl-3 H]-thymidine (DNA synthesis) uptake. Both bacterioplankton assemblages showed significant (p < 0.05) inhibition of BSP, BGE, and μ rates when exposed to PAR radiation; in contrast, responses to UV radiation were more variable. At noon, BSP inhibition was 49 to 53% (PAR), 13 to 30% (UV-A), and 5 to 14% (UV-B) for both assemblages. At sunset, in surface assemblages, protein and DNA synthesis were more limited by UV-A than by UV-B, whereas protein synthesis in the subsurface assemblage was more inhibited by UV-B than by UV-A. The same inhibition patterns were found for BGE and μ, especially with regard to protein synthesis. The daily inhibition of BSP, BGE, and μ in both assemblages was mainly a function of PAR followed by UV-A and UV-B. Our results suggest that solar radiation could play an important role in modulating bacterioplankton dynamics (especially protein synthesis) during active upwelling periods in the HCS.

show abstract

Section: Biogeochemical Hcs Implicationsmentioning

confidence: 92%

Section: Biogeochemical Hcs Implicationsmentioning

confidence: 99%

Effects of solar radiation on bacterioplankton production in the upwelling system off central-southern Chile

Hernández¹,

Quiñones²,

Daneri³

et al. 2006

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…Upwelling tends to occur at the converged isobaths whether they occur near the head of the canyon (Yuan, 2002) or near the mouth (Waterhouse et al, 2009). Some of the clearest observations of enhanced upwelling near isobath convergence is seen at the head of Bio Bio Canyon (Sobarzo et al, 2001). …”

Section: Converging Isobathsmentioning

confidence: 99%

“…Thus even though Monterey Canyon is a long canyon, canyondriven upwelling is weak (Rosenfeld et al, 1994). Upwelling in the long Bio Bio Canyon is strong but complicated by the complex currents occurring within Arauco Bay (Sobarzo et al, 2001). Perhaps uniquely, Barrow Canyon is dominated by a strong down-canyon flow caused by the Bering Strait through-flow (Münchow and Carmack, 1997).…”

Section: Observations Of Upwelling/downwelling In Canyonsmentioning

confidence: 99%

A review of the role of submarine canyons in deep-ocean exchange with the shelf

2009

View full text Add to dashboard Cite

Abstract. Cross shelf-break exchange is limited by the tendency of geostrophic flow to follow bathymetric contours, not cross them. However, small scale topography, such as canyons, can reduce the local lengthscale of the flow and increase the local Rossby number. These higher Rossby numbers mean the flow is no longer purely geostrophic and significant cross-isobath flow can occur. This cross-isobath flow includes both upwelling and downwelling due to wind-driven shelf currents and the strong cascading flows of dense shelfwater into the ocean. Tidal currents usually run primarily parallel to the shelf-break topography. Canyons cut across these flows and thus are often regions of generation of strong baroclinic tides and internal waves. Canyons can also focus internal waves. Both processes lead to greatly elevated levels of mixing. Thus, through both advection and mixing processes, canyons can enhance Deep Ocean Shelf Exchange. Here we review the state of the science describing the dynamics of the flows and suggest further areas of research, particularly into quantifying fluxes of nutrients and carbon as well as heat and salt through canyons.

show abstract

“…Along the HCS, the biological productivity is very patchy in space, centered around isolated areas with special topography, like the shelf off Concepcion, Chile, at 36°30' S (Sobarzo et al 2001). During the austral summer (September-March), the mean surface wind in the study area is southerly, favouring the development of upwelling events with the consequent strengthening of biological productivity.…”

Section: Discussionmentioning

confidence: 94%

Interaction between southern sea lions Otaria flavescens and jack mackerel Trachurus symmetricus commercial fishery off Central Chile: a geostatistical approach

Hückstädt

Krautz²

2004

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

A spatial description of the operational interaction between southern sea lions and jack mackerel fishing fleet off Central Chile is presented. The descriptive analysis showed a similar spatial trend for the number of sea lions per haul and catch per haul, both increasing in the SE direction, and decreasing in the NW direction. The number of sea lions was positively correlated with catches at intermediate distances from land, while negatively correlated with the number of fishing vessels at the greatest distance from the land. The geostatistical analyses corroborate the trends found during the descriptive analysis: 2 nuclei of high abundance of sea lions were found, which spatially overlapped 2 nuclei of high jack mackerel catches; nuclei that we proposed here as hot-spots for this interaction. Both hot-spots were located on the continental slope and over the deep ocean bed. No spatial relation was found between the number of sea lions and the number of fishing vessels. Thus, it is proposed that the area enclosed between 38-40°S and 74-75°30' W constitutes the sector of higher interaction between the southern sea lions and jack mackerel industrial fishing fleet.

show abstract

Upwelling of subsurface water into the rim of the Biobı́o submarine canyon as a response to surface winds

Cited by 64 publications

References 16 publications

Effects of solar radiation on bacterioplankton production in the upwelling system off central-southern Chile

Effects of solar radiation on bacterioplankton production in the upwelling system off central-southern Chile

A review of the role of submarine canyons in deep-ocean exchange with the shelf

Interaction between southern sea lions Otaria flavescens and jack mackerel Trachurus symmetricus commercial fishery off Central Chile: a geostatistical approach

Contact Info

Product

Resources

About