Southwestern Africa: Northern Benguela Current Region

Boyer, D. C.; Cole, James; Bartholomae, C.

doi:10.1016/s0025-326x(00)00106-5

Cited by 43 publications

(35 citation statements)

References 38 publications

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“…A counter example to larval retention is found on the western shores of South Africa and Namibia where the north-flowing Benguela current is characterized by strong coastal upwelling (Boyer et al 2000). Under upwelling favorable winds, Ekman transport would transport larvae in the surface waters offshore.…”

Section: Discussionmentioning

confidence: 99%

Linking ocean conditions to year class strength of the invasive European green crab, Carcinus maenas

Yamada

Kosro

2009

Biol Invasions

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Once a non-native species arrives and survives in an area, its long-term persistence depends on its recruitment success. If conditions are not favorable for recruitment it will ultimately disappear. The European green crab (Carcinus maenas) has a 6 year life span and has persisted at low densities in Oregon and Washington coastal estuaries for the past 12 years. We show here that after the arrival of the strong founding year class of 1998, significant selfrecruitment to the Oregon and Washington populations occurred only in 2003, 2005 and 2006. Warm winter water temperatures, high Pacific Decadal Oscillation and Multivariate ENSO (El Niño Southern Oscillation) Indices in March, late spring transitions and weak southward shelf currents in March and April are all correlated with the these strong year classes. Cold winter water temperatures, low Pacific Decadal Oscillation Indices, early spring transitions and strong southward (and offshore) currents in March and April are linked to year class failure. Right now, green crabs are still too rare to exert a measurable effect on the native benthic community and on shellfish culture in Oregon and Washington. However, if their numbers were to increase, we would be able to predict the arrival of strong year classes from ocean conditions and alert managers and shellfish growers of possible increases in predation pressure from this invader.

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Section: Discussionmentioning

confidence: 99%

Linking ocean conditions to year class strength of the invasive European green crab, Carcinus maenas

Yamada

Kosro

2009

Biol Invasions

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“…It has been considered a semi-permanent convergence zone (Boyer et al 2000), and this could lead to the accumulation of jellyfish (see Graham et al 2001). Phytoplankton (Estrada andMarrasé 1987, Brown et al 1991) and zooplankton (Shannon andPillar 1986, Olivar andBarange 1990) biomass is also higher in the south-central area of the shelf, and both decline to the north.…”

Section: Distributionmentioning

confidence: 99%

“…Shelf waters off Namibia are subject to coastal upwelling, and pelagic fish communities were dominated by sardine Sardinops sagax and anchovy Engraulis encrasicolis prior to the mid-1970s. These small pelagic fish are considered wasp-waist species (Cury et al 2000) that use the high primary production relatively efficiently, and they were subject to industrial fisheries that date back to the mid-20th century (Boyer et al 2000). Annual sardine catches were around 200 000 tonnes for much of the 1950s (Le Clus et al 1987), then increased throughout the 1960s to more than 1.5 million tonnes in 1968 after good recruitment in the late 1950s and early 1960s (reviewed by Cury and Shannon 2004).…”

mentioning

confidence: 99%

Temporal and spatial patterns in the abundance of jellyfish in the northern Benguela upwelling ecosystem and their link to thwarted pelagic fishery recovery

Flynn

Richardson

Brierley

et al. 2012

African Journal of Marine Science

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“…Some even argue that the Indian Ocean influences the timing and intensity of ENSO (Annamalai et al, 2005;Wu and Kirtman, 2004). Though not the focus of study in this work, it is important to acknowledge other noteworthy phenomena driving regionally-important climate variability across Africa including the Benguela Niño (Boyer et al, 2000;Shannon et al, 1986), tropical Atlantic interdecadal oscillations (Giannini et al, 2003;Paz et al, 2003;Tourre et al, 1999Tourre et al, , 2006, and an equatorial, quasi-biennial Atlantic SST oscillation (Balas et al, 2007;Giannini et al, 2003;Hirst and Hastenrath, 1983;Latif and Groetzner, 2000;Tourre et al, 1999;Zebiak, 1993).…”

Section: A Williams and N P Hanan: Enso And Iod Teleconnectionsmentioning

confidence: 99%

ENSO and IOD teleconnections for African ecosystems: evidence of destructive interference between climate oscillations

Williams

Hanan

2011

Biogeosciences

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Abstract. Rainfall and vegetation across Africa are known to resonate with the coupled ocean-atmosphere phenomena of El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). However, the regional-scale implications of sea surface temperature variability for Africa's photosyntheis have received little focused attention, particularly in the case of IOD. Furthermore, studies exploring the interactive effects of ENSO and IOD when coincident are lacking. This analysis uses remotely sensed vegetation change plus a land surface model driven with observed meteorology to investigate how rainfall, vegetation, and photosynthesis across Africa respond to these climate oscillations. In addition to the relatively well-known ENSO forcing, the IOD induces large departures of photosynthesis across much of Africa associated with anomalies in rainfall and vegetation greenness. More importantly, sizeable independent effects can be suppressed or even reversed by destructive interferences during periods of simultaneous ENSO and IOD activity. For example, effects of positive IOD on southeastern Africa tended to dominate those of El Niño during their coincidence spanning 1997-1998, with sign reversal of El Niño's typically strong suppression of photosynthesis in this region. These findings call into question past analyses examining teleconnections to ENSO or IOD in isolation, and indicate the need to consider their simultaneous states when examining influences on hydroclimatic and ecological conditions across Africa.

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Southwestern Africa: Northern Benguela Current Region

Cited by 43 publications

References 38 publications

Linking ocean conditions to year class strength of the invasive European green crab, Carcinus maenas

Linking ocean conditions to year class strength of the invasive European green crab, Carcinus maenas

Temporal and spatial patterns in the abundance of jellyfish in the northern Benguela upwelling ecosystem and their link to thwarted pelagic fishery recovery

ENSO and IOD teleconnections for African ecosystems: evidence of destructive interference between climate oscillations

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