An overview of the living marine resources of Namibia

Boyer, D. C.; Hampton, Ian

doi:10.2989/025776101784528953

Cited by 87 publications

(71 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3), while SST anomalies of up to 5°C off the coast of Angola and Namibia are observed (e.g., Junker et al 2017). Benguela Niños/Niñas are known to have a strong impact on precipitation variability over adjacent countries (e.g., Rouault et al 2003) as well as on the marine ecosystem and local fisheries (Gammelsrød et al 1998;Boyer and Hampton 2001). There is a tremendous social and economic interest within the southern African community in the prediction of these climate anomalies.…”

Section: History Of Physical Oceanography In Angolamentioning

confidence: 99%

Eastern Boundary Circulation and Hydrography Off Angola: Building Angolan Oceanographic Capacities

Tchipalanga

Dengler

Brandt

et al. 2018

Bulletin of the American Meteorological Society

123

View full text Add to dashboard Cite

The eastern boundary region off Angola encompasses a highly productive ecosystem important for the food security of the coastal population. The fish-stock distribution, however, undergoes large variability on intraseasonal, interannual, and longer time scales. These fluctuations are partly associated with large-scale warm anomalies that are often forced remotely from the equatorial Atlantic and propagate southward, reaching the Benguela upwelling off Namibia. Such warm events, named Benguela Niños, occurred in 1995 and in 2011. Here we present results from an underexplored extensive in situ dataset that was analyzed in the framework of a capacity-strengthening effort. The dataset was acquired within the Nansen Programme executed by the Food and Agriculture Organization of the United Nations and funded by the Norwegian government. It consists of hydrographic and velocity data from the Angolan continental margin acquired biannually during the main downwelling and upwelling seasons over more than 20 years. The mean seasonal changes of the Angola Current from 6° to 17°S are presented. During austral summer the southward Angola Current is concentrated in the upper 150 m. It strengthens from north to south, reaching a velocity maximum just north of the Angola Benguela Front. During austral winter the Angola Current is weaker, but deeper reaching. While the southward strengthening of the Angola Current can be related to the wind forcing, its seasonal variability is most likely explained by coastally trapped waves. On interannual time scales, the hydrographic data reveal remarkable variability in subsurface upper-ocean heat content. In particular, the 2011 Benguela Niño was preceded by a strong subsurface warming of about 2 years’ duration.

show abstract

Section: History Of Physical Oceanography In Angolamentioning

confidence: 99%

Eastern Boundary Circulation and Hydrography Off Angola: Building Angolan Oceanographic Capacities

Tchipalanga

Dengler

Brandt

et al. 2018

Bulletin of the American Meteorological Society

123

View full text Add to dashboard Cite

show abstract

“…Average annual sardine landings dropped from around 750,000 t in the 1960s to <70,000 t in the 1980s and 1990s. Since the beginning of the 21st century, sardine catches have averaged <20,000 t yr ) and were high for 2 yrs in the late 1980s, possibly because of an exceptional influx of recruits from the SB (Boyer and Hampton 2001), before dropping to insignificant levels (averaging less than 5000 t yr −1 ) in the last 15 yrs. Although Whitehead's round herring is present in Namibian waters, the population there is thought to be small (Boyer and Hampton 2001) and this species has never significantly contributed to pelagic catches.…”

Section: Faunal Trajectories In the Northern Benguelamentioning

confidence: 99%

Jellyfication of Marine Ecosystems as a Likely Consequence of Overfishing Small Pelagic Fishes: Lessons from the Benguela

Roux¹,

Lingen²,

Gibbons³

et al. 2013

BMS

128

View full text Add to dashboard Cite

Changes in two contrasting ecosystems of the Benguela upwelling region, one dominated at mid-trophic level by jellyfishes (Namibia, northern Benguela ecosystem, where small pelagic fish abundance has been severely depleted) and one still dominated by small pelagic fishes (South Africa, southern Benguela) were compared in an effort to determine ecosystem trajectories under different exploitation regimes. The role of small pelagic fishes (clupeoids) was highlighted in the context of their importance in maintaining interactions in marine ecosystems. In particular, we examined trophic cascades and possible irreversible changes that promote the proliferation of jellyfishes in marine systems. We found that the presence of large populations of small pelagic fishes has a fundamental role in preserving beneficial trophic interactions in these marine ecosystems. The implications of trophic cascades, such as those observed in the northern Benguela, for ecosystem-based management were apparent. In addition, this comparison provides contrasting case studies to inform the development of management scenarios that avoid ecosystem shifts that affect predators and reduce the value of fisheries production.

show abstract

“…For example, some major stocks, particularly small pelagics, failed to recover as expected (Boyer and Hampton 2001), and the status of some vulnerable and endangered species such as Cape gannets Morus capensis, African penguins and bank cormorants Phalacrocorax neglectus worsened (Crawford et al 1999, Kemper et al 2001, Du Toit et al 2002. Total fish landings in the northern Benguela continued to decline in the 1990s, falling to just over 560 000 tons in 2000, consisting mostly of horse mackerel (58.6%).…”

Section: Fisheries Management Since Namibia's Independencementioning

confidence: 99%

“…The second phase in the history of the northern (Oelofsen 1999, Boyer andHampton 2001). As Cape hake catches started to decline in the early 1970s, and after the crash of the sardine fishery, the midwater trawl fishery that was targeting horse mackerel expanded considerably.…”

Section: Pre-independence 20 Th Century Fisheries Expansionmentioning

confidence: 99%

See 1 more Smart Citation

Ecosystem approach to fisheries management in the northern Benguela: the Namibian experience

Roux¹,

Shannon²

2004

African Journal of Marine Science

View full text Add to dashboard Cite

An overview of the living marine resources of Namibia

Cited by 87 publications

References 0 publications

Eastern Boundary Circulation and Hydrography Off Angola: Building Angolan Oceanographic Capacities

Eastern Boundary Circulation and Hydrography Off Angola: Building Angolan Oceanographic Capacities

Jellyfication of Marine Ecosystems as a Likely Consequence of Overfishing Small Pelagic Fishes: Lessons from the Benguela

Ecosystem approach to fisheries management in the northern Benguela: the Namibian experience

Contact Info

Product

Resources

About