Benguela twilight-zone fish tracked krill and low-oxygen boundaries

Namibian hydroacoustic surveys showed prey coupling and a daily association with the oxygen-minimum zone.

Wild Lands Ecological Intelligence Editor
Wild Lands Institute · 2 November 2026

Evidence: Peer-reviewed
Geography: Northern Benguela off Namibia; survey years 2017 and 2019
System: Mesopelagic fish, krill and oxygen minimum zone

WHAT THE EVIDENCE SAYS

Multifrequency echo surveys separated fish, krill and other plankton in 2017 and 2019. Mesopelagic fish acoustic density tracked krill and more productive water and concentrated near the upper daytime oxygen-minimum-zone boundary.

WHY IT MATTERS / OUR READ

Potential new mesopelagic fisheries should examine trophic location and acoustic classification limits rather than infer harvest potential from bulk scattering.

CAVEATS / UNCERTAINTY

Acoustics are an imperfect biomass/species proxy; two survey years cannot establish trends or fishery sustainability.

SOURCE

African Journal of Marine Science / AJOL — Kashindye et al. (29 Oct 2026)
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