Exchange of Pb from Indian to Atlantic Ocean is driven by Agulhas current and atmospheric Pb input from South Africa.

Using a spatiotemporal dataset of dissolved lead (dPb) from the subtropical oceans surrounding South Africa, this study quantifies the exchange of dPb between the Indian and Atlantic Oceans. Despite the absence of a major Pb source within the South Atlantic sector and the complete phase-out of leaded petroleum in Southern Africa, the ecologically important southeast Cape Basin shows an elevated surface dPb concentration (21-30 pmol kg). We estimated up to 90% of the measured dPb in surface waters of the Cape Basin was delivered from the Indian Ocean via the Agulhas Current (AC).

Oceanographic anomalies coinciding with humpback whale super-group occurrences in the Southern Benguela.

Seasonal feeding behaviour of humpback whales (Megaptera novaeangliae) has been observed in the coastal waters of the Southern Benguela where the species has been observed forming super-groups during the austral spring in recent years since 2011. Super-groups are unprecedented densely-packed aggregations of between 20 and 200 individuals in low-latitude waters and their occurrences indicate possible changes in feeding behaviour of the species. We accessed published data on super-groups occurrence in the study area in 2011, 2014 and 2015, and investigated oceanographic drivers that support prey availability in this region.

Regulation of the Phytoplankton Heme Iron Pool During the North Atlantic Spring Bloom.

Heme is an iron-containing co-factor in hemoproteins. Heme concentrations are low (<1 pmol L) in iron limited phytoplankton in cultures and in the field. Here, we determined heme in marine particulate material (>0.