Minerals Report - International Seabed Authority

iological productivity in this area, there are large fisheries present off the
west coast, starting from the Orange River, going up into Northern
Namibia, and extending into Angola. He also said that this is an area that
is in demand by a large number of different users of marine resources.
He stated that these other uses of marine resources in the area has
a key bearing on the way De Beers Marine has been looked at, and the
evolution of its approach to environmental management. With slides, Dr.
Corbett showed the relative proximity of areas of rock lobster and other
fisheries to the Atlantic 1 Mining Licence that is one of De Beers’ diamond
producing areas on the continental shelf.
With another slide, Dr. Corbett said that a further feature of the
macro scale Benguela system is that there is natural low oxygen depletion
in the system. He indicated an area up in the north in which he said
oxygen is depleted from deep water. He also pointed out an area on the
continental shelf characterized by natural low oxygen conditions, that he
said actually lies right over an area in which De Beers’ mining operations
occur. He emphasized the fundamental importance of an overall
understanding of the marine life in that region.
Dr. Corbett informed participants that one of the other principal
natural phenomena on this coast is the discharge from the Orange River
into the Atlantic, periodically flooding the Benguela system. Dr. Corbett
said that this discharge contains large volumes of suspended materials
that are flushed out onto the continental shelf, creating extremely large
sediment plumes out. He said that unlike the deep ocean where
sedimentation from land sources is very low, this area is subjected to very
large inputs. Another contributory phenomenon according to Dr. Corbett
is the easterly winds that blow vast volumes of dust from the Kalahari
Basin to the coast.
Dr. Corbett said that in 1990 when the whole issue of
environmental impact assessment was first being looked at in considerable
detail, De Beers tried to grapple with the state of knowledge of the natural
variability within the ecosystem as distinguished from impacts from
mining. De Beers had to ask itself if the level of knowledge about this
ecosystem was sufficient to allow the differentiation of the local scale
environmental impact driven directly by mining as opposed to the very
large macro scale natural events in the system. He stated that during his
INTERNATIONAL SEABED AUTHORITY 653