NAMAGROEN EMPR Amendment.pdf - DLIST Benguela

Addendum to EMPR for Concessions 8(a), 9(a) and 8(b) 29Deposition of suspendedsediments from overspill ontoreef habitatsSmothering of vulnerable benthicreef communities resulting inmortality and potential reduction inbenthic biodiversity, caused bydeposition of sediments lost in theoverspill onto reefs adjacent to thedredging target areasStatusNegativeProbability Highly probable (most likely)Confidence Medium; depends on the quantity andnature of the sediments and the proximityof reef communities.Extent Regional; emergent reefs occur insubstantial portions of both the 8(a) and9(a) and 8(b) Concessions.Duration (a)-concessions:Short-term; depositing sediments will berapidly re-distributed in the waveinfluencednearshore regions.(b)-concession:Long- to Very Long-term; depending on thedepth of the reef and the extent ofsmothering, recovery may take decades.Intensity (a)-concessions:Mild; the sediment layer thickness isexpected to be minimal and mostnearshore reef organisms are adapted tohigh natural deposition rates.(b)-concession:Moderate; most adverse effects appearonly under high sediment rates and longtermdeposition.Significance (a)-concessions: Low(b)-concession: MediumSuspended sediment effects on Status Negativerock lobstersMobilisation and redistribution of Probability Improbable; although elevated suspendedsuspended sediments may havesediment concentrations are a typical byproductsublethal or lethal impacts on rockof mining activities, effects onlobster pueruli (and the larvalmarine organisms are unlikely. However,stages of other macrofaunalthere is insufficient information availablespecies). Deposition of theon rock lobster settlement and recruitmentresuspended sediment may smotherareas on the Namaqualand coast.suitable rock lobster habitats Confidence Mediumthereby reducing settlement stimuli Extent Regional; recruitment failure on thefor pueruli and precluding larvalsettlement, and/or reducing foodshallow water reefs in Concessions 8(a) and9(a) may affect lobster populations onsupply for juveniles. This maylocal fishing grounds, as well as fishingaffect recruitment success of rocklobsters in the area. Durationgrounds further away.Medium- to Long-term; recruitment failurecan have long lasting affects on thefishery.Namagroen Prospecting & Investments October 2008