Tete Iron Ore Project Ichthyology and Baseline

TETE IRON ORE PROJECT ICHTHYOLOGY AND BASELINE AQUATIC HABITAT STUDY Prepared for: Prepared by: ANTON BOK AQUATIC CONSULTANTS Trading as ANTON BOK & ASSOCIATES Capitol Resources Limitada (A member of Anton Bok Aquatic Consultants cc the Baobab Group) Rua Fernão Melo e Castro 261 5 Young Lane, Mill Park, Bairro da Sommerschield Port Elizabeth 6001 Maputo Tel.: 041 3733464 Moçambique E-MAIL: [email protected] & South African Institute for Aquatic Biodiversity Private Bag 1015 Grahamstown 6140 APRIL 2015 Ichthyology and Baseline Aquatic Habitat Study - April 2015 EXECUTIVE SUMMARY Objectives and Terms of Reference The primary objective of the present study is to undertake baseline studies to assess the habitat integrity of the aquatic habitats potentially impacted by the proposed Tete Iron Project and to determine the fish species present, particularly the presence of IUCN Red Data listed species. This information is used to determine and assess the potential impacts of the mining venture on aquatic biota, particularly fish, and to propose reasonable mitigation measures to reduce impacts to acceptable levels. The Study Area The main surface water-body of concern is the Revuboe River, which runs from north to south through the center of the ore deposits, and thus could potentially be impacted by any contaminated run-off from the mine site. This large perennial tributary of the Zambezi River, with a MAR of approximately 1000 million m3 per annum, is also a potential supply of water for mining operations. The smaller, seasonal Nhambia River is located immediately downslope of the Project Area and could also be potentially impacted by mining operations. No river diversions are anticipated during this initial phase of the project. In addition, the proposed new haul road to be constructed from the mine to the railway line at Moatize will require a bridge or causeway over the perennial Ncondezi River and will also cross a number of smaller rivers and streams, including the seasonal Moatize and Modizo Rivers in the south-east. These road crossings over the various watercourses will require environmentally-friendly designs and construction protocols to prevent ecological damage, including the blocking of natural fish migrations within these perennial and seasonal rivers. Methods During the wet season field trip (March 2013) eight sampling sites were surveyed for fish using a variety of fishing gear including and electro-fisher, gill nets, seine nets and fyke nets, as well as a variety of dip-nets. Sampling areas included five sites on the larger Revuboe River, which were surveyed by boat and three sites surveyed on the Nhambia River system. The two northern sites on the Revuboe River are considered upstream of the area of influence of the mine and could therefore serve as future reference sites for comparison with sites impacted by the mine. The Ncondezi River was inaccessible during the wet season and was not sampled at this time. During the dry season field trip (September 2013) the lack of a suitable boat and presence of large crocodiles restricted sampling to 2 sites in the Revuboe, while the absence surface water did not allow sampling in the seasonal Nhambia River and tributaries. Three sites in the perennial Ncondezi River, located along the proposed haul road routes to Moatiz, were sampled near the proposed crossings. The seasonal Moatize and Modizo rivers along the proposed haul road route, were not sampled at this time. The most appropriate fishing gear used depended on the available aquatic habitats and conditions. The presence of large crocodiles in the Revuboe River restricted fishing activities, but appropriate gear (gill nets, fyke nets and long-lines) were used effectively using a small boat. An electro-fisher and small seine nets and dip-nets were used in the smaller and shallower Nhambia and Ncondezi rivers and tributaries. The habitat preferences and requirements of the various fish species captured, as well as their sensitivity to environmental changes, were obtained from the literature (e.g. Skelton et al.2001; IUCN 2012) and expert knowledge. This information, together with the field data on the present Coastal & Environmental Services (Pty) Ltd i Tete Iron Ore Project Ichthyology and Baseline Aquatic Habitat Study - April 2015 aquatic habitat integrity within the Study Area, was used to assess potential impacts of the mining venture on the fish species found within the affected rivers. Results and Discussion Habitat Integrity or Present Ecological Status Both the in-stream and riparian habitat integrity of the Revuboe River and Ncondezi River in the Study Area are considered largely unmodified with the ecosystem functioning being essentially unchanged compared to the undisturbed state. The destruction and clearing of woody riparian vegetation for agriculture, however, is considered to have limited negative impacts in terms of increased sediment input and elevated turbidity. The dense reed (Phragmites sp.) beds in the backwaters and margins of the Revuboe River may be partly due to the destruction of the riparian trees. These reed beds trap sediments, exacerbating the problem of channel siltation and the loss of important in-stream habitat diversity. Fish species captured A total of 25 fish species were captured in the Study Area, of which only one species, namely the Mozambique tilapia (Oreochromis mossambicus), is categorized in the IUCN Red Data listings (IUCN 2012) as near threatened (NT). However, two fish species captured in the rapid and riffle habitat in fast-flowing water in the Ncondezi River (Chiloglanis cf. neumanni and Zaireichthys cf. monomotopa) both belong to species complexes with uncertain taxonomic affinities and are categorised as data deficient (DD) by the IUCN. These two species should be considered of special concern until further data on the distribution and conservation status are available. The remaining 23 species are all classified as being of Least Concern (LC). Tigerfish (Hydrocynus vittatus) were captured at four of the five sites in the Revuboe River and is considered an indicator of good quality water. Although not considered threatened due to its wide distribution in southern Africa, some populations of this species have declined due to habitat destruction, pollution and overfishing. Due to its value as are a potential indicator species as well as angling properties, tigerfish warrant close attention in the Study Area. Fish Utilisation by Local Communities All fish species of all sizes appear to be captured for domestic consumption by local villagers when available. Although hook and line fishing is carried out, fish are mainly captured using fish fences, seine and gill nets. Although this fish resource appears relatively small, it is thought to form an important source of protein in the diet of local villagers living near the rivers. However, the socio-economic importance of this fish resource for the broader community in the Study Area may be limited. This issue is reported upon elsewhere in the social impact assessment report. Assessment of Potential Mining Impacts A summary of the five main potential impacts (or issues) identified and assessed both with and without mitigation is given Table A below. Table A: Summary of the assessment of mining impacts on the surface waters. (C =; Construction; O = Operation; D = Decommissioning; All = All project phases). Impacts during the design and planning phase were not significant and are not included. All impacts are negative unless listed as positive. SIGNIFICANCE ISSUE IMPACT Without With mitigation Mitigation 1. Water 1.1 Sedimentation & increased turbidity in rivers (All)) High Moderate Coastal & Environmental Services (Pty) Ltd ii Tete Iron Ore Project Ichthyology and Baseline Aquatic Habitat Study - April 2015 Quality 1.2 Contamination from non-ore pollutants (C & O) Moderate Low 1.3 Ore-related contamination – AMD (C, O & D) High low 2. Hydrology 2.1 Alternation of river flow dynamics (C & O) Moderate Low 3. 3. Habitat 3.1 Aquatic habitat modification (C & O) High Moderate Modification 3.2 Loss of species of special concern (C & 0) High Moderate 4. Habitat 4.1 Instream structures blocking migrations (C, O & D) High Low Fragmentation 5. Fisheries 5.1 Over-utilization of fish resources (C, O & D) Moderate Low Resource As can be seen from the above table, the main impacts are related to altering river flow patterns and pollution of surface waters. Pollution could be via contaminated groundwater seeping into the rivers and polluted surface run-off from the mine area, including from the tailings storage facility (TSF) and waste rock dump site entering the adjacent rivers and streams. Although habitat fragmentation due to construction of instream barriers has a high potential impact, this could be readily mitigated by ensuring all instream structures are appropriately located and designed. As expected, the most severe impacts are associated with the construction and operational phases. Mitigation and Recommendations As shown in Table A, all of the potential mining-related impacts can be adequately mitigated to acceptably low levels by adopting appropriate best-practice management protocols that are strictly regulated according to comprehensive construction and operational environmental management plans (EMPs). It is critical that there is strict adherence to industrial best practice to prevent, or reduce to acceptable levels, all potential water pollution (including acid mine drainage contamination) and elevated sedimentation

Load more