Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
THE IMPACTS OF QUARRYING ON BIODIVERSITY: SETTING THE BASIS FOR ASSESSMENT AT AKOSOMBO QUARRY
Prepared by Japheth S.T. Roberts Submitted to HEIDELBERG CEMENT Group GHACEM LTD September, 2012 Accra
Contributors
1. Yahaya Musah- Amphibians and reptiles 2. Reuben Garshong- Large and Small mammals 3. Daniel Acquah-Lamptey- Insects 4. Sigismund Anderson Roger - Insects 5. Japheth Roberts- Birds 6. Abigail Kuranchie
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
ACKNOWLEDGEMENT
The completion of this research has been the joint effort of many people who contributed in many diverse ways. I would like to acknowledge HeidelbergCement Group, for the opportunity to conduct this research through the Quarrylife Award competition and to GHACEM for all their help in facilitating this research with seed money and field work logistical support. To my team Reuben, Yahaya, Daniel, Sigismund, Abigail and Apala, your dedication and sacrifice ensured that this research was done. However, my greatest thanks go to God almighty for the gift of life for my team.
EXECUTIVE SUMMARY
• Fifty nine species of birds were recorded within the concession of which all are of Least Concern on the IUCN Redlist. Fourteen species of herpetofauna were on the concession, 6 of which are amphibians and 8 reptiles. Four other reptiles were thought to be present based on interviews. The site has 14 mammal species present and sixteen orders of insects with 103 families
• The areas around the lake shore, stream bank and the uphill thickets were identified to be areas of ecological concern as they are the preferred habitat for amphibians and Odonates and serve as faunal refugia respectively.
• It is recommended that amphibians and insects specifically of the Orders: Odonata, Lepidoptera, Diptera and Coleoptera be used as key indicators for monitoring. However for better scientific assessment a yearly faunal survey would provide vital information. This if continued throughout the lifetime of the quarry would enable long term assessment of quarrying impacts on biodiversity.
• If the biodiversity plots idea is used, it could be further developed as learning tool for children in the surrounding communities to learn about biodiversity. This can be achieved by establishing wildlife clubs in the schools. Additionally, Ghacem should embark on a ‘Biodiversityclinic’ program. This should include regular visits by 1st and 2nd cycle school students to the biodiversity plots. These visits will be used to teach them practically the importance of biodiversity. Staff could also be trained under this program to collect data for monitoring purposes.
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
Contents 1.0 INTRODUCTION...... 1 2.0 METHODOLOGY ...... 1 2.1 Study Area ...... 1 2.2 Insects Survey ...... 2 2.2.1 Sweep-Netting ...... 2 2.2.2 Flight Interceptor Trap ...... 2 2.2.3 Yellow Pan Trapping ...... 3 2.2.4 Pitfall Trapping ...... 3 2.3 Avifaunal Survey ...... 3 2.4 Mammals Survey ...... 4 2.4.1 Live-trapping of Small Mammals ...... 4 2.4.2 Large Mammals ...... 5 2.5 Herpetofaunal Survey ...... 5 2.5.1 Direct Observation/Refuge Examination ...... 5 2.5.2 Interviews ...... 6 3.0 RESULTS ...... 6 4.0 DISCUSSION ...... 12 5.0 CONCLUSIONS ...... 14 6.0 RECOMMENDATIONS ...... 15 REFERENCES ...... 16
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
1.0 INTRODUCTION
The Quarry life Award is a competition organized by HeidelbergCement for the purposes of protecting and promoting biodiversity. HeidelbergCement recognizing the need to manage biodiversity before, during and after extraction offered young scientists the opportunity to conduct projects within their quarries addressing four main Areas. These areas were discovering biodiversity in mining sites with the goal of increasing the knowledge about biodiversity in the selected mining sites, biodiversity and rehabilitation in order to promote biodiversity in quarry rehabilitation (nature protection, forestry, agriculture, recreation, housing area), biodiversity and education towards developing a concept for social activities focusing on mining and biodiversity (events, nature trails, cooperation with schools, NGOs, universities) and biodiversity management during extraction to optimize the biodiversity value of the quarry during the extraction period. (www.quarrylifeaward.com/about)
This project titled “The impacts of Quarrying on Biodiversity: Setting the Basis for assessment at Akosombo Quarry” was selected as one of the top 5 finalists to execute the projects in the competition in Ghana. This project sought to tie in with two of the goals of the competition by providing baseline information on the biodiversity occurring within the site based on which recommendations would be offered to enhance biodiversity management during the extraction period.
1.1 Aim The study sought to establish the biodiversity baseline of the proposed quarry by documenting the faunal diversity of the concession by specifically providing amphibians, birds, insects, mammals and reptile species checklists.
2.0 METHODOLOGY
2.1 Study Area The proposed Akosombo Quarry site is located within the Asuogyaman District of the Eastern region of Ghana, approximately 1.5km from the village of Sedorm. The concession is estimated to cover an area of 0.052km2. The habitat is highly degraded with secondary vegetation growth, Acacia trees, neem trees and a few scattered Ceiba pentandra. The area is bordered by the Volta Lake and some steep ridges; it is about 120m above sea level.
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
2.2 Insects Survey
The Insect survey was conducted using a habitat-specific approach. This approach is preferred in that it offers the use of standardized methods that are cost effective while allowing the collection of large amounts of data. Sweep netting was deployed in areas with low vegetation whereas flight interception traps (Malaise trap) and pan traps were used in areas of open vegetation. Pitfall traps were used to target soil and leaf litter insects within the various habitats.
2.2.1 Sweep-Netting
Sweep nets were used to randomly collect prey samples by sweeping through the vegetation against the direction of the wind. Invertebrates trapped would be put into a bucket containing cotton wool soaked in ethyl acetate, collected and preserved in 70 % alcohol
2.2.2 Flight Interceptor Trap
The Malaise trap is a flight interceptor trap that is targeted at flying insects. It works on the principle that flying insects either fly upwards or downwards when confronted with an obstacle. Hence the malaise trap, constructed from dark semi-transparent tiny mesh with long sides open and a central vertical partition that stretches lengthwise. One end of this tent-like shape is raised higher than the other (see fig 1.0). This enables the trap to take advantage of flying insect behaviour. Insects that meet the obstacle and fly upwards would be funnelled in a collecting pot. Whereas, those that drop on meeting the obstacle created by the central portion would be collected at the bottom with collecting trays. These traps were set up and inspected and all caught insects collected on a daily basis.
Fig. 1.0 Malaise trap being set up
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
2.2.3 Yellow Pan Trapping
The traps were filled to about a quarter full with soapy water and randomly placed on the ground in the various microhabitats at the study site (See fig 2.0). The traps were inspected after two nights, and any trapped organisms processed with forceps and stored in 70 % alcohol.
Fig. 2.0 Yellow pan trap Fig. 3.0 Pitfall trap
2.2.4 Pitfall Trapping
Insect pitfall traps with the upper rims of the traps about flush with the ground were filled to about a quarter full with soapy water (to prevent trapped animals from escaping) and inspected after three days (see fig 3.0). These traps were deployed within the various habitats and all trapped organisms processed using forceps and preserved in 70 % alcohol.
2.3 Avifaunal Survey Transect walks and mist netting was used to assess the avian diversity of the area. Transect walks involved continuous walking along a chosen transect and recording all birds seen or heard. This method allows more ground to be covered and more birds to be recorded. The method also significantly reduces double counting of birds as the observer is continually moving. Mist netting was however done to support the transect walks because transect walks tend to overlook silent and under canopy birds.
A transect was selected that traversed all the identified micro habitats within the Akosombo quarry site. The selected transect cut through the associated farmlands, the wooded area, along the hills and to the lakeshore. The transect was walked twice a day between the hours of 06:00 – 10:00 hours GMT and 16:00 – 18:00 hours GMT and the direction of start reversed each day. These periods are known to be the peak periods for bird activity and the reversal was necessary to reduce biases associated with the time of day each section of the transect was surveyed. The
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
mist nets (four - 18m nets) were also operated within the same time frames and the study was conducted over five days.
2.4 Mammals Survey
2.4.1 Live-trapping of Small Mammals Sherman Traps: Four consecutive nights of trapping, constituting 320 trap-nights was carried out. The site was divided into three different ecotypes: (i) upland thicket/scrubland (Upland Thicket 1, Upland Thicket 2 and Upland Scrubland), (ii) farmlands and (iii) grasslands/wooded grasslands. The Sherman traps were baited with a mixture of peanut butter and corn meal and placed at 10-m intervals along varying transect lengths per area. Traps were set, rebaited and replaced at sunset around 16:00 hrs GMT and inspected around 06:00 hrs GMT the next morning throughout the study period.
Fig. 4.0
Pitfall Traps: traps made up of 17 litre buckets were sunk in the ground with their rims flush with ground level, along a drift fence made of a 1-metre high mosquito netting stapled in a vertical position to thin wooden stakes. The drift fence ran across the middle of each pitfall bucket which was buried flush with the ground. Each study site had 50-metre long pitfall traps with 26 buckets buried at 2-metre intervals. The traps were checked daily in the morning.
Fig. 5.0
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
The captured small mammals were euthanized using chloroform then identified, sexed (using the ano-genital distance, which is longer in males), weighed and examined for reproductive condition (abdominal or scrotal testes in males and enlarged nipples, perforate vaginas and pregnancy in females). Lactating females had bare areas around the mammae, indicating suckling from the young. Pregnancy was determined by weight and palpation of the abdomen. Reproductive males exhibited prominent scrotal testes. Field handling techniques followed Davies & Howell (2004). The following standard morph metric measurements (body, tail, ear, and hind limb lengths) were taken: (i) TOTL (total body and tail length; from nose-tip to end of tail), (ii) TL (tail length; from base of tail at right angle to body to the tip of tail), (iii) HBL (head and body length, TOTL – TL), (iv) HFL (hind foot length; from heel to the tip of the longest toe), (v) EL (ear length; from basal notch to the distal tip of pinna) and (vi) WT (weight in grams).
The terrestrial small mammal species larger than Sherman traps and less cryptic were spotted with the naked eyes. In order to minimize double counting, the highest number sighted in a day was recorded as the number of individuals observed in the area.
Mist netting: One 18 m mist nest was constructed along the pond close to the workshop area to trap bats. To aid in identification of bats, forearm length and weight of bats were measured.
2.4.2 Large Mammals These mammals are difficult to capture. The best means of observation is therefore though their signs such as spoors, footprints, faecal pellets etc. or by spotting. Transect walks were cut through the various selected habitat types and walked twice in a day – early in the morning around 06:00 GMT and around 05:00 GMT. Opportunistic searches were also used. Mammal identification guides included Kingdon (2004) and Rosevear (1969).
2.5 Herpetofaunal Survey
2.5.1 Direct Observation/Refuge Examination Visual encounter surveys either opportunistically or with acoustic searching were undertaken by turning over rocks and logs, peeling bark, digging through leaf litter, and scanning on trees and buildings. The surveys were conducted during the day and night to detect both diurnal and nocturnal species. Ponds and puddles in and around the plots were also checked for the presence of amphibians. Other areas searched were rotten tree stumps, tree buttresses, and termite mounds, sheets of scrap metals and derelict car bodies, as well as digging out holes in the ground (Heyer et al., 1994).
Pitfall Trapping with Drift Fences: Same was used for small mammal survey (Section 2.4)
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
2.5.2 Interviews A cross-section of inhabitants of the study area was interviewed to provide supplementary evidence to the other methods. The interviews focused on the different types of species commonly found in the study area and some indication of their abundance (commonness and rarity). The respondents were shown photographs from field manuals to guide them in identifying the various herpetofaunal species.
3.0 RESULTS
Insects
The insect survey sampled 16 orders of insects representing 103 families. Odonata families collected were from four families, 14 species. Butterfly families collected were of nine families, 84 species: Nymphalidae, Papillionidae, Danidae, Acraedae, Hesperidae, Pieridae, Satyridae and Lycaenidae with the Pieridae family dominating. Detailed species lists can be found in the appendix.
Orthoptera Hymenoptera Dictyoptera Lepidoptera Isoptera Homoptera Collembola Diptera Coleoptera Trichoptera Thysanoptera Dermaptera
Fig. 6.0 A pie chart showing the percentage abundance of insect orders recorded during the Quarry Life Award project in Akosombo
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
Avifauna
A total of 59 species of birds were observed within the site. All the observed birds were of Least Concern (LC) with respect to the IUCN Redlist.
Common Name Scientific Name
Pin-Tailed Whydah Vidua macroura Northern Grey-headed Sparrow Passer griseus Village weaver Ploceus cucullatus Black-headed Weaver Ploceus melanocephalus Vieillot's Black Weaver Ploceus nigerrimus Red-Headed Quelea Quelea erythrops Yellow-mantled Widowbird Euplectes macroura Northern Red Bishop Euplectes franciscanus Black-winged Bishop Euplectes hordeaceus Simple leaflove Chlorocichla simplex Common Bulbul Pycnonotus barbatus Snowy-crowned Robin Chat Cossypha niveicapilla African Thrush Turdus pelios Malachite Kingfisher Alcedo cristata Abyssinian Roller Coracias abyssinicus Bar-breasted Firefinch Lagonosticta rufopicta Orange-cheeked Waxbill Estrilda melpoda Bronze Mannikin Spermestes cucullatus Black-and-white Mannikin Spermestes bicolor Blue-billed Firefinch Lagonosticta rubricate Black- bellied Firefinch Lagonosticta rara Green-backed Heron Butorides striata White-faced Whistling Ducks Dendrocygna viduata Double-spurred Francoline Francolinus bicalcaratus African Jacana Actophilornis africanus Water Thick-knee Burhinus vermiculatus Tambourine Dove Turtur tympanistria Blue-spotted Wood dove Turtur afer Red-eyed Dove Streptopelia semitorquata Laughing Dove Streptopelia senegalensis
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
Western Grey Plantain-eater Crinifer piscator Klaas's Cuckoo Chrysococcyx klaas Senegal Coucal Centropus senegalensis Greyish Eagle owl Bubo(africanus)cinerascens Woodland Kingfisher Halcyon senegalensis Didric Cuckoo Chrysococcyx caprius Double-toothed Barbet Lybius bidentatus Little Swift Apus affinis Little Greenbul Andropadus virens Red-faced Cisticola Cisticola erythrops Stone Patridges Ptilopachus petrosus Tawny-flanked Prinia Prinia subflava Grey-backed Camaroptera Camaroptera brachyuran Green-headed Sunbird Cyanomitra verticalis Collared Sunbird Hedydipna collaris Scarlet-chested Sunbird Chalcomitra senegalensis Marsh Tchagra Bocagia minuta Yellow-billed Kite Milvus migrans parasites African Grey Hornbil Tockus nasutus Pied Crow Corvus albus Copper Sunbird Cinnyris cupreus Rufous-chested Swallow Cecropis semirufa Black-necked Weaver Ploceus nigricolis Green Turaco Tauraco persa Violet Turaco Musophaga violacea African Paradise Flycatcher Terpsiphone viridis African Hobby Falco cuvierii
Mammals
A total of 320 trap-nights yielded 48 individuals of small mammals, constituting two orders (Rodentia: Muridae, Sciuridae, Nesomyidae and Chiroptera: Vespertilionidae and Pteropodidae) of 11 species. The Natal’s Multimammate Mouse (Mastomys natalensis) was the commonest and most abundant of the small mammal species, occurring in all five habitat types. Foot prints of what was likely to be the bush duiker (Sylvicapra grammia) and the Civet Cat (Civettictis civetta) were observed at the Upland Thicket 1. Only one House Bat (Scotophilus sp.) was captured compared to eight of the Flying Calves (Nanonycteris veldkampi). A straw coloured Fruit Bat (Eidolon helvum), a near threatened species was also observed.
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
Capture Data of Mammals in Different Habitats within the Akosombo Quarry Site (* indicates presence of species)
SMALL MAMMALS Conservation Trapping Number of individuals Order Family Common name Scientific name Total status method UT1 UT2 USB GWG FMD Mastomys Natal's multimammate 1 5 1 3 4 14 natalensis mouse LC Sherman 1 2 3 Mus minutoides Pygmy mouse LC Pitfall Leminiscomys Typical striped grass 1 3 4 striatus mouse LC Sherman Muridae Lophuromys 1 2 3 sikapusi Rusty-bellied rat LC Sherman Tullberg's soft-furred 2 2 Rodentia Praomys tullbergi rat LC Sherman Arvicanthis African grass rat/ Nile 1 1 niloticus rat LC Sherman Euxerus Striped ground 4 5 9 erythropus squirrel LC Sight Sciuridae Heliosciurus 1 1 gambianus Gambian sun squirrel LC Sight Cricetomys Giant Gambian 2 2 Nesomyidae gambianus pouched rat LC Sight Mist 1 1 Vespertilionidae Scotophilus sp. House bat LC netting Chiroptera Nanonycteris Mist 8 8 Pteropodidae veldkampi Flying calf LC netting Total 3 6 12 11 16 48 Number of trap nights 60 52 40 100 68 320 LARGE MAMMALS Common Number of individuals Order Family Scientific name Sign name UT1 UT2 USB GWG FMD Foot Carnivora Viverridae Civettictis civetta Civet cat prints * Foot Artiodactyla Bovidae Sylvicapra grammia Bush duiker prints *
Legend
UT1-Upland Thicket 1 USB-Upland Scrub FMD-Farmlands
UT2-Uplandd Thicket 2 GWG-Grassland/wooded grassland LC-Least Concern
Herpetofauna
Ninety-two individuals belonging to 10 families and 14 species were directly recorded in the entire study area with a Shannon-Wiener diversity index of 2.25. There were 73 amphibians belonging to six species and four families; Bufonidae, Ranidae, Petropedetidae and Arthroleptidae and 19 reptiles belonging to eight species and six families; Agamidae, Scincidae, Chamaeleonidae, Varanidae, Elapidae and Atractaspidae.
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
Also, there were four snake species belonging to three families; Pythonidae, African python (Python sebae) and Royal python (Python regius), Colubridae, Green tree snake (Philothamnus irregularis) and Elapidae, Green mamba (Dendroaspis viridis) that were not directly encountered but were deduced to be present based on the interviews of the locals in the area.
Species List and Distribution of Herpetofauna at the Akosombo Quarry Site
Only species directly recorded were included in calculation of diversity index.
Legend
Methods of Recording Species (MRS): H = Caught/Handled, C = Calls, Si = Sighted, I = Interview
National Protection Status (NPS): Sch. I = First Schedule, Sch. II = Second Schedule, Sch. III = Third Schedule, Sch. IV = Fourth Schedule, Sch. V = Fifth Schedule, NL = Not Listed. IUCN Status: LC = Least Concern
Natural Habitat (NH) of species: S = Savanna, F = Forest, FC = Forest Clearing (farm bush, degraded forest and forest edges)
Common NH Scientific Name Name Hills A B C D Lakeside TOTAL CS NPS MRS AMPHIBIA BUFONIDAE Amietophrynus Flat-backed S, maculates toad 0 4 3 2 1 0 10 LC NL Si, H FC Square- S, Amietophrynus marked FC regularis toad 0 7 5 1 2 0 15 LC NL Si, H RANIDAE Hoplobatrachus Crowned Si, S, occipitalis bullfrog 5 10 0 0 0 5 20 LC NL H, C FC Grassland S, Ptychadena sp. frogs 2 0 0 2 2 2 8 NL C FC PETROPEDETIDAE Phrynobatrachus Natal S natalensis puddle frog 0 0 0 3 4 8 15 LC NL C ARTHROLEPTIDAE Leptopelis viridis Rusty tree 0 0 0 0 0 5 5 LC NL C S
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
frog REPTILIA: LARCITILIA AGAMIDAE Rainbow S, Agama agama lizard 0 4 0 0 0 0 4 LC NL Si FC SCINCIDAE Trachylepis sp. Mabuya sp. 0 6 0 0 0 0 6 NL Si Orange- S, Trachylepis flanked FC perrotetti Mabuya 0 2 0 0 0 0 2 LC NL Si CHAMAELEONIDAE Graceful F, Chamaeleo gracilis Chameleon 0 0 0 1 0 0 1 NL Si, H FC VARANIDAE S, Nile FC, Varanus niloticus monitor 2 0 0 0 0 0 2 LC Sch.I Si F REPTILIA: SERPENTES ELAPIDAE Forest F, Naja melanoleuca cobra 0 0 0 1 0 0 1 LC Sch.V Si, H FC Spitting S, Naja nigricollis cobra 0 2 0 0 0 0 2 LC Sch.V Si, H FC ATRACTASPIDIDAE Burrowing Atractaspis sp. viper 1 0 0 0 0 0 1 LC Sch.V Si, H Total individuals 10 35 8 10 9 20 92 Total species 4 7 2 6 4 4 14 Shannon-Wiener Diversity Index 1.22 1.81 0.66 1.7 1.27 1.29 2.25 PYTHONIDAE
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
Royal S, Python regius python LC Sch.II I FC African S, Python sebae python LC Sch.II I FC COLUBRIDAE: COLUBRINAE Philothamnus Green tree S, irregularis snake LC NL I FC ELAPIDAE Green FC, Dendroaspis viridis mamba LC Sch.V I F
4.0 DISCUSSION
Insect have been studied extensively and are known to be good indicators of environmental quality (Saether 1979; Chovanec and Waringer, 2001; Schindler et al., 2003; Chovanec et al., 2004; Smith et al., 2006; Takahashi et al., 2008).Most butterflies were recorded in open areas and flying high over grass fields and bushes. Most of the high fliers such as the Papilio spp and the Catopsila spp were recorded in these open areas as well.
Dragonflies (Anisoptera) were also recorded mostly in open areas and none of those recorded were of conservation concern. As is typical, large numbers of dragonflies were captured in the grassland areas along the Volta River close to the quarry site. A few species found the temporary pond created by excavation on the site conducive hence it served as a breeding pond for species like Palpopleura lucia, Bradynogya strachani and Orthetrum julia. Though these species are generalists, they serve as immediate indicators of the little level of contamination in this pond as they showed some breeding signs. This indicates the ability to attract odonates as primary colonizers of pit ponds to be created during and after operations.
The 59 different species of birds seen in and around the Akosombo quarry site, though being of Least Concern in terms of conservation importance form an important component of the area’s biodiversity. These birds occurrence in the area are based on the vegetation, the lake shore and the various land use. This diversity may either increase or decrease as active quarrying begins, this is as a result of the change in habitat that would take place.
The monitoring of these changes in bird diversity would be indicative of the environmental condition of the site, hence the importance of this baseline. The indicative potential of bird diversity monitoring is highest if the data is collected over many years and can give a measure of
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
impacts over larger areas. As the site is very small bird diversity would not provide a very good indicative measure of impact.
However in order to protect bird diversity during the extraction period it would be best not to clear vegetation in areas that are not being used. These areas should be left to grow naturally, for use by the birds and other fauna. They could be reserved as biodiversity plots within the concession area. Tree planting with preferably indigenous species around the area would greatly improve the bird diversity by creating suitable habitat for use by the birds.
Since the survey was carried out in a portion of the rainy season it is most likely that during the minor raining season more birds would utilize the area, most especially Palearctic migrants. The Palearctic migrants are very important, in that they migrate from Europe to overwinter in Sub- Saharan Africa, Ghana being one of the areas. Their populations have been on the decline and this has been attributed to habitat loss within the wintering grounds. Thus protecting the habitat would be of great importance to the Palearactic migrants.
None of the mammalian species captured seemed to be out of place. All the species caught are those species one would expect to find in such a degraded environment. All the rodents depict the habitat type in which they were captured. The mist nets were set close to a pond, which implied that the parts were coming to drink of its water after feeding. Upland Thicket 1 is the habitat that may harbour quite a number of species. Its thicket was impenetrable compared to the other and had disturbance from the use of machines far from it. It may therefore harbour more species than was realized. In general, the entire habitat looked disturbed and quite unfavourable to sensitive species.
Based on the IUCN Red List of Threatened species, all the herpetofaunal species found within the site are of Least Concern. However, nationally, three species; one lizard, V. niloticus and two snakes, P. sebae and P. regius are protected. The former, V. niloticus is fully protected under the First Schedule whiles the two pythons deduced to be present in the area based on interviews with the locals, are partially protected under the Second Schedule.
This baseline survey recorded 6 amphibians which falls short of the range recorded in some of forest surveys undertaken in Ghana. This baseline survey has established based on the percentage of savanna herpetofaunal species (77.8%) as against forest herpetofaunal species (11%) that, before the mining by Ghacem, the area is more of savanna than a forest. Any change in the habitat structure in the course of mining is expected to show in the changes that would occur in the composition of savanna and forest herpetofauna of the area. For instance, if more pools or puddles are created which support short grasses more of Phrynobatrachus spp would occur (Rodel et al., 2004). Also, more ponds created by mining would support more Hoplobatrachus occipitalis.
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
This is not to say that, mining the area would only create avenues for more species, consequently, some existing habitat structures would be destroyed and species living exclusively in such habitats would be lost. For instance, while many reptiles and amphibians thrive in human-disturbed areas, others are restricted to specific microhabitats and do not persist in the face of habitat destruction. Given this setting, preserving sensitive habitats is the most effective method of conserving reptiles and amphibians (Leache et al., 2006). In particular, the forest habitats (in this case the secondary forest/thicket on the Hills: northside) and specifically the riparian vegetation bordering streams and rivers are sensitive areas (in this case the edge of the Lake). Some frogs appear to inhabit and breed exclusively in these areas (e.g., Hyperolius torrentis, Phrynobatrachus plicatus, Amnirana albolabris, and Leptopelis hyloides: none of which was recorded in the study area). It is assumed that these species once had widespread distributions throughout some parts of Ghana but habitat modification nearly eliminated them from many areas (Leache et al., 2006).
In summary the site has a fair representation of faunal diversity in consonance with its prevailing habitat condition. It does not have species of major conservation significance but the uphill thickets seem to serve as refugia for the fauna within the area. The areas around the stream bank and the Volta Lake are important for amphibians and Odonates, and as such any activity occurring around these areas should be done cautiously so as not to destroy this habitat. The amphibians and odonates would therefore be better placed as indicators for monitoring when compared to the birds, reptiles and mammals.
An in-depth description of floral diversity and ecological mapping was not done due to the intensive nature of the faunal survey and the area’s apparent highly degraded nature. The site had fallow lands, farm lands and a few scattered Neem trees, Ceiba pentandra and an Acacia plantation on the fringes of the concession. The size of the area was very small hence our inability to do the ecological mapping. However the study identified the stream bank, lake shore and the uphill thickets as zones for conservation action.
5.0 CONCLUSIONS
The study of the Akosombo quarry site recorded 16 orders of insects belonging to 103 families, 59 species of birds (which are of Least Concern on the IUCN Redlist), 12 species of mammals, 6 species of amphibians and 8 species of reptiles. The faunal diversity conforms to the degraded secondary vegetation of the area. Nationally, three species; one lizard, V. niloticus and two snakes, P. sebae and P. regius are protected. The former, V. niloticus is fully protected under the First Schedule whiles the two pythons deduced to be present in the area based on interviews with the locals, are partially protected under the Second Schedule.
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
The lake shore, stream bank and the uphill thickets are zones of ecological concern as they are preferred habitats for amphibians and Odonate’s and serve as refugia for fauna respectively within the concession.
6.0 RECOMMENDATIONS It is also recommended that a complete yearly faunal survey be carried out. These surveys should be done to cover both dry and wet season. Quarterly monitoring of the amphibians should be carried out throughout the life cycle of the quarry as vicissitudes to serve as early warning signals of habitat change. The amphibian diversity recorded in any future survey after commencement of quarrying will not only inform management about the direct effect of the quarrying on the vegetation but its attendant effect on amphibian species.
The population of insects’ taxa in general and specifically of the Orders: Odonata, Lepidoptera, Diptera and Coleoptera should be assessed and monitored since the large number of butterfly species recorded is an indicator of a high diversity of plant species whereas dung beetles (Scarabaeidae) are also good biological indicators. Their presence indicates the presence of large mammals. Though just a few were recorded during the survey probably due to the rains, their presence indicates that there are large mammals on the quarry site. The Chironomids in the family Chironomidae are very good indicators of water quality. Their numbers indicate the extent to which a water body is polluted. Large numbers of Chironomids indicate that a water body is much polluted and vice versa. However only six Chironomids were recorded during the survey and their populations when monitored can be used as first levels of indicators of the quality of the Volta River. Odonates are also known as good indicators of water and its related ecotones quality, however, they can be used as early indicators of contamination of the water body adjacent the quarry. There is a need therefore to monitor their assemblages to enable their use as indicators. Some Dragonfly species (Palpopleura lucia, Bradynogya strachani, Orthetrum Julia) serve as early colonizers of water habitats hence an indication of a possible increase in biodiversity during and after quarrying not ignoring the possibility of a loss as well. This indicates the possibility of having Odonates as primary colonizers of pit ponds to be created during and after operations.
If extraction would not be carried out on the uphill tickets, it is recommended that they be allowed to grow naturally to enhance their function as refugia. They could be designated as biodiversity plots. It is also recommended that tree planting be encouraged in areas of the concession where there is no active work going on as well as in the surrounding communities. 15
Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
This would go a long way to improve the degraded habitat, but as much as possible indigenous species should be used for the tree planting.
If the biodiversity plots idea is used, it could be further developed as learning tool for children in the surrounding communities to learn about biodiversity. This can be achieved by establishing wildlife clubs in the schools. Additionally, Ghacem should embark on a ‘Biodiversityclinic’ program. This should include regular visits by 1st and 2nd cycle school students to the biodiversity plots. These visits will be used to teach them practically the importance of biodiversity.
REFERENCES
AMPHIBIAWEB (2009). Worldwide Amphibian Declines: How big is the problem, what are the causes and what can be done? URL: [amphibiaweb.org/declines/declines.html] Chovanec A. and Waringer, J. (2001). Ecological integrity of river-floodplain systems- assessment by dragonfly surveys (Insecta: Odonata). Regul. River, 17 (4-5): 493-507. Chovanec, A., Waringer, J., Rajj, R., and Laister, G. (2004). Lateral connectivity of a fragmented large river system: assessment on a macroscale by dragonfly surveys (Insecta: Odonata). Aquatic Conservation – Marine and Freshwater Ecosystems 14, 163– 178. Davies, G. and Howell, K. (2004). Small Mammals: Bats, Rodents and Insectivores. In: African Forest Biodiversity, (G. Davies and K. Howell, Eds.) Earthwatch Institute, UK. Happold, D. C. D. (1979). Age structure of a population of Praomys tullbergi (Muridae, Rodentia) in Nigerian Rainforests. Revue d’Ecologie: La Terre et la Vie, 33: 253-274. Heyer, W. R., Donnelly, M. A., McDiarmid, R. W., Hayek, L.-A. C., and Kent, M. S. (1994). Measuring and Monitoring Biological Diversity: standard methods for amphibians. Smithsonian Institution Press, Washington, DC. 364 p. Hillers, A. and M.-O. Rödel (2007): The amphibians of three National Forests in Liberia, West Africa. Salamandra 43: 1-10. Hughes, B. (1988). Herpetology of Ghana (West Africa). British Herpetological Society Bulletin,. 25:29-38 Kingdon, J. (2004). The Kingdon Field Giude to African Mammals. Academic Press/Harcourt Brace, San Diego, U. S. A. Leaché, A.D., M.-O. Rödel, C.W. Linkem, R.E. Diaz, A. Hillers, and M.K. Fujita (2006). Biodiversity in a forest island: Reptiles and amphibians of the West African Togo Hills. Amphibian and Reptile Conservation 4:22-45.
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Malcom, J. R. and Ray, J. C. (2000). The influence of timber extraction routes on central African small-mammal communities, Forest Structure and Tree Diversity. Conservation Biology, 14: 1623-1638. Natural Resource Conservation Services (NRCS) (2006). Amphibians and Reptiles: Fish and Wildlife Habitat Management Leaflet, No. 35,Wildlife Habitat Council Orr, T.R. (1982). Vertebrate Biology. (5th Edition). Saunders, California, USA, pp: 103 – 124 Rödel, M-O., Msuya C. A., Pickersgill M., Minter L., Largen M. J., and Lötters S. (2004). Phrynobatrachus natalensis. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.1.
Takahashi, M. A., Higuti, J., Bagatini, Y. M., Zviejkovski, I. P. and Velho, L. F. M. (2008). Composition and biomass of larval chironomid (Insecta, Diptera) as potential indicator of trophic conditions in southern Brazil reservoirs. Acta Limnol. Bras., 20 (1): 5-13.
Appendix 1
Families and species of butterflies and Odonata caught or encountered during the field study.
FAMILY SPECIES ABUNDANCE NYMPHALIDAE Euryphene barombyna 1 Euphaedra sarcoptera 3
Euphaedra medon 2
Euphaedra xypete 1
Eurytela dryope 3
Pseudoacrea sp. 2
Diestogina feronia 1
Neptis melicerta 6
Neptis Agatha 3
Neptis metella 4
Neptis merosa 2
Hamanumida daclalus 5
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
Junonia terea 5
Junonia oenone 3
Junonia Octavia 2
Phalanta phalanta 4
Ariadne enotera 2
Aterica galena 1
Byblia achelola 4
Byblia sp. 1
Hypolimnas salmacis 18
Hypolimnas missipus 12
Hypolimnas dinarcha 9
ACRAEDAE Acraea epaea 6 Acraea zetes 58
Acraea Terpsichore 5
Acraea sp. 2
Bematistis epaea 8
SATYRIDAE Bicyclus zinebi 5 Bicyclus safitza 3
Mycalensis safitza 2
PAPILIONIDAE Papilio demodocus 14 Papilio nireus 1
Graphium policenes 3
DANIDAE Amauris niavus 12 Amauris egialea 8
Amauris sp. 2
Danaus chryssipus 54
Danaus limniace 11
PIERIDAE Eurema brigitta 39 Eurema senegalensis 7
Eurema hecabe 32
Eurema lisa 5
Eurema sp. 2
Colias philodice 2
Pieris rapae 8
Pieris sp. 3
Nepheronia thalassina 78
Nepheronia argia 29
Nepheronia sp 11
Leptosia alcesta 5
Leptosia medusa 3
Leptosia sp. 1
Appias phaola 3
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Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
Dixeia Astarte 5
Colotis erone 37
Colotis danae 15
Colotis evippe 29
Colotis antevippe 53
Colotis eunoma 17
Anthocharis cardamine 8
Belinois calypso 58
Belinois creona 36
Belinois theora 28
Belinois gidica 9
Belinois aurota 13
Belinois theuszi 7
Catopsilla florella 29
Catopsilla sp. 14
Mylothris chloris 24
Mylothris poppea 5
Mylothris sp. 2
Mylothris rhodope 8
CHARAXIDAE Charaxes varanes 1 LYCAENIDAE Castalius carana 3 Lycaena helloides 5
Meza indusiata 2
Euchrysops albistriata 6
Osmodes adon 1
Spalgis lemolea 2
HESPERIDAE Pyrrhiades lucagus 69 Lerodea sp. 1
Hesperia leonardus 8
Hesperia sp. 2
Appendix 2
ABUNDANCE OF INSECT ORDERS RECORDED FROM THE VARIOUS TRAPS
ORDER FIT MALAISE TRAP YELLOW PAN TRAP CHARAXES PITFALL TRAP SWEEP NET Orthoptera 10 3 5 2 27 7 Hymenoptera 16 19 36 15 28 15 Dictyoptera 3 1 0 0 3 0 Lepidoptera 4 11 0 10 0 7 Isoptera 0 0 0 0 3 0 Homoptera 14 15 6 0 10 8 Collembola 12 3 2 0 6 0 19
Impacts Of Quarrying On Biodiversity:: Setting The Basis For Assessment At Akosombo Quarry 2012
Diptera 116 108 46 122 8 40 Coleoptera 13 6 10 88 8 16 Trichoptera 2 3 3 0 0 0 Thysanoptera 3 4 3 0 2 2 Dermaptera 1 1 0 0 2 0 Hemiptera 6 2 8 0 5 16 Neuroptera 0 0 0 0 0 1 Phasmida 0 0 0 0 0 1
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