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ZOOLOGY 300 RESEARCH PROJECTS ON OFFER 2016 1. Microplastics Microplastics, small plastic particles with an upper size limit of 5 mm, may have “potential ecological and human health risks” when associated with marine organisms. For example, they may become vectors for the transportation of toxic chemicals, originating from either the plastic item (additives, monomers and by-products) or the surrounding marine environment (persistent organic pollutants). Thus, when ingested by various fauna, there is a potential for toxic compounds to bio-magnify through the food-web. Although investigations into the extent and effect of microplastic pollution have increased dramatically, knowledge is still scarce, including the impact these microplastics may have on human health and food consumption. A recent study conducted at Rhodes University investigated the extent of microplastic pollution along the south eastern coast of South Africa. Results from this study suggest microplastic pollution along the South African coast is in the same range as more developed countries in the Northern Hemisphere. In addition, this study highlighted that microfibres represent a significant source of pollution, possibly originating from the breakdown of synthetic garments during the washing process. This study served as the first step, which is to identify and evaluate the extent of the problem. Thus, the next step will be to investigated the effect this problem may have on marine organisms, especially economically important species consumed by the South African population. o Title: Impact of sampling method and spatial heterogeneity on microplastic densities on two South African beaches. o Title: The extent of microplastic contamination in the tissue of the alien and native mussel, Mytilus galloprovincialis and Perna perna respectively. Supervisor: Dr H.A. Nel and Co-supervisor: Prof. P.W. Froneman 2. Ephemeral pond ecology Ephemeral ponds are an essential habitat for a number of unique invertebrates and amphibians and represent important foraging grounds for a variety of birds (O’Niell and Thorp 2014). Many of these systems are often ecologically degraded due to land use activities, mainly commercial agriculture, and freshwater abstraction. Despite their ecological importance, for the greater majority of these systems we have a poor understanding of their ecosystem functioning. Studies conducted in the northern hemisphere, however, indicate that the food web dynamics within these systems are strongly linked to the hydroperiod (wet/dry phase), dimension/volume of pond and the diversity of invertebrates within these systems (O’Niell and Thorp 2014). Overall, larger ponds with high insect diversity are characterized by more complex trophic structures than those systems dominated by crustaceans (O’Niell and Thorp 2014). The proposed research project will assess the temporal variability in selected physicochemical and biological variables in three ephemeral ponds in the immediate vicinity of Grahamstown. Physico-chemical samples will be collected using a portable probe and biological samples using nets. Sampling will be conducted on a monthly basis to assess the link between the hydroperiod and the food web structure of these systems. Two projects are on offer. References O’Niell BJ, Thorp JH (2014). Untangling food-web structure in an ephemeral ecosystem. Freshwater Biology 59: 1462-1473 Supervisors: Professor PW Froneman and Mr T Dalu 3. Ecosystem engineers The sand prawn Calianassa kraussi has been identified as an important systems engineer within temporarily open/closed estuaries. Bioturbation generated by the sand prawn contributes to decreased biomass of both the microphytobenthic algae and epifauna. This project will investigate the influence of the sand prawn burrowing activities on the macrobenthic community structure within a temporarily open/closed Eastern Cape estuary during summer and winter. Two projects are on offer Supervisor: Prof PW Froneman 4. Macrobenthic community structure in a freshwater deprived estuary. Long term data sets on the spatial and temporal patterns in the invertebrate faunal community structure in southern African estuaries are lacking. This study will investigate the spatial patterns in the macrofauna within four different soft sediment estuarine habitats within the permanently open Kariega Estuary situated along the Eastern Cape coastline. Data collected during the present study will be compared to a similar study conducted within the estuary two decades previously. Two projects are on offer Supervisor: Prof PW Froneman THIRD YEAR (Zoology or Entomology): 1. Frog predation on the biocontrol agent, the flea beetle Lysathia sp. (Coleoptera: Chrysomelidae), released against the Parrot's Feather (Myriophyllum aquaticum) Biocontrol agents are released against various invasive plants, and for the agent to be effective, they need to eventually cause the plant to die, through their herbivorous actions, whilst avoiding predators. In some instances, although the agent has been found to be effective in laboratory conditions, natural conditions present the agents with novel problems. Frogs are prolific predators on invertebrates in the natural environment and this study aims to investigate whether the presence of the painted reed frog Hyperolius marmoratus verrucosus significantly reduces the population numbers of the biocontrol agent, the flea beetle Lysathia sp. (Coleoptera: Chrysomelidae), released against the Parrot's Feather (Myriophyllum aquaticum). Proposed methods Controlled environment experiments will be conducted with four experimental setups: (1) With three adult H. m. verrucosus and the biocontrol agent, (2) with three subadult H. m. verrucosus and the biocontrol agent, (3) only the biocontrol agent, (4) no biocontrol agent or frogs (control setup). Beetle population numbers will be counted after two weeks, and analyses of the effect of frog predation on the population numbers will be determined. References Du Preez, L. H., Carruthers, V., & Burger, M. (2009). A complete guide to the frogs of southern Africa. Struik Nature. Snyder, W. E., & Ives, A. R. (2001). Generalist predators disrupt biological control by a specialist parasitoid. Ecology, 82(3), 705-716. 5. Snake diversity is lower in fields that have been burned recently compared to an unburned area. (Luke Kemp has already taken this project) Globally, reptile population numbers have been declining, reminiscent of the recent decline in amphibian populations. An understanding of the factors that lead to population declines in reptiles is crucial to mitigate future declines. Diversity and abundance of animals have been shown to be reduced when a habitat has been burned. In fire-prone biomes such as the fynbos biome and the grassland biome, populations of reptiles experience periodic fires that destroy the habitat, including the predatory snake species. However, the ultimate reason for the low abundance in predators may be not entirely due to the lack of shelter in a burned area, but may be due to the low abundance of prey items. Snakes locally found in the Grahamstown area are either carnivorous, feeding on rodents and frogs, or are specialised eggeaters. In a burned area, we expect that the snake diversity in a burned area will be lower than in an unburned area, due to the low abundance of prey items. Proposed methods o Snake diversity and abundance will be measured through collection using pitfall traps during the months of November 2015 to April 2016, and a correlation between time since the burn and abundance will be investigated. o Comparative abundance of snakes in burned and unburned fields will be investigated. References Gibbons J.W., Poppy S., Winne C. T. et al. (2000) The global decline of reptiles, déjà vu amphibians. Bioscience 50, 653–66. Gorissen S., Mallinson J., Greenless M., Shine R. (2015) The impact of fire regimes on populations of an endangered lizard in montane south-eastern Australia. Austral Ecology. 40(2): 170-177 Supervisor: Dr Shelley Edwards (SE), Office S19, Biological Sciences Building, Email: [email protected]; Tel: 046-603-8086 6. Convergence in the angularity of snouts in burrowing reptiles In an arid region, such as southern Africa, many lizards and snakes have adapted to sheltering in soil to escape predators or the heat of the day. Many reptiles dive headfirst into the soil, instead of digging their way in, and as such have evolved unique, shovel-shaped snouts to facilitate entry into the substrate. Due to the resistance of the soil particles, it is hypothesized that the angle of the snout would be optimally effective in a range of between 45° and 60°. This project aims to investigate whether there is a similarity in the angle of the snout of various burrowing lizards, and therefore to show that reptiles have evolved convergent morphologies in response to the same selective pressure. Proposed methods o Ten species of borrowing or diving reptiles will be used, namely Meroles anchietae, Meroles cuneirostris, Acontias meleagris, Acontias gracilicauda, Prosymna sundervallii, Prosymna bivittata, Gerrhosaurus skoogi, Typhlacontias sp., Scelotes anguineus, Scelotes bipes. o Photographs of five individuals of each species will taken at the Bayworld museum in Port Elizabeth. Angles of the snouts will be measured on the photographs and statistics will be used to investigate the convergence of angles between species. References Hanken, J. (1993). The skull, volume 3: Functional and evolutionary mechanisms (Vol. 3). University of Chicago Press. Etheridge, R. (2000). A review of lizards of the Liolaemus wiegmannii group (Squamata, Iguania, Tropiduridae), and a history of morphological change in the sanddwelling species. Herpetological Monographs, 293-352. Supervisor: Dr Shelley Edwards (SE), Office S19, Biological Sciences Building, Email: [email protected]; Tel: 046-603-8086 7. Painted reed frog Hyperolius marmoratus verrusosus (Hyperoliidae) abundance and distribution around Grahamstown is tied to particular habitats The Painted reed frog Hyperolius marmoratus verrusosus is a relatively common species occurring along the coastal regions of the Eastern Cape and Western Cape Provinces. It is often found around water bodies, sheltering amongst reeds. However, as the Eastern Cape is a region that receives rainfall year-round, as opposed to the winter-rainfall regime of the Western Cape, ephemeral puddles and water bodies are often formed in vegetation in the Eastern Cape. The frogs may be utilising these nonpermanent water bodies, as well other types of vegetation (such as arum lilies) for shelter. This project aims to investigate the habitats that the painted reed frogs are associated with in the Grahamstown area, and to estimate the density of frogs in various types of habitats, at various times of the year. Proposed methods o Frog calls will be recorded at various points around Grahamstown during twilight and early evening times for a period of three months. In addition, information on the weather preceding, and during, sample days will be noted. The particulars of the habitat at each sample site will be recorded. o Frog density will be determined through identification of number of frogs calling at a particular location. o Frog density (i.e. number of frogs calling) will be correlated with habitat characteristics, as well as with climatic (weather) characteristics. References Du Preez, L. H., Carruthers, V., & Burger, M. (2009). A complete guide to the frogs of southern Africa. Struik Nature. Pellet, J., & Schmidt, B. R. (2005). Monitoring distributions using call surveys: estimating site occupancy, detection probabilities and inferring absence. Biological Conservation, 123(1), 27-35. Pierce, B. A., & Gutzwiller, K. J. (2004). Auditory sampling of frogs: detection efficiency in relation to survey duration. Journal of Herpetology, 38(4), 495-500. Please note that similar projects can be offered to investigate the density of other frogs such as the raucous toad (Amietophrynus rangeri), bronze caco (Cacosternum nanum), and Boettger’s caco (Cacosternum boettgeri). Supervisor: Dr Shelley Edwards (SE), Office S19, Biological Sciences Building, Email: [email protected]; Tel: 046-603-8086 Zoology 3 2016 Note: Students are encouraged to bring their own ideas for projects; however, all students must do some reading around any potential project prior to booking an appointment with a potential supervisor to discuss topic selection. 1. Intertidal amphipods of the Eastern Cape Supervisor: Nicole Richoux A variety of amphipods flourish in the intertidal region of the rocky shore, as they can utilise the macroalgae as food and/or shelter. Students can design questions to investigate amphipod ecology at different sites in the Eastern Cape. Starter references Buschmann (1990) Intertidal macroalgae as refuge and food for Amphipoda in central Chile. Aquatic Botany 36:237-245 Chavanich and Wilson (2000) Rocky intertidal zonation of gammaridean amphipods in Long Island Sound, Connecticut. Crustaceana 73:835-846 Skadsheim (1983) The ecology of intertidal amphipods in the Oslofjord. Distribution and responses to physical factors. Crustaceana 44: 225-244 2. Organic content of the fecal pellets of estuarine consumers Supervisor: Nicole Richoux Aquatic invertebrates represent important vehicles for the uptake and transformation of energy and nutrients. For example, the production of fecal pellets can represent an enormous transfer of organic material from the water column to the benthos over short temporal scales. This flux of material, in turn, has important ramifications for the availability and quality of food in the benthos, but limited information exists for shallow coastal systems. In this study, a student can carry out field collections of different estuarine organisms with the intention of collecting naturally produced fecal pellets. These samples will be analysed for their organic contents to assess the contribution and quality of detritus settling to the benthos in estuarine systems. Starter references Turner (2002). Zooplankton fecal pellets, marine snow and sinking phytoplankton blooms. Aquatic Microbial Ecology 27:57-102 Wotton and Malmqvist (2001). Feces in aquatic ecosystems. BioScience 51:537-544 3. Temporal variability of suspended particulate material over a tidal cycle Supervisor: Nicole Richoux Various marine invertebrates are dependent on suspended particulate material (SPM) as their food source. Because their physical environment changes extensively through time, particularly over tidal cycles, animals are subject to rapid changes in the quality of their food sources. In this study, students will determine changes in SPM characteristics during a tidal cycle. Potential measurements to be taken include: chlorophyll a concentrations, dry mass, organic content, inorganic content and possibly stable isotope ratios (if funding permits). Starter references: Bodineau, L., Thoumelin, VB & Wartel, M (1998). Tidal time-scale changes in the composition of particulate organic matter within the estuarine turbidity maximum zone in the macrotidal Seine Estuary, France: the use of fatty acid and sterol biomakers. Eastuarine, Coastal & Shelf Science 47: 37-49. Danovaro, R & Fabiano, M (1997). Seasonal changes in quality and quantity of food available for benthic suspension-feeders in the Golfo Marconi (north-western Mediterranean). Eastuarine, Coastal &l Shelf Science 44: 723-736. 4. Faunal diversity associated with rocky shore macroalgae, mussel beds and/or polychaete beds Supervisor: Nicole Richoux Some organisms represent important habitat for other organisms. Rocky shore macroalgae, mussels and tube-building polychaetes represent a few potential habitats for organisms. Students will assess the biodiversity associated with each of these habitats. Starter references Koivisto ME, Westerbom M (2010) Habitat structure and complexity as determinants of biodiversity in blue mussel beds on sublittoral rocky shores. Mar Biol 157:1463–1474 Lintas, C. and Seed, R. (1994) Spatial variation in the fauna associated with Mytilus edulis on a wave-exposed rocky shore. Journal of Molluscan Studies, 60, 165–174. 5. Drifting components in a river/estuary continuum Supervisor: Nicole Richoux A variety of organic and inorganic material is transported through rivers and estuaries. Students will design a field study to quantify the nature and amount of drift transported through a river. Starter references Shannon et al. 1996. Organic drift in a regulated desert river. Can. J. Fish. Aquat. Sci. 53:11360-1369 Eckblad et al. 1984. Allochthonous drift from backwaters to the main channel of the Mississippi River. American Midland Naturalist 111(1): 16-22 Andersson E, Nilsson C 2002. Temporal variation in the drift of plant litter and propagules in a small boreal river. Freshwater Biology 47:1674–1684 6. Life in the intertidal – does vertical position in the rocky intertidal affect the condition of grazing or suspension-feeding invertebrates Supervisor: Nicole Richoux The rocky shore is a highly variable environment inhabited by a variety of invertebrate species. Tidal changes are key structuring features for the physiology and ecology of these organisms. A student will design a study to investigate the effects of vertical position on the condition (e.g. using condition factors, gonado-somatic index, morphology, etc.) of several species of interest. Starter reference: Gagné F, Burgeot T, Hellou J, St-Jean S, Farcy É, Blaise C (2008) Spatial variations in biomarkers of Mytilus edulis mussels at four polluted regions spanning the Northern Hemisphere. Environmental Research 107:201–217 Zoology 3 Projects: Supervisor Prof. A. Craig Fiscal Shrike territorial behaviour For several years we have monitored Fiscal Shrike territories on the campus. Although the birds change, territory sites tend to remain constant. Colour-ringed individual birds can be observed throughout the year; males and females show differences in their defence of the territory. Birds will be caught and ringed where needed. Two students can be involved in this project. Soobramoney, S, Downs, CT, Adams, NJ. 2004. Territorial behaviour and time budgets of the fiscal shrike Lanius collaris along an altitudinal gradient in South Africa. African Zoology 39: 137-143. Birds at nectar feeders At several households in Grahamstown, nectar feeders are in regular use. Provision of extra food for wild birds may make them dependent on these food sources, changing their distribution and foraging patterns. Camera traps and ringing can be used to clarify how regularly individual birds visit a particular site. Two students can be involved in this project. Brockmeyer, T, Schaefer, HM. 2012. Do nectar feeders in Andean nature reserves affect flower visitation by hummingbirds? Basic and Applied Ecology 13: 294-300. Birds at garden feeders Seed (and often bread, sometimes also fruit) are provided regularly at many homes. As with nectar feeders, this may make birds dependent on these food sources. Camera traps and ringing can be used to clarify how regularly individual birds visit a particular site. Two students can be involved in this project. Galbraith, JA, Beggs, JR, Jones, DN, Stanley, MC. 2015. Supplementary feeding restructures urban bird communities. Proceedings of the National Academy of Sciences E2648-2657 Supervisor: Prof A Hodgson Distribution, density and population structure of the Shaggy Sea Hare Bursatella leachii (Gastropoda) in the Knysna Estuary (This project can be undertaken by up to two students) The shaggy sea hare is a shell-less mollusc that appears to be particularly abundant in the Knysna Estuary. Furthermore, preliminary investigations have revealed that it is present throughout the year. Because of its abundance it is possible that it plays an important role in the ecology of the estuary. As a first step towards studying the biology of this species it is necessary to determine some basic information on this gastropod. The aims of this project, therefore, are to record the density of this sea hare at different sites within the Knysna estuary and by measuring specimens also look at its population size structure. Note: this project will require the ability to snorkel in shallow water and therefore student should have their own snorkelling equipment and a wet suit. The dining habits of the Shaggy Sea Hare Bursatella leachii (Gastropoda) The shaggy sea hare can be found roaming over soft sediment and algae. They are said to be algal grazers, but it is not known for certain. The aim of this project would be to use gut contents analysis, faecal analysis and perhaps stable carbon isotope ratios to determine what these gastropod molluscs are actually feeding on. Distribution, density and population structure of the invasive gastropod snail Myosotella myosotis (Mollusca: Ellobiidae) in the Knysna Estuary (A project for up to two students) Myosotella myosotis is a snail found in salt marsh vegetation of estuaries. Herbert (2012) records it presence in the Knysna estuary which is part of the Garden Route National Park. Casual observations (Hodgson pers. obs.) suggest that it is very abundant but there is no quantitative data on its density, population structure and distribution within the intertidal and within the estuary. The aims of this project are to provide some fundamental data on this snail within the salt marshes of the Knysna estuary. It may also be possible to establish a laboratory population to determine growth rate and fecundity. Lead-in Reference Herbert, D.G. 2012. Myosotella myosotis (Mollusca: Ellobiidae) - an overlooked but well-established introduced species in South Africa. African Journal of Marine Science 34(3): 459-464.