Research Articles (Biodiversity and Conservation Biology)

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p-Coumaric acid differential alters the ion-omics profile of chia shoots under salt stress
(MDPI, 2024) Badiwe, Mihlali; Nkomo, Mbukeni; Niekerk, Lee-Ann
p-Coumaric acid (p-CA) is a phenolic compound that plays a crucial role in mediating multiple signaling pathways. It serves as a defense strategy against plant wounding and is also presumed to play a role in plant development and lignin biosynthesis. This study aimed to investigate the physiological and ionomic effect of p-CA on chia seedlings under salt stress. To this end, chia seedlings were supplemented with Nitrosol® containing 100 μM of p-CA, 100 of mM NaCI, and their combined (100 mM NaCI + 100 μM p-CA) solutions in 2-day intervals for a period of 14 days along with a control containing Nitrosol® only. The treatment of chia seedlings with 100 mM of NaCI decreased their growth parameters and the content of the majority of the essential macro-elements (K, P, Ca, and Mg), except for that of sodium (Na). The simultaneous application of p-CA and a salt stress treatment (p-CA + NaCI) alleviated the effect of salt stress on chia seedlings’ shoots, and this was indicated by the increase in chia biomass. Furthermore, this combined treatment significantly enhanced the levels of the essential microelements Mg and Ca. In summary, this brief report is built on the foundational work of our previous study, which demonstrated that p-CA promotes growth in chia seedlings via activation of O2 −. In this brief report, we further show that p-CA not only promotes growth but also mitigates the effects of salt stress on chia seedlings. This mitigation effect may result from the presence of Mg and Ca, which are vital nutrients involved in regulating metabolic pathways, enzyme activity, and amino acid synthesis.
Kelp holdfasts in the Great African Seaforest provide habitat for diverse assemblages of macroinvertebrates
(Inter-Research, 2024) Samaai, Toufiek; Katharoyan, Chaitanya; Peer, Nasreen
Kelp forests along the southwestern and west coasts of South Africa, dominated by the species Ecklonia maxima and Laminaria pallida, are locally termed ‘the Great African Seaforest’. They form 3-dimensional biogenic habitats that provide 4 distinct microhabitats—canopy, fronds, stipe and holdfast—with the latter typically supporting the highest abundance and diversity of associated macroinvertebrates. The macrofauna inhabiting kelp holdfasts in South Africa have rarely been studied, resulting in a near complete lack of baseline data. In this study, macrobenthic assemblages from 40 E. maxima holdfasts were examined over 2 marine ecoregions and 4 locations. Macroinvertebrates were identified and counted for univariate and multivariate analyses using family-level data. A total of 120 families from 9 phyla were identified and were generally dominated by Arthropoda (48 families), Annelida (24 families) and Mollusca (23 families). Marine ecoregion had no significant effect on composition of macroinvertebrate assemblages, whereas location had a significant effect. There was no significant relationship between holdfast volume and macroinvertebrate diversity or abundance, suggesting that other environmental and physicochemical factors are important in determining community structure. This study serves as a baseline for future research aimed at understudied holdfast macroinvertebrate communities in the Great African Seaforest.
A complete guide to the snakes of Southern Africa
(African Journal of Herpetology, 2023) Maritz, Bryan
Background: The new edition of A Complete Guide to the Snakes of Southern Africa represents the third iteration in a series of books that started three decades ago. The latest edition replaces the 2004 edition (Marais Citation2004)—an excellent book in its own right (Bauer Citation2004). In the nearly two decades since the last edition, there have been several important advances in the study of snakes in southern Africa. These include changes in systematics and the description of new species, a substantial formalisation of conservation assessment processes, and the remarkable growth of citizen/community science platforms that have improved the quantity and quality of geographic distribution data and natural history information
Nitrogen fertilization increases the growth and nutritional quality of the forage legume, calobota sericea – A preliminary investigation
(Heliyon, 2023) Britz, Ethan; Cyster, Lilburne; Samuels, Igshaan; Clement, Cupido
Calobota sericea is being evaluated as a forage for drought stressed areas. The nutritional quality of C. sericea from native populations are poor, and this is believed to be due to poor soil fertility. Therefore, a greenhouse trial was established to determine the impact of N-fertilization level (0, 25, 50, 75 and 100 kg/ha) on the growth and nutritional quality of C. sericea plants. Three-month-old plants were harvested and the root and shoot length, as well as branching intensity on each plant determined. Thereafter, the shoots were separated into leaves and stems and all plant parts were oven dried for dry mass determination. After weighing, the leaves and stems for each plant were combined and the dried shoots used for nutrient determination.
Taxonomy of the small southern African endemic genus Echiostachys Levyns (Boraginaceae: Boraginoideae)
(South African Journal of Botany, 2023) Velani, N; Boatwright, J.S; Magee, A.R
The small genus Echiostachys Levyns (Boraginaceae: Lithospermeae) is revised. It was segregated from Lobostemon Lehm. on the basis of the herbaceous habit, radical foliage, spiciform inflorescence, slightly accrescent calyx, and lack of staminal scales. Three species are recognised. An identification key, descriptions, full nomenclature, illustrations, and distribution maps are provided.
Stakeholder-derived recommendations and actions to support deep-reef conservation in the Western Indian Ocean
(Wiley, 2022) Stefanoudis, Paris V.; Talma, Sheena; Samaai, Toufiek
Deep reefs below 30mprovide essential ecosystem services for ocean health and human well-being such as food security and climate change resilience. Yet, deep reefs remain poorly researched and largely unprotected, including in the Western Indian Ocean (WIO). Here, we assessed current conservation approaches in the WIO focusing on deep reefs, using a combination of online surveys and semi-structured interviews. Results indicated that deep-reef data are sparse and commonly stemming from non-peer-reviewed or non-publicly available sources, and are often not used to inform conservation of WIO marine protected areas.
Descriptive epidemiology of and response to the high pathogenicity avian influenza (h5n8) epidemic in South African coastal seabirds, 2018
(Wiley, 2023) Roberts, Laura C.; Abolnik, Celia; Waller, Lauren J.
High pathogenicity avian infuenza (HPAI) clade 2.3.4.4b H5N8 virus was detected in coastal seabirds in late 2017 in South Africa, following a devastating epidemic in the commercial poultry and ostrich industries. By May 2018, the infection had been confrmed in ffteen seabird species at 31 sites along the southern coast, with the highest mortality recorded in terns (Family Laridae, Order Charadriiformes). Over 7,500 positive or suspected cases in seabirds were reported. Among those infected were three endangered species: African penguins (Spheniscus demersus Linnaeus, 1758), Cape cormorants (Phalacrocorax capensis Wahlberg, 1855), and Cape gannets (Morus capensis Lichtenstein, 1823). Te scale and impact of this outbreak were unprecedented in southern African coastal seabirds and raised logistical challenges in resource allocation, risk mitigation, and outbreak response. It required the collaboration of multiple stakeholder groups, including a variety of government departments and nongovernmental organizations. With another HPAI outbreak in South African seabirds in 2021 and major incursions in seabird species in the northern hemisphere in 2022, it is vital to share and consolidate knowledge on the subject. We describe the epidemic, the lessons learned, and recommendations for developing contingency plans.
Initial evaluation of the care and rehabilitation success of Cape Cormorants Phalacrocorax capensis rescued from Robben and Jutten islands, South Africa, in January 2021
(Taylor and Francis Group, 2023) Phillips, Jesse; Ludynia, Katrin; Waller, Lauren J
The population of the endangered Cape Cormorant Phalacrocorax capensis more than halved over the last three decades (BirdLife International 2018a). In January 2021, nearly 2 000 Cape Cormorant chicks were found abandoned, suffering from dehydration and heat stress, at two important nesting sites. The chicks were rescued and rehabilitated by the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB, Cape Town, South Africa). About half (53.7%) of the cormorant chicks were successfully rehabilitated and released back into the breeding colonies. This study found a direct link between the initial body mass of cormorant chicks admitted to the rehabilitation centre and their probability of surviving during rehabilitation, with birds that were initially heavier having a greater probability of eventual release. Most cormorant chicks that died (80.7%) did so within the first 5 days of admission. This rescue required SANCCOB to care for and rehabilitate the largest number of Cape Cormorant chicks that has ever been admitted to its rehabilitation centre at one time, making it the first rescue of its kind. Despite the presumably limited positive impact on overall population numbers of Cape Cormorants, the rescue campaign improved SANCCOB’s preparedness to respond successfully to future disaster events and to deal with different species, both locally and globally.
The diurnal activity budgets of extralimital giraffe (Giraffa camelopardalis giraffa) in the Western Cape Province, South Africa
(Wiley, 2023) Paulse, Jamie; Couldridge, Vanessa; Cupido, Clement
Despite being an extralimital species in the region, South African giraffes (Giraffa camelopardalis giraffa, Schreber 1784) are continuously being introduced into the Albany Thicket Biome of the Western Cape Province of South Africa. This study aimed to determine the diurnal activity budgets of two extralimital giraffe populations in the Western Cape of South Africa. Diurnal activity budgets are important to provide baseline information on the adaptability of species in newly introduced areas and for more detailed ecological studies such as those relating to habitat suitability, animal–plant interactions and interactions with other resident animals.
Implications of the breakdown in the indigenous knowledge system for rangeland management and policy: A case study from the Eastern Cape in South Africa
(Taylor and Francis Group, 2023) Finca, Andiswa; Linnane, Suzanne; Samuels, M Igshaan
Communal rangelands in South Africa are generally perceived as overgrazed owing to complexities in their histories and collective utilisation which often leads to improper management. A suitable solution has not been found in land management policies because local people’s contexts and their indigenous knowledge are ignored. Hence, this paper is aimed at (i) assessing the role indigenous knowledge can play in communal rangeland management, (ii) exploring working solutions to incorporate indigenous knowledge into effective communal rangeland management and land use policies, (iii) assessing mechanisms for generational transfer of indigenous knowledge. Findings from the Participatory Geographic Information System (PGIS) and Focus Group Discussion, conducted with Cata and Guquka villages in the Eastern Cape province were synthesised. This revealed that communal farmers have in-depth knowledge of their communal land, past and present rangeland management strategies and changes in rangeland condition. However, there is breakdown in the indigenous knowledge system whereby this knowledge is not being transferred and translated into good rangeland management practice, owing to the ageing population of communal farmers, limited youth involvement in livestock farming and limited access to extension services. This suggests a need for new policy approaches that would include participation of local people in policy planning and development.
Nitrogen fertilization increases the growth and nutritional quality of the forage legume, Calobota sericea – A preliminary investigation
(Elsevier, 2023) Britz, Ethan; Cyster, Lilburne; Samuels, Igshaan
Calobota sericea is being evaluated as a forage for drought stressed areas. The nutritional quality of C. sericea from native populations are poor, and this is believed to be due to poor soil fertility. Therefore, a greenhouse trial was established to determine the impact of N-fertilization level (0, 25, 50, 75 and 100 kg/ha) on the growth and nutritional quality of C. sericea plants. Three-monthold plants were harvested and the root and shoot length, as well as branching intensity on each plant determined. Thereafter, the shoots were separated into leaves and stems and all plant parts were oven dried for dry mass determination. After weighing, the leaves and stems for each plant were combined and the dried shoots used for nutrient determination. Results indicated that increased N application levels is positively correlated with improved C. sericea growth. Similarly, mineral nutrient uptake increased significantly under all the N-fertilization treatments and crude protein content increased from 9.6% to 18.6%. Plant growth was only statistically significantly (p < 0.05) improved when N was applied at rates of 50 kg/ha and more, but crude protein content increased from the lowest N application rates (25 kg/ha). The improved growth and nutrient uptake could primarily be explained by improved resource allocation under N-fertilization. Therefore, appropriately fertilized C. sericea can result in improved forage production and improved quality forages and when N is applied at high enough rates.
Understanding the creek dynamics and environmental characteristics that determine the distribution of mangrove and salt marsh communities at Nahoon Estuary
(Elsevier, 2016) Geldenhuys, Chanel; Cotiyane, Phumlile; Rajkaran, Anusha
The southern distributional limit for mangroves on the east coast of Africa is thought to be at the planted mangrove forest at Nahoon Estuary (33° S) in the Eastern Cape, South Africa. This study investigated the influence of a tidal creek on the intertidal zone and the physical and biological differences between the salt marsh and mangrove forest communities at Nahoon Estuary. Three transects were established across the tidal creek and one transect in each of the following habitats mangrove, mangrove–salt marsh, and the salt marsh area. The tidal creek introduced oxygenated (~6 mg.l−1) and saline water with high levels of total suspended solids (120–424 g.l−1) into the intertidal zone. In areas where tidal water was retained, algal mats formed over pneumatophores during summer. The vegetation distribution in the mangrove–salt marsh community was significantly affected by elevation, ammonium concentration, and porewater temperature while the salt marsh vegetation distribution was influenced by porewater salinity, sediment, pH and the percentage of sand content. Porewater nitrogen was mostly present as ammonium, and phosphate concentrations were moderate ranging from 1.3 μM in the salt marsh to 3.7 μM in the mangrove community. Mangrove and salt marsh communities are clearly constrained by the physical characteristics of the intertidal area (elevation) and this will ensure that both communities will be maintained at Nahoon Estuary. However with climate change and sea level rise, this may change in the long term with mangroves expanding into elevated areas.
Development of a compendium of local, wild-harvested species used in the informal economy trade, Cape Town, South Africa
(Resilience Alliance, 2012) Petersen, L. M.; Moll, E. J.; Collins, R.
Wild harvesting has taken place over millennia in Africa. However urbanization and cash economies have effectively altered harvesting from being cultural, traditional, and subsistence activities that are part of a rural norm, to being a subculture of commonly illicit activities located primarily within the urban, cash-based, informal economy. This paper focuses on Cape Town, South Africa where high levels of poverty and extensive population growth have led to a rapidly growing informal industry based on the cultural, subsistence, and entrepreneurial harvesting and consumption of products obtained from the local natural environment. Through a process of literature reviews, database analysis, and key informant interviews, a compendium of harvested species was developed, illustrating the breadth of illicit harvesting of products from nature reserves, public open space, and other commonage within the City. The compendium records 448 locally occurring species (198 animals and 250 plants) that are extracted for medicinal, energy, ornamental, sustenance, nursery, and other uses. The sustainability of harvesting is questionable; nearly 70% of all harvested flora and 100% of all collected fauna are either killed or reproductively harmed through the harvesting processes. Furthermore, for the 183 indigenous flora species currently recorded on the International Union for Conservation of Nature (IUCN) Red List, 28% (51) hold assessments ranging from Declining through to Critically Endangered. With respect to the more poorly assessed fauna (46 spp.), approximately 24% (11) have Declining or Threatened status.
Cross-shelf movement of chrysaora fulgida (scyphozoa; discomedusae) off namibia inferred from stable isotopes (δ15n and δ13c)
(Taylor and Francis Group, 2021) Skrypzeck, Heidi; van der Lingen, Carl David; Gibbons, Mark J
Large and small specimens of two species of metagenic Scyphozoa (true jellyfishes) can be found in nearshore waters off central Namibia throughout the year. Whereas populations of Chrysaora africana are largely restricted to inshore waters, C. fulgida occurs across the shelf, with small individuals found inshore and large individuals primarily found offshore. We examined stable isotopes δ15N and δ13C of both species in Walvis Bay and found that large-sized C. fulgida have lower δ15N values than small individuals and C. africana throughout the year. These differences are interpreted to reflect cross-shelf changes in δ15N baseline levels, with greater nitrogen recycling (and hence lower δ15N values) occurring offshore. The occasional/seasonal nearshore appearance of large C. fulgida with low δ15N values therefore implies routine, onshore advection. The values of δ13C did not show cross-shelf differences, which suggests that jellyfish populations across the shelf are supported by phytoplankton-based food chains. This study emphasises the value of using stable isotopes to examine the mesoscale structuring of jellyfish populations.
Renosterveld conservation in South Africa: A case study for handling uncertainty in knowledge-based neural networks for environmental management
(International Society for Environmental Information Sciences, 2009) Chandra, R.; Knight, Richard; Omlin, C. W.
This work presents an artificial intelligence method for the development of decision support systems for environmental management and demonstrates its strengths using an example from the domain of biodiversity and conservation biology. The approach takes into account local expert knowledge together with collected field data about plant habitats in order to identify areas which show potential for conserving thriving areas of Renosterveld vegetation and areas that are best suited for agriculture. The available data is limited and cannot be adequately explained by expert knowledge alone. The paradigm combines expert knowledge about the local conditions with the collected ground truth in a knowledge-based neural network. The integration of symbolic knowledge with artificial neural networks is becoming an increasingly popular paradigm for solving real-world applications. The paradigm provides means for using prior knowledge to determine the network architecture, to program a subset of weights to induce a learning bias which guides network training, and to extract knowledge from trained networks; it thus provides a methodology for dealing with uncertainty in the prior knowledge. The role of neural networks then becomes that of knowledge refinement. The open question on how to determine the strength of the inductive bias of programmed weights is addressed by presenting a heuristic which takes the network architecture and training algorithm, the prior knowledge, and the training data into consideration.
Porolithon improcerum (porolithoideae, corallinaceae) and mesophyllum macroblastum (melobesioideae, hapalidiaceae): New records of crustose coralline red algae for the Southwest Atlantic Ocean
(Magnolia Press, 2014) Bahia, Ricardo Da Gama; Amado-Filho, Gilberto Menezes; Maneveldt, Gavin William
Here we describe in detail two crustose coralline red algal (CCA) species newly reported for the southern Atlantic: Porolithon improcerum and Mesophyllum macroblastum. Porolithon improcerum was recorded on the remote oceanic island of Martim Vaz (ca. 1,200 km off the Brazilian Coast) and M. macroblastum on the Cagarras Archipelago (ca. 5 km off the coast of Rio de Janeiro city). Within the genus Porolithon, P. improcerum is characterized by thin vegetative thallus composed mostly of two cell layers and thalli forming several applanate branches overgrowing one another. Within the genus Mesophyllum, M. macroblastum is characterized by bearing volcano-like multiporate tetrasporangial conceptacles with a raised rim and sunken central pore plate in addition to pore canals of conceptacles being lined by cells that are similar in size and shape to other roof cells. While, P. improcerum has previously been reported for the northern Atlantic Ocean, this study represents the first report of M. macroblastum for the Atlantic Ocean.
2-phenoxyethanol as anaesthetic in removing and relocating 102 species of fishes representing 30 families from sea world to uShaka Marine World, South Africa
(AOSIS, 2008) Vaughan, D.B.; Penning, M.R.; Christison, K.W.
The South African Association for Marine Biological Research, incorporating Sea World, Oceanographic Research Institute and the Dolphinarium relocated from their old premises of 46 years on Durban’s beach front in March and April 2004 to the new Point Development’s marine theme park, uShaka Marine World in Durban, South Africa. Netting of fishes from the large exhibits could cause physical damage to struggling fishes, increasing the risk of opportunistic secondary bacterial infections (Inoue, dos Santos Neto & Morales 2004) which could not be treated in time for the opening of uShaka Marine World on 30 April 2004.
Is penguin circovirus circulating only in the antarctic circle? Lack of viral detection in namibia
(MDPI, 2023) Roberts, Laura C.; Molini, Umberto; Ludynia, Katrin
The known host range of circoviruses is continuously expanding because of more intensive diagnostic activities and advanced sequencing tools. Recently, a new circovirus (penguin circovirus (PenCV)) was identified in the guano and cloacal samples collected from Adélie penguins (Pygoscelis adeliae) and chinstrap penguins (Pygoscelis antarcticus) in Antarctica. Although the virus was detected in several asymptomatic subjects, a potential association with feather disease was speculated. To investigate the occurrence and implications of PenCV in other penguin species located outside of Antarctica, a broad survey was undertaken in African penguins (Spheniscus demersus) on two islands off the southern Namibian coast. For this purpose, specific molecular biology assays were developed and validated. None of the 151 blood samples tested positive for PenCV. Several reasons could explain the lack of PenCV positive samples. African penguins and Pygoscelis species are separated by approximately 6000 km, so there is almost no opportunity for transmission. Similarly, host susceptibility to PenCV might be penguin genus-specific. Overall, the present study found no evidence of PenCV in African penguin colonies in Namibia. Further dedicated studies are required to assess the relevance of PenCV among different penguin species.
Iterative mapping of marine ecosystems for spatial status assessment, prioritization, and decision support
(Frontiers Media, 2023) Sink, Kerry J.; Adams, Luther A.; Makwela, Mapula
South Africa has taken an iterative approach to marine ecosystem mapping over 18 years that has provided a valuable foundation for ecosystem assessment, planning and decision-making, supporting improved ecosystem-based management and protection. Iterative progress has been made in overcoming challenges faced by developing countries, especially in the inaccessible marine realm. Our aim is to report on the approach to produce and improve a national marine ecosystem map to guide other countries facing similar challenges, and to illustrate the impact of even the simplest ecosystem map. South Africa has produced four map versions, from a rudimentary map of 34 biozones informed by bathymetry data, to the latest version comprising 163 ecosystem types informed by 83 environmental and biodiversity datasets that aligns with the IUCN Global Ecosystem Typology.
Transhumance pastoralism in West Africa – its importance, policies and challenges
(African Journal of Range & Forage Science, 2023) Samuels, Igshaan; Timpong-Jones, Eric Cofie; Sarkwa, Felix Owusu
The Economic Community of West African States (ECOWAS) recognises transhumance pastoralism as a beneficial livestock production system that can contribute to food security together with economic and political stability. Thus, the subregional bloc put together the ECOWAS Protocol on Transhumance and supporting regulations to actualise these benefits. These policies seek to regulate transhumance pastoralism by ensuring that herd movements are along defined migratory corridors among member states. This review assesses the importance of transhumance pastoralism in West Africa, local and cross-border policies, and associated challenges, with emphasis on herder–farmer conflicts. It was realised that the movement of large numbers of livestock into rangelands (1) provides employment for many, and thus improves livelihoods; (2) improves productivity through high milk production and high fertility; (3) reduces moribund and combustible forage materials in the dry season; and (4) enhances seed dispersal, soil fertility and plant diversity on rangelands. This review shows that the ECOWAS cross-border transhumance protocols have led to infrastructural developments in some member states, but the partial enforcement of protocols has led to herder–farmer conflicts. We conclude that transhumance pastoralism and the regulatory policies have several benefits. However, to ensure policy compliance and avoid herder–farmer conflicts, the policies need to be reviewed and discernible gaps eliminated.

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