An evaluation of coral reef fish communities in South African marine protected areas.

Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2010.Differences in coral reef fish assemblages were investigated on six South African and one southern Mozambican reef under varying management regimes. All of the South African reefs fall within marine protected areas (MPA) but are zoned for differing types and intensities of human activity. Reefs where no human activities are allowed were termed Sanctuaries, while those on which restricted fishing and SCUBA diving are permitted were termed Protected. The reef in southern Mozambique is subjected to unrestricted fishing and SCUBA diving and was consequently termed Open. This study consists of two parts. The first dealt with a community assessment which investigated and provided baseline data on the trophic structure, density, and species diversity of fish assemblages on each of the seven study reefs. The objective was to compare the aforementioned metrics between reefs and thereafter compare them between the different protection zones. The second part of this study focused on assessing the impacts of human activities using 25 fish indicator species. These species were selected a priori based on their ecological importance and sensitivity to human activity (fishing and diving). The selection process was then guided by the results of the community assessment. The objective was to use these species as indicators of recreational diving and fishing pressure in the different protection zones. Density, biomass and size frequency analyses comprised the primary metrics in this assessment. Randomly stratified underwater visual censuses (UVC) were used to collect the fish data and these were conducted on reefs inhabited by a coral community considered to be the core community on South Africa’s reefs in terms of biodiversity and coral cover. The fish community assessment consisted of timed counts in which all non-cryptic fish species were quantified. Indicator species counts employed the point count technique with a radius of 10 m. An average of 11 community counts and an average of 62 point counts were conducted per reef. Various environmental variables and habitat characteritics were recorded during the UVCs. Multivariate analysis of the fish assemblages indicated that the fish community structure differed significantly according to reef protection status. Sanctuary reefs were significantly different from the Open reef in Southern Mozambique. Mean fish abundance was highest on Sanctuary reefs and lowest on the Open reef. In terms of overall species diversity, a total of 284 species belonging to 50 families were recorded, this being comparable to other reefs in the WIO region. Six families contributed more than 50% towards the fish community composition: Labridae, Acanthuridae, Chaetodontidae, Lutjanidae, Pomacentridae and Serranidae. All predator categories were well represented on Sanctuary reefs, while top-level predators were scarce on the High-Diving and the Open reef. Generalised linear model (GLM) regression analysis indicated that human activities were significant variables in accounting for the variance in fish community structure. The total fish abundance and biomass of the selected indicator species were significantly higher in Sanctuary zones and lowest in the Open zone. In addition, Sanctuary zones were characterised by high numbers of large predators, while non-Sanctuary zones were characterised by higher abundances of prey species. Target species were also larger and more abundant in Sanctuary zones. The data revealed that recreational fishing and high diving intensity may be influencing the fish community structure on southern African coral reefs, which was confirmed by GLM regression analysis. Long-term monitoring of these fish communities is recommended to confirm the trends observed in this data set

Assessing disease risk perceptions of wild meat in savanna borderland settlements in Kenya and Tanzania

Wild meat hunting and trade across African savannas is widespread. We interviewed 299 people in rural settlements along the Kenya-Tanzania border to examine impacts of COVID-19 on wild meat consumption and perceptions about wild meat activities associated with zoonotic disease risks. Education level played a key part in understanding COVID-19 transmission. Information about the pandemic was mostly acquired from the media. Nearly all respondents recognized that COVID-19 originated in China. As many as 70% reported no impact of COVID-19 on wild meat consumption; some believed that there was an increase. Over half of the respondents believed that consumption of wild meat leads to food-borne illnesses. Respondents recognized disease risks such as anthrax and brucellosis and accepted that people slaughtering and handling wild meat with open cuts were at greater risk. Ungulates were the most consumed animals, followed by birds, rodents, and shrews. Respondents perceived that hyenas, monkeys, donkeys, and snakes were riskier to eat. More than 90% of the respondents understood that handwashing with soap reduces risks of disease transmission. Country level (11 answers), education and gender (three answers each) and household economy (158 answers) were significant. Country differences were linked to differences in nature legislation; 50% of Kenyan respondents believed that wild meat should not be sold because of conservation concerns. Men were more worried about getting COVID-19 from live animals and perceived that wildlife should not be sold because of conservation reasons. Overall, there was a very strong inclination to stop buying wild meat if other meats were less expensive. Our results allow us to better understand the impact of the COVID-19 pandemic on wild meat-related activities. Differences between countries can frame the attitudes to wild meat since wild meat trade and consumption were found to be country specific

First observation of Acropora pinguis on the high-latitude coral reefs of South Africa: a species range extension

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Variation in germline mtDNA heteroplasmy is determined prenatally but modified during subsequent transmission

A genetic bottleneck explains the marked changes in mitochondria! DNA (mtDNA) heteroplasmy that are observed during the transmission of pathogenic mutations, but the precise timing of these changes remains controversial, and it is not clear whether selection has a role. These issues are important for the genetic counseling of prospective mothers and for the development of treatments aimed at disease prevention. By studying mice transmitting a heteroplasmic single-base-pair deletion in the mitochondrial tRNA(Met) gene, we show that the extent of mammalian mtDNA heteroplasmy is principally determined prenatally within the developing female germline. Although we saw no evidence of mtDNA selection prenatally, skewed heteroplasmy levels were observed in the offspring of the next generation, consistent with purifying selection. High percentages of mtDNA genomes with the tRNAMet mutation were linked to a compensatory increase in overall mitochondrial RNA levels, ameliorating the biochemical phenotype and explaining why fecundity is not compromised

Author Correction: Global status and conservation potential of reef sharks

An Amendment to this paper has been published and can be accessed via a link at the top of the paper.</p

Widespread diversity deficits of coral reef sharks and rays

A global survey of coral reefs reveals that overfishing is driving resident shark species toward extinction, causing diversity deficits in reef elasmobranch (shark and ray) assemblages. Our species-level analysis revealed global declines of 60 to 73% for five common resident reef shark species and that individual shark species were not detected at 34 to 47% of surveyed reefs. As reefs become more shark-depleted, rays begin to dominate assemblages. Shark-dominated assemblages persist in wealthy nations with strong governance and in highly protected areas, whereas poverty, weak governance, and a lack of shark management are associated with depauperate assemblages mainly composed of rays. Without action to address these diversity deficits, loss of ecological function and ecosystem services will increasingly affect human communities

Global status and conservation potential of reef sharks

Decades of overexploitation have devastated shark populations, leaving considerable doubt as to their ecological status1,2. Yet much of what is known about sharks has been inferred from catch records in industrial fisheries, whereas far less information is available about sharks that live in coastal habitats3. Here we address this knowledge gap using data from more than 15,000 standardized baited remote underwater video stations that were deployed on 371 reefs in 58 nations to estimate the conservation status of reef sharks globally. Our results reveal the profound impact that fishing has had on reef shark populations: we observed no sharks on almost 20% of the surveyed reefs. Reef sharks were almost completely absent from reefs in several nations, and shark depletion was strongly related to socio-economic conditions such as the size and proximity of the nearest market, poor governance and the density of the human population. However, opportunities for the conservation of reef sharks remain: shark sanctuaries, closed areas, catch limits and an absence of gillnets and longlines were associated with a substantially higher relative abundance of reef sharks. These results reveal several policy pathways for the restoration and management of reef shark populations, from direct top-down management of fishing to indirect improvement of governance conditions. Reef shark populations will only have a high chance of recovery by engaging key socio-economic aspects of tropical fisheries