22 research outputs found
Finally seen : a rare sighting of Antarctic blue whale cowâcalf pair off the west coast of South Africa
Blue whales are rarely sighted off the coasts of South Africa due to their low numbers and offshore habitat preference. Visual observations to search for marine mammals were conducted onboard a platform of opportunity during the Integrated Ecosystems Programme survey in November 2019. A cowâcalf pair of blue whales Balaenoptera musculus was sighted offshore Kleinzee (30°05âČ02.4" S, 14°24âČ53.2" E) at a water depth of 1670 m on the west coast of South Africa in the southern Benguela Current System. The pair was identified as Antarctic blue whales B. m. intermedia based on the size of the cow (~â29 m), âtorpedo-shapedâ body of the cow, known distribution ranges and recent acoustic data showing that pygmy blue whales B. m. brevicauda do not occur in these waters. The calf was likely born in the Benguela ecosystem given its relatively small size. This is the first sighting of Antarctic blue whale cowâcalf pair in South African waters post whaling, indicating that animals might still use this area as a calving or nursing ground. Improved protection of this region in the low latitudes might benefit the recovery and conservation of the species.The Department of Forestry, Fisheries and the Environment.https://link.springer.com/journal/300hj2023Mammal Research Institut
Year-round acoustic monitoring of Antarctic blue and fin whales in relation to environmental conditions off the west coast of South Africa
Antarctic blue and fin whales were once abundant in the southeastern Atlantic Ocean, yet their occurrence and ecology in this region is still poorly understood. Seasonal acoustic occurrence and behaviour of Antarctic blue and fin whales off the South African west coast were determined using bio-acoustic data collected through two autonomous acoustic recorders between December 2015 and January 2017. Blue whale Z-calls were detected year-round with a peak in July, while fin whale 20 Hz pulses were detected seasonally with a peak in June by a recorder deployed at 1118 m water depth. Blue and fin whale calls were detected seasonally with a similar peak in May by a recorder deployed at 4481 m water depth. The blue whale 27 Hz chorus, and blue and fin whale 18â28 Hz chorus followed a similar trend as the seasonal acoustic occurrence of individual Z-calls and 20 Hz pulses. A maximum detection range of 800 km estimated by acoustic propagation modelling suggests that detected calls originate from whales within the South African west coast waters. Random forest models classified month of the year, wind speed, log-transformed chlorophyll-a, and sea surface temperature anomaly as the most important predictors of blue and fin whale acoustic occurrence and behaviour. Our study highlights the South African west coast as an important year-round habitat and seasonal breeding or overwintering habitat of these whales. Additionally, the year-round acoustic occurrence in this region supports the notion that blue whale migration patterns are more dynamic than previously perceived.The National Research Foundation and the South African National Antarctic Programme.https://link.springer.com/journal/227hj2023Mammal Research Institut
An open access dataset for developing automated detectors of Antarctic baleen whale sounds and performance evaluation of two commonly used detectors
Since 2001, hundreds of thousands of hours of underwater acoustic recordings have been made
throughout the Southern Ocean south of 60° S. Detailed analysis of the occurrence of marine mammal
sounds in these circumpolar recordings could provide novel insights into their ecology, but manual
inspection of the entirety of all recordings would be prohibitively time consuming and expensive.
Automated signal processing methods have now developed to the point that they can be applied
to these data in a cost-efective manner. However training and evaluating the efcacy of these
automated signal processing methods still requires a representative annotated library of sounds to
identify the true presence and absence of diferent sound types. This work presents such a library of
annotated recordings for the purpose of training and evaluating automated detectors of Antarctic blue
and fn whale calls. Creation of the library has focused on the annotation of a representative sample of
recordings to ensure that automated algorithms can be developed and tested across a broad range of
instruments, locations, environmental conditions, and years. To demonstrate the utility of the library,
we characterise the performance of two automated detection algorithms that have been commonly
used to detect stereotyped calls of blue and fn whales. The availability of this library will facilitate
development of improved detectors for the acoustic presence of Southern Ocean blue and fn whales.
It can also be expanded upon to facilitate standardization of subsequent analysis of spatiotemporal
trends in call-density of these circumpolar species.http://www.nature.com/srep/index.htmlpm2022Mammal Research Institut
Developing Literacy Learning Model Based on Multi Literacy, Integrated, and Differentiated Concept at Primary School
The main issue addressed in this research is the low writing skills of primary school students. One of the reasons for this condition is that the existing model of writing literacy learning is not appropriate. The purpose of this study is to explain MID-based literacy teaching model and the impact of the model in increasing primary school students\u27 writing skills. This study used combined methods of exploratory type. The samples were elementary school students coming from six schools with three different characteristics. Based on the data analysis, it can be concluded that the implementation of MID-based literacy learning model has proven to signi cantly contribute to the improvement of students\u27 writing skills. Taking place in all sample schools, the improvement may suggest that the model ts not only to students with high- ability but also those with low-ability. Therefore, the MID-based literacy learning model is needed to improve the ability to write various text types appropriately
Impact of recapitalisation and development programme on performance of land reform beneficiary farmers in KwaZulu-Natal, South Africa
Providing appropriate post-settlement support to farmers is crucial for sustainable development of smallholder agriculture in South Africa. In unravelling this, the South Africaâs Recapitalization and Development Programme (RADP) was initiated. Hence, this study analysed the impact of RADP on performance of land reform beneficiary farmers in KwaZulu-Natal, South Africa. A multistage sampling procedure was used to select (n = 264) respondents for the study. Accounting for endogeneity issues in RADP assessments and its impact on the performance of land reform farmers, an endogenous switching regression model (ESRM) was employed. In the same vein, a doubly-robust inverse probability weighted regression adjustment was used as credible remedy for potentially biased estimates of ATT and POM of endogenous treatment model. The main findings revealed that tax compliance, secondary organization, legal entity, farm potential income at acquisition, farmers receiving third party assistance and strategic partnership were statistically significant in influencing the participation of farmers in RADP. Mentorship remains an extremely challenging element in post-settlement. However, through the strategic partnership of RADP farmers had likelihood to improve the farm and increase farm income. The results of the suggest that the RADP can contribute to a deep process of change and empowerment of farmers. In the same vein, strategic partnership of RADP is likely to improve the farmersâ performance. Therefore, there is a need to strongly improve mentorship and strategic partnership programme to encourage participation of land reform farmers in the support programmes.Non-PRIFPRI3; 4 Transforming Agricultural and Rural Economies; 5 Strengthening Institutions and Governance; DCADSG
An open access dataset for developing automated detectors of Antarctic baleen whale sounds and performance evaluation of two commonly used detectors
Funding Information: The annotated library was made possible with funding from: IWC-SORP Grant âAn annotated library of underwater acoustic recordings for testing and training automated algorithms for detecting Southern Ocean baleen whalesâ; IWC-SORP Grant âIWC-SORP Project 5âAcoustic trends in abundance, distribution, and seasonal presence of Antarctic blue whales and fin whales in the Southern Ocean: 5-year strategic meetingâ; Australian Antarctic Science Projects 4101, and 4102âAntarctic baleen whale habitat utilisation and linkages to environmental characteristics, and Population abundance, trend, structure and distribution of the endangered Antarctic blue whale; Research grants from the Korean Ministry of Oceans and Fisheries (KIMST20190361; PM20020; PE20230). This report is NOAA/PMEL contribution number 5005. South African National Antarctic Programme Grant/Award Number: SNA 2011112500003.Since 2001, hundreds of thousands of hours of underwater acoustic recordings have been made throughout the Southern Ocean south of 60° S. Detailed analysis of the occurrence of marine mammal sounds in these circumpolar recordings could provide novel insights into their ecology, but manual inspection of the entirety of all recordings would be prohibitively time consuming and expensive. Automated signal processing methods have now developed to the point that they can be applied to these data in a cost-effective manner. However training and evaluating the efficacy of these automated signal processing methods still requires a representative annotated library of sounds to identify the true presence and absence of different sound types. This work presents such a library of annotated recordings for the purpose of training and evaluating automated detectors of Antarctic blue and fin whale calls. Creation of the library has focused on the annotation of a representative sample of recordings to ensure that automated algorithms can be developed and tested across a broad range of instruments, locations, environmental conditions, and years. To demonstrate the utility of the library, we characterise the performance of two automated detection algorithms that have been commonly used to detect stereotyped calls of blue and fin whales. The availability of this library will facilitate development of improved detectors for the acoustic presence of Southern Ocean blue and fin whales. It can also be expanded upon to facilitate standardization of subsequent analysis of spatiotemporal trends in call-density of these circumpolar species.Publisher PDFPeer reviewe