Fannie Shabangu
University of Pretoria, Zoology and Entomology, Graduate Student
Research Interests: Computer Science, Medicine, Standardization, Whale, Underwater, and 6 moreGC, Za, Marine Mammal, Detector, Baleen, and Das
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ABSTRACT South Africa’s marine ecosystem has been subjected to unfavourable anthropogenic effects brought about by mismanagement and over-exploitation. In order to manage exploited marine resources properly, knowledge is needed about... more
ABSTRACT South Africa’s marine ecosystem has been subjected to unfavourable anthropogenic effects brought about by mismanagement and over-exploitation. In order to manage exploited marine resources properly, knowledge is needed about their size and distribution, and how their exploitation can potentially impact on the remainder of the ecosystem. Hydro-acoustic methods can facilitate the study of aquatic animals and their environment without causing any significant environmental damage or change. The authors describe how hydro-acoustic technology can be used in fisheries research, oceanography and geomorphology in South African waters. They also highlight opportunities for how this technology can be further developed and identify needs and opportunities for further research in the South African context.
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Seasonal acoustic occurrences and diel singing patterns of humpback whale (Megaptera novaeangliae) songs and Antarctic minke (Balaenoptera bonaerensis) whale are described using acoustic recordings from the west coast of South Africa and... more
Seasonal acoustic occurrences and diel singing patterns of humpback whale (Megaptera novaeangliae) songs and Antarctic minke (Balaenoptera bonaerensis) whale are described using acoustic recordings from the west coast of South Africa and Maud Rise, Antarctica. Acoustic data were recorded from early 2014 to early 2017. Acoustic occurrences (i.e., presence) of humpback and minke whale sounds were identified through visual scrutiny of spectrograms of recorded data. Environmental conditions associated with humpback whale song occurrences were ranked according to their model-predicted relative importance. In South Africa, humpback whale songs were detected from June to December but peaked in September. In Antarctica, humpback whale songs were detected from March to May (singing peaked in April). Minke whale sounds were only recorded in 2014, between June and September in Antarctica and between September and November in South Africa. Humpback whales were more vocally active at night in all recording sites whereas minke whales were more vocally active during the day. This is the first study to describe the seasonal acoustic occurrences of humpback and minke whales off the west coast of South Africa. Such knowledge could be essential for the conservation and management of these species in both South Africa and Antarctica.
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Research Interests: Mechanical Engineering, Environmental Science, Oceanography, Endangered Species, Medicine, and 15 moreMultidisciplinary, Chlorophyll, Animals, PLoS one, Ecosystem, Minke whale, Interdisciplinary Engineering, Conservation of Natural Resources, Environment, Electrical And Electronic Engineering, Area Under Curve, Monte Carlo Method, Latitude, Oceans and Seas, and Longitude
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Seasonal occurrence, diel‐vocalizing patterns, and call‐types of Antarctic minke whales are described using bio‐acoustic recordings from the west coast of South Africa and the Maud Rise, Antarctica. In Antarctica, minke whale bioduck... more
Seasonal occurrence, diel‐vocalizing patterns, and call‐types of Antarctic minke whales are described using bio‐acoustic recordings from the west coast of South Africa and the Maud Rise, Antarctica. In Antarctica, minke whale bioduck calls were detected in seven of nine months of hydrophone deployment (peaking in May and September) while downsweeps were only detected in June. Bioduck calls were sporadically detected in South African waters with peak calling in September/October, and no bioducks were detected from March through August. Bioduck call occurrence was high during daytime in Antarctica but there was no diel‐vocalizing pattern in South African waters. We split bioduck B call‐type into two subtypes: B1 with 13 ± 1 pulses (Dominello & Širović, 2016) and B2 with 9 ± 1 pulses (this study). Bioduck B2 was detected both in Antarctic and South African waters, with harmonics up to 2 kHz. Similar bioduck call‐types were detected in Antarctic and South African waters, with bioduck A2 being the most common. Month of the year was the most important predictor of bioduck occurrence both in Antarctic and South African waters. This is the first study to describe the seasonal occurrence, diel‐vocalizing behavior and call‐types of Antarctic minke whales off the South African west coast and eastern Weddell Sea.
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Anthropogenic underwater noise has been shown to negatively affect marine organisms globally; yet little to no noise research has been conducted in most African waters including South Africa's. This study aimed to quantitatively... more
Anthropogenic underwater noise has been shown to negatively affect marine organisms globally; yet little to no noise research has been conducted in most African waters including South Africa's. This study aimed to quantitatively describe sources of underwater noise and effects of underwater noise on the acoustic detectability of Antarctic blue, fin, minke, humpback, and sperm whales off South Africa's west coast. Noise from vessel traffic (<35 km to the location of recorders) dominated the soundscape below 500 Hz while wind-generated noise increased with wind speed above 5 m s-1 and dominated the soundscape above 500 Hz. Acoustic detectability of humpback, minke and sperm whales decreased with increasing ambient noise levels whereas blue and fin whale acoustic detectability increased with the ambient noise levels. We provide baseline information on underwater noise sources and the effects of underwater noise on whale acoustic detectability off the west coast of South Africa.
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Abstract The world's oceans are subject to the multiple impacts of human activity and to the consequent threats to the health of many and varied ocean ecosystems. Oceans around South Africa are no exception and, with the need for... more
Abstract The world's oceans are subject to the multiple impacts of human activity and to the consequent threats to the health of many and varied ocean ecosystems. Oceans around South Africa are no exception and, with the need for economic growth in the country, anthropogenic stressors on ocean resources are rapidly increasing. In this study, we investigated 14 different anthropogenic stressors that impacted ocean health between 2003 and 2013, and their cumulative anthropogenic effects on cetaceans in the South African Exclusive Economic Zone (EEZ) and South African Marine Protected Areas (MPA), Important Marine Mammal Areas (IMMA), Ecologically or Biologically Significant Areas (EBSA) and ecoregions. We determined cetacean species richness in these five area categories using ensemble models, and identified anthropogenic impacts from relevant literature. We calculated and compared the average species richness, the average trend for each anthropogenic stressor and average cumulative impact between 2003 and 2013 in the five areas. Results highlight that climate related stressors (such as sea surface temperature and ocean acidification), together with shipping stressors, are increasing more rapidly than other stressors across the EEZ. Cetacean species richness was highest along the west coast shelf and shelf edge where sea level rise, ocean acidification, shipping, and commercial pelagic fishing with low by-catch were most pronounced. The results of this study will inform marine spatial planners and policy makers in determining priority areas for cetacean conservation and in identifying anthropogenic stressors that need to be addressed to mitigate cumulative anthropogenic impacts on cetaceans.
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Bioacoustics has emerged as a useful method of data collection and analysis for diverse animals in a wide range of environments and has helped to describe, monitor, and conserve some of Africa's species biodiversity. However, little... more
Bioacoustics has emerged as a useful method of data collection and analysis for diverse animals in a wide range of environments and has helped to describe, monitor, and conserve some of Africa's species biodiversity. However, little is known about how much it contributes to the continent's research corpus. We report results from a systematic review of bioacoustics applications in Africa that summarises the current state of the field and identifies research opportunities. Using keyword searches of bibliographic databases, scanning reference lists, and placing appeals to the bioacoustics community in Africa we identified 727 publications between 1953 and mid-2020. We documented variables ranging from publication type and author affiliation, geographic location, biome and habitat, biological groups, and research type. Most (69%) studies were focused on animal behaviour, with terrestrial species (88.6%), particularly mammals, substantially outweighing research on freshwater (4.8%) and marine (6.6%) habitats. The majority (74.3%) of authors who have contributed to this body of knowledge were non-African affiliates. Our review suggests that bioacoustics research in Africa has considerable room to expand institutionally, taxonomically, and thematically. We highlight the need and potential for more locally driven research and provide a roadmap for future bioacoustics applications across the continent.
Research Interests: Zoology and Bioacoustics
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Research Interests: Zoology and Bioacoustics
Knowledge of cetacean occurrence and behaviour in southern African waters is limited, and passive acoustic monitoring has the potential to address this gap efficiently. Seasonal acoustic occurrence and diel-vocalizing patterns of sperm... more
Knowledge of cetacean occurrence and behaviour in southern African waters is limited, and passive acoustic monitoring has the potential to address this gap efficiently. Seasonal acoustic occurrence and diel-vocalizing patterns of sperm whales in relation to environmental conditions are described here using passive acoustic monitoring data collected off the west coast of South Africa. Four autonomous acoustic recorders (AARs) were deployed on 3 oceanographic moorings from July 2014 to January 2017. Sperm whale clicks were detected year round in most recording sites, with peaks in acoustic occurrence in summer and late winter through spring. Diel-vocalizing patterns were detected in winter, spring and summer. Higher percentages of sperm whale clicks were recorded by AARs deployed at 1100 m water depth compared to those concurrently deployed at 850 and 4500 m, likely inferring that the whales exhibited some preference to water depths around 1100 m. Acoustic propagation modelling sugges...
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In southern African waters, information about species distribution and habitat preferences of many cetacean species is limited, despite the recent economic growth that may affect them. We determined the relative importance of eight... more
In southern African waters, information about species distribution and habitat preferences of many cetacean species is limited, despite the recent economic growth that may affect them. We determined the relative importance of eight environmental variables (bathymetry, distance to shore, slope, chlorophyll-a, salinity, eastwards sea water velocity, northwards sea water velocity and sea surface temperature) as drivers of seasonal habitat preferences of Bryde’s whales (Balaenoptera brydei), humpback whales (Megaptera novaeangliae), southern right whales (Eubalaena australis) and sperm whales (Physeter macrocephalus). Using presence only data from multiple sources, we constructed predictive species distribution models (SDMs) consisting of ensembles of seven algorithms for these species during both summer and winter. Predicted distribution for all cetaceans was high in southern Africa and, in particular, within the South African Exclusive Economic Zone (EEZ). Predictive models indicated ...
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A decrease in the frequency of two southeast Pacific blue whale song types was examined over decades, using acoustic data from several different sources in the eastern Pacific Ocean ranging between the Equator and Chilean Patagonia. The... more
A decrease in the frequency of two southeast Pacific blue whale song types was examined over decades, using acoustic data from several different sources in the eastern Pacific Ocean ranging between the Equator and Chilean Patagonia. The pulse rate of the song units as well as their peak frequency were measured using two different methods (summed auto-correlation and Fourier transform). The sources of error associated with each measurement were assessed. There was a linear decline in both parameters for the more common song type (southeast Pacific song type n.2) between 1997 to 2017. An abbreviated analysis, also showed a frequency decline in the scarcer southeast Pacific song type n.1 between 1970 to 2014, revealing that both song types are declining at similar rates. We discussed the use of measuring both pulse rate and peak frequency to examine the frequency decline. Finally, a comparison of the rates of frequency decline with other song types reported in the literature and a disc...
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ABSTRACT Marine mammals, and in particular Antarctic blue whales, represent an important predator component of marine ecosystems. These mammals are considered to be critically endangered due to unsustainable whaling practices in the... more
ABSTRACT Marine mammals, and in particular Antarctic blue whales, represent an important predator component of marine ecosystems. These mammals are considered to be critically endangered due to unsustainable whaling practices in the previous century. Currently, it is also difficult to monitor the species’ population recovery through the use of sighting surveys. Passive acoustic monitoring (PAM) can be used to research Antarctic blue whales because they are quite vocal and can be detected over long distances through the use of this technology. PAM also has considerable application potential to other baleen species that reside in South African waters, including fin whales (Balaenoptera physalus). It is, however, still an emerging methodology in South Africa and a number of challenges need to be addressed before it reaches the same level of maturity as visual surveys in South Africa and around the world.
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Two of the Antarctic pack ice seals, Ross, Ommatophoca rossii, and leopard, Hydrurga leptonyx, seals, are extremely difficult to study via traditional visual survey techniques, yet are ideal for an acoustic survey as they are highly... more
Two of the Antarctic pack ice seals, Ross, Ommatophoca rossii, and leopard, Hydrurga leptonyx, seals, are extremely difficult to study via traditional visual survey techniques, yet are ideal for an acoustic survey as they are highly vociferous and produce an array of underwater sounds during the austral summer. To determine their acoustic occurrence in the Antarctic pack ice, we use their calls, detected within 680 acoustic recordings made between 1999 and 2009 as part of two multinational programmes. Siren calls of Ross seals were detected mainly in January, and 9.88 calls per minute from low siren calls was the highest call rate for this species. High numbers of Ross seal calls were detected close to the ice edge in areas between 0° and 20° E and 60° and 130° E, suggesting these are important summer habitats. Leopard seal calls were detected mainly in December and January, and December had the highest percentage of calls. Call rate of 11.93 calls per minute from low double trills ...
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<p>Those with acoustic detections of Antarctic blue whales are shown as yellow dots. Locations with no blue whale detections are shown as red dots. The black line represents the positions of SBACC based on Orsi et al. [<a... more
<p>Those with acoustic detections of Antarctic blue whales are shown as yellow dots. Locations with no blue whale detections are shown as red dots. The black line represents the positions of SBACC based on Orsi et al. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0172705#pone.0172705.ref031" target="_blank">31</a>].</p
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Anthropogenic underwater noise has been shown to negatively affect marine organisms globally; yet little to no noise research has been conducted in most African waters including South Africa's. This study aimed to quantitatively describe... more
Anthropogenic underwater noise has been shown to negatively affect marine organisms globally; yet little to no noise research has been conducted in most African waters including South Africa's. This study aimed to quantitatively describe sources of underwater noise and effects of underwater noise on the acoustic detectability of Antarctic blue, fin, minke, humpback, and sperm whales off South Africa's west coast. Noise from vessel traffic (<35 km to the location of recorders) dominated the soundscape below 500 Hz while wind-generated noise increased with wind speed above 5 m s-1 and dominated the soundscape above 500 Hz. Acoustic detectability of humpback, minke and sperm whales decreased with increasing ambient noise levels whereas blue and fin whale acoustic detectability increased with the ambient noise levels. We provide baseline information on underwater noise sources and the effects of underwater noise on whale acoustic detectability off the west coast of South
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Africa.
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Little is known of the movements and seasonal occurrence of humpback whales (Megaptera novaeangliae) of South Africa and the Antarctic, populations once brought to near extinction by historic commercial whaling. We investigated the... more
Little is known of the movements and seasonal occurrence of humpback whales (Megaptera novaeangliae) of South Africa and the Antarctic, populations once brought to near extinction by historic commercial whaling. We investigated the seasonal occurrence and diel-vocalizing pattern of humpback whale songs off the west coast of South Africa (migration route and opportunistic feeding ground) and the Maud Rise, Antarctica (feeding ground), using passive acoustic monitoring data collected between early 2014 and early 2017. Data were collected using acoustic autonomous recorders deployed 200-300 m below the sea surface in waters 855, 1,118 and 4,400 m deep. Acoustic data were manually analyzed for humpback whale vocalizations. While non-song calls were never identified, humpback whale songs were detected from June through December in South African waters, with a peak in percentage of acoustic occurrence around September/October in the austral spring. In Antarctic waters, songs were detected...
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Antarctic blue whales are one of the endangered large baleen whales recovering from the extensive whaling pressure experienced in the 20th century. Blue whales are very vocal marine mammals capable of producing powerful sounds that can... more
Antarctic blue whales are one of the endangered large baleen whales recovering from the extensive whaling pressure experienced in the 20th century. Blue whales are very vocal marine mammals capable of producing powerful sounds that can travel from a hundred to thousand or so kilometers, and these sounds can be used to estimate the relative abundance of the blue whales population. This study uses acoustic data collected from 409 of over 700 sonobuoys deployed between 1995 and 2009, on IWC research cruises (the International Decade of Cetacean Research and Southern Ocean Whale and Ecosystem Research circumpolar cruises) in the Southern Ocean south of 60oS in summer, when co-incidental visual observations of blue whales were made during line transect surveys. Blue whale presence/absence shows a high correlation between the visual and acoustic data. Both the quantity and call type of blue whale vocalisations detected from sonobuoys varied significantly between years although was depende...
The South African Blue Whale Project is aimed at estimating the relative abundance, distribution and seasonal movements of Antarctic blue whales (Balaenoptera musculus intermedia) within the South Eastern Atlantic Ocean. As part of the... more
The South African Blue Whale Project is aimed at estimating the relative abundance, distribution and seasonal movements of Antarctic blue whales (Balaenoptera musculus intermedia) within the South Eastern Atlantic Ocean. As part of the project, we applied for, and received, the International Whaling Commission's International Decade of Cetacean Research/Southern Ocean Whale and Ecosystem Research (IWC IDCR/SOWER) Antarctic and low latitude acoustic recordings from sonobuoy deployments on these cruises. The examination and collation of the data resulted in the compilation of a dataset which included the sourcing and reviewing of acoustic files and the development of a database comprising both acoustic recording files and associated station data, while also removing duplicate files. Cataloguing, file reviewing and naming of the acoustic data resulted in some 7500 acoustic recording files from over 700 stations across both the IWC SOWER Antarctic cruises from 1996/1997 through to 2...
Growing to 30 m long and weighing up to 163 tonnes, Antarctic blue whales, Balaenoptera musculus intermedia, are the largest animal that ever lived on the planet; yet despite their enormous size, they feed on small Antarctic krill... more
Growing to 30 m long and weighing up to 163 tonnes, Antarctic blue whales, Balaenoptera musculus intermedia, are the largest animal that ever lived on the planet; yet despite their enormous size, they feed on small Antarctic krill (Euphausia superba). Blue whales are not easily seen at sea as their numbers are severely reduced, however, they are great sound producers and their sounds can travel hundreds to thousands of metres from the vocalizing animal. We present here an experimental design and its contribution towards improving the knowledge of Antarctic blue whale abundance, distribution and seasonal patterns.
Research Interests: Zoology and Bioacoustics
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Page 1. Acoustic attenuation by air bubbles in bad weather conditions; a comparison of hull-and keel-mounted transducers Fannie Welcome Shabangu Master in Fisheries Biology and Management Department of Biology Faculty of Mathematics and... more
Page 1. Acoustic attenuation by air bubbles in bad weather conditions; a comparison of hull-and keel-mounted transducers Fannie Welcome Shabangu Master in Fisheries Biology and Management Department of Biology Faculty of Mathematics and Natural Sciences ...
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We examined the decrease in the frequency of the dominant southeast Pacific blue whale song type (SEP2) from 1996 to 2017, using acoustic data from five different sources ranging between the equator and Chilean Patagonia. The pulse rate... more
We examined the decrease in the frequency of the dominant southeast Pacific blue whale song type (SEP2) from 1996 to 2017, using acoustic data from five different sources ranging between the equator and Chilean Patagonia. The pulse rate of the song units as well as their peak frequency were measured using two different methods (summed auto-correlation and Fourier transform). We assess the sources of error associated with each measurement. There was a linear decline in both parameters for SEP2. A shorter comparative analysis also showed frequency decline in the scarcer southeast Pacific song type (SEP1) between 1970 to 2014, revealing that both SEP1 and SEP2 are declining at similar rates. We discuss the use of measuring both pulse rate and peak frequency to examine frequency decline. We also compare the rates of frequency decline with other song types reported in the literature.
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The International Whaling Commission (IWC) carried out blue whale research within its annual austral summer Southern Ocean Whale and Ecosystem Research (SOWER) cruises between 1996 and 2010. Over 700 sonobuoys were deployed to record blue... more
The International Whaling Commission (IWC) carried out blue whale research within its annual austral summer Southern Ocean Whale and Ecosystem Research (SOWER) cruises between 1996 and 2010. Over 700 sonobuoys were deployed to record blue whale vocalisations during 11 Antarctic and three low latitude blue whale cruises off Australia, Madagascar and Chile. The recorded acoustic files from these deployments were collated and reviewed to develop a database of both the digital acoustic files and the associated deployment station metadata of 7,486 acoustic files from 484 stations. Acoustic files were analysed using the automated detection template and visual verification method. We found a significant difference between the total number of acoustic recording hours (2,481) reported for these cruises (in the associated cruise reports) and the currently available number of acoustic recording hours (1,541). Antarctic blue whale vocalisations (9,315 D-calls and 24,902 Z-calls) were detected o...
The International Whaling Commission (IWC) carried out blue whale research components within its annual austral summer Southern Ocean Whale and Ecosystem Research (SOWER) cruises between 1996 and 2010. Over 700 sonobuoys were deployed to... more
The International Whaling Commission (IWC) carried out blue whale research components within its annual austral summer Southern Ocean Whale and Ecosystem Research (SOWER) cruises between 1996 and 2010. Over 700 sonobuoys were deployed to record blue whale vocalizations during 11 Antarctic and three low latitude blue whale cruises off Australia, Madagascar and Chile. The recorded acoustic files from these deployments were collated and reviewed to develop a database of both the digital acoustic files and the associated deployment station metadata of 7,486 acoustic files from 484 stations. Acoustic files were analysed using the automated detection template and visual verification methods. We found a significant difference between the total number of acoustic recording hours (2,481) reported for these cruises (in the associated cruise reports) and the currently available number of acoustic recording hours (1,541). Antarctic blue whale vocalizations (9,315 and 24,902 Dand Z-calls) were d...
Descriptions of seasonal occurrence and behaviour of Antarctic blue and fin whales in the Southern Ocean are of pivotal importance for the effective conservation and management of these endangered species. We used an autonomous acoustic... more
Descriptions of seasonal occurrence and behaviour of Antarctic blue and fin whales in the Southern Ocean are of pivotal importance for the effective conservation and management of these endangered species. We used an autonomous acoustic recorder to collect bioacoustic data from January through September 2014 to describe the seasonal occurrence, behaviour and detection ranges of Antarctic blue and fin whale calls off the Maud Rise, Antarctica. From 2479 h of recordings, we detected D- and Z-calls plus the 27 Hz chorus of blue whales, the 20 and 99 Hz pulses of fin whales and the 18-28 Hz chorus of blue and fin whales. Blue whale calls were detected throughout the hydrophone deployment period with a peak occurrence in February, indicating continuous presence of whales in a broad Southern Ocean area (given the modelled detection ranges). Fin whale calls were detected from January through July when sea ice was present on the latter dates. No temporal segregation in peaks of diel calling...
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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... more
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 t...