Stephanie Plön

Stephanie Plön
Stellenbosch University and Bayworld Centre for Research and Education · Department of Pathology

PhD

About

84
Publications
28,062
Reads
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513
Citations
Introduction
My research interests focus on the general ecology of cetaceans (whales and dolphins), including their natural history, trophic ecology, anatomy, population genetics, strandings and health. For this I use a diverse array of research methods and also collaborate widely with colleagues in related research areas to gain a more holistic picture of variations in the populations found in our local Eastern Cape waters in South Africa.
Additional affiliations
March 2017 - present
Nelson Mandela University
Position
  • Head- Ocean Health Unit
October 2013 - November 2015
Nelson Mandela University
Position
  • Research Associate
October 2013 - December 2016
Nelson Mandela University
Position
  • Research Associate
Education
January 1996 - December 2004
Rhodes University
Field of study
  • Zoology
October 1991 - June 1994
Swansea University
Field of study
  • Marine Biology

Publications

Publications (84)
Article
Blubber is a highly specialised and dynamic tissue unique to marine mammals and presents a reflection of the individuals' nutrition, environment, and life history traits. Few studies have investigated the histomorphology of cetacean blubber in sub‐tropical environments. The aim of this study was to investigate the blubber histomorphology of three d...
Article
Plans for large-scale economic developments in the Indian Ocean, including increased shipping, oil and gas exploration and offshore mining, have resulted in concerns about potential impacts on cetaceans. Two species of particular interest are the resident, coastal Indian Ocean humpback dolphin Sousa plumbea and the migratory humpback whale Megapter...
Article
Full-text available
In 2014, the South African government launched ‘Operation Phakisa’ under which port developments play a significant role in supporting ocean economic growth. These developments will likely increase vessel traffic to and from South African ports, making it imperative to monitor for changes in underwater sound budgets with potential negative effects...
Article
Full-text available
The Indian Ocean humpback dolphin Sousa plumbea has been described as South Africa’s most endangered marine mammal due to its low abundance, reliance on coastal habitats with increasing anthropogenic threats and high rates of mortality from bycatch in bather protection nets (BPNs). Although the species has been well studied in South Africa, only a...
Article
Full-text available
The Indian Ocean humpback dolphin (Sousa plumbea) is "endangered" with likely less than 500 animals remaining in South African waters. Established in 2016, the SouSA Consortium is a formalised network of scientists and conservationists to combine knowledge and research efforts, and make coordinated decisions with the aim of conserving the species....
Article
Full-text available
Mammalian spermatozoa are a notable example of metabolic compartmentalization.¹ Energy in the form of ATP production, vital for motility, capacitation, and fertilization, is subcellularly separated in sperm cells. While glycolysis provides a local, rapid, and low-yielding input of ATP along the flagellum fibrous sheath, oxidative phosphorylation (O...
Preprint
Full-text available
Mammalia spermatozoa are a notable example of energetic compartmentalization. While mitochondrial oxidative phosphorylation is restricted to the midpiece, sperm-specific glycolysis operates in the flagellum. Consequently, these highly specialized cells exhibit a clear adaptability to fuel substrates. This plasticity is essential to ensure sperm mot...
Article
Full-text available
Bather protection nets have been in place off the coast of KwaZulu-Natal (KZN), South Africa, since the 1950’s. Besides sharks, they also catch a number of other marine vertebrates, including dolphins, the majority of which are Indo-Pacific bottlenose dolphins Tursiops aduncus . Previous analyses of dolphin bycatch in the nets indicated the potenti...
Article
Despite their typical large group sizes, limited research exists on the occurrence of common dolphins Delphinus delphis because of the pelagic, offshore nature of this species and the lack of barriers to their movement in this environment. The main purpose of our study was to investigate the occurrence of common dolphins off the Wild Coast of South...
Article
The present study represents the first reported boat-based photographic identification study of Indo-Pacific bottlenose dolphins (Tursiops aduncus) off the Wild Coast of southeast South Africa. This area is known for the annual sardine run, which attracts apex predators to the region during the austral winter. Dedicated photo-identification surveys...
Article
Full-text available
Concern about the effects of maritime vessel collisions with marine animals is increasing worldwide. To date, most scientific publications on this topic have focused on the collisions between large vessels and large whales. However, our review found that at least 75 marine species are affected, including smaller whales, dolphins, porpoises, dugongs...
Article
Full-text available
The four currently recognised species of Sousa are all threatened on the IUCN Red List. To date they have not been included in any of the available software platforms that have been developed for the automated matching of cetaceans from photo-ID data. Because of their unique morphology, existing algorithms are unlikely to be successful and new algo...
Article
Crassicauda spp. (Nematoda) infest the cranial sinuses of several odontocetes, causing diagnostic trabecular osteolytic lesions. We examined skulls of 77 Indian Ocean humpback dolphins Sousa plumbea and 69 Indo-Pacific bottlenose dolphins Tursiops aduncus, caught in bather-protecting nets off KwaZulu-Natal (KZN) from 1970-2017, and skulls of 6 S. p...
Article
Full-text available
The life history of Risso's dolphins (Grampus griseus) remains poorly known and data from strandings can help provide important information. Data from 126 Risso's dolphins stranded or bycaught along the southeastern coastline of South Africa between 1958 and 2017 were analyzed in relation to their sex, age structure, and diet. Mean estimated length...
Article
Full-text available
The common dolphins (genus Delphinus) are widely distributed in all temperate and tropical oceans. Over this wide geographical distribution they show considerable range in morphological variation, which has led to descriptions of several species in the genus. Until recently, only two species of Delphinus were accepted, but this classification has b...
Article
Full-text available
We investigated the phylogeography of the dugong (Dugong dugon) across its original range using museum material from 14 natural history museum and university collections. The mitochondrial DNA control region was successfully amplified from samples of bone or tooth powder from 162 individuals. These samples range from 1827 to 1996 and span the histo...
Conference Paper
Full-text available
Off South Africa, nearshore Indian Ocean humpback dolphins (Sousa plumbea), an IUCN listed endangered species with a declining population off the South African east coast, face several anthropogenic threats, including fisheries, pollution and shark nets deployed off the coast of KwaZulu-Natal (KZN). Documented diseases in this population include pn...
Article
PBDEs, HBCD, DBDPE, PBEB and HBB, dechloranes and OPFRs, as well as natural MeO-PBDEs were monitored in muscle tissue of three dolphin species from the southwestern Indian Ocean (Delphinus delphis, Sousa plumbea and Tursiops aduncus) collected between 2012 and 2015. The mean PBDE concentration was 416 ± 333 ng g ⁻¹ lw. BDE-47 was found in all sampl...
Article
Full-text available
Taxonomy plays an important role in conservation biology. Despite the variety of methods used to differentiate units, some groups, such as Delphinidae within the Cetacea have proven difficult to untangle. This study aimed to shed light on morphological variation of the genus Tursiops in South African waters using geometric morphometrics and to dist...
Article
Full-text available
The macroscopic morphology of structures involved in sound generation in the Indian Ocean humpback dolphin (Sousa plumbea) were described for the first time using computed tomography imaging and standard gross dissection techniques. The Indian Ocean humpback dolphin may represent a useful comparative model to the bottlenose dolphin (Tursiops sp.) t...
Article
Full-text available
In South Africa, the humpback dolphin (Sousa plumbea) has been recognized as the most endangered marine mammal, with a low abundance, a discontinuous distribution, and numerous threats. This research was initiated in 2008 to estimate the number of individual humpback dolphins in Algoa Bay, as well as studying their residency patterns and distributi...
Article
Full-text available
The Indian Ocean humpback dolphin was recently uplisted to 'Endangered' in the recent South African National Red List assessment. Abundance estimates are available from a number of localized study sites, but knowledge of movement patterns and population linkage between these sites is poor. A national research collaboration, the SouSA project, was e...
Article
We examined external morphometric parameters in incidentally caught long-beaked common dolphins (Delphinus capensis) from the east coast of South Africa for evidence of sexual dimorphism. We evaluated sexual dimorphism and allometric growth in 26 external body measurements from 211 individuals and assessed size and shape dimorphism. Most characteri...
Poster
The taxonomy of bottlenose dolphins Tursiops spp. and Delphinus spp. remains unresolved with suggestions that animals from Southern Africa may represent a separate clade. We used a molecular analysis of museum specimens to investigate this. Despite inherent difficulties, analysis of DNA for preserved material (“ancient” DNA) has been extensively ut...
Article
Full-text available
Increasingly, baseline knowledge of habitat preferences and movement patterns of marine species is required to inform anthropogenic developments. The aim of this study was to determine baseline spatio-temporal distribution and habitat preference of cetaceans in the coastal waters of Algoa Bay. Areas of potential conflict with anthropogenic activiti...
Article
Full-text available
During the austral winter, cetaceans and other apex predators follow the annual northeastward movement of shoaling sardines, known as the sardine run, along the southeast coast of South Africa, including a 400-km stretch called the Wild Coast. In total, 131 opportunistic aerial surveys were conducted between May and July, from 1996 to 2014, to moni...
Conference Paper
Southern right whales (Eubalaena australis) were absent along the Eastern Cape coast, South Africa, for more than a century after overexploitation by land-based whalers in the early 1800s. Currently, mother-calf pairs in particular are again frequently sighted in this area, raising concerns about the effect of recent port developments on their occu...
Article
The KwaZulu-Natal (KZN) Sharks Board in Durban, South Africa, has been managing bather protection nets off KZN’s most popular beaches since 1952 to mitigate shark-human interaction. The nets catch potentially dangerous sharks, but also take a bycatch of other marine megafauna, including the Indo-Pacific bottlenose dolphin Tursiops aduncus. A total...
Article
Full-text available
This study assessed the extent of sexual dimorphism in striped dolphin (Stenella coeruleoalba) cranial size and shape off the South African coast. Dorsal and ventral features of 60 striped dolphin crania from both the western and eastern coasts of South Africa were analyzed using landmark-based geometric morphometrics. Although there was no evidenc...
Article
Full-text available
Coastal dolphins are more prone to cumulative impacts of environmental and anthropogenic changes than pelagic species. However, few studies use historical comparisons to evaluate those impacts across a temporal scale. The study presented here describes the pattern of occurrence, group size, behavior, and habitat use of humpback dolphins in Algoa Ba...
Article
Full-text available
The continuous disposal of persistent organic pollutants (POPs) in South Africa (SA) warrants concern about their detrimental effects on humans and wildlife. We surveyed six dolphin species (n=90) incidentally captured in shark net installations or stranded off the SA east and south coast from 2005 to 2009 to study the POP exposure. Sousa plumbea,...
Article
Full-text available
Although most knowledge on the biology of Sousa plumbea has primarily come from South African waters, a number of research gaps remain on the natural history and status of the species in the region. Research on two populations in South African waters for which some historical data exist may aid in highlighting long-term changes in the biology and n...
Article
Full-text available
Globally, the increasing need to conduct both research and surveillance of the health of wild animal populations has been recognized as an important tool in conservation and management. While such studies on terrestrial wildlife are frequent in the southern African sub-region, their counterparts in the marine environment seem to be largely lacking....