We work with local and international scientists; postgraduate students and interns to conduct innovative shark research
SHARK RESEARCH PROJECTS
The challenges facing sharks are many and seemingly overwhelming. More than 100 million are slaughtered every year for their fins, whilst climate change dramatically disrupts the oceanic ecosystem and food chain.
To address this critical issue, the Shark Research Unit proposes to undertake both long-term and short-term strategic research projects. By doing so, we aim to provide valuable information and guidance to South Africa’s governing authorities in their management and conservation policies. Ultimately, our goal is to contribute towards the sustainability of shark species inhabiting our waters.
Project status (active or past) is dependent on obtaining the correct research permit.
We conduct continuous photographic identification research to assess the populations of sharks at both regional and national levels. To achieve this, we utilize ‘mark-recapture’ analytical techniques, which rely on identifying distinct physical features of individual sharks from photographic data. These unique features may comprise pigmentation patterns, dorsal fin notches, distinctive wounds, as well as variations in size and gender. Our research primarily concentrates on multiple species of sharks, including the great white shark, blacktip shark, sand tiger shark, puffadder shy shark, and pyjama shark.
> Sighting rates (CPUE) of target shark species
> Local population estimates of target shark species
> National population estimates of target shark species
> Sex ratio and distribution of target shark species
> Site-specific size distribution of target shark species
“These projects represent a crucial opportunity for non-invasive exploration into the long-term population sustainability and numbers of the target shark species. Given the significant ecological and human-induced pressures faced by shark populations, ongoing evaluation of their health and numbers is one of the most effective tools we have to ensure their survival.”
Mossel Bay, located in the Western Cape province of South Africa, is known for its rich diversity of shark species. Some of the common shark species found in the area include:
Great White Shark (Carcharodon carcharias)
Bronze Whaler Shark (Carcharhinus brachyurus)
Ragged-tooth Shark (Carcharias taurus)
Soupfin shark (Galeorhinus galeus)
Smooth hammerhead shark (Sphyrna zygaena)
Pyjama shark or Stripped catshark (Poroderma africanum)
Puffadder shyshark (Haploblepharus edwardsii)
Leopard catshark (Poroderma pantherinum)
> Diversity and relative of shark species on reefs within the Mossel Bay region
>Variation in shark abundance and diversity as a function of season
>Variation in shark abundance and diversity as a function of environmental conditions.
Assessing shark diversity is important for several reasons. First, sharks play a vital role in maintaining the balance of marine ecosystems, and changes in their populations can have cascading effects throughout the food chain. By monitoring shark diversity, researchers can gain insights into the health of these ecosystems and make informed decisions about conservation efforts.
Second, sharks are often apex predators, meaning they are at the top of the food chain. As such, they can serve as indicators of the overall health of the ecosystem. Changes in shark populations can signal imbalances or other issues that may be affecting other marine species.
Finally, understanding the diversity of sharks in an area is crucial for managing human activities that may impact these animals. By identifying areas where sharks are particularly abundant or vulnerable, researchers and policymakers can work to minimize the impact of activities like fishing and tourism on these important species.”
In the last few years, the use of environmental DNA to document the presence and distribution of shark species (without visual information), has developed as a powerful tool to quickly and cheaply determine the absence or presence of a certain shark species in an area. At the Shark Research Unit we are advancing this technique to measure relative abundance and reliability of this technique through ground truthing it with sighted shark numbers.
> Can eDNA be used to assess abundance of sharks in a specific region
> Concordance between shark sighting rate (CPUE) and measurements of shark abundance derived from eDNA measurements.
“Using metrics, such as eDNA, that don’t require visual observation, may be one of the most fascinating new techniques to assess the diversity and abundance of sharks in a specific region.”
The Shark Research Unit actively participates in the Oceanographic Research Institute’s Cooperative Fish Tagging Project (ORI-CFTP), a long-term collaborative marine environmental project aimed at promoting the responsible and sustainable use of southern Africa’s marine resources. Tagging is a crucial tool utilized by fishery biologists to study individual aquatic animals or populations. By marking or tagging aquatic animals, researchers can gather valuable information essential for research or management purposes.
In summary, by participating in the ORI-CFTP, the Shark Research Unit contributes to important research aimed at promoting the sustainable use of southern Africa’s marine resources.
How can we contribute to research?
1- Stock identification – By determining whether stocks or sub-populations are connected and being used for sport or commercial fisheries, we can better understand the distribution of a particular species.
2- Migrations – The tagging data can help researchers identify the path and distance of a species’ migration, rate of movement, and homing tendencies.
3- Behaviour – By analyzing the tagging data, researchers can identify factors that limit abundance, such as habitat selection and intra- and inter-species interactions.
4- Age – Tagging data can be used to validate the age of fish, particularly for aging methods such as counting growth rings on a scale. This information is vital in determining growth rates.
5- Mortality rates – By following the effects of natural and fishing mortality on a fish population, we can gain insight into the sustainability of a particular fishery.
The ability of sharks to change their colour is an under-studied field of research. Historically a number of sharks have proven to have hormonally induced colour change abilities. The observation of background matching (adapting to the colour of a background) is thought to enable such sharks to increase camouflage in varied environments where they hunt for food or avoid detection from predators. At the shark research unit we are investigating the ability of the Great Whtie Shark to modify its colour in response to different environments and behavioural activities.
> Does the great white shark present hormonally induced colour change abilities?
> What hormones are responsible for inducing either darkening or lightening effects in great white sharks?
> Does activity type impact the phenotypic display of colouration in great white sharks.
“The ability of a shark to vary its colour to match differring environments may be critical to its ability to maintain its ecological position when faced with todays changing climate.”
Non-targeted fishing and incidental capture of sharks can have a severe impact on their survival, causing significant injuries that can hinder their ability to thrive. This is especially critical in Marine Protected Areas, where sharks should receive a high degree of protection from fishing activities.
To address this issue, the Shark Research Unit is actively conducting research on the extent of human and fishing-induced injuries among shark populations residing within Marine Protected Areas. Our ongoing research also involves monitoring the health, recovery, and behavior of injured sharks from the time of injury until full recovery.
Our goal is to better understand the impact of fishing activities on shark populations and to develop effective measures to protect these important marine species. By improving our understanding of the challenges that sharks face in these protected areas, we can work towards more effective conservation strategies to safeguard these critical ecosystems.
> What is survival likliehood following fishing induced injury to sharks
> Do fishing injury pressence impact behaviour of sharks at a shark diving area
> Describe the recovery timeframe of sharks injured by fishing equipment. Specifically as a function of injury severity
“Sharks possess remarkable healing abilities; however, they remain susceptible to injuries caused by human activities such as commercial fishing, boat strikes, and entanglement in fishing gear. These injuries can have severe consequences for individual sharks and their populations, underscoring the significance of responsible human behaviour and conservation efforts to safeguard these magnificent creatures.
Human-induced injuries can impair a shark’s ability to hunt, reproduce, and defend itself, ultimately threatening the survival of the entire species. Moreover, some shark populations are already facing severe threats due to overfishing and habitat destruction. These threats are compounded by human-induced injuries, further exacerbating the challenges faced by these remarkable animals.
It is imperative that we take steps to minimize human impact on shark populations, such as reducing bycatch and implementing sustainable fishing practices. Additionally, supporting conservation efforts aimed at preserving vital habitats and raising awareness about the importance of sharks to the health of our oceans can help ensure their survival for generations to come.”
The Shark Research Unit is actively involved in the ELMO AFRICA project, a citizen science initiative focused on collecting data on South African shark, ray, and skate populations. As part of this project, we collect information on elasmobranch eggs that wash up on Mossel Bay beaches, contributing to a central database that is used to inform conservation efforts.
By collecting and submitting data to the ELMO AFRICA project, we are helping to build a more comprehensive understanding of elasmobranch populations in South Africa. This information can be used by scientists, politicians, and stakeholders to make informed decisions about conservation efforts, ultimately helping to protect these vulnerable species.
Through our involvement with the ELMO AFRICA project, we are contributing to a larger effort to promote citizen science and engage the public in conservation efforts. We believe that this type of collaboration between scientists and the public is key to promoting a more sustainable and responsible approach to environmental conservation.
In recent years, there has been a notable shift in the distribution of Great White Sharks, resulting in an increase in sightings at Plettenberg Bay, South Africa. This area is home to a resident population of Cape fur seals, who inhabit the mainland rocks surrounded by shallow waters.
To better understand the dynamics between predator and prey in this unique environment, the Shark Research Unit is conducting observation studies. These studies aim to describe how Great White Sharks capture and exploit the Cape fur seal resource in this location.
Understanding the behaviour of Great White Sharks in Plettenberg Bay is crucial for the development of effective conservation strategies to protect both the sharks and their prey. By gaining insights into the predator-prey dynamics, we can determine how changes in the shark population may impact the ecosystem as a whole.
Overall, the Shark Research Unit’s studies at Plettenberg Bay are contributing to a deeper understanding of Great White Shark behaviour and their role in marine ecosystems. Through ongoing research, we hope to inform conservation efforts and ensure the long-term survival of these apex predators and their prey.
> What behavioural hunting techniques do white sharks utilise when hunting Cape fur seals at Robberg Peninsula colony.
> Success rates of predatory attempts by white sharks on Cape fur seals at Robberg.
> Behavioural predator avoidance strategies utilised by Cape fur seals at Robberg.
This project presents a valuable opportunity to investigate the long-term population sustainability of White Sharks in the region using non-invasive methods. As ecological and human-induced pressures on these sharks continue to mount, ongoing population health assessments are becoming increasingly vital in our efforts to protect and conserve the species.
By monitoring the population numbers of White Sharks over the long-term, we can gain a better understanding of their ecological role and how they are impacted by changes in the environment. This information can be used to inform conservation strategies that aim to mitigate the effects of human activities and protect these iconic apex predators.
Importantly, the non-invasive nature of this research helps to minimize any potential harm to the sharks, enabling us to study their populations in a sustainable and ethical manner. By utilizing such methods, we can continue to gather critical data on the health and numbers of White Sharks in the region, supporting ongoing conservation efforts to safeguard their long-term survival.
Overall, this project represents a significant step towards better understanding the population dynamics and sustainability of White Sharks, providing valuable insights that can inform conservation strategies aimed at protecting these majestic creatures from the mounting pressures they face.
Modification of shark perception by humans is critical to generate wide scale support for shark conservation efforts. Shark tourism has long been touted as a powerful tool to facilitate this desired change in perception. At the shark research unit we determine the impact of shark tourism on human perceptions, as well as, determining effective communication and education tools that tourism operations can use to effect such perception change in shark diving and adventure tourists.
> Does shark diving and ecotourism activities cause perception changes in humans towards sharks.
> Is the degree of perception change induced independent of the level of active education perople receive whilst on shark diving expereicnes?
> Is the degree of perception change induced independent of the type of active education people receive whilst on shark diving expereicnes?
“A recent study on public opinions of sharks in conjunction with shark bite occurrences discovered that individuals living near shark-frequented beaches value sharks highly and that these values do not appear to be negatively influenced by shark bite accidents.”
The scientists of the Shark Research Unit have lead and conducted many of South Africa’s most ambitious and successful shark research projects during the past 20 years. Some of the highlights include
Satellite tracking Great White Sharks. Satellite tracking over 50 great white sharks throughout South Africa, Mozambique, Madagascar, Seychelles and as far as Australia.
Acoustic telemetry on Great White Sharks. Conducting both passive and active tracking of over 150 great white sharks using VEMCO based telemetry arrays. Establishing fine scale movements, residency patterns, habitat use patterns.
Predatory encounters between great white shark to hunt humpback whales. Documented and analysed strategic predatory approach of a great white shark hunting and drowning a weakened juvenile humpback whale.
Shark Bite Force. Assessing bite force of great white sharks through measuring maximum bite pressure on custom designed bite force meter. Determining bite progression patterns and relating maximum bite force to shark size.
Residency patterns of Great White Sharks. Use of photographic identification and passive listening stations to determine residency patterns of great white sharks in the Mossel Bay region. Specifically investigating site fidelity as a function of shark total length, gender and seasonal patterns in occurrence.
Impact of White Shark Cage Diving. Conducted a six year impact assessment on the impact of white shark cage diving on the ecology of the great white shark, and the impact on relationship between sharks and humans.
The Shark Research Unit is a shark and marine research and conservation institute driven by a passionate team of shark experts. We are located in South Africa and work in two regions of priority – Aliwal Shoal and Mossel Bay.
Our core purpose is to conduct and support original shark research, conservation and education programs through strategic partnerships with marine scientists, postgraduate students, ecotourism operators and academic institutes.
Our focus extends to nurturing a new generation (of all ages) of shark scientists, professionals and enthusiasts. We achieve this through our great white shark research internship, learner outreach programs and expert guided shark edu-tours