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:

1. Great White Shark (Carcharodon carcharias)
2. Bronze Whaler Shark (Carcharhinus brachyurus)
3. Ragged-tooth Shark (Carcharias taurus)
4. Soupfin shark (Galeorhinus galeus)
5. Smooth hammerhead shark (Sphyrna zygaena)
6. Pyjama shark or Stripped catshark (Poroderma africanum)
7. Puffadder shyshark (Haploblepharus edwardsii)
8. 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.

Nico Booyens

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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. 

Sophu Qoma

“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 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.

Ryan Johnson

“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

Nico Booyens 

“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.”

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.

Nico Booyens

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?

Nico Booyens

“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.