Nico is using acoustic telemetry and BRUVs around Seychelles to explore how reef sharks are using their reef homes. What are they eating? What prey is available? His project aims to explore what factors influence ideal habitats for sharks and will combine information from both pristine and degraded reefs to create a model to test this suitability. The point? To build on work by the Marine Futures Lab across the Indian Ocean and the Indo-Pacific and to help identify priority shark conservation areas.
Ever since I saw my first shark in 2013, I knew that I wanted to become a marine biologist and work with these fascinating animals one day. I grew up in Germany, some three hours’ drive from the nearest ocean, but discovered my passion for marine life at the age of 11 when I dived for the first time with my dad. That was in the Red Sea, in Egypt, and I remember being blown away by the colours and the number of fish we encountered – unlike anything I’d ever seen before. On finishing school, I flew to Seychelles...
To investigate the relationship between reef habitat complexity and habitat use in different species of reef shark. By combining benthic habitat zonation and structural complexity metrics, prey availability surveys, and acoustic tracking and video observations of reef sharks, we will assess how changes to reef structure, and associated changes in reef fish communities, can affect the fine-scale habitat suitability choices of top coral reef predators.
Over the past decades, increases in shark fishing and climatic disturbance events have led to a global, cumulative decline in populations of coastal sharks and their associated habitat, coral reefs. A global study of coastal shark habitats found that sharks were absent from 20% of the 371 reefs surveyed. Indian Ocean areas were not only highlighted as being in critical need of protection, but also identified as having great potential for the implementation of predator-based management approaches.
This project will use cutting-edge technology and state-of-the-art ecological modelling to improve our understanding of the complex behaviour of reef sharks and inform regional management strategies. Identifying critical habitat for reef shark species in a near-pristine environment will help us to inform the effective management and protection of shark species in Seychelles’ waters. In addition, filling the knowledge gaps in functional predator ecology will aid in the effective management of these species and enable healthy reef environments to be safeguarded. By using a high-tech and low-cost approach, we will maximise the possibilities of replicating the study and the accessibility of digital approaches, both of which can assist long-term monitoring projects, predator studies and ecological modelling efforts.
The concept of top-down control in coral reef communities as well as trophic cascades induced by declines in shark populations have long been studied. Our understanding of these processes is complicated by the dynamic and complex nature of coral reef communities and much of what is known of these phenomena stems from field-based studies and associated food web modelling approaches. The drivers of non-trophic effects on reef communities are, however, often excluded from such investigations. In many cases, physical characteristics such as wave energy, current velocity and habitat dynamics are likely to impact foraging behaviour and success, for example. Habitat structure and complexity impact the distribution and availability of prey resources and are important components in interpreting inter-species interactions. Defining fine-scale habitat use patterns and environmental requirements as well as inter-species variations in reef dependence is crucial to understanding the role of sharks on reefs and predicting the consequences of their loss. Taking a bottom-up approach to modelling reef shark habitat interactions will give novel insights into the sharks’ complex behaviour patterns and the role benthic communities play in predator–prey interactions.
Anna is collecting genetic information from white shark fin clips to assess this species’ population size in South Africa. Using close-kin mark-recapture analysis instead of traditional methods, she hopes to provide an accurate account of South Africa’s white shark population size. She also aims to develop a monitoring protocol that can use genetic samples collected during shark net and drumline patrols by the KwaZulu-Natal Sharks Board. This information is needed in South Africa, where the conservation of a protected species is balanced against concerns about bather safety, and where sharks are caught in bather protection gear.
Faqih is filling the gaps in the scant knowledge of giant guitarfish in Java’s Karimunjawa National Park marine protected area (MPA). Karimunjawa is located near Northern Java’s main fishing grounds, but evidence of giant guitarfish caught in some of the use-zones of the MPA hints that the park may be a sanctuary for the species. Managing giant guitarfish in Karimunjawa requires species-specific information.
Faqih’s project is a socio-ecological one to help inform management and draws on new information about relative abundance and distribution, historical occurrence and fishing pressures to paint a contemporary picture of the species in the park.
Cindy wants to know if bonnethead sharks in the Eastern Pacific constitute a third, cryptic species. The Bonnethead complex need clarification in all its distribution range, and Panama is a key country to solve this question since we have the Caribbean sea and the Pacific Ocean. By collecting fin clip samples to compare species at the genetic level and collecting specimens to compare how they look (morphology), Cindy hopes to resolve the taxonomy of Sphyrna tiburo vespertina – that is, whether it’s a cryptic third species for bonnetheads in the region. Her information can help update the IUCN Red List for bonnetheads and improve fisheries policies in Latin America where bonnethead sharks are commonly caught.