This story has a classic beginning. Every Sunday afternoon I would climb onto the armrest of my father’s chair, joining him for what was my favourite time of the week: the screening of Jacques Cousteau’s voyages on television. I pulled my little legs close, chin resting on my knees, and followed the Calypso’s crew on their marine adventures as though I were one of them. At my side I kept a shortlist of what I wanted to be when I grew up: photographer, veterinarian, scuba diving instructor, archaeologist, journalist, conservationist, marine biologist… The list was mixed up, tumbled around, re-evaluated, thrown away and re-written many times.
I followed the long, winding and often painful road of academia, hoping that it would one day end by the sea. The result was a colourful CV that reflects the random approach I had to a lack of both money and confidence as a young biology student. I interned wherever I could, working with animals that no-one else wanted to work with and funded by organisations that otherwise would perhaps never have seen my potential among students with shining records. But time brought experience, knowledge and confidence and here I am today, proudly calling myself a marine ecologist and working on a project that combines two disciplines I find truly fascinating: citizen science and the reproduction of South African catsharks.
Two of the world’s largest oceans meet off South Africa: the Atlantic with its cold, nutrient-rich Benguela Current to the west and the Indian with its fast, tropical Agulhas Current to the east. This unique setting has created three distinct biodiversity zones in South Africa: subtropical, warm-temperate and cold-temperate. It is no surprise that biodiversity is thriving in the country, making it an ecologist’s paradise. Life on land and life in the sea have always interacted with each other. One of the best places to observe this is at Cape Point, where baboons harvest shellfish from the intertidal zone.
Humans have perfected the exploitation of marine resources and South Africa has considerable commercial and recreational fisheries. Even though the country boasts an extraordinary abundance of marine life, harvesting it with increased efficiency and decreased selectivity has taken its toll, affecting primarily the species that have a narrow geographical range. Fishing pressure on endemic species is strong in South African waters and it is crucial that we understand the biology of these species and their role in the ecosystem if there is to be a healthy ecological balance.
South Africa has more than 100 shark species, but only the largest and toothiest are lucky enough to receive substantial public attention. Although their importance cannot (and should not) be denied, it is the small shark species that really make South Africa’s reefs unique: 14 of 16 catshark species occur nowhere else in the world. Their local abundance has led to the misconception that there are plenty of catsharks, but the reality is that pressure from both commercial and recreational fisheries is threatening their existence. As of today, seven endemic catshark species feature as threatened to some degree on the IUCN Red List and three species are still Data Deficient. We urgently need to improve our understanding of catsharks and their biology in order to protect them.
All South African catsharks produce eggs, which remain on the reef for up to 12 months until they hatch. This makes it easy to detect breeding grounds and to monitor the development of catshark embryos in shallow water. In this project we, the South African Elasmobranch Monitoring (ELMO) team, will work with citizen scientists to gather knowledge about the breeding seasons and habitats of South African catsharks. Recreational scuba divers all over South Africa will help us to identify areas that are of exceptional importance for catshark reproduction by answering questions about the occurrence of the sharks and their eggs on their local reefs. We call this group of participants Local Reef Reporters.
Another group of divers will go a step further and closely monitor one particular reef and the development of every single egg on it over the course of a whole year. This group of divers are called Elmoblitzers. In a workshop held by the ELMO team, they will learn how to identify, tag and safely handle a shark egg. We will demonstrate how to use a torch to look through the eggcase membrane and how to record the growth and survival of a shark pup. There is a lot more interesting information that we are asking the divers to record, such as organisms growing on the egg (‘biofouling’), predators, hatching success, the substrate on which the egg is found and the water temperature.
This study will actively involve the public in research and will improve our understanding of the factors that influence the survival and development of a catshark pup. Participation in the project is not limited to divers; anyone can take part by reporting sightings of catsharks or their eggs – even those found on the beach. All participating dive centres will be equipped with educational material, so if you would like to get involved feel free to visit one of the dive centres we are working with (a list will soon be published at https://www.elmoafrica.org/elmoblitz).