Shark Spotters: Update on OCEARCH white shark research at Seal Island, False Bay 15 – 16 April 2012
Crew and scientists fit a real-time satellite tag, draw blood, and collect parasites from a large white shark. While on the platform a wet towel covers the sharks’ eyes, and a hose continuously flushes oxygenated seawater over the sharks gills.
The research in False Bay started at 3 pm on Sunday 15 April until 7:30 pm and again the next day, Monday 16th April from 8 am until 3 pm, when the southeasterly wind resulted in unsafe working conditions for the crew and scientists on the ship’s platform and prevented further work from taking place.
In total four sharks were captured and tagged at Seal Island. The sharks were brought onto the ship’s work platform where the crew and scientists were able to attach real-time satellite tags and acoustic tracking tags, with ten year battery life to enable long range and long term monitoring of movement and migration patterns. The scientists also drew blood, collected muscle samples for hormone and stable isotope analysis to determine their reproductive status and diet, collected length and other measurements, and collected parasites and bacterial samples from places like the teeth and gums.
Alison Kock, Research Manager at Shark Spotters and lead scientist in False Bay, was on board throughout the whole operation and in communication with our team on land, reported that the capture and sampling process was skillfully and expertly handled with the welfare of the crew, scientists and the sharks at the forefront. Alison said that the scientific value of the work being done in South Africa is unprecedented and the knowledge gained will enhance the ability of managers to make informed decisions to ensure the sustainability of South Africa’s white shark population. Furthermore, the information will ultimately contribute to our enhanced understanding of the sharks’ behaviour which will assist us in providing better information to enhance water user safety.
All sharks captured were females and ranged in length from 3.9 to 5 meters. The capture time ranged from 18 to 38 minutes and the time the sharks were on the research platform ranged from 11 to 16 minutes. One of the sharks had an old injury, a damaged dorsal fin (more than likely caused by a boat propeller) and could not have a satellite transmitter attached, but she was in good health and fitted with a long life acoustic transmitter and all the other data was collected. Another shark was entangled in fishing gear which was removed during the process.
It was observed that the amount of chum used was insignificant compared to daily existing natural chum created by Seal Island, and compared to daily chum created in the bay through normal fishing activities and sources such as Kalk Bay harbour. Further, chumming was equitable to the collective amount undertaken by the cage diving industry in the bay on a daily basis.
Ten sharks need to be tagged at Seal Island to collect data from a representative sample of the population. The research team has currently moved up the coast in search of better weather, and will complete the work at Seal Island when the conditions improve and a minimum of two days have passed as per permit condition.
To see the sharks’ tracks you can visit https://www.facebook.com/OCEARCH
A large, mature male white shark tagged in Gansbaai is ready to return to the ocean after attaching the satellite tag and all the scientific data has been collected.
Below is the latest statement issued by DEA regarding the research expedition.
MEDIA STATEMENT: Issued by the Department of Environmental Affairs
16 APRIL 2012
OCEARCH-SHARKMEN RESEARCH PROJECT
The Department of Environmental Affairs would like to respond to some misleading and inappropriate statements issued by certain individuals that have no mandate to issues Shark Alerts to the public. These alarmist statements individuals are creating unnecessary public concern. This also diminishes the value of real alerts, such as, sharks being attracted to the Buffels Bay area by the whale which washed up on the beach a few days ago.
1. The Department has recently completed a draft Conservation Plan for Sharks. The plan emphasizes that Sharks are both poorly understood and that many species are threatened by human activities. It also notes the need for research in order to understand the basic life histories of a number of species, including migration, reproduction and population status. To achieve this, fairly large scale research is needed including finding out where animals move at different stages of their life and how they move between and utilize different habitats on shorter time-scales.
The Sharkmen initiative presented a unique opportunity for researchers to answer these questions. The initial data is already showing rapid large scale and coastal migrations, including several white sharks moving into the Southern Ocean and another moving between the Eastern Cape and KwaZulu-Natal and back (also showing where it stopped along the way). Genetic and other microbiological results will take longer to analyze but should allow statistically valid conclusions to be made about white sharks populations and their biology.
2. The sampling protocols developed for this project are the most comprehensive for any similar marine work in South Africa, if not globally for sharks. They were at all times designed to have the minimum impact on the sharks needed to accomplish the scientific objectives. In addition they have further been improved by undertaking an assessment of each shark immediately after being caught as part of this project before tagging or other work is done in order to ensure minimum impact. One of the aspects of the research also involves measuring the stress of sampling on sharks, which will guide future sampling.
3. When the work shifted to False Bay concerns for human safety became the main public issue. This is understandable as False Bay is a multi-user marine environment, and also has had a number of shark attacks recently. Therefore additional pre-cautionary measures were put in place by not allowing any chumming within the Table Mountain National Park Marine Protected Area, which effectively includes the coast from Cape Point to Muizenberg to a distance of at least 5 km offshore. Elsewhere in False Bay no chumming is allowed within 2 km of the coast. The amount of chum to be used in the Bay has unfortunately been exaggerated in some statements. For example, it is suggested all of the chum on board would be used in False Bay. This is definitely not the case. Not only is the amount of chum on board actually substantially less than the original estimated, but it is also being used at a lower rate than anticipated. An experienced Departmental official on board is monitoring this activity. In addition the City of Cape Town placed a senior staff member (unassociated with the project) on board on Sunday afternoon (from 1500-1930) to monitor operations, during which a white shark of 3.9 m was caught, tagged and released. He reported that “the entire operation was skillfully and professionally done and it was obvious to me that all involved care for these animals.”
4. The potential of sharks moving away from the White Shark Cage Diving areas following sustained increased activity, is something that was taken into consideration by restricting the amount of time that the research vessel could spend in the same area to 48 hours to be followed by a similar length break (e.g. work elsewhere) before sampling could resume in the same area.
5. Although the above comments pertain to white shark research, a few days have been set aside for research on other species of sharks, such as seven gill sharks. As the catching of these species is not the management responsibility of the DEA, but rather the Department of Agriculture Forestry and Fisheries, this work is primarily authorized through them.
The Sharkmen/Ocearch project is a collaborative research initiative comprising research on large sharks in SA waters. The initiative comprises a number of projects involving leading SA shark researchers in collaboration with a few international scientists. Following internal evaluation in December 2012 the project was authorized by an umbrella permit issued by the Department of Environmental Affairs to Ocearch in early January 2011. This was subject to each research project being authorized and issued with its own research permit.
It was agreed from the outset that a specialist panel including members from inside and outside government, including a state vet with considerable experience in working on sharks, would draw up detailed protocols for each type of sampling activity in order to ensure that the sharks were treated ethically. These sampling protocols were augmented by additional permit conditions indicating what methods could be used to catch sharks. Further permit conditions for work in False Bay and Gansbaai were added based on consideration of feedback from the City of Cape Town, the experience of researchers on the first leg (to Mossel Bay and Algoa Bay in March), and inputs from White Shark Cage Dive (WSCD) permit holders who were sent a Communication Statement about the planned research on 20 March 2012, and again on 10 April 2012.
Issued by the Department of Environmental Affairs
For further inquiries contact:
082 898 6483
021 819 2423
Link to statement from Department of Environmental Affairs (16 April 2012)
Link to statement from Dyer Island Conservation Trust (14 April 2012)
Link to statement from Shark Spotters (12 April 2012)