Crittercams to be attached to white sharks in Fish Hoek
There is currently an opportunity to attach a Crittercam to various great white sharks in the inshore area of False Bay through a collaboration between the Save Our Seas Shark Centre and National Geographic Society.
Specific focus will be given to attempting to attach the crittercam to a white shark in Fish Hoek bay as this will provide a significant opportunity to further our understanding of why these sharks use this area in particular during the summer season. If successful, information from the crittercam will be particularly important to better understand why Clovelly Corner and Sunny Cove are areas of high activity during the summer months.
Crittercams have successfully been deployed 29 times at Seal Island, False Bay and interesting behavior has been collected. We know that sharks are primarily around the seal colony to predate on the Cape fur seals and aggregate in the area from May to September. The research programme has identified through tagging that the sharks display a seasonal shift in habitat use during summer, spending more time closer to shore.
The Shark Spotting Programme has recorded 765 shark sightings between November 2004 and September 2010, almost all during the summer months. However, we have a limited understanding of what they are doing inshore and as a consequence would like to attach the Crittercams to sharks during summer in these areas to learn more about what they do there.
In Fish Hoek there are additional questions we would like to answer, due to the area being the location of two fatal shark attacks, and many more interactions with surfskiiers and kayaks. Are the sharks hunting fish or other prey in the area? How are the sharks using the area? Are they swimming near the bottom? The Crittercam has the potential of providing us with novel information on their behavior in these areas.
The Crittercam is on loan from the National Geographic Society for the period November 2010 to end of February 2011 and as such the City will work with the Save Our Seas Shark Centre to try and successfully attach the Crittercam on sharks in Fish Hoek bay as well as off remote coastal areas around Macassar, Wolfgat and Strandfontein.
Attaching the Crittercam, or while it is attached, poses no increased risk to beach or water users. However, due to the emotive nature of white shark issues the City has provided the following conditions for the research to take place:
1. No chumming in the inshore area will be permitted at any time,
2. The research programme may only attempt to attach a Crittercam in the following inshore areas:
- Fish Hoek Bay including the back of Sunny Cove to Glencairn and north up to Kalk Bay harbour
- Remote coastal areas at least 1km away from any recreational nodal points
3. No Crittercams may be deployed in the inshore area between 1 December 2010 and 9 January 2011
4. At Fish Hoek, no Crittercams may be deployed on weekends or on Tuesdays when lifesaving training takes place
5. No sharks may be actively attracted to the inshore area and only sharks observed already in the inshore area by Shark Spotters in Fish Hoek may be approached
6. In Fish Hoek, the Crittercam may only be attached under White Flag conditions when the beach is already closed
7. At Fish Hoek, close and ongoing communication between the research vessel, the shark spotters and the lifesaving club is required at all times during deployment efforts
8. A representative from the Fish Hoek Lifesaving Club must be invited to be onboard the vessel during all efforts to attach a Crittercam in Fish Hoek.
In making the decision to be part of the research programme as well as to allow the placing of Crittercams on white sharks in the inshore area the City carefully considered and evaluated all safety concerns as well as consulted with key groups from Fish Hoek.
The City has approved the deployment of the Crittercam as of 10 November 2010.
If anyone would like to raise concerns regarding the deploying of the Crittercam in Fish Hoek they are welcome to contact Gregg Oelofse of the City of Cape Town at 021 487 2239 of via e-mail at firstname.lastname@example.org
Crittercams are small animal-bourne cameras.
They are used to study the behaviour and ecology of wild animals. Crittercam has contributed to basic understanding of numerous wild species, and revealed ‘never seen before’ behaviour such as how humpback whales bubble feed in groups, it revealed completely unexpected foraging behaviour and habitat use of the endangered Hawaiian monk seal and discovered that adult green sea turtles in Baja California and Australia feast on invertebrates and scavenge dead fish. The Save Our Seas Shark Centre in collaboration with the National Geographic Society have been attaching Crittercams to white sharks since 2004 to gain a better understanding of their hunting and social behaviour.
Crittercams don’t just take photos from the shark’s eye-view.
They are fitted with depth, temperature and acceleration sensors and are able to collect information from the shark on what it’s doing that no other research tool is able to collect.
How are they attached and retrieved?
Crittercams are attached to a clamp that fits temporarily over the first dorsal fin of the shark. National Geographic Society has designed a special pole to deploy the clamp on the dorsal fin from the side of the research boat on a free-swimming shark. The Crittercams are only on the shark temporarily for a maximum of eight hours. After the time period has elapsed the Crittercam and clamp are programmed to release from the shark. The Crittercams are slightly positively buoyant and float to the surface where they are located using a VHF radio receiver.
In this case we also plan to attach an acoustic transmitter to the Crittercam which will allow us to follow the shark’s detailed movements while it has the Crittercam on. In this way we will know the exact area the shark is in and will be able to match this up with the footage to be able to determine what the shark was doing in a specific area.
Crittercams are only temporarily attached to the sharks for a maximum of eight hours. The clamp is positioned around the dorsal fin and no part pierces the skin. Once the camera releases there is no trace of the clamp or camera. With 29 successful deployments on white sharks we know that the sharks return immediately to normal behaviour like hunting directly after being fitted with a camera
Methodology proposed for Fish Hoek
To be able to attach the Crittercam the shark needs to be right alongside the research boat (within 1 metre) with its dorsal fin completely out of the water. To be able to achieve this, the shark needs to be temporarily attracted next to the research vessel. What we propose is to be on standby until the Shark Spotters record sharks in the Fish Hoek area. Once sharks are being spotted the SOS research vessel will be on standby in the area ready with the equipment.
Contrary to popular belief white sharks are very cautious animals and are very sensitive to disturbance. We therefore need to be able to create a scenario where the shark decides to approach us because riding up to the shark trying to get close won’t work as it will more than likely cause the shark to swim or dive away from us. If a shark is sighted in Fish Hoek or the immediate adjacent areas the research boat will slowly and cautiously approach the shark and throw out a tuna bait tied to a rope to attempt to attract its attention. The tuna bait will only be used once the boat is within a few meters of the shark, and for less than 5 minutes per shark – boat interaction. The tuna bait will not be in the water for more than 5 minutes and once out of the water and trace of the tuna will disperse within minutes and have no lasting effect in the area. The City of Cape Town together with Shark Spotters will close the beach temporarily as per normal when a shark is seen close to shore in this area.
Chances of success
From experience approaching white sharks and successfully tagging them, using this methodology, has a small chance of success. However, we believe the potential knowledge gained is worth the effort. We don’t want to create expectations that can’t be reached, but because we know so little about their behaviour in these areas, every small piece of new information will make a contribution to our understanding.
Crittercam at a glance:
- National Geographic Crittercam is a scientific research tool that collects video, audio and environmental data while safely worn by an animal.
- A compact device the size of a petite thermos, Crittercam allows scientists to see the world through animals’ eyes while unobtrusively gathering insights into their behavior and providing clues as to how we can conserve and protect them.
- Crittercam was envisioned and invented by marine biologist and filmmaker Greg Marshall.
- In 1986 during a diving trip off Belize, Marshall was inspired to create the first Crittercam after he noticed a shark swim by with a remora (or sucker fish) clinging to its back. Marshall suspected that if he could replace the remora with a camera, he could observe the shark’s behavior without human interference.
- The first Crittercam prototype took its maiden voyage in 1987 on the back of a loggerhead sea turtle.
- Crittercam technology has been deployed hundreds of times around the world on more than 60 different animals, including penguins, whales, seals, turtles, sharks, lions and grizzlies.
- More than a camera, Crittercam records video, audio, depth, temperature, velocity and acceleration and even makes three-dimensional profiles of the dives of sea creatures.
- Designed to be worn comfortably without inhibiting the animal’s natural movements, Crittercam usually is attached with harness or suction cup and automatically breaks free at a preset time or condition. A VHF receiver enables scientists to recover the device.
Through the eyes of animals Crittercam has:
- Found that emperor penguins find prey along the bottom of sea ice rather than during deep portions of their dives, as previously believed.
- Revealed the distinctive hunting patterns of tiger sharks and how those patterns influence behavior of their prey.
- Found that male harbor seals use and defend locations offshore, where they use vocalizations to attract mates and/or repel competitors.
- Revealed completely unexpected foraging techniques and habitats of the Hawaiian monk seal, information that is critical to protecting this highly endangered species.
- Revealed the underwater dynamics and specialized roles of individuals in groups of humpback whales that are practicing a complex foraging behavior known as bubble-net feeding.
- Found that adult green sea turtles in Baja California and Australia feast on invertebrates and scavenge dead fish, overturning the idea that they outgrow their juvenile carnivorous habits and become strict vegetarians.
- Found that leatherback sea turtles do mate in waters near nesting beaches, contradicting a previous assumption that all mating takes place far out at sea. This means that males and females in this dwindling species must undergo long migrations to nesting beach regions, where entanglement in fishing gear is more likely. Crucial mating activities taking place in these waters also could be disrupted by other human activities.
CITY OF CAPE TOWN MEDIA RELEASE 03 NOVEMBER 2010
Media enquiry: Gregg Oelofse, Head of Environmental Policy and Strategy, City of Cape Town, Cell: 083 940 8143
Alison Kock, Save Our Seas Shark Centre, Cell: 072 661 9516
This sounds like an exciting and extremely well timed project given that a large white shark has been a regular visitor to Fish Hoek and Clovelly during the past week as reported on: http://scenicsouth.co.za//2010/11/shark-alert-high-activity-in-fish-hoek/ Eds Comment