Expedition Australia shark-tagging underway

OCEARCH, the non-profit shark-research organisation, has tagged its first shark in Australian waters. The 3.50-metre long (11ft 8in) tiger shark named Jedda, after the Australian movie and first of its kind to star two Aboriginal actors in leading roles, was caught and released off the SE Queensland coast during the initial stages of Expedition Australia.

You can enjoy near-real-time tracking of the big tiger using the free OCEARCH app (Global Shark Tracker App) available from the download store and online via the website.

Big in the social media space, OCEARCH and Expedition Australia are working with local scientists to tag and sample tiger sharks to garner more information on their migration, behaviour and habits and to help safeguard shark populations around the world.

More than 50 researchers from 20-plus institutions have collaborated with OCEARCH to date with over three dozen research papers in process or completed. Seventeen research expeditions have been conducted to date, with seven more scheduled through the end of 2015.

Expedition Australia moved from Brisbane to Fraser Island this week before moving to Mackay and Cairns later this month. The shark trackers also plan to head to WA. More at www.OCEARCH.org.

1. How was Australia chosen for this next expedition?
Australia was chosen because of the urgent need for data related to the migration patterns of mature sharks, including the drivers (food, environmental change or reproduction) of migration. OCEARCH’s unique capacity for safely providing hands-on access to mature, large sharks will enable multi-year SPOT (Smart Position and Temperature) tagging and tracking in real-time for the scientific community and public safety officials, and near real-time tracking for the general public – wherever the shark travels and its fin breaks the surface long enough for satellite(s) to establish its position. Simultaneous to the SPOT tagging, numerous other studies will be conducted on each shark as a result of having safe working access to the animals.

2. How can I track the sharks that are tagged in Australia?
Anyone can track the sharks that are tagged in Australia in near real time on OCEARCH.ORG or by downloading our free mobile app for Android and Apple devices. See TrackerApp_OCEARCH

3. What is the role of tiger sharks in the ocean?
As top predators growing to over 5m in length, tiger sharks are capable of consuming large bodied prey, and they have a potential to exert considerable impacts on ecosystem dynamics across wide areas. In short, they help maintain ecosystem balance.

4. What do we already know about tiger sharks?
Tiger sharks are found throughout warm temperate and tropical seas worldwide and inhabit a diverse array of marine ecosystems from coastal to pelagic waters making it possible to examine their movements, trophic interactions and levels of specialisation across a diversity of contexts. Studies, to date, suggest that tiger sharks are capable of making long distance migrations as well as more localised movements.

5. What are your objectives for this expedition?
The objectives for this expedition are as follows:
>> To determine the migration of tiger sharks on the east coast of Australia, including the drivers (food, environmental change or reproduction) of migration and individual variability in strategies.
>> To identify fine-scale foraging tactics and feeding requirements of tiger sharks, and use this information to interpret broad-scale movement patterns.
>> To confirm the reproductive cycle of tiger sharks.
>> To determine the effectiveness of the Great Barrier Reef Marine Park in protecting tiger sharks, and identify critical habitats e.g. foraging, mating and pupping grounds.
>> To delineate connectivity of tiger sharks in Australia, which is crucial for defining stock structure.
>> To map the movements and residency times of tiger sharks at swimming beaches, and provide long-term monitoring data that can be used in planning public safety.
>> To monitor the stress from capture and subsequent recovery time after release.

6. What method will you use to catch the tiger sharks?
The tiger sharks will be caught using OCEARCH methods i.e. hand lines from tender and brought onboard the mother ship platform. OCEARCH’s unique method enables capturing of mature sharks over 5m in length, where they are manoeuvred onto a 34,000kg custom lift. The sharks are then released after researchers have completed their 15 minutes of work. The shark is guided by hand in the water on and off the lift.

7. What studies will you run on the tiger sharks?
Once caught, the tiger sharks will be measured, sexed, tissue will be collected (blood, muscle and fin clip) and the sharks will be tagged with satellite and acoustic transmitters. Several individuals will also be fitted with accelerometer/camera packages before being released. The fin clips are removed with a pair of scissors and a muscle sample will be removed from the flank with an 8mm biopsy punch and blood will be taken from the caudal vein. Fin samples are stored in alcohol, and the muscle samples will be kept in ice and frozen as soon as possible after collection. Blood samples will be spun in a centrifuge to separate the cells' androgen plasma with both components immediately placed on ice and transferred to a freezer.

8. Will the studies impact the shark’s health?
While the tagging method, which has been used on sharks and other species for over a half century may cause some level of brief discomfort, there is no evidence that it impacts their behavior or survival post-release. Scientific data from blood obtained from sharks on the lift show that they are minimally stressed compared to other shark species caught using other methods. Data from the accelerometers show that the animals regularly recover and start swimming strongly within 2-4 hours after release. Data from the Global Shark Tracker provides strong evidence that the animals tagged using this method show long-term survival and long-distance migrations indicative of normal function and reproductive cycles.

9. Why is this research important?
This research will help provide important insight into the movement behavior of predators in marine ecosystems and its potential to structure and link ecosystems.

10. How will this research impact Australia?
By monitoring shark movements, a better understanding of the threat of human-shark interactions can be gained – enabling advancements in public safety and conservation.

11. What happens to the data you’ve collected?
The data is shared in an open source environment with collaborating institutions who utilise it to conduct studies that are eventually published in peer-reviewed scientific journals. The papers, which can take two to four years years to publish, are utilised to assist in policy decisions. The data is also shared with all PhD candidates who request it. There are approximately 50 research papers currently in preparation or completed by more than 70 researchers from over 40 institutions, based on OCEARCH expeditions and resulting studies. The studies become a basis for enabling informed policy and management decisions.

12. Are tiger sharks protected in Australia?
The only form of full protection currently available is provided by protected areas; meaning the sharks are only protected during the time spent in protected areas. As tiger sharks are highly mobile we need to understand their migration strategies and movement behavior to quantify the time spent in protected areas (or heavily fished areas) and to identify critical areas that should be protected. On the Great Barrier Reef there is a network of marine protected areas and approximately 33 per cent of the 348,000 square kilometers park is protected through no-take zones. However there is no information on how effective the marine park is for protecting tiger sharks.

13. Is there a plan to study the effects of drumlines on tiger sharks during this expedition?
Yes. In this study, we will track tiger shark movements in relation to drumline positions to determine their residency vs. migration at swimming beaches. In addition, the insights into foraging behaviour and tactics in relation to different prey from the video and accelerometers work may prove helpful in understanding when, how and why tiger sharks are foraging near beaches, which can feed back into non-lethal planning for public safety.

14. How many researchers are embarking on this expedition?
There are nine researchers embarking on the expedition.

15. Where does Caterpillar Fit in?
Through a multi-year partnership, Caterpillar enables the MV OCEARCH to execute expeditions anywhere in the world that scientists have a need for access to mature marine apex predators to fill knowledge gaps. The MV OCEARCH vessel is powered by two Cat 3412 engines and three Cat (4.4, 6.6) generators.

16. Are there other socially innovative partnerships?
Costa Sunglasses supports filming aboard the vessel, which is shared in near-real time with the public, worldwide. Shell provides partnership support for OCEARCH sustainable scientific efforts, while in-kind support is provided by DYT Yacht Transport, Contender, Yamaha, SAFE Boats, MUSTAD and Landry’s Inc.