When people ask what I
do for work and I reply that I am a marine biologist, most people seem to have
the impression of this exciting life where marine biologists are continually
out in the field in exotic locations. Although we do get out in the field in
some amazing places (mind you, some are not so amazing), the majority of our
time can be spent in front of a computer analysing data, writing reports and publications
or in a laboratory analysing samples.
Unfortunately, a great percentage of our time these days is spent writing grant applications and chasing funds to keep our research going. So, when we do get out in the field it can be a welcomed respite from the office. These escapes out into the field are also hard work, but when things are going well and you are collecting lots of data, the long hours don’t seem to matter.
However, when the field work does not go to plan, the trips can be exceedingly frustrating.
The field trip to False Bay this
year is a great example of a frustrating field trip, where a few things have not gone to plan.
Our main goal was to retrieve and re-deploy our acoustic receivers and tag 12 sevengill sharks. Additional goals included collecting tissue and blood for stable isotope (for the analysis of diet and residency), hormone (reproductive status) and genetic analysis, as well as conducting as many dives as possible to start the photo ID component of the study (see project pages on leopard sharks and sevengill sharks for more info on Photo ID, and see an earlier post in our blog Spot the Leopard Shark going strong).
So, what didn't go to plan?
This trip was hampered by extremely strong winds, so our time out at sea was limited to just a few days. On top of this, we had engine troubles on the 3rd day.
After retrieving our receivers, we also had equipment problems, so thus far we have not been able to download the data to see what our 17 sevengill sharks tagged with acoustic transmitters earlier in the year have been doing. It appears that we need a new communication device to access the data, and this has to come from Canada.
To top it all off, the summer holiday season is now underway in Cape Town, meaning with so many people in the water, we can’t capture and tag sharks.
So, this trip resulted in only one sevengill shark being acoustically tagged and tissue collected. This is documented in images below. I also dived once with our friends at Shark Explorers (a great adventure dive company) where I saw 13 sevengill sharks.
Anyway, that’s how field work goes sometimes.
But not all is lost: I had some great meetings about future work and future students to be included in this project , gave a talk to the dive community about helping us with the spot the seven gill shark project, and met many people interested in the OIQ site, which will help us gain more exposure.
My South African colleagues Alison Kock and staff from Two Oceans Aquarium will continue the tagging work in late January 2014 (after the holiday season).
In the meantime, I head to Mozambique to satellite tag tiger sharks. Hopefully I will have better luck on that trip.
Our main goal was to retrieve and re-deploy our acoustic receivers and tag 12 sevengill sharks. Additional goals included collecting tissue and blood for stable isotope (for the analysis of diet and residency), hormone (reproductive status) and genetic analysis, as well as conducting as many dives as possible to start the photo ID component of the study (see project pages on leopard sharks and sevengill sharks for more info on Photo ID, and see an earlier post in our blog Spot the Leopard Shark going strong).
So, what didn't go to plan?
This trip was hampered by extremely strong winds, so our time out at sea was limited to just a few days. On top of this, we had engine troubles on the 3rd day.
After retrieving our receivers, we also had equipment problems, so thus far we have not been able to download the data to see what our 17 sevengill sharks tagged with acoustic transmitters earlier in the year have been doing. It appears that we need a new communication device to access the data, and this has to come from Canada.
To top it all off, the summer holiday season is now underway in Cape Town, meaning with so many people in the water, we can’t capture and tag sharks.
So, this trip resulted in only one sevengill shark being acoustically tagged and tissue collected. This is documented in images below. I also dived once with our friends at Shark Explorers (a great adventure dive company) where I saw 13 sevengill sharks.
Anyway, that’s how field work goes sometimes.
But not all is lost: I had some great meetings about future work and future students to be included in this project , gave a talk to the dive community about helping us with the spot the seven gill shark project, and met many people interested in the OIQ site, which will help us gain more exposure.
My South African colleagues Alison Kock and staff from Two Oceans Aquarium will continue the tagging work in late January 2014 (after the holiday season).
In the meantime, I head to Mozambique to satellite tag tiger sharks. Hopefully I will have better luck on that trip.
Tag and release of Sevengill shark in images
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| Setting up our platform for holding the shark when it's first caught. |
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Alison and I waiting for the sharks to turn up.
Shark fishing - hours of boredom which hopefully culminates in minutes of excitement when you get one!
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| Ah! wrong species. |
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| We have one! Leading it into the cradle |
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| The shark is brought into a sling on the platform. |
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| The shark is a small one (188 cm), so we use the sling to bring it on board to work on. A hose with running water is put in its mouth to keep the gills flushed with fresh seawater. We also use the hose to flush the sharks stomach to see what they have eaten. This shark's stomach contained a baby dolphin. |
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| The team at work, collecting the data and tagging the shark before we release it. |
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Releasing the shark. It's a girl!
188 cm is immature for females.
Females mature at around 220 cm, and males between 150-170 cm.
Females will grow to 300 cm, whereas males probably about 250 cm.
I have only ever caught 1 male over 240 cm.
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| Bye Bye girl! |
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