Summer shark project off Southeast NC

[Captain Crocs]

Hey all,

I have a request for some of you guys (and gals).
I am doing some independent shark counts off Wilmington this summer, and am trying to get some indications of populations, counts, sizes, species, and sex ratios for sharks in the area. I will be going out as often as possible, but the more people that help me, the more robust our data will be!

I am trying this as my own stand-alone project possibly as a jump-off platform for some later ecology work on sand tigers or sandbars. I don't have any funding or anyone to report to, so im doing it my way.

So here is the stuff I am looking for:
If you go out, see sharks, and want to help me out, please post this information on this thread or PM it to me:

Dive site, date, water temp (minimum), time of day, shark species seen, number of each species, approximate sizes, and number of each sex (M or F). I understand if you can't get all this info, or if you can't ID the species, or get the gender (though that should be easy if you can see the shark clearly). Any and all info will be extremely helpful!

To admins- I decided to post this to NC wreck divers instead of the shark forum because of it's geographical restriction. If it needs to be moved, that's ok.


Thanks!

 

[Captain Crocs]

oh and P.S. Also list if there were any unusual circumstances that may have influenced the counts- really bad vis, hurricane the week before, etc.

 

[StreetDoctor]

If you want to hook me up with a boat ride and some 32% fills I'd be happy to dive everyday and count for you June 16-21st

 

[Thalassamania]

Can you tell us a little more about your data collection plan and how the data will be analyzed?

 

[Captain Crocs]

Sure thing. The plan right now is to try to understand when the sharks are coming onto the wrecks, in what numbers, how long they are staying there, and what the species and sex makeup ratios are. I plan to run some stats on the sex ratios to determine if there are statistical differences in the number of each sex, and if I can get good length estimations, then I will run an analysis of variance to see how significant the size differential is between the sexes. The data will be also be qualitatively analyzed.
The long term idea would be using these population, size and sex ratio estimations (coupled with dates) to see just how important these wrecks are to the sharks, and to see if there are any gaps or anomalies in their presence (for example, so far I have found no males, only female sand tigers and sandbars). Long term, I'd love to look at interaction between individuals and see if the sharks coming back to certain locations every year are the same ones, and if so, if they represent any familiar or genetic structure as a population. Like I said, these are long term goals which would be realized with a more proper funding base. But by getting this base information (where the sharks are, what size, species and sex they are) down now, this gives jumping off points for the future.


If you have any suggestions, I am completely open to them.

 

[Captain Crocs]

If you want to hook me up with a boat ride and some 32% fills I'd be happy to dive everyday and count for you June 16-21st

Haha, how about a bathtub and some blown up balloons? Can't say my budget is much higher than that

But if you are coming down to NC to do some wreck diving feel free to let me know

 

[battles2a5]

I was out on May 2 out of Morehead City. Dove on the Papoose (Hutton) at around 9:30am. There were about 8-10 sand tigers, varying in size from 6-10ft. Mostly females (juveniles and adults) with a few adult males (from what I can tell). I have video evidence as well if you want to get any more info out of it

NC Wreck Diving- Papoose/ Hutton May 2 2010 on Vimeo

 

[battles2a5]

Out again today out of Wilmington. Nothing on the Gill, 2 sandies on the Hyde. One was a young juvenile, 3.5ft long, and a mature female, 7-8ft.

 

[Captain Crocs]

(This will be long)

Thanks Ryan for that. Very interesting- I was out at the Gil, Hyde and Markham the past 2 days. The Gill had 1 sand tiger (approx 10 feet) the first day and 2 (about 4 and 8 feet) the next day. The 8 footer (male) was lying motionless under a piece of hull and pumping water over it's gills, something I have never seen them do before. There was also a dead Sandbar shark laying on the bottom of the Gil on the 11th, so fresh it was probably killed around 6 am. The next day the Markham had 2 or 3 sand tigers, one about 4-5 feet and another about 10 feet long.

Then the Hyde...

We dove down and I immediately saw 3 juveniles (3-4 feet) on the deck. One got curious and followed me for a few minutes. There were well over a dozen fully grown, fat adults, as i counted 8 at one time near the stern prop shaft. Most were circling around the wreck itself at about 70-80 feet. 4 individuals stick out in my mind in particular- the first was a female, complete with massive bite wounds on her abdomen from male selection. the second was an adult with a gash running down almost the entire dorsal surface. The third had a large gash on the left side of its jaw, quite distinctive. Several times it followed and kept pace with me, sometimes swimming in the same direction as its fellows, seeing me, and making a complete 180 to survey me. Curious guy. The fourth was a shark that I could have swore I had seen on the Hyde 2 years previously- the only reason I remember it is because it had a lead leader with hook caught on the left side of it's 1st dorsal fin. This shark had a leader in the same place, only this time the leader looked really worn and the wound had scarred over. I am cautious to say this was the same shark, but if it isn't then it bears a funny resemblance.

So, in the course of two weeks, the Hyde has gone from sparse to plentiful. How interesting...