Palm Beach Dive Thread

[Pavao]

Yeah, that pie chart definitely represents accurately the diversity seen in specific dive sites and times of the year, but most definitely not the diversity in the area. Of 450 sightings 80% being Lemons/Bulls/Sandtiger (~160/160/45), while about less than 5% being Caribbean Reefs (~20)?

There’s not enough information on the post to know the chart is intended to represent the area as a whole, although I almost certainly think it is, and I’m also definitely not criticizing anyone or the study, I certainly support any effort towards understanding and conservation of sharks not just in our area, but anywhere.

It’s just a little detail I think many of us familiar with the diving in the area would immediately recognize.

 

[HalcyonDaze]

@NothingClever - Unfortunately I was not at this presentation. Can you provide some context of what the presenter was saying with regards to the image below, i.e. where the dives took place, at what time of year, were these feeding dives, over what length of time were the dives, are they subset of other dives where no sharks were observed, etc?


Adding Since First Posted: I went to the American Shark Conservancy website and found the data sheet for partners, Shark Data Sheet

So I am guessing the pie chart came from the data sheets that have been submitted? Would still like to hear what the presenter had to say.

I asked Hannah for clarification on where those data come from. That's older data presented to the American Elasmobranch Society a few years back and collected by Hannah and ASC staff volunteers, not sourced from the community. It was also taken primarily on shark-specific (read: baited) trips and if I had to guess probably a lot of them were snorkel trips on or past the Jupiter Deep Ledge - hence the low numbers of Caribbean reef sharks (which do show up out there occasionally) and high numbers of bulls along with sandbars and silkys. Lemons I presume would be primarily from Lemon Drop and Wreck Trek areas, although sometimes they are on the Deep Ledge (tiger and great hammerhead sharks are usually from the Wreck Trek area, but sometimes the ledge and Lemon Drop).

 

[PBcatfish]

@NothingClever - Unfortunately I was not at this presentation. Can you provide some context of what the presenter was saying with regards to the image below, i.e. where the dives took place, at what time of year, were these feeding dives, over what length of time were the dives, are they subset of other dives where no sharks were observed, etc?


Adding Since First Posted: I went to the American Shark Conservancy website and found the data sheet for partners, Shark Data Sheet

So I am guessing the pie chart came from the data sheets that have been submitted? Would still like to hear what the presenter had to say.

My experience locally, within 10 miles of BHB, is that most sharks are bull sharks, next most common is spinners, then hammerheads, and there is a smattering of black tip, fine tooth, sharp nose, great white, and nurse sharks. That's out of the 70% that I think I can identify with some certainty. About 1/3 of the ones I see, I just recognize as unknown sharks. I see more sharks when I'm fishing, than I do when I'm diving. When fishing, the view I get is not as long & not as complete, so identification becomes more difficult. The large number of lemon sharks in that chart surprises me. I'll have to get more familiar with that breed.

The large number of spinners I see in this area may be skewed by the fact that the area hosts a breeding center for them. Once per year, they are thick as thieves for a few days in a certain shallow spot. I've seen them so thick that there wasn't a 5' square of water without one for more than 100 yards. Throughout the rest of the year, they remain common in the near shore fishing grounds south of the inlet. The hammers are there too, but they are more common to the north, off of Juno. The bulls are everywhere and seem to be the most aggressive feeders.

I am counting bonnet heads as hammer heads. Bonnets make up nearly half of the hammers that I see. Most of the bonnets are small. The fact that bonnets are retainable under the fishing regs, may have something to do with that. The other hammers are common in the 4-6' size range and occasionally I see a really big one.

The largest shark I have personally run into in this area was about 12-15'. A person I know who lives on his boat full time claims to have been chased out of the water during his morning swim by a hammer that he estimated at 18' & another time by a great white that was larger. Tracking tag data confirmed the presence of a large great white at the time he described that contact.

 

[LI-er]

I booked a few wreck dives with Stuart Scuba during my upcoming trip in April.

Even though I've never dived with them they were extremely accommodating and friendly people, immediately updating their schedule to accommodate my choices and putting steel nitrox tanks aside for me as requested.

Conversely the other 3 West Palm Ops who I've dived with several times before were a disappointment.

Pura Vida said they'd "put in a request" for my choice of wreck dives but no promises, and pointed out that they've accommodated me in the past but there's a difference, they no longer post specific wreck dives on their schedule, now it's been changed to a much less detailed itinerary and doesn't say anything wrecks at all.

Pirates and Walkers with whom I've dived before didn't even respond to my email inquiries and their schedules don't provide any information about where they'll be going, even in the next few days.

 

[Pavao]

I see more sharks when I'm fishing, than I do when I'm diving.

Right, and it reflects on your numbers.

If I were to answer a survey of population of dolphins in the area, I could say that in over 20 years diving in the area I have never seen a dolphin underwater, so the number would be zero.
But of course that wouldn’t be true as I see them all the time on the surface from the boat, indicating a healthy population.

What we are seeing on the pie chart is a representation of very few and specific dive sites, rather than the area as whole.

 

[NothingClever]

Can you provide some context of what the presenter was saying with regards to the image below, i.e. where the dives took place, at what time of year, were these feeding dives, over what length of time were the dives, are they subset of other dives where no sharks were observed, etc?

Hannah spoke so fast that I wasn’t able to take very good notes. I walked away with a favorable impression of ASC more than I did a more educated diver.

Long-winded way of answering your question with “No”.

 

[johndiver999]

Yeah, that pie chart definitely represents accurately the diversity seen in specific dive sites and times of the year, but most definitely not the diversity in the area. Of 450 sightings 80% being Lemons/Bulls/Sandtiger (~160/160/45), while about less than 5% being Caribbean Reefs (~20)?

perhaps you have a typo or misread the chart, but I think you mean sandbar, not sand tiger?

 

[Pavao]

perhaps you have a typo or misread the chart, but I think you mean sandbar, not sand tiger?

Yeah.
It’s really more about the lemons and bulls, I lumped the sandbars together with it because bulls + sandbars draws a line at 50% of the pie and makes for easy visualization of the numbers. You could change the sandbar slice to virtually any other species and my point would still remain, including Caribbean reefs.

 

[tekkydiver]

perhaps you have a typo or misread the chart, but I think you mean sandbar, not sand tiger

The fisherman between Key West to Vero will tell you the sandbar shark population is out of control

 

[johndiver999]

Yeah I think I see a lot of them, although I am probably not that good at shark ID. I'm not sure if I have seen sand tigers in palm beach, ever? I have a vague feeling I might have a long time ago, but really not sure.