Palm Beach Dive Thread

[NothingClever]

On Friday, 27 February 2025, Pura Vida is hosting Hannah Medd, founder of the American Shark Conservancy. The American Shark Conservancy is the nexus for local shark conservation ecology. Their research focuses on understanding how human activities may be affecting these important and vulnerable species along the Florida coast.

Because Shayna, co-owner of Pura Vida, is an accomplished marine biologist, I'm confident this will be a first class presentation.

I'm attending and so is @DiveFlag = Target.

The following morning we're both booked to tag along with Hannah Medd on Pura Vida's 08:00 charter.

Pretty excited to listen and learn from a shark expert!

Human Impacts on Florida Sharks

February is the month of love, and we love our Florida sharks! They are vital to preserving a healthy reef and a thriving ocean.

www.puravidadivers.com

 

[Scuba_Jenny]

Hannah is pretty cool.

 

[NothingClever]

Great presentation by Hannah from American Shark Conservancy tonight at Pura Vida dive shop. She’s clearly a disciplined scientist and enthusiastic SME.

Pura Vida provided plenty of finger foods and BEER

Half of the audience.

Amber, one of PuraVida’s senior DMs, introducing Hannah.

Hannah gave a thorough presentation on the focus areas and efforts of the non-profit she leads. Throughout the presentation she epitomized scientific objectivity, sharing trends in observations, non-traditional research methods, and clarifying where she didn’t have enough data yet to draw conclusions.

I look forward to reaching out to understand how I might be able to lend a hand.

 

[Johnoly]

Many of us have dove with Hannah and she's a very nice diver.

... she epitomized scientific objectivity,

I understand that her data collection will be on-going but 76 dives is a small sample size. It also shows in her pie chart how sharks are very territorial so if you don't visit certain reefs like 'Tunnels, Area51, Kurles' the chart won't reflect the large number of reefies that just get right in your face as they gang up on you. Again, nothing bad about her dives and they are on-going and she is building her data which is fantastic because it can help the community if she publishes her raw data. There are ALOT of divers recording raw shark data. Some share the raw data - some don't. SEDAR has the most wide area data because shark move with water temps and food.

how I might be able to lend a hand.

Easily the best and most effective way to lend a hand is the REEF.ORG fish surveys. You can sign up now or their big event is coming up in July with the Great Annual Fish Count event. It's open to ANYONE even snorkelers. When scientists publish studies with a small sample size, the Reef.Org huge database can focus some brighter light to see things better. I actively support Reef.org when it comes to lionfish.

Thanks for the writeup on the Pura Vida presentation, they are a great shop & people!!

 

[NothingClever]

First drop today was Juno Ledge (probably my favorite PB dive), calm waves on top, 20m vis, 3mil water temp below at 22m.

Captain Chris - new-to-Pura Vida, training
Captain Dean - Co-owner of Pura Vida training Chris
Amber - senior DM training Delaney
Delaney - DM in training
Quinne - dry DM

1 x GG
1 x Reef (lapper)
1 x Loggerhead T
1 x Green T
1 x Nurse
3 x Reef

Amber led and Delaney dragged the float. @DiveFlag = Target and I creeped to the front of the group and stayed there. He’s smoothly racking up the hours on his RB and lookin’ boss in his Otter DS (no jealousy here ).

Second drop - Corridor (Ana Cecilia, Mizpah, PC1174 and Amaryllis), very calm on top although not glass, steady current, 15m vis, 3mil temps at ~20m.

Quinne led, Amber and Delaney dry DM’d. I was first to the wreck and dive-bombed straight into the hold, swam a J formation and then loitered on the deck. Got impatient and took advantage of the strong current and cruised by myself north on the Florida underwater moving sidewalk.

3 x Reef
8+ x Barracuda
1 x Grouper

During the SI, Hannah from American Shark Conservancy talked about her three years in South Africa. One of the best SIs ever.

In general news, Pura Vida hires great people. The vessels are tip top but the
crew makes all the difference. New members Chris and Delaney are already crushin’ it. I hope PADI takes extra effort to recognize the shop. Super excited to organize some clown gas dives with Justin the shop manager.

 

[Pipehorse]

@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.

 

[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.

 

[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.