Dave H
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Posts posted by Dave H
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The problem with "scientific" studies is that often they start as a way to prove a persons ideas, not necessarily to find the truth. For every negative study on a subject, you will find an equally scientific positive study. While I will look forward to the article, I will read it with a certain grain of salt until I read it through. Even so, it could easily by negated by someone else's equally exhaustive "study" down the road.To the poster who made the specious comment about how many dead seahorses do you see... REALLY? REALLY?? I double dog dare you to locate a dead hippocampus....they are hard enough to find when they are moving around.
Dead Seahorse Number 1 underwater:
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To answer #2 & 3, you have Dave Harasti , who says he was flashing seahorses frequently for 4 years without any noticeable damage. It was a wasted opportunity, since he could've checked out the eyes after it died to look for damage.As for #4.... TMI dude!
Hmmmmm, and how many times have you found a dead seahorse whilst diving????
In the many hundreds of dives that I have done on seahorses as part of my PhD research I've been lucky enough to find 3 dead animals.... two of them had their heads missing and the other was so decompossed that any analysis on the eye structure would have been impossible!!! And to be honest, given my seahorses managed to survive for at least 4 years I'm pretty sure there eye sight was okay as they obviously hadn't starved to death!
As John is aware, I've just finished a study on the impacts of flash photography on seahorses with the results to be published in a journal shortly.
cheers,
Dave
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Alex,
The Spotted Handfish in the Derwent estuary in Hobart is regarded as one of Australia's most endandgered fish species. If you are interested in going for a dive on them drop me a PM and I'll put you in touch with someone who might be able to take you for a dive on a small colony of them.
I dived it in Winter last year and whilst seeing handfish was fantastic, the 9 degree water wasn't so good! You will need a drysuit if diving in the Derwent!
Also, Tinderbox Marine reserve is also a god macro dive just out of Hobart, I had a good dive there several years ago.
cheers,
Dave
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Thanks Dave. Do you know who grouped the Brevperula and Tentaculata together and when? I just checked FishBase and it does seem they bunched them together.Not sure why they were merged together as A. tentaculata as I can't find a reference for it. There was probably a reason for a species merge on Fishbase however its odd that Kuiter doesn't reflect it in his new book which is the most comprehensive guide to syngnathids, Rudie obviously has his own reason for keeping them seperate. Genetic analysis would provide the most diffinitive answer!
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If you follow Rudie Kuiter's new book "Seahorses and their relatives - 2009) the species would be Acentronura brevperula. A. tentaculata is considered to be endemic to the Red Sea whilst A gracillissima is recorded from Japan. I've seen A.brevperula throughout the Indo Pacific and it is very variable in colour.
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I finally got a reply from the ISP:
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Dear Mr. Harasti,
As I mentioned yesterday, I contacted the administrator of the web site - acvariidevis.ro- and I forwarded your messages. The administrator of the web page said he would contact you in this regard. We are merely hosting the web site and this is why we can not remove the contents unless we have a request from our client or a court decision.
I am confident that you will reach an understanding with the owner of the web site.
Yours truly,
Tudor Edu
ITC
tel. 0040-21-2320970
fax 0040-21-2320468
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Still haven't heard anything from the aquarium website...
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It is a juvenile filefish/leatherjacket of some sort.
Looks very similar to the pygmy leatehrjacket below that we get in southern Australia.
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Hi everyone,
I need some help. It was recently brought to my attention a Romanian website that has stolen hundreds of my fish photo's to assist with sales in their aquarium fish business. Basically, about 90% of the fish and invertebrate image on their website have been stolen from my Marine Species database that I set up to help people with ID's: www.speciesspotlight.com
This is the offending website: http://www.acvariidevis.ro/pagina/despre-noi
Not only are they using my images, they have actually watermarked their website details onto each of my pics!!! This has really p1ssed me off.
Some examples can be seen here:
http://www.acvariidevis.ro/pesti/serranida.../potato-cod/269
http://www.acvariidevis.ro/pesti/serranida...land-groper/295
http://www.acvariidevis.ro/pesti/gobiidae/...finned-goby/173
The good people on Diveoz.com.au have given me some good advice so far however now I'm stuck. I've sent several emails to the company (office@acvariidevis.ro) and they won't reply. I emailed the company's ISP (http://www.itcnet.ro/) and sent them a 'DMCA Takedown Message' but they also won't reply.
Anyone on wetpixel able to offer any more suggestions? Anyone on wetpixel live in Romania and own a baseball bat?
thanks,
Dave
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Dave,Your pics turned out great!
I'm strongly considering purchasing the Canon SD990IS, which I believe is the same as your camera. What buttons/controls do you use to manually change the shutter speed on your camera? Based on the instructions in the user manual, it looks like in manual mode you use the "control wheel" to change the shutter speed. However, the Ikelite housing (and the Canon housing) doesn't give access to the "control wheel". So, how did you do change shutter speed?
Thanks.
I was also scratching my head about this one when I first got the housing!
To change the shutter speed you enter 'manual' mode and then you must hold down the Canon 'print' button (this is the button on the top left above the control pad). When the print button is held down you can move the left and right control buttons to adjust the shutter speed. Works really well.I haven't used this system with a strobe just yet but all I can say is that using a strobe is only going to improve image quality. I've got a small Ikelite DS51 that I might test out with it.
cheers,
Dave
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The first species is Chromodoris fidelis and the second is Chromodoris geometrica.
cheers.
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OK, I dive in Anilao for eight years now, but have never heard of any site called "secret bay" .Is this the same site as "Mainit Muck" that is next to Mainit Point on the beach where the big hotel is still being built?
I think it could be the same site, except were we stayed they never referred to it as Mainit Point. But there is a MASSIVE hotel being built there, I wrote a summary of my first dive there in this article which includes a surface shot of the site: http://www.daveharasti.com/Phils09/article/index.html
I propose it's renamed to 'Cephalopod Bay' given that I saw 10 different species there in 5 days.
I have been diving this site for 4 years, and based upon the number of dive boats that are there in the afternoons, there is absolutely NO secret about it, at least anymore.I must have been lucky! I've dived it twice a day for 5 days straight last week and didn't see another boat the entire time! So it was still secret last week....
Leslie - Thanks for the Synchiropus kuiteri ID, I just found a shot of a juvenile in Kuiter's World Atlas of Fish and it's identical.
Drew - Fish 2 has been stumped. I couldn't see any dorsal fin what so ever, I'll see if Rudie Kuiter recognises it.
thanks,
Dave
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I'm stuck on confirming the ID of the below 3 fish species taken on a recent trip to the Philippines
Fish 1: About 2cm in length - Secret Bay - Anilao
Fish 2: Some sort of Dragonet about 5cm long. not sure of species - Secret Bay - Anilao
Fish 3: Another dragonet, about 1-2cm long - Photographed at Dauin. Is it possibly a juvenile Fingered Dragonet (Dactylopus dactylopus)?
Any input appreciated.
cheers,
Dave
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I've just recently returned from Anilao where I had some of my best ever critter dives at Secret Bay. Whilst there, I photographed 6 species of octopus however I can't work out the ID of this species. The occy was pretty small, max length of about 8cm.
Anyone know what it is?
ta,
Dave
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Scuba Snoopy Tracks Down the Tiger Tail
Scuba Snoopy has a thing for seahorses. Not in that weird sort of fetish way, but more of a fascination for an animal that looks like a scientific experiment between a horse and a dragon that had gone horribly wrong. Plus Scuba Snoopy is bigger than seahorses so they don’t scare him! Scuba Snoopy (aka Snoops) had seen many seahorses in his time, ranging from the huge Pot Belly Seahorse in Australia that was almost as big as him, to the tiny pygmy seahorses in Indonesia that he needed a magnifying glass to see.
But there was one seahorse that continued to elude Scuba Snoopy... the mysterious bad @rse Tiger Tail Seahorse of the Indo Pacific that had been avoiding him for many years. Snoops wanted this seahorse... and he wanted it bad! Previous leads had taken him throughout Indonesia and Thailand and on each occasion it was case of ‘you should have been here last week’; this seahorse was more of a Houdini than Bin Laden, it just didn’t want to be found!
This time round Snoops had good hard intelligence, the sort of intel that James Bond would give his life for. There had been a recent sighting of the Tiger Tail running the show at Ducomi Pier located off Dumaguete in the central Philippines. A quick smashing of the VISA and Snoops was on his flight, off to finally have it out with his arch nemesis the Tiger Tail. 30 hours later, via a brief layover in Singapore Airport where Snoops was almost signed up as a F1 driver, Snoops was kicking back in the pool at Pura Vida resort, home to Sea Explorers dive centre.
The next morning they were off on the hunt, now was the moment of truth for Snoops. He wasn’t getting any younger and these globe-trotting adventures around the globe were starting to take their toll on his body; he wasn’t the spritely young puppy anymore that he used to be! It was only 10 mins into the dive when the seahorse tracker (aka dive guide) started banging away like a bed head in Kings Cross; he’d found the goods!
Snoops dashed over to encounter the tracker with a seahorse cruising around in front of him... but it was the wrong seahorse! This was just your run of the mill average Joe Blow ‘common seahorse’...didn’t the seahorse tracker realise that the Tiger Tail has double cheek spines whilst the common seahorse only has one??? Snoops was peeved!!! He’d flown all this way on the promise of a Tiger Tail only to be shown a boring #%#! seahorse that he’d seen a billion times before. This just wasn’t good enough and Snoops turned his back and swam off in disgust!
4 more days of searching and the Tiger Tail was still proving to be elusive, Snoops was at his wits end. All this way, all this money and the Tiger Tail wasn’t to be seen. Snoops did however manage to get rather up close with a curious flamboyant cuttlefish. This was pretty cool until the cuttlefish started to change colour and wrapped her tentacles around his body...even though it was doing a good job at matching his fin colour, Snoops was very reluctant as he wasn’t all that keen on interspecies relationships!!!
There was one more dive to go, and Snoops was insistent that they went back to Ducomi Pier for one last look. It didn’t matter that the Tiger Tail hadn’t been seen there for the past 5 days; he was chucking all his bones in the one basket and hoping his Tiger Tail numbers would come up trumps.
As Snoopy was approaching one of the pylons he encountered a Giant Snake Eel in the sand. Just as Snoops was checking him out all hell broke loose. Unbeknownst to Snoops, the snake eel was in cahoots with the Tiger Tail and lashed out dragging Snoops into his den. The world went dark for Snoops... was this it – could this be the end for Scuba Snoopy?
But in a moment of ‘Bondness’, Snoops pushed his reg down the eels throat and purged... purged like he’d never purged before. With an almighty burp, the Snake eel spat Snoops out and sent him flying into one of the jetty pylons.
However a miracle occurred! By divine intervention, Snoops had been thrown into the sacred pylon. There it was, right in front of his little black button nose, the holy grail of the seahorse world. The top dog, the underworld king, the Tiger Tail had been found clinging to a sponge under Ducomi Pier. Now was the moment of truth, was the Tiger Tail willing to cooperate or was Snoops going to have to open a ‘can of kick@rse’ and perform his Jackie Chan moves. But it was over in a flash... the Tiger Tail stuck out his tail with a “How do you do’ and Snoops was in... he’d been accepted into the brotherhood of seahorses.
And that was it. Snoops had at long last tracked down his seahorse and could finally hang the sign “Mission Accomplished”. Finally, this little puppy dog could sleep in peace and not worry about whether the Tiger Tail would ever be found, his work here was done.
So where to next for this aging Puppy Dog? One heard rumours that the sharks were calling again...the sharks with the big pointy teeth were asking who let the dogs out....
More images from diving Dauin and Anilao can be seen here:
http://www.daveharasti.com/Phils09/
cheers,
Dave
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About 5 months ago, my point and shoot digital camera (Sony P100) that I carried in my BC pocket died. I needed a camera that was small enough to carry in my BC pocket whilst doing seahorse surveys as lugging around a slr and searching for seahorses was impossible! Following advice from a wetpixel post, I ended up buying the Canon Ixus 980is as it was the only P&S that offered full manual control (can change shutter speed and aperture) and was above 10mp (it’s 14mb). This was actually a Christmas present for my partner... little did she know that a housing was going to be her second present! Kind of like the Homer Simpson bowling ball present...
I ended up getting the new Ikelite compact housing for the camera and it arrived last week. The camera housing fits perfectly in my Zeagle tech pocket which I have attached to my KISS. This pocket is probably slightly larger than a normal BC pocket but is very versatile as it can actually be fitted to almost any BC!
So today I took the camera and housing out for a test dive and had a heap of fun! Below are couple of shots from the Pipeline in Nelson Bay. All images were taken just using the internal flash.
Two of my all time favourite seahorses, named 'Grandpa' and 'Goldilocks'. Grandpa is actually my oldest seahorse, he was tagged over 3.5 years ago.
Ornate Ghostpipefish
Nelson Bay Anglerfish
Blue-lined Octopus
Mating nembrotha's
Cerastoma nudibranch
A couple more images from the dive can be seen here:
Overall I have to say that I am very impressed with this camera underwater. The colours are excellent and the focus is fast enough to capture animals that are actually moving. Manual control is easy to change and there are two aperture values to select from (f2.8 and f8). I just left it on f8 the whole dive and varied exposure by changing the shutter speed. I found that it’s essential that the Ikelite external diffuser is attached to the front of the housing because without it there is a huge black shadow in the right of the image where the flash is blocked by the port. The diffuser eliminates this problem. Also, make sure you attach the diffuser to the housing with some fishing line otherwise you will lose the diffuser!
Whilst I don’t think this camera is going to be replacing my dslr, being able to take a small P&S camera and capture decent enough images for research and ID purposes is very handy. And did I mention it fits in my BC pocket!!!
cheers,
Dave
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Hello,interesting. Whish agencies?
TDI run a solo diver course, I did it a couple of years ago and it took 2 days. 99.9% of my diving is solo on a rebreather....there's nothing better than complete silence whilst underwater taking pics! :-)
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also, i am not a scientist here but does any observation about the long term strobing of particular sample subjects have any relevance? ie, an individual sample pygmy could turn half blind from incessant strobing and not die, but still be impacted on the reproductive end or survival capability, which overall would bring down population averages.This indeed could possibly true however I think testing/proving it would be almost impossible. I can say that the population of White's Seahorses (Hippocampus whitei) at one of my sites has been photographed extensively by myself as part of my PhD research for the past 4 years (as well as being photographed by many other recreational photographers) and I can say that there has been no change in population size, their behaviour or survival rates (through mark-recapture analysis) which indicates to me that its unlikely that flash photography is having an impact on them. The same animals are being sen on a regularly basis, they are staying on their same habitat even after being photographed and they have no problems in reproducing and mating. This data has only been recorded on the one species (H. whitei) so it's not known whether other seahorse species would respond the same. I'm currently writing up a paper on the longterm study of H. whitei (probably the longest dataset collected for a single seahorse species) which provides details of population size, survivability etc.... might finish it this year however I just keeping thinking another year of data would be nice!
Personal experience also shows that H. abdominalis have no problems being photographed on a regularly basis (same animals have been found in Sydney Harbour for just over two years) and research off Motupore Island in PNG suggested that H. bargibanti showed no ill response to being photographed as part of a study that focused on using photo's to identify individual animals (through locations of pustules etc...).
So until proven otherwise, I have no reason to believe that flash photography has a detrimental impact on seahorses. However, the practise of photographer's regularly poking and proding seahorses (particularly pygmies) and the breaking of their habitat would be a different story. :-(
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I would be interested in hearing underwater photographer and seahorse biologist Dave Harasti's view on this - when he bumps into this thread.Thanks for dobbing me in Alex!
Having spent the past 4 years diving and photographing seahorses on a weekly basis as part of my PhD research I might be able to provide some insight.
Part of the research I have been undertaking is the use of photo ID's to individually identify seahorses. Basically, I photography a seahorse and look for any distinctive marks and use these marks for future individual identification. I have taken A LOT of photographs of individuals and given that they are still currently alive and in the same spot that I first found them I consider it very unlikely that flash photography is having an impact on them. A good example is my 'Grandpa' seahorse who I have been photographing for 3 and half years and he's still alive, currently mating with a real hot gold female (well she's 'hot' in seahorse eyes!
) and is still found in the same spot says to me that flash photography does not cause seahorses to die or migrate from their location. I should point out that the work I have been doing is on the White's Seahorse (Hippocampus whitei) and to a lesser extent on the Pot Belly Seahorse (Hippocampus abdominalis) so I cannot say that flash photography doesn't impact on ALL seahorse species. However, some of the work we did in PNG involved photo ID of the pygmy seahorse (Hippocampus bargibanti) and there was also no impact on this species from flash photography!So in short, I have never seen a negative impact of strobe photography on the seahorses that I have studied and in my humble opinion photography poses no harm to seahorses. However, photographers touching and moving seahorses and their habitats is a completely different story!
cheers,
Dave
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Lucky dude - I have seen them do this in fish tanks at a seahorse farm, but never in the wild. Amazing timingKevin is incredibly lucky!!! I've been doing 2 hour dives at the Pipeline 4 times a week since the middle of September studying the seahorses during their breeding season (this is my PhD research in my spare time). Out of all the hours spent underwater looking at these buggers I've never seen them give birth, seen plenty of mating action but never a male popping the babies out! If you look closely at the seahorse you will see it has a green spot near the abdomen, this animal has been sitting on the same sponge for 4 weeks and was pregnant again when I checked on him a couple of days ago.
Also, I should point out its not a world first for photographing a seahorse giving birth, I know of a couple of people who have photographed and filmed several different species with Rudie Kuiter having some great shots in his book "Seahorses, Pipefish and their Relatives" of Hippocampus whitei giving birth and mating.
cheers,
Dave
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I think he has actually lost it already Mike.Yep, well and truely... I think Snoopy is keeping me sane (or insane) underwater!
For those interested in the next instalement of scuba snoopy there is another story that you might finde 'interesting', it's Scuba Snoopy's search for the Sunfish in Balie(I forgot to post this story on wetpixel!). See link:
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Scuba Snoopy was bored. It had been 4 months since his last big adventure when he was off encountering Mola mola in Bali and since then diving had been pretty dull. He’d done a couple of dives in Nelson Bay looking at seahorses, nudibranchs and anglerfish, however he’d become bored of the Bay. Snoopy even thinks that Nelson Bay diving is over rated and doesn’t understand why anyone would want to spend so much time looking at tiny little critters.... some people are just weird!
Snoopy wanted some big fish action and he’d always wanted to see a shark. However Snoopy was rather wary as he’d seen on Discovery channel what sharks do to seals so imagine what they would do to a poor little puppy dog!. But Snoopy had been told there is a shark they call the giant puppy dog of the sea, the grey nurse shark. Surely he’d be safe as one puppy dog wouldn’t eat another, would it?
He got on the phone and rang his good friend Peter ‘The Hoff’ Hitchins from South West Rocks Dive Centre to see if the conditions were any good at Fish Rock. The reply of “its 22 degrees, 20 metres vis and bucket loads of sharks” was all it took for Snoopy to hop in his fully sick snoop dog car and head up the Pacific Highway.
The next morning he was on the new SW Rocks Dive Centre boat, appropriately called Fish Rocket. Snoopy liked this boat as it was big and roomy and went as fast as a space rocket. They arrived at Fish Rock in no time at all and as they were gearing up The Hoff gave a dive brief to Snoopy. “We’ll just swim through the deep entrance of the cave, up to the shallow end and hopefully we’ll see some grey nurse sharks hanging out”.
Well hang on a minute!!! Snoopy was keen to see a shark, not swim through some pitch black friggin cave. Snoopy was scared... he didn’t have his cave dive certification and he’d never dived in a cave before. But the Hoff assured him all would be cool and gave him a special drink called ‘Harden Up’ and Snoopy felt revitalised, he was ready to take on the big black cave and anything it was willing to throw at him! Bring it on!!!
As they entered the cave Snoopy felt rather alone... all he could do was follow the torch light in front of him and hope that he didn’t bump into anything. up a narrow dark chimney and then he saw it in the distance, a beautiful bright blue light that was the opening to the shallow entrance of the cave, it was so beautiful and surreal that Snoopy decided there and then that he liked caves. In fact he decided this might be one of his favourite dives and he hadn’t even seen a shark yet!
But he wasn’t here for caves, he wanted sharks. So he positioned himself at the entrance to the cave and waited... and waited... and waited some more. There wasn’t a shark to be seen. Snoopy was starting to think he was jinxed!
And then he saw it! A small torpedo shape in the distance was approaching the cave entrance and it was getting bigger and bigger. It was a shark.... Snoopy’s first shark!!! Okay, Snoopy won’t admit it but he was more than a little bit scared when he first shark.... it was humungous and after seeing the big pointy white teeth he was glad he’d packed the brown budgie smugglers! After eye balling the shark off to show that Snoopy was tougher, the shark got the hint and slowly turned away and exited the cave. Snoopy had taken on the shark and won!!!
The next thing Snoopy saw was a turtle, this was Snoopy’s first ever turtle encounter. He was losing his diving virginity left, right and centre, First a cave then a shark and now a turtle!!! The only problem was that this small Hawkbill Turtle thought Snoopy looked rather like a tasty sponge and was about to bite into him until the Hoff appeared from nowhere and pulled Snoopy away to safety. The Hoff was a hero, just like he was on Snoopy’s favourite TV show Baywatch! Phew.
As they swam back to the boat Snoopy passed over several other grey nurse sharks, it had been a good day! A scary day but a very good day. Now that Snoopy has mastered eyeballing off the grey nurse he needs a new challenge...maybe it’s time to take on the Great Whites! [
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THE END
Whilst I was waiting for Snoopy to see his first shark I managed to snap off a couple of pics, these are my favourites.
The rest of the gallery can be seen here:
cheers,
Dave
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just heard from Eric, he has the tanks so all is sorted.
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I have stayed at both Kima Bajo and Cocotinos over the past 12 months and Cocotinos wins hands down. Kima Bajo is a beautiful resort however the hill to the room requires sherpa's to carry stuff for you and the price of food in the restraunt is a turn off.
Cocotinos on the other hand was built by divers for divers and this is easily the best dive resort that I have stayed at. Food is excellent, resort is stunning and the dive guides are the best critter hunters I have dived with. I wrote a short article on diving with Cocotinos here: http://www.daveharasti.com/articles/Cocotinos.html
cheers,
Dave
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How big is your BC pocket?
On a more serious note, I'd have a look at one of the Canon A series in a Canon housing in addition to the G9 (or recently released G10).
Well, its not actually a BC pocket! I have a Zeagle pocket attached to my rebreather that easily accomodates a spare mask so should fit a camera okay. I've played with the Canon G9 and it's slightly bigger than what I want, I want something thin and flat. I'll check out the Canon A Series cameras...
I was checking out the Sony DSC-T20 (Graham Abbott from diving4images uses it for his pics which are very good) and this is the camera I'm starting to lean towards - just need to find one in the flesh to try out!
Damage to marine animals eyes by strobes.
in The Galley: General Chat
Posted
Yep, part of my research looked at the predation of seahorses and the octopus was found to be a major predator.
Dead seahorse number 2 underwater:
So finding a dead Hippocampus underwater isn't impossible after all, just incredibly rare!!.