Damage to marine animals eyes by strobes.

Bother is one thing David, but the thread is about damage to the eyes and if it's permanent. I'm afraid unless someone takes a specimen, flashes one eye and leaves the other alone to see the damage caused, the only next best thing is Dave Harasti's paper, which I assume is through observation.

That paper may open pandora´s box... I would hate to listen to people justifying machinegunlike shooting just because someone wrote a paper saying it´s harmless...

By the way, you reminded me of a local yellow seahorse that was one eyed, it really lacked an eye and it lived well for a long time so, even if we are hurting the seahorse, it may be able to keep on living its life... but that does not give us the right to hurt it. I will try to find this seahorse pictures because it really looked odd.

About strobes affecting coral, how close is your subtronic to the coral? Besides photosensitivity, heat sensitivity would be an interesting study, but I'm sure climate change scientists are already monitoring the changes.

They were about 30cm appart approx... It is a good exercise to put a hand in front of the strobe and feel the heatwave when shot. It would also be a good exercise for video lights too.

Shooting a higher ISO really lowers the needed energy output without losing quality (specially on newer cameras and macro). I think is better to shoot two 1/2 power shots with some seconds in between than one full shot.

Very interesting topic from a number of anlges, including the practical aspect of getting better shots.

My experience and research is in fresh water, and while I suspect vision is similar between the environments, I not sure, because vision in aquatic creatures varies according to the depth they inhabit, the cover they utilize, etc.

One aspect is how fish adjust from daylight to night vision and vise-versa by reversing rod cells and cone cells. It is a gradual process, and the best I've heard it explained is to compare what we experience when coming from a dark thearter into full sunlight. It hurts, but our eyes adjust in seconds. The same kind of thing takes three or four hours for fish. They don't have eyelids and can't squint. Because they live in envornoments where light is refracted and diffused quickly, they adjust to the light by changing depths or backing into shaded areas. Would this mean that, because their eyes adjust slowly to light, that sudden bursts of light effect their vision more, or less?

At any rate, this indicated they are sensitive to dramatic changes in light intensities, and I would suspect sudden, intense light would have a blinding effect, often creating the "deer in the headlights" response. Whether it does any damage is debatable and open to true scientific research, but I doubt such a study is forthcomming, given the miniscule occurences. Might make a good doctural paper.

I have noticed from documentaries that fish living in the dark environments of the ocean floor seem totally unbothered by the intnese light of filming. Cavefish seem uneffected as well. Sight-feeders and predators seem most effected.

Nevertheless, I know for a fact that minnows are attracted by strong lights at night used by fishermen. Bugs are attracted to the light, minnows are attracted by the bugs and larger fish are attracted by the minnows. It would seem that if this intense, foreign light was hurtful or harmful, the minnows and larger fish would stay away.

From my own photographic experiements, I've noticed they react less to a steady light than a strobe, but there is nothing controlled or scientific about my observations. I suspect steady light dissorients, or temporarily blinds, them more, which from a practical photographic perspective, give me more time and chances to get a good shot.

There are so many variables, but one thing I know: light behaves differently under water and fish don't process light in the same way as we do.

Thanks Drew.

 

Can you point me in the direction of this research?

 

My brother is a professor of animal care and welfare at Shanghai Agricultural University. He is not aware of any research on the subject. Who would fund it?

 

The thrust of my article is that it's not the flash but what's attached to it (the person) that does the damage! If you are worried about the fish - get out of the water.

 

My own experience subjecting animals to pulses of light in the order or 20,000 - 40,000joules in controlled conditions during the eighties was limited to cats, dogs, rodents, chickens, ducks, chameleons, toucans, parrots, horses, snakes, tortoises, chimpanzees and (most like pigmy seahorses) head-lice. My experience underwater is only anecdotal.

Question- you mention 20,000 to 40,000 joule experiments and I assume the same animals received repeated exposure. Most marine animals, in the wild, receive a limited amount of exposure (obviously certain, rare and large creatures like whales would get more) due to the ocean being so big, the creatures being tiny, and the virtual improbability of tracking the same creature (again certain creatures are an exception). Also, you said that camera strobes are far less then 100 joules. So given the limited amount of exposure, and the power levels being so dramatically different how does one correlate the 20-40k joule experiments to actual real life usage? That would be like saying X product possibly could poison someone if that someone was exposed to 400x the normal dosage....repeatedly - and it's virtually unlikely due to many factors of that ever happening. If it's not a very likely situation, then who cares?

Yes it would be good to know if we are hurting marine life but it would be good to know this within the reasonable (or even SLIGHTLY unreasonable) situations we currently put the marine animals in. Not many people care for extreme examples that are not going to happen.

On the other side i have seen a turtle swim headlong at speed into a rock after a strobe was fired in his/her face on a night dive, so surely there must be some reprecutions...

 

Olly

Post hoc, ergo propter hoc comes to mind

Would it be plausible that the Emperor dive-guides were right in trying to ban people from using strobes?

 

Should we be discouraging wetpixellers from shining lights/strobes at marine animals?

Hi, John -

Apologies - I have been out of the country and hadn't been back to check this thread! I was in Lembeh. Using strobes. And Sola lights, too. Sometimes in tandem. And that will preface my answer:

It is my personal opinion that although the scenario described initially (e.g., retinal damage) is plausible, it would require pretty extreme conditions. The experimental situations that I've read about are extreme, either involving constant and very bright light, animals with unpigmented eyes, or both. These were performed to prove a point, not necessarily to recapitulate a real-life condition. Disclaimer - I have not done any new literature searches on this subject, so I may not be quite up-to-date... Keep in mind that I am talking about permanent retinal damage due to cell loss, not a temporary condition (ref: "flash blindness).

You can also think about it like this - and I truly do not mean this to be derogatory to anyone in any way - MOST photographers, even those with huge strobes, (1)are not taking shots close to the eyes of the marine animal - as the number one rule is always "get closer" - most people just don't get that close (2)lots of photographers don't bother to shoot the eyes at all - "butt" or "helicopter" shots are very common (3) Most people are not repeatedly shooting/working one subject, but they have a "trip to the zoo" approach - follow dive guide- take 5 pictures - follow dive guide to next subject - take 5 pictures... (4) Finally, while there are certainly situations where the same creature is photographed over and over and over - most of the time, I know that I happen across a subject; rarely do I come across the same exact subject time and again, and I dive the same few sites locally often once or twice a week, and year-round.

What do you think??

Hi, John -

 

Apologies - I have been out of the country and hadn't been back to check this thread! I was in Lembeh. Using strobes. And Sola lights, too. Sometimes in tandem. And that will preface my answer:

 

It is my personal opinion that although the scenario described initially (e.g., retinal damage) is plausible, it would require pretty extreme conditions. The experimental situations that I've read about are extreme, either involving constant and very bright light, animals with unpigmented eyes, or both. These were performed to prove a point, not necessarily to recapitulate a real-life condition. Disclaimer - I have not done any new literature searches on this subject, so I may not be quite up-to-date... Keep in mind that I am talking about permanent retinal damage due to cell loss, not a temporary condition (ref: "flash blindness).

 

You can also think about it like this - and I truly do not mean this to be derogatory to anyone in any way - MOST photographers, even those with huge strobes, (1)are not taking shots close to the eyes of the marine animal - as the number one rule is always "get closer" - most people just don't get that close (2)lots of photographers don't bother to shoot the eyes at all - "butt" or "helicopter" shots are very common (3) Most people are not repeatedly shooting/working one subject, but they have a "trip to the zoo" approach - follow dive guide- take 5 pictures - follow dive guide to next subject - take 5 pictures... (4) Finally, while there are certainly situations where the same creature is photographed over and over and over - most of the time, I know that I happen across a subject; rarely do I come across the same exact subject time and again, and I dive the same few sites locally often once or twice a week, and year-round.

 

What do you think??

Alisen:

I agree mostly with what you are saying, and most lab experiments were not designed to evaluate photographers in the wild. Also, as noted before, most fish have some significant regeneration capacity (if we only could move that to people's hearts). That being said, I try to take only enough pics of a given subject to either use for an ID for a database for example or to try to get something artistic. The only case that I think of as being really special is that of some pygmy seahorses in places like Lembeh where diver after diver after diver takes shot after shot after shot of them. The clearly don't like it (they turn away) so in those cases, I personally try to be a bit less greedy. Not because I think I will do them ultimate retinal damage but simply to give them a bit of a vacation from temporary flash brightness.

Bill

Alisen:

I agree mostly with what you are saying, and most lab experiments were not designed to evaluate photographers in the wild. Also, as noted before, most fish have some significant regeneration capacity (if we only could move that to people's hearts). That being said, I try to take only enough pics of a given subject to either use for an ID for a database for example or to try to get something artistic. The only case that I think of as being really special is that of some pygmy seahorses in places like Lembeh where diver after diver after diver takes shot after shot after shot of them. The clearly don't like it (they turn away) so in those cases, I personally try to be a bit less greedy. Not because I think I will do them ultimate retinal damage but simply to give them a bit of a vacation from temporary flash brightness.

 

Bill

Oh, Bill, I should have known you'd hit Pub Med immediately!!! I'll have to look at some of the ref's I saw that you've listed for my own interest - certainly the mammalian retinas I've seen do not have a lot of regeneration capacity (let's talk about this in person next time I see you), but it has been 7+ years since I had the chance to participate in extensive comparative ophthalmology rounds - I used to attend them during both my residency and postdoc, but I don't remember seeing many fish!! From a veterinary standpoint, that type of work is so specialized that very few people really get to become familiar with the histologic intricacies of nonmammalian eyes - vet eye pathology is already incredibly specialized. At any rate, the bottom line is the same - probably not a catastrophically damaging issue in many cases.

FWIW, I agree with you 100% on the seahorse thing. I have very few seahorse shots (a few of one seahorse each from Lembeh and Dumaguete - I have seen many, but if they weren't positioned for either a front-facing or perfect profile shot, I don't bother, I just feel terrible) and I have never shot a pygmy at all - same as you, watching people line up to shoot them just turns me off.

Hope you're well - please tell your wife congrats on her recent comp win!! We would love to dive with you guys again soon.

The Ageing Scribe's article is out, published in the March edition of Diver Magazine.

After all the hype on this thread I found it surprisingly non contentious with some interesting facts.

Nice one JB

For those of you that don't have access to the paper version the article will be on Divernet.com in a month or so's time

Nige Wade

http://www.divernet.com/Photography/796395...he_animals.html

(with a clumsily written incorrect caption to one of the pictures!)

http://www.divernet.com/Photography/796395...he_animals.html

An interesting read. Thanks for sharing, John.

Alex

Quite frankly, after diving a lot with rebreathers, I think that our bubbles stress the fish much more than strobes do (with the exception of pygmy seahorses of course, that can be photographed by hundreds of divers per day and have nowhere else to go), so if some dive operator feels the need to ban strobe photography for the sake of keeping stress levels low, he is shooting himself in the foot as diving itself is much more stressful to the fish than photography.

P.S.: I say that based on pure personal observation and my conclusions have no scientific basis.

http://www.divernet.com/Photography/796395...he_animals.html

with a clumsily written incorrect caption to one of the pictures now corrected!