HID Lights blinding Fish?

[ZenDiver]

I hear people say that HID lights blind and permantly damage the eyes of fish and other reef creatures . Some say it doesn't and some say it does. Anyone know of any difinitive research one way or the other?

Brian

 

[wedivebc]

I hear people say that HID lights blind and permantly damage the eyes of fish and other reef creatures . Some say it doesn't and some say it does. Anyone know of any difinitive research one way or the other?

Brian

A study would be difficult since they are never willing to read the eye charts

 

[akscubainst]

What would make a 10W HID any worse than a 100W Halogen? OR sunlight for that matter. I've never noticed fish crashing into things after being exposed to my light.

I don't know,

Dave

 

[Uncle Pug]

While I don't know about the actual long term or permanent damage to fish eyes I think that in the short term it would make them more vunerable.

At any rate here is an experiment that you can try some evening near a busy highway:

Have someone blindfold you for 30 minutes and then remove the blindfold and shine an 18w HID directly into your open eyes for as long as it takes to say, "Oh... look and the pretty fish" 25 times.

Then have them lead you by the hand to the edge of the highway and see if you can make it across.

 

[msandler]

can't be good for them.

 

[Corigan]

I know on my aquariums I have to stagger the lights on with a low wattage light before I let the really high powered lights kick on. If you just turn the high powered lights on from dark the fish freak out and slam into walls. If you just stagger on the lights with a really dim light (like dawn), it doesn't bother them as badly. I would say you could definately blind some fish with a HID.

Matt

 

[cyklon_300]

My fish are unable to locate food at the surface for ~10 min after turning on the fluorescent tank light, I'd imagine an HID would fry their sight for quite a bit longer....

 

[Northeastwrecks]

My fish are unable to locate food at the surface for ~10 min after turning on the fluorescent tank light, I'd imagine an HID would fry their sight for quite a bit longer....

I don't know for sure, but I try to err on the side of caution.

I was diving earlier today. My buddy and I came across a fairly large sculpin just sitting out on the sand. Since we both use 18W HID's, we did not shine the light directly on the fish. We did focus the beams nearby so that the scatter provided enough light to see him.

 

[Uncle Pug]

I have a Q40 ziptied (of course) to the goodman handle on both my 10w HID and my 21w HID. I use that for looking at critters with sensitive eyes.

 

[archman]

Anyone know of any difinitive research one way or the other?

Most "basic" fish physiological research like this was performed in the mid-20th century. If I were in my office I could refer you to more detailed information, like general light tolerances.

Fishes are highly diverse (26,000+ species), dwelling in myriad habitats of differing light quality. And although the basic architecture of fish eyes is not too radically dissimilar from those of mammals, you'll find astonishing variation in things like pigment densities, wavelength absorptions, focusing power, and the like.

As a loose rule, shallow but night-active fishes have more sensitive eyes than their daytime counterparts. So do fishes with larger eyes. Holocentrids (squirrel and soldierfishes) would be more likely to be traumatized by an HID light than scarids, for example. At an even more basic level, shine a flashlight in your face. If its so bright that it blinds YOU, its a fair bet that it'll blind the fish. I don't know of any HID lights that DON'T fall under this category.

Photoreceptive pigments can be physically BLEACHED out by extremely high (relative to each species) light intensities. This happens to deepwater animals all the time, when they are brought to the surface. Being an area of my expertise, I can cite two examples. I had a deepwater crab in an aquarium last year that had been permanently blinded by ROOM LIGHTS. And DSV Alvin is now believed to permanently blind alvinocarid shrimps with its floodlights, when visiting hydrothermal vent communities. So everytime that sub goes down to survey or visit, it does lasting damage to the ecosystem just by LOOKING AROUND. Bleah!

So don't shine HID lights at critters, unless they're naturally blind! And be stingy with your strobes and other bright-light producing devices too! Stick with the golden rule and you should be okay, at least in shallow water.