Marine Life and Dive Lights

[ArcticDiver]

Just what effect does a dive light have on fish? Same for all species? What brought this up was an experience I recently had.

A barracuda was swimming a few feet away, sort of keeping an eye on me the way barracuda do. Usually when I get a bit nervous about it I just make a small movement toward the fish and away it goes. But, this time when I shined my light on it it just kept on hanging out. I got so close I could touch it. Very unusual. I wondered if it was just that particular barracuda, or if the effect was common? I found I could replicate this scenario any time the amibient light was dim enough that my light beam could be seen on the fish's body.

Was this just the fish equivalent of the human reaction to a bright light shined in the eyes and not a long term problem?

 

[Mr.X]

I found I could replicate this scenario any time the amibient light was dim enough that my light beam could be seen on the fish's body.

Was this just the fish equivalent of the human reaction to a bright light shined in the eyes and not a long term problem?

This experiments was conducted with one particular fish - right?

X

 

[ScubaSeanMaui]

I don't think it's a problem for the fish. I find Barracuda to be pretty bold but everything else seems to swim off...

They have a huge Barracuda off the Liberty Wreck at Tulamben, Bali who will not move no matter how close you get:

Sean

 

[tfsails]

Man, that puppy's got some big ole teeth!!!

 

[ArcticDiver]

This experiments was conducted with one particular fish - right?

X

Same species but different fish.

 

[Mr.X]

Same species but different fish.

Very interesting. More experiments are in order with an all-Kevlar suit!

Did some light tests with critters up in your neck of the woods and they didn't seem to care much as long as it the beam didn't mimic shadows, or something big swimming overhead. Of course, the bigger predators like Ling didn't seem too bothered.

X

 

[Gombessa]

Try it with a 250w HMI with a spot reflector

 

[dpbishop]

Lobsters don't hang around long when you shine a light on them.

 

[Mr.X]

Try it with a 250w HMI with a spot reflector

Are you talking about the new Salvo HMI? I think fish would get a sunburn underwater, and small crustaceans (like lobsters) would be peel-n'-eat under the intense beam!

X

 

[ArcticDiver]

Lobsters don't hang around long when you shine a light on them.

Unless you catch them under a ledge. I saw several that would just freeze in their "hiding place" when illuminated. Eyes glowing and antennae quivering.