View Full Version : Here fishy fishy...
craigdiver
27-08-06, 11:49
Here is a question for the people in the know (Yes, that's you Charlie;) )
When on a night dive, when I shine my billion giga-watt torch in some poor fishies eyes, why doesn't it startle the fish, crab, orca, great white etc.
As a human (at the moment - still trying to grow gills!), my eyes are very sensitive to bright lights and have an autonomous reaction to close my eyes when some bugger shines their torch in my eyes on a night dive:eek:
I don't think fish have eyelids, so does it hurt their little eyes?
CraigDiver
Marine Psychologist B.O. POO STELLA
bubblemaker
27-08-06, 15:56
simple answer...yes.
the light might not necessarily startle them, but it can easily disorient them. it can be seen when you shine lights smaller fish sometimes that the swim into rocks when trying to get away from you.
it should clearly be avoided, as it makes them easier prey for bigger fish that want to eat them.
try usiong the outside edge of your light.
craigdiver
27-08-06, 17:27
it should clearly be avoided, as it makes them easier prey for bigger fish that want to eat them.
try usiong the outside edge of your light.
I'll take lots of care where I shine my torch because "Fish are friends, not food":rolleyes:
CraigDiver
Marine Physiotherapist
bubblemaker
27-08-06, 18:28
physiotherapist, and psychologist... you are well qualified!!!
craigdiver
27-08-06, 21:10
physiotherapist, and psychologist... you are well qualified!!!
I'll let you into a secret..... If it wasn't for my spell checker I couldn't spell physiotherapist or psychologist never mind know anything about either! But I guessed you sussed that already;)
I wonder if you actually get Marine physiotherapists and psychologists, I really should stay off the Magners!
CraigDiver
I'll take lots of care where I shine my torch because "Fish are friends, not food":rolleyes:
CraigDiver
Marine Physiotherapist
Except when deep fried in batter with chips, salt and brown sause, need to go I'm hungry now.....:D
bubblemaker
04-09-06, 18:24
I wonder if you actually get Marine physiotherapists and psychologists, I really should stay off the Magners!
CraigDiver
Bizarely.. you do technically get them, but not in the way you mean. Marine psychology is interested in the learned behaviour of marine life, mostly fish. And what would be considered marine physiotherapy deals with water sports injuries...
though you do get pet psychologists, who deal with animal's mental issues!!
Bizarely.. you do technically get them, but not in the way you mean. Marine psychology is interested in the learned behaviour of marine life, mostly fish. And what would be considered marine physiotherapy deals with water sports injuries...
though you do get pet psychologists, who deal with animal's mental issues!!
And you get Diving Psychologists who study the mentality of us lot... scary! :rolleyes:
Ask cheeky_diver (http://www.congeralley.com/forums/member.php?u=27): he's about to start a PhD at Plymouth on the very subject. :eek:
Oh, and don't talk to me about mental pets: I have plenty experience of them! :mad:
Here is a question for the people in the know (Yes, that's you Charlie;) )
When on a night dive, when I shine my billion giga-watt torch in some poor fishies eyes, why doesn't it startle the fish, crab, orca, great white etc.
As a human (at the moment - still trying to grow gills!), my eyes are very sensitive to bright lights and have an autonomous reaction to close my eyes when some bugger shines their torch in my eyes on a night dive:eek:
I don't think fish have eyelids, so does it hurt their little eyes?
CraigDiver
Marine Psychologist B.O. POO STELLA
it would not matter how many billion watts you shone in their eyes.
fish are susseptable to light tempreature, not wattage.
example:-
i own a greenforce (modular) with a 50 watt xonophote (halogen) head.
the colour temprature is around 2500 kelvins & appears orange/red in colour.
i also own a 45 watt (equivelent) greenforce LED head.
the colour temprature is around 6500 kelvins & appears blue/white in colour.
if i use my xonophote the fish rarely move.
if i use my LED, i can cut through shoals like butter & part them into little groups during the daytime or at night.
a little like sheep herding, but without the sheep!
similar rules apply with white balance on cameras.
stewart
Marine Psychodontnomuchelseaboutlightsbutthat. loves. stella
craigdiver
05-09-06, 09:22
it would not matter how many billion watts you shone in their eyes.
fish are susseptable to light tempreature, not wattage.
example:-
i own a greenforce (modular) with a 50 watt xonophote (halogen) head.
the colour temprature is around 2500 kelvins & appears orange/red in colour.
i also own a 45 watt (equivelent) greenforce LED head.
the colour temprature is around 6500 kelvins & appears blue/white in colour.
if i use my xonophote the fish rarely move.
if i use my LED, i can cut through shoals like butter & part them into little groups during the daytime or at night.
a little like sheep herding, but without the sheep!
similar rules apply with white balance on cameras.
stewart
Marine Psychodontnomuchelseaboutlightsbutthat. loves. stella
Thanks for that, that explains the reaction from my LED torch.
Cheers
CraigDiver
craigdiver
05-09-06, 09:23
though you do get pet psychologists, who deal with animal's mental issues!!
'mental' being the operative here!
CraigDiver