[NatureNS] red tide?

From: Christopher Majka <c.majka@ns.sympatico.ca>
To: naturens@chebucto.ns.ca
Date: Tue, 5 Aug 2008 10:19:46 -0300
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Hi Annabelle,

On 4-Aug-08, at 5:19 PM, annabelle wrote:

> I am originally from way up north in NB,  on the Bay of Chaleur we  
> also has phos.... but it seems to me you could wiggle your hand &  
> get it to shine, it didn't shine unless disturbed.

As I understand it what happens is that when dinoflagellates sense  
pressure waves in the water, indicating motion around it, for instance  
by a copepod which might be interested in consuming the  
dinoflagellate, they luminesce, thereby hoping to to attract an even  
larger predator (a mysid or euphasid shrimp, for instance) that might  
consume the copepod and hence spare the dinoflagellate - an  
interesting behavioral and evolutionary tactic.

I recall scuba diving at night in Passamaquaddy when we were doing  
research on benthic communities. There were so many dinoflagellates  
luminescing that I could see my fellow divers outlined in a glowing  
"reverse shadow". It was like an underwater light show! On ships at  
night in the south Pacific I would watch the bow waves at the front of  
the vessel which glowed continuously like a wave of fire.

> Also it seems to me that one could get it in deep water too.

Depends on how deep you mean. Dinoflagellates are algae so they tend  
to be found in the photic zone near the surface where there is  
sufficient light for them to photosynthesize. The have two flagellae  
which allow them to move around in the water column. I have seen them  
luminescing down at least to a depth of at least 10 meters however.


>
>> Responding to Cindy's musings...
>>
>> When I was a kid, we called the sparkly bits at the water's edge  
>> "phosphoresence"... probably a misnomer, but it's descriptive.

A misnomer, in that no actual raw phosphorus is involved, however the  
energy for the reaction does come from adenosine tri-phosphate (the  
"energy" molecule of cells) so one could argue that in that sense the  
term is not misplaced. :-> The term phosphoresence, however, has been  
in use since the 17th century, although since the work of Henri  
Becquerel (1852-1908) and Philipp Lenard (1862-1947), two physicists  
who in the late 19th century investigated the origins of  
phosphoresence, the term has mostly restricted to mineral phenomena  
related to radioactivity, so biologists prefer the  term  
bioluminescence.

Cheers!

Chris


Christopher Majka
Nova Scotia Museum, 1747 Summer St., Halifax, Nova Scotia, Canada  B3H  
3A6
c.majka@ns.sympatico.ca




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<html><body style=3D"word-wrap: break-word; -webkit-nbsp-mode: space; =
-webkit-line-break: after-white-space; ">Hi =
Annabelle,<div><br><div><div>On 4-Aug-08, at 5:19 PM, annabelle =
wrote:</div><br class=3D"Apple-interchange-newline"><blockquote =
type=3D"cite"><div>I am originally from way up north in NB, &nbsp;on the =
Bay of Chaleur we also has phos.... but it seems to me you could wiggle =
your hand &amp; get it to shine, it didn't shine unless disturbed. =
&nbsp;</div></blockquote><div><br></div><div>As I understand it what =
happens is that when dinoflagellates sense pressure waves in the water, =
indicating motion around it, for instance by a copepod which might be =
interested in consuming the dinoflagellate, they luminesce, thereby =
hoping to to attract an even larger predator (a mysid or euphasid =
shrimp, for instance) that might consume the copepod and hence spare =
the&nbsp;dinoflagellate - an interesting behavioral =
and&nbsp;evolutionary&nbsp;tactic.</div><div><br></div><div>I recall =
scuba diving at night in Passamaquaddy when we were doing research on =
benthic communities. There were so many dinoflagellates luminescing that =
I could see my fellow divers outlined in a glowing "reverse shadow". It =
was like an underwater light show! On ships at night in the south =
Pacific I would watch the bow waves at the front of the vessel which =
glowed continuously like a wave of fire.</div><div><br></div><blockquote =
type=3D"cite"><div>Also it seems to me that one could get it in deep =
water too.</div></blockquote><div><br></div><div>Depends on how deep you =
mean. Dinoflagellates are algae so they tend to be found in the photic =
zone near the surface where there is sufficient light for them to =
photosynthesize. The have two flagellae which allow them to move around =
in the water column. I have seen them&nbsp;luminescing&nbsp;down at =
least to a depth of at least 10 meters =
however.</div><div><br></div><div><br></div><blockquote =
type=3D"cite"><div><br><blockquote type=3D"cite">Responding to Cindy's =
musings...<br></blockquote><blockquote =
type=3D"cite"><br></blockquote><blockquote type=3D"cite">When I was a =
kid, we called the sparkly bits at the water's edge "phosphoresence"... =
probably a misnomer, but it's =
descriptive.</blockquote></div></blockquote><br></div><div>A misnomer, =
in that no actual raw phosphorus is involved, however the energy for the =
reaction does come from adenosine tri-phosphate&nbsp;(the "energy" =
molecule of cells) so one could argue that in that sense the term is not =
misplaced. :-> The term&nbsp;phosphoresence, however, has been in use =
since the 17th century, although since the work of&nbsp;Henri Becquerel =
(1852-1908) and&nbsp;Philipp Lenard (1862-1947), two physicists who in =
the late 19th century investigated the origins of&nbsp;phosphoresence, =
the term has mostly restricted to mineral phenomena related to =
radioactivity, so biologists prefer the &nbsp;term =
bioluminescence.</div><div><br></div><div>Cheers!</div><div><br></div><div=
>Chris</div><div><br></div><div><br></div><div =
apple-content-edited=3D"true"> <span class=3D"Apple-style-span" =
style=3D"border-collapse: separate; border-spacing: 0px 0px; color: =
rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: =
normal; font-variant: normal; font-weight: normal; letter-spacing: =
normal; line-height: normal; text-align: auto; =
-khtml-text-decorations-in-effect: none; text-indent: 0px; =
-apple-text-size-adjust: auto; text-transform: none; orphans: 2; =
white-space: normal; widows: 2; word-spacing: 0px; "><div =
style=3D"word-wrap: break-word; -khtml-nbsp-mode: space; =
-khtml-line-break: after-white-space; "><div>Christopher =
Majka</div><div>Nova Scotia Museum, 1747 Summer St., Halifax, Nova =
Scotia, Canada&nbsp; B3H 3A6</d