“The best way to communicate with a fish is to drop them a line”

“Drop a line” used to be a way of saying that someone was making a telephone call. A fishing joke is:
 
“The best way to communicate with fish is to drop them a line.”
   
“How would you communicate with a fish? Drop it a line” was cited in print in 1958.
     
 
15 December 1958, The Times Record (Troy, NY), “Fun Time—The Riddle Box,” pg. 21, col. 4:
How would you communicate with a fish?
Drop it a line.
 
19 May 1960, The Times Record (Troy, NY), “Fun Time—The Chuckle Box,” pg. 2, col. 5:
Bill: How can a person communicate with a fish?
Jim: By dropping him a line!
 
Google News Archive
23 April 1971, The Free Lance-Star (Fredericksburg, VA), “Fun Time—The Chuckle Box,” pg. 13, col. 4:
Bill: How can a person communicate with a fish?
Jim: By dropping him a line.
 
Washington (DC) Post
WHERE TO DROP THEM A LINE SO THE FISH WILL COME CALLING
By GENE MUELLER June 8, 1984
Little more than ten years ago the Potomac River’s downtown portion was the butt of more jokes than Rodney Dangerfield. But all that’s changed.
 
Google News Archive
6 June 1992, Calhoun Times and Gordon County News (Calhoun, GA), “A Little Bit of Humor,” pg. 16, col. 4:
Darkita: How do you communicate with a fish?
Jane: Drop it a line,
     
1 September 1992, Detroit (MI) News, “Sunday Best” by Joe Falls, pg. 8E, col. 1:
Idle Thought: The best way to communicate with fish is to drop them a line.
 
10 January 1993, Des Moines (IA) Sunday Register, “Focus Is On Primary School” by Maury White, pg. 11D, col. 5:
I remember My Neighbor Walt saying the best way to communicate with fish is to drop them a line.
 
Walleye Message Central
How to catch saugeye?
Erie
05-22-2003, 12:12 PM
(...)
“Just Remember” that the way to communicate with the fish is to drop them a line 😉
 
Google Groups: alt.humor.puns
Puns of the Weak 03-15-04
Stan Kegel
3/16/04
(...)
The best way to communicate with a fish is to drop them a line. (Pun of the Day)
 
Google Groups: alt.humor.puns
Kids Puns of the Weak 12-14-04
Stan Kegel
12/14/04
(...)
The best way to communicate with a fish is to drop them a line. (Douglas Helsel)
 
Twitter
Robert Popoff
‏@Rob_Popoff
The best way to communicate with a fish is to drop them a line.
11:29 PM - 13 Apr 2009
 
Twitter
AbigailNorth
‏@AbigailNorth
The best way to communicate with a fish is to drop them a line. http://b1of.us/?13cx5l
6:52 PM - 21 Sep 2009
 
Marketing with Class
The Best Way to Catch a Fish Is to Drop Them a Line
by MICHELLE CLASS on JANUARY 2, 2015
Fishing is a pastime that I have learned to enjoy; whether it’s with family, alone, or even watching Tim Farmer on the TV show Kentucky Afield.