Fraction fish harvested p year(
	[(0,0)-(30,0.1)],(0,0),(5,0),(10,0),(15,0),(20,0),(25,0),(30,0))
	~	1/year
	~		|

Food fish harvest=
	Food fish*Fraction fish harvested p year(Time)
	~	fish/year
	~		|

Ratio of food fish to predators=
	Average food fish pop/"Average shark & skate pop"
	~	
	~		|

Sharks and skates= INTEG (
	"Shark & skate net births" - Shark and skate harvest,
		 20)
	~	fish
	~		|

Average food fish pop= INTEG (
	chng in avg food fish pop,
		Food fish)
	~	fish
	~		|

"Average shark & skate pop"= INTEG (
	"chng in avg shark & skate pop",
		25)
	~	fish
	~		|

chng in avg food fish pop=
	(Food fish - Average food fish pop)/time to avg populations
	~	fish/year
	~		|

"chng in avg shark & skate pop"=
	(Sharks and skates - "Average shark & skate pop")/time to avg populations
	~	fish/year
	~		|

time to avg populations=
	12
	~	year
	~		|

Food fish= INTEG (
	Food fish net births - Food fish harvest,
		 1000)
	~	fish
	~		|

Shark and skate harvest=
	Sharks and skates*Fraction fish harvested p year(Time)
	~	fish/year
	~		|

"Shark & skate net births"=
	"shark & skate nbf"*Sharks and skates
	~	fish/year
	~		|

Food fish net births=
	food fish nbf*Food fish
	~	fish/year
	~		|

"shark & skate nbf" = "shark & skate nbf LOOKUP"(Food fish)
	~	fish/fish/year
	~		|

"shark & skate nbf LOOKUP"( (0, -0.3), (200, -0.24), (400, -0.18), (600, -0.12), (800\
		, -0.06), (1000, 0), (1200
, 0.06), (1400, 0.12), (1600, 0.18), (1800, 0.24), (2000, 0.3) )
	~	fish/fish/year
	~		|

food fish nbf = food fish nbf LOOKUP(Sharks and skates)
	~	fish/fish/year
	~		|

food fish nbf LOOKUP( (0, 2), (5, 1.54), (10, 1.16), (15, 0.76), (20, 0.38), (25, 0),\
		 (30, -0.42), (35, -0.82
), (40, -1.22), (45, -1.64), (50, -2) )
	~	fish/fish/year
	~		|

INITIAL TIME  = 0
	~	year
	~		|

FINAL TIME  = 30
	~	year
	~		|

TIME STEP  = 0.25
	~	year
	~		|

SAVEPER  = 0.25
	~	year
	~		|

\\\---/// Sketch information - do not modify anything except names
V300  Do not put anything below this section - it will be ignored
*Predator & prey interactions
$192-192-192,0,Comic Sans MS|18||0-0-0|0-0-0|0-0-255|-1--1--1|-1--1--1|72,72
10,1,Food fish,402,103,47,26,3,3,0,32,0,0,0,0,0-0-0,0-0-0,Comic Sans MS|14||0-0-0
10,2,food fish nbf,237,238,57,14,8,3,2,33,0,0,0,0,128-128-128,0-0-0,Comic Sans MS|14||0-0-0
10,3,Sharks and skates,321,324,50,28,3,3,0,32,0,0,0,0,0-0-0,0-0-0,Comic Sans MS|14||0-0-0
10,4,food fish nbf LOOKUP,130,168,58,25,8,3,3,1,0,0,0,0,128-128-128,0-0-0,|14||0-0-0
10,5,"shark & skate nbf",479,226,90,17,8,3,2,33,0,0,0,0,128-128-128,0-0-0,Comic Sans MS|14||0-0-0
10,6,"shark & skate nbf LOOKUP",636,301,79,25,8,3,3,1,0,0,0,0,128-128-128,0-0-0,|14||0-0-0
1,7,3,2,1,2,0,0,1,0,0,0-0-255,|18||0-0-0,1|(255,294)|
1,8,4,2,0,3,0,0,1,0,0,0-0-255,|18||0-0-0,1|(185,204)|
1,9,6,5,0,3,0,0,1,0,0,0-0-255,|18||0-0-0,1|(555,262)|
1,10,1,5,1,2,0,0,1,0,0,0-0-255,|18||0-0-0,1|(448,142)|
12,11,48,209,106,8,8,0,3,0,32,-1,0,0,0,0-0-0,0-0-0,Comic Sans MS|14||0-0-0
1,12,14,1,4,0,0,22,0,0,0,-1--1--1,,1|(325,105)|
1,13,14,11,100,0,0,22,0,0,0,-1--1--1,,1|(250,105)|
11,14,48,289,105,6,8,34,3,0,0,1,0,0,0
10,15,Food fish net births,289,138,58,25,40,3,0,32,-1,0,0,0,0-0-0,0-0-0,Comic Sans MS|14||0-0-0
1,16,2,15,1,2,0,0,1,64,0,0-0-255,|18||0-0-0,1|(244,188)|
1,17,1,15,1,1,0,0,1,64,0,0-0-255,|18||0-0-0,1|(364,167)|
12,18,48,500,326,8,8,0,3,0,32,-1,0,0,0,0-0-0,0-0-0,Comic Sans MS|14||0-0-0
1,19,21,3,4,0,0,22,0,0,0,-1--1--1,,1|(408,328)|
1,20,21,18,100,0,0,22,0,0,0,-1--1--1,,1|(475,328)|
11,21,48,452,328,6,8,34,3,0,0,1,0,0,0
10,22,"Shark & skate net births",452,364,72,28,40,3,0,32,-1,0,0,0,0-0-0,0-0-0,Comic Sans MS|14||0-0-0
1,23,5,21,1,2,0,0,1,64,0,0-0-255,|18||0-0-0,1|(477,286)|
1,24,3,21,1,1,0,0,1,64,0,0-0-255,|18||0-0-0,1|(396,278)|
12,25,48,586,104,8,8,0,3,4,32,-1,0,0,0,0-0-0,0-0-0,Comic Sans MS|14||0-0-0
1,26,28,25,4,4,0,22,0,0,0,-1--1--1,,1|(551,104)|
1,27,28,1,100,4,0,22,0,0,0,-1--1--1,,1|(481,104)|
11,28,48,519,104,6,8,34,3,4,0,1,0,0,0
10,29,Food fish harvest,519,137,42,25,40,3,4,32,-1,0,0,0,0-0-0,0-0-0,Comic Sans MS|14||0-0-0
12,30,48,122,325,8,8,0,3,4,32,-1,0,0,0,0-0-0,0-0-0,Comic Sans MS|14||0-0-0
1,31,33,30,4,4,0,22,0,0,0,-1--1--1,,1|(160,325)|
1,32,33,3,100,4,0,22,0,0,0,-1--1--1,,1|(236,325)|
11,33,48,196,325,6,8,34,3,4,0,1,0,0,0
10,34,Shark and skate harvest,196,358,71,25,40,3,4,32,-1,0,0,0,0-0-0,0-0-0,Comic Sans MS|14||0-0-0
1,35,1,28,1,4,0,0,1,64,0,0-0-255,|18||0-0-0,1|(453,58)|
1,36,3,34,1,4,0,0,1,64,0,0-0-255,|18||0-0-0,1|(290,396)|
10,37,Fraction fish harvested p year,666,174,75,25,8,3,4,32,0,0,0,0,0-0-0,0-0-0,Comic Sans MS|14||0-0-0
10,38,Fraction fish harvested p year,177,440,79,25,8,2,4,33,-1,0,0,0,128-128-128,0-0-0,Comic Sans MS|14||128-128-128
1,39,37,29,0,4,0,0,1,64,0,0-0-255,|18||0-0-0,1|(582,153)|
1,40,38,34,0,4,0,0,1,64,0,0-0-255,|18||0-0-0,1|(184,405)|
10,41,Time,672,106,30,14,8,2,8,3,-1,0,0,0,128-128-128,0-0-0,|18||128-128-128
1,42,41,29,0,8,0,0,0,64,0,-1--1--1,,1|(608,118)|
10,43,Time,77,389,40,20,8,2,8,3,-1,0,0,0,128-128-128,0-0-0,|18||128-128-128
1,44,43,34,0,8,0,0,0,0,0,-1--1--1,,1|(114,379)|
\\\---/// Sketch information - do not modify anything except names
V300  Do not put anything below this section - it will be ignored
*Average populations
$192-192-192,0,Times New Roman|12||0-0-0|0-0-0|0-0-255|-1--1--1|-1--1--1|72,72
10,1,Food fish,183,137,48,14,8,2,0,41,-1,0,0,0,128-128-128,0-0-0,Comic Sans MS|18||128-128-128
10,2,Sharks and skates,170,371,53,25,8,2,0,41,-1,0,0,0,128-128-128,0-0-0,Comic Sans MS|18||128-128-128
10,3,Average food fish pop,480,135,58,27,3,3,0,40,0,0,0,0,0-0-0,0-0-0,Comic Sans MS|18||0-0-0
10,4,"Average shark & skate pop",485,351,57,31,3,3,0,40,0,0,0,0,0-0-0,0-0-0,Comic Sans MS|18||0-0-0
12,5,48,288,133,8,8,0,3,0,40,-1,0,0,0,0-0-0,0-0-0,Comic Sans MS|18||0-0-0
1,6,8,3,4,0,0,22,0,0,0,-1--1--1,,1|(385,133)|
1,7,8,5,100,0,0,22,0,0,0,-1--1--1,,1|(316,133)|
11,8,48,342,133,6,8,34,3,0,0,1,0,0,0
10,9,chng in avg food fish pop,342,166,70,25,40,3,0,40,-1,0,0,0,0-0-0,0-0-0,Comic Sans MS|18||0-0-0
12,10,48,282,349,8,8,0,3,0,40,-1,0,0,0,0-0-0,0-0-0,Comic Sans MS|18||0-0-0
1,11,13,4,4,0,0,22,0,0,0,-1--1--1,,1|(387,349)|
1,12,13,10,100,0,0,22,0,0,0,-1--1--1,,1|(312,349)|
11,13,48,341,349,6,8,34,3,0,0,1,0,0,0
10,14,"chng in avg shark & skate pop",341,387,78,30,40,3,0,40,-1,0,0,0,0-0-0,0-0-0,Comic Sans MS|18||0-0-0
10,15,time to avg populations,286,253,97,14,0,3,0,40,0,0,0,0,0-0-0,0-0-0,Comic Sans MS|18||0-0-0
1,16,15,9,0,0,0,0,1,64,0,0-0-255,|12||0-0-0,1|(306,220)|
1,17,15,13,0,0,0,0,1,64,0,0-0-255,|12||0-0-0,1|(312,298)|
1,18,3,8,1,0,0,0,1,64,0,0-0-255,|12||0-0-0,1|(403,75)|
1,19,4,13,1,0,0,0,1,64,0,0-0-255,|12||0-0-0,1|(412,289)|
1,20,2,14,1,0,0,0,1,64,0,0-0-255,|12||0-0-0,1|(254,395)|
1,21,1,9,1,0,0,0,1,64,0,0-0-255,|12||0-0-0,1|(264,165)|
10,22,Food fish,503,208,48,14,8,2,8,43,-1,0,0,0,128-128-128,0-0-0,Comic Sans MS|18||128-128-128
1,23,22,3,0,8,0,0,0,0,1,-1--1--1,,1|(495,184)|
10,24,Sharks and skates,571,446,53,25,8,2,8,43,-1,0,0,0,128-128-128,0-0-0,Comic Sans MS|18||128-128-128
10,25,Ratio of food fish to predators,595,233,89,25,8,3,0,40,0,0,0,0,0-0-0,0-0-0,Comic Sans MS|18||0-0-0
1,26,3,25,0,0,0,0,1,64,0,0-0-255,|12||0-0-0,1|(532,179)|
1,27,4,25,0,0,0,0,1,64,0,0-0-255,|12||0-0-0,1|(537,294)|
///---\\\
:GRAPH STATE_SPACE
:TITLE STATE_SPACE
:X-AXIS Sharks and skates
:X-DIV 4
:Y-DIV 4
:SCALE
:VAR Food fish
:GRAPH DYNAMICS
:TITLE DYNAMICS
:WIP
:X-DIV 4
:MAX-POINTS 2000
:SCALE
:VAR Sharks and skates
:Y-MIN 0
:LINE-WIDTH 1
:SCALE
:VAR Food fish
:Y-MIN 0
:LINE-WIDTH 2
:GRAPH 
:TITLE 
:X-DIV 4
:SCALE
:VAR Food fish
:LINE-WIDTH 2
:VAR Average food fish pop
:LINE-WIDTH 3
:GRAPH AVG_SHARK_&_SKATE_POPULA
:TITLE Avg Shark & Skate Populations
:X-DIV 4
:SCALE
:VAR Sharks and skates
:LINE-WIDTH 2
:VAR "Average shark & skate pop"
:LINE-WIDTH 3
:L<%^E!@
1:volterra.vdf
1:lotka.vdf
9:volterra
15:0,0,0,1,0,0
19:100,1
27:0,
4:Time
5:Ratio of food fish to predators
24:0
25:30
26:30