Table 1.

${\zeta }_{AB}$ estimated from observations in available literature for multiple trophic interaction

Prey, A	Predator, B	$\langle A\rangle \langle B\rangle$	$\langle A^{\prime }{B}^{\prime }\rangle$	${\zeta }_{AB}$	Ref.
Phytoplankton	Copepods	1,680	21,000	13.5	(14)
Copepods	Micronekton	96	1,340	14.9	(14)
Micronekton	Dolphins	20	480	26.0	(14)
Micronekton	Tunas	0.094	3.24	35.5	(39)
Copepods	Whales	0.066	3.35	56.8	(40)
Salmon	Humans	0.088	7.62	87.5	(41)*

^*Humans are not included explicitly in the present model, but the estimate of ${\zeta }_{AB}$ illustrates the magnitude of the fishing effect on fish populations.