Environmental Analysis Tools - Environmental Impact Analysis: Process and Methods - page 286

The marine food web was deemed a critical component of the ecological
assessment endpoint selection; therefore, impact on the food web, both toxic
and habitat alteration effects from tailings disposal, was a major concern.
Thus the make-up dynamics, and relationships of the food web were criti-
cal components of the environmental analysis impact prediction conceptual
model (see Section 5.3.1) and the ecological risk assessment conceptual site
model. However, the academic and expansive food web developed for the
EIS (Figure 7.4) was unusable for the risk assessment and measurement end-
point approach used in ecological risk assessment. Consequently, a series of
simplified models for each major exposure pathway were developed for the
risk assessment (Figure 7.5 example for the Pacific herring). These revised
and simplified food webs were key inputs to the critical ecological endpoint
development step.
Based on these criteria and the adapted food web model, measurement
endpoints were developed and their relationship to assessment endpoints
documented (Figures 7.5 and 7.6). Also to facilitate risk characterization and
input to decision makers, risk thresholds, comparable to environmental
analysis impact significance criteria (Section 5.3.2) were developed for each
endpoint (Table 7.5).

Marine
mammals

Marine
mammals

Marine
birds

Halibut Eagles

Octopus

Dead fish
of all types

Skates

Adult
salmon

Cod

Arrowtooth
f lounder

Walleye
pollock

Tanner
crabs

Herring
sand lance
capelin
eulachon

Shortfin
eelpout

Northern
lampfish

Colus halli
neptunea spp.
B. Plectrum

Longsnout
prickleback

Pandalid shrimp
Crangon shrimp

Flathead
sole

Jellyfish

Squid

Arrow
worms

?

Ctenophores

H ermit
crabs

Polychaetes

?

Mud star

Bivalves

Larvaceans

Brittle stars

Euphausiids
copepods

Hyperiid
amphipods

Rhynchocoela
(ribbon worm)

Gammarid
amphipods

Deposited Organics/Detritus/Meiofauna/
Small benthic

Suspended organics/Phytoplankton

Animal remains

LEGEND
Dominant pathway
Important pathway

Predominantly pelagic community
Predominantly demersal community

FIGURE 7.4
Initial food web as part of AJ Mine EIS conceptual site model.