Vl. Emery et al., DEVELOPMENT OF A CHRONIC SUBLETHAL SEDIMENT BIOASSAY USING THE ESTUARINE AMPHIPOD, LEPTOCHEIRUS-PLUMULOSUS (SHOEMAKER), Environmental toxicology and chemistry, 16(9), 1997, pp. 1912-1920
Based an the need for a test to evaluate chronic sublethal toxicity in
estuarine sediments, a 28-d sediment bioassay with the estuarine amph
ipod Leptocheirus plumulosus (Shoemaker) was developed. The test was i
nitiated with animals less than 2 weeks old (i.e., 425-600 mu m sieved
size class). Test endpoints included survival, growth (mu g dry weigh
t/d), and reproduction (number of neonates/surviving female). Factors
with the potential to influence test animal performance (i.e., nontrea
tment factors) such as artificial sea salts, salinity, food ration, si
ze at test initiation, intraspecific density, sediment grain size, and
diet were evaluated. For example, intraspecific densities between 10
and 60 animals/beaker (i.e., 0.18-1.4 animals/cm(2)) did not affect su
rvival, growth, or reproduction. Similarly, L. plumulosus were toleran
t of a wide range of sediment grain sizes with only extremely fine gra
ined (e.g., >75% clay) or coarse grained (e.g., >75% sand) material si
gnificantly affecting survival, growth, and reproduction. Test perform
ance criteria included control survival (>80%) and reproduction (produ
ction of offspring in all control replicates), and response to a refer
ence toxicant test with cadmium chloride in a control chart format.