Acute toxicity of cadmium to two species of infaunal marine amphipods (tube-dwelling and burrowing) from New Zealand.

Abstract

Chapman reviewed the range of species and different response levels used in sediment toxicity testing. He recommended that a battery of sediment bioassays incorporating different response criteria should be used in sediment toxicity evaluations as there is no single test which gives adequate assessment of sediment toxicity. However, one test which is becoming accepted as the {open_quotes}benchmark{close_quotes} technique, and which is now commonly included in any battery of tests, is the amphipod bioassay. This test was developed in North America and uses the phoxocephalid Rhepoxynius abronius. It has been subjected to rigorous interlaboratory evaluation and its sensitivity and usefulness has been demonstrated in a wide range of applications. Unfortunately, species import controls makes the use of existing test species (such as R. abronius) impractical for sediment toxicity testing in New Zealand. In view of the demonstrated sensitivity, reproducibility and value of the amphipod bioassay, we therefore initiated preliminary studies to assess the possibility of developing a test with a native New Zealand amphipod. Examination of intertidal sediments in several northern New Zealand estuaries has shown that the amphipods Proharpinia hurleyi, Paracorophium excavatum and Paracalliope novizealandiae can be found, at times, in large numbers (hundreds per square metre). The results ofmore » benthic studies in Auckland`s Manaukau Harbour also suggested that P. excavatum and P. hurleyi may be sensitive to pollution, as these species were noticeably absent from sites where there was measurable sediment contamination. Using the protocol of Swartz et al., we undertook to test the sensitivity and laboratory performance of two local amphipod species; the tube-dweller P. contrasting modes of existence may differ in their level of exposure to sediment contaminants and, therefore, show different toxic responses. 12 refs., 2 tabs.« less