The response of marine benthic fauna exposed to continuous and pulsed exposures of contaminated sediment: a study of avoidance and toxicity

摘要: This study aimed to develop environmentally relevant chronic toxicity test methods build on routine sediment quality assessment techniques currently in use. A series of experiments were used assess the suitability new Australian benthic invertebrate species for testing and investigate use behavioural endpoints enable development more robust guidelines. Many researchers are evaluating representative organisms yet rapid tests sublethal lethal effects contaminants. Four harpacticoid copepods, identified as Nitocra spinipes, Tisbe tenuimana, Robertgurneya hopkinsi Halectinosoma sp., assessed potential species. The influence diet life cycle progression (development) was a mixed tri-algal found be superior commercial fish food alone. Water-only bioassays showed that times required cause 50% lethality (LT50) 24 (22-27) h at 50 μg Cu/L T. tenuimana; 114 (100-131) 36 (32-40) 200, 400 Cu/L, respectively, N. 119 (71-201) 7 (4-10) 200 800 R. hopkinsi. 96-h thresholds also determined spinipes exposed Cd, Cu, Zn, ammonia phenol water-only exposures. Species ranked based ease handling, culturing, rate maturity, selectivity sensitivity copper. most suitable it robust, easily cultured sensitive dissolved avoidance response M. plumulosa, snail Phallomedusa solida when contaminated sediments investigated. Test vessels P g e | i designed allow moving between sediments. Each observed disperse evenly chambers contained reference sediment. In presence sediment, avoided early 6, following exposure P. respectively. Avoidance generally greater which elicited 10-d lethality. have ability respond chemical cues environment inhabit provided best opportunity survival. Rapid screening could developed using an endpoint. Acute associated with short, intermittent four field collected plumulosa spinipes. Increasing duration caused decrease survival during bioassays. addition, reproduction decreased For reduced fecundity appeared occur from reproductive occurred follwoing shorter exposures than needed sense avoid contaminant exposure. Thus, while behaviours may prevent acute lethality, slow responses not effects. indicates utilise static continuous over-estimate would location. However, by preventing avoiding unfavourable sediments, these provide precautionary possible effects, is usually aim assessments frameworks.