Fipronil is highly toxic to fish and aquatic invertebrates. Its tendency to bind to sediments and its low water solubility may reduce the potential hazard to aquatic wildlife.[27] Fipronil is toxic to bees and should not be applied to vegetation when bees are foraging.[27] Based on ecological effects, fipronil is highly toxic to upland game birds on an acute oral basis and very highly toxic on a subacute dietary basis, but is practically nontoxic to waterfowl on both acute and subacute bases.[28] Chronic (avian reproduction) studies show no effects at the highest levels tested in mallards (NOEC = 1000 ppm) or quail (NOEC = 10 ppm). The metabolite MB 46136 is more toxic than the parent to avian species tested (very highly toxic to upland game birds and moderately toxic to waterfowl on an acute oral basis).[28] Fipronil is highly toxic to bluegill sunfish and highly toxic to rainbow trout on an acute basis.[28] An early-lifestage toxicity study in rainbow trout found that fipronil affects larval growth with a NOEC of 0.0066 ppm and an LOEC of 0.015 ppm.