SURVIVAL, GROWTH, AND REPRODUCTION OF LAKE TROUT (SALVELINUS-NAMAYCUSH) AND YELLOW PERCH (PERCA-FLAVESCENS) AFTER NEUTRALIZATION OF AN ACIDIC LAKE NEAR SUDBURY, ONTARIO

Bowland Lake, an acidified lake (pH 4.8-5.2), was treated with calcite in 1983. Neutralization allowed for successful reproduction by reintroduced lake trout. Mortality of lake trout embryos and juveniles in field toxicity tests decreased from 52-99% preneutralization to 0-30% postneutralization. The resident yellow perch appeared unaffected by the chemical treatment. Both inter- and intraspecific competition were evident in the growth and body condition of perch and stocked lake trout in the years after neutralization. Springtime acid episodes continued to occur in the nearshore areas after the lake was neutralized, but no adverse effects on fish species were detected. (See also 90L/08128, 08129 and 08193). -Authors