Josephson Daniel C, Robinson Jason M, Chiotti Justin, Jirka Kurt J, Kraft Clifford E
Department of Natural Resources, Cornell University, Ithaca, NY, 14853-3001, USA,
Environ Monit Assess. 2014 Jul;186(7):4391-409. doi: 10.1007/s10661-014-3706-9. Epub 2014 Mar 27.
Honnedaga Lake in the Adirondack region of New York has sustained a heritage brook trout population despite decades of atmospheric acid deposition. Detrimental impacts from acid deposition were observed from 1920 to 1960 with the sequential loss of acid-sensitive fishes, leaving only brook trout extant in the lake. Open-lake trap net catches of brook trout declined for two decades into the late 1970s, when brook trout were considered extirpated from the lake but persisted in tributary refuges. Amendments to the Clean Air Act in 1990 mandated reductions in sulfate and nitrogen oxide emissions. By 2000, brook trout had re-colonized the lake coincident with reductions in surface-water sulfate, nitrate, and inorganic monomeric aluminum. No changes have been observed in surface-water acid-neutralizing capacity (ANC) or calcium concentration. Observed increases in chlorophyll a and decreases in water clarity reflect an increase in phytoplankton abundance. The zooplankton community exhibits low species richness, with a scarcity of acid-sensitive Daphnia and dominance by acid-tolerant copepods. Trap net surveys indicate that relative abundance of adult brook trout population has significantly increased since the 1970s. Brook trout are absent in 65 % of tributaries that are chronically acidified with ANC of <0 μeq/L and toxic aluminum levels (>2 μmol/L). Given the current conditions, a slow recovery of chemistry and biota is expected in Honnedaga Lake and its tributaries. We are exploring the potential to accelerate the recovery of brook trout abundance in Honnedaga Lake through lime applications to chronically and episodically acidified tributaries.
纽约阿迪朗达克地区的洪内达加湖尽管经历了数十年的大气酸沉降，但仍维持着一个传统的溪鳟种群。1920年至1960年期间观察到酸沉降的有害影响，酸敏感鱼类相继消失，湖中仅存溪鳟。到20世纪70年代末，溪鳟的敞湖陷阱网捕获量连续二十年下降，当时溪鳟被认为已从湖中灭绝，但仍在支流避难所中生存。1990年的《清洁空气法》修正案要求减少硫酸盐和氮氧化物排放。到2000年，溪鳟重新在湖中定居，同时地表水硫酸盐、硝酸盐和无机单体铝含量降低。地表水的酸中和能力（ANC）或钙浓度没有变化。观察到的叶绿素a增加和水透明度降低反映了浮游植物丰度的增加。浮游动物群落的物种丰富度较低，酸敏感的水蚤稀缺，耐酸的桡足类占主导地位。陷阱网调查表明，自20世纪70年代以来，成年溪鳟种群的相对丰度显著增加。在65% ANC <0 μeq/L且有毒铝含量（>2 μmol/L）的长期酸化支流中没有溪鳟。鉴于当前状况，预计洪内达加湖及其支流的化学和生物群将缓慢恢复。我们正在探索通过向长期和间歇性酸化的支流施用石灰来加速洪内达加湖溪鳟数量恢复的潜力。
