DTU Aqua, Charlottenlund Slot, DK 2920 Charlottenlund, Denmark.
J Fish Biol. 2010 Nov;77(8):1899-911. doi: 10.1111/j.1095-8649.2010.02782.x.
Environmental factors act on individual fishes directly and indirectly. The direct effects on rates and behaviour can be studied experimentally and in the field, particularly with the advent of ever smarter tags for tracking fishes and their environment. Indirect effects due to changes in food, predators, parasites and diseases are much more difficult to estimate and predict. Climate can affect all life-history stages through direct and indirect processes and although the consequences in terms of growth, survival and reproductive output can be monitored, it is often difficult to determine the causes. Investigation of cod Gadus morhua populations across the whole North Atlantic Ocean has shown large-scale patterns of change in productivity due to lower individual growth and condition, caused by large-scale climate forcing. If a population is being heavily exploited then a drop in productivity can push it into decline unless the level of fishing is reduced: the idea of a stable carrying capacity is a dangerous myth. Overexploitation can be avoided by keeping fishing mortality low and by monitoring and responding rapidly to changes in productivity. There are signs that this lesson has been learned and that G. morhua will continue to be a mainstay of the human diet.
环境因素直接和间接作用于鱼类个体。可以通过实验和实地研究来研究对速度和行为的直接影响，特别是随着用于跟踪鱼类及其环境的智能标签的出现。由于食物、捕食者、寄生虫和疾病的变化而产生的间接影响则更难估计和预测。气候可以通过直接和间接的过程影响所有的生活史阶段，尽管可以监测生长、存活和繁殖产量方面的后果，但通常很难确定原因。对北大西洋整个鳕鱼种群的研究表明，由于大规模的气候强迫导致个体生长和状况下降，生产力发生了大规模的变化。如果一个种群受到严重捕捞，那么生产力的下降可能会导致其衰退，除非捕鱼水平降低：稳定承载能力的概念是一个危险的神话。通过保持低捕捞死亡率以及监测和迅速应对生产力变化，可以避免过度捕捞。有迹象表明，这一教训已经被吸取，鳕鱼将继续成为人类饮食的主要来源。
