Effects of climate change on fish reproduction and early life history stages

Abstract

Abstract. Seasonal change in temperature has a profound effect on reproduction in fish. Increasing temperatures cue reproductive development in spring-spawning species, and falling temperatures stimulate reproduction in autumnspawners. Elevated temperatures truncate spring spawning, and delay autumn spawning. Temperature increases will affect reproduction, but the nature of these effects will depend on the period and amplitude of the increase and range from phaseshifting of spawning to complete inhibition of reproduction. This latter effect will be most marked in species that are constrained in their capacity to shift geographic range. Studies from a range of taxa, habitats and temperature ranges all show inhibitory effects of elevated temperature albeit about different environmental set points. The effects are generated through the endocrine system, particularly through the inhibition of ovarian oestrogen production. Larval fishes are usually more sensitive than adults to environmental fluctuations, and might be especially vulnerable to climate change. In addition to direct effects on embryonic duration and egg survival, temperature also influences size at hatching, developmental rate, pelagic larval duration and survival. A companion effect of marine climate change is ocean acidification, which may pose a significant threat through its capacity to alter larval behaviour and impair sensory capabilities. This in turn impacts on population replenishment and connectivity patterns of marine fishes.

Projected climate change in Australian marine and freshwater environments

“…Tropical fish may also be affected, in ways that are only becoming apparent as a result of novel experiments (e.g. Munday et al 2009;Pankhurst and Munday 2011). Aragonite saturation horizons will occur at shallower depths in future, especially in the Antarctic and Australian southern margins, threatening a wide range of larval and adult benthic and pelagic calcifying organisms (e.g.…”

Fish physiology and ecology: the contribution of the Leigh Laboratory to the collision of paradigms

“…Male fishes typically produce the androgens, testosterone (T) and 11-ketotestosterone (11KT), and females also produce T which is then metabolised to the estrogen 17b-estradiol (E 2 ). Both sexes also produce a progesterone-like maturational steroid (17,20b-dihydroxy-4-pregnen-3-one [17,20bP] or 17,20b,21-trihydroxy-4-pregnen-3-one [20b-S]) in response to gonadal stimulation by LH (reviewed in Pankhurst & Munday 2011). Early studies had shown that T, 11KT and E 2 were all inhibited by stress, with consequent suppression of a range of reproductive functions (reviewed in Schreck 2010).…”

Detecting range shifts among Australian fishes in response to climate change

“…Climate-change drivers such as temperature and rainfall can operate directly to affect range or indirectly through effects on habitat or food resources of fishes (e.g. Morrongiello et al 2011;Pratchett et al 2011) or on their reproduction (Pankhurst and Munday 2011). Climatechange drivers can also interact with other factors such as overfishing, habitat removal, disease and pollution to reduce or spatially shift species.…”