Hypoxia impairs embryo development and survival in black bream (Acanthopagrus butcheri)

被引:47
作者
Hassell, Kathryn L. [1 ]
Coutin, Patrick C. [2 ]
Nugegoda, Dayanthi [1 ]
机构
[1] RMIT Univ, Sch Appl Sci, Bundoora, Vic 3083, Australia
[2] Fishery Res Branch, Dept Primary Ind, Queenscliff, Vic 3225, Australia
关键词
dissolved oxygen; early life stage; reproduction; Sparidae; seabream; porgies; Australia;
D O I
10.1016/j.marpolbul.2008.02.045
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Coastal environments are threatened by the increasing frequency, extent and severity of hypoxic events. Hypoxia affects vast areas around the world and often causes fish kills, reduced abundance, altered distribution, low benthic biomass and declines in fisheries. In Australia, many fisheries are based on sparid fishes and in the southern states black bream (Acanthopagrus butcheri) is important to both the recreational and commercial sectors. This species completes its entire life cycle in estuaries and annual recruitment is highly variable and very likely influenced by environmental conditions during the spawning season. In a laboratory-based experiment, fertilised black bream eggs (embryos) were exposed to five different levels of dissolved oxygen (DO). The DO levels were maintained in small test wells using nitrogen gas in a novel chamber design. Embryo development was assessed over a 2-day period and hatched larvae were observed until Day 2 post-hatch. Significant differences (p < 0.05) were observed in embryonic development and survival as a function of DO level. In severely hypoxic conditions (30% saturation) survival to 1 day was reduced and no hatching occurred. In moderately hypoxic conditions (45-55%S), both precocious and delayed hatching was observed and hatch rates were reduced, whilst the number of hatched larvae with deformities increased, resulting in reduced larval lengths. No larvae survived to Day 2 post-hatch when held in hypoxic conditions (< 55%S). This study demonstrates the detrimental effect that severe hypoxia can have on the early development of black bream which could result in reduced recruitment and lowered abundance. Other species that share similar early life histories may also be at risk. (c) 2008 Elsevier Ltd. All rights reserved.
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页码:302 / 306
页数:5
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