Running the gauntlet: inhibitory effects of algal turfs on the processes of coral recruitment
Running the gauntlet: inhibitory effects of algal turfs on the processes of coral recruitment
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DOI：
10.3354/meps08724
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发表时间：
2010-01-01
影响因子：
2.5
通讯作者：
Mumby, Peter J.
中科院分区：
文献类型：
--
作者：
Arnold, Suzanne N.;Steneck, Robert S.;Mumby, Peter J.
由于白化、疾病和藻类过度生长，珊瑚的死亡率正在上升。在加勒比，珊瑚补充率低，造成珊瑚礁生态系统恢复速度缓慢或无法察觉。尽管藻类长期以来一直被怀疑会干扰珊瑚的补充，但这种相互作用的机制仍不清楚。我们通过实验测试了草坪藻类丰度对3个顺序因素的影响，这些因素对珊瑚的招募很重要：浮游珊瑚幼虫的生物物理传递，它们的定居倾向，以及它们生存的微生境的可用性。我们部署了珊瑚定居板内，外雀鲷Stegastes spp。花园和笼子雀鲷的侵略减少了鱼类的食草性，笼子里被草皮藻类污染，局部增加了板块周围的藻类生物量。这减少了冲洗率苗圃微栖息地的板下侧，限制幼虫可用于解决。珊瑚苗优先解决了早期的连续甲壳类珊瑚Titanoderma prototypum，但也对或附近的其他珊瑚藻类，生物膜，和钙质多毛类蠕虫管。定居后的生存率最高，在充分放牧，最低的藻类生物量的治疗，27个月后的'苗'密度高73%，在这个治疗。“挑战”是指珊瑚必须生存以补充的生态过程的顺序。最高比例的珊瑚苗成功运行的挑战这样做的条件下，低藻类生物量造成的食草动物增加。如果珊瑚的补充在很大程度上受到这种挑战的控制，那么珊瑚礁管理人员可以通过减少藻类生物量来提高珊瑚礁的补充潜力。
Mortality of corals is increasing due to bleaching, disease and algal overgrowth. In the Caribbean, low rates of coral recruitment contribute to the slow or undetectable rates of recovery in reef ecosystems. Although algae have long been suspected to interfere with coral recruitment, the mechanisms of that interaction remain unclear. We experimentally tested the effects of turf algal abundance on 3 sequential factors important to recruitment of corals: the biophysical delivery of planktonic coral larvae, their propensity to settle, and the availability of microhabitats where they survive. We deployed coral settlement plates inside and outside damselfish Stegastes spp. gardens and cages. Damselfish aggression reduced herbivory from fishes, and cages became fouled with turf algae, both locally increasing algal biomass surrounding the plates. This reduced flushing rates in nursery microhabitats on the plate underside, limiting larvae available for settlement. Coral spat settled preferentially on an early successional crustose coralline alga Titanoderma prototypum but also on or near other coralline algae, biofilms, and calcareous polychaete worm tubes. Post-settlement survival was highest in the fully grazed, lowest algal biomass treatment, and after 27 mo 'spat' densities were 73 % higher in this treatment. The 'gauntlet' refers to the sequence of ecological processes through which corals must survive to recruit. The highest proportion of coral spat successfully running the gauntlet did so under conditions of low algal biomass resulting from increased herbivory. If coral recruitment is heavily controlled at very local scales by this gauntlet, then coral reef managers could improve a reef's recruitment potential by managing for reduced algal biomass.