Curtin University, Perth, Australia.
Fisheries Ecology Research Lab, University of Hawai'i at Mānoa, Honolulu, HI, USA.
Sci Rep. 2017 Mar 9;7:43819. doi: 10.1038/srep43819.
Blooms of alien invasive marine algae have become common, greatly altering the health and stability of nearshore marine ecosystems. Concurrently, herbivorous fishes have been severely overfished in many locations worldwide, contributing to increases in macroalgal cover. We used a multi-pronged, interdisciplinary approach to test if higher biomass of herbivorous fishes inside a no-take marine reserve makes this area more resistant to invasive algal overgrowth. Over a two year time period, we (1) compared fish biomass and algal cover between two fished and one unfished patch reef in Hawai'i, (2) used acoustic telemetry to determine fidelity of herbivorous fishes to the unfished reef, and (3) used metabarcoding and next-generation sequencing to determine diet composition of herbivorous fishes. Herbivore fish biomass was significantly higher in the marine reserve compared to adjacent fished reefs, whereas invasive algal cover differed by species. Herbivorous fish movements were largely confined to the unfished patch reef where they were captured. Diet analysis indicated that the consumption of invasive algae varied among fish species, with a high prevalence of comparatively rare native algal species. Together these findings demonstrate that the contribution of herbivores to coral reef resilience, via resistance to invasive algae invasion, is complex and species-specific.
外来入侵海洋藻类的大量繁殖已变得十分常见，这极大地改变了近岸海洋生态系统的健康和稳定性。同时，在世界许多地方，草食性鱼类都遭到了严重的过度捕捞，这导致了宏观藻类覆盖的增加。我们采用了多管齐下的跨学科方法，以测试在一个无捕捞海洋保护区内，草食性鱼类更高的生物量是否会使该地区更能抵抗入侵藻类的过度生长。在两年的时间里，我们（1）比较了夏威夷两个有捕捞和一个无捕捞的补丁礁中的鱼类生物量和藻类覆盖情况，（2）使用声学遥测技术来确定草食性鱼类对无捕捞礁的忠实程度，以及（3）使用代谢组学和下一代测序技术来确定草食性鱼类的饮食组成。与相邻的有捕捞礁相比，保护区内草食性鱼类的生物量明显更高，而入侵藻类的覆盖则因物种而异。草食性鱼类的活动范围主要局限于无捕捞的补丁礁，它们在那里被捕获。饮食分析表明，不同鱼类对入侵藻类的消耗存在差异，相对罕见的本地藻类物种的消耗更为普遍。这些发现共同表明，草食性鱼类对珊瑚礁恢复力的贡献，通过抵抗入侵藻类的入侵，是复杂的，并且具有物种特异性。
