Detached kelps from distant sources are a food subsidy for sea urchins
Detached kelps from distant sources are a food subsidy for sea urchins
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来自远方的分离海带是海胆的食物补贴
DOI：
10.1007/s00442-008-1061-7
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发表时间：
2008
期刊：
影响因子：
2.7
通讯作者：
T. Wernberg
中科院分区：
文献类型：
--
作者：
M. Vanderklift;T. Wernberg
营养补贴将生境联系起来，可以决定补贴生境的群落结构。了解营养相互作用的空间范围对于理解食物网和使空间管理实践更有效是很重要的。我们证明了在相隔数公里的离散岩礁中，辐射海带（kelpelklonia radiatia）和紫海胆（heliocidaris erythrograma）的分离（漂移）碎片之间的营养联系。海胆在一个近岸礁石上非常丰富，那里的漂流生物量通常很高。在那里，海胆捕获分离的海带的比率很高，尽管当地海带的丰度很低。珊瑚礁上的大部分分离的海藻都被海胆保留了下来。礁石上丰富的分离海草没有被海胆大量保留。用拴着的海带做的实验表明，海胆只吃分离的海带碎片，不吃附着的海带。从近海珊瑚礁收集的离体海带碎片与从近海珊瑚礁收集的附着海带的形态比较表明，很大比例（30-95%，不同日期不同）的海带碎片起源于遥远的珊瑚礁（≥2公里）。在近岸礁石上，海胆。红藻由分离的海带资助，分离的海带碎片在景观中运输。因此，跨生境资源补贴将相隔数公里的非珊瑚礁生境连接起来。
Trophic subsidies link habitats and can determine community structure in the subsidised habitats. Knowledge of the spatial extents of trophic interactions is important for understanding food webs, and for making spatial management practices more efficient. We demonstrate trophic linkages between detached (drift) fragments of the kelpEcklonia radiataand the purple sea urchinHeliocidaris erythrogrammaamong discrete rocky reefs separated by kilometres. Sea urchins were abundant at one inshore reef, where the biomass of drift was usually high. There, sea urchins trapped detached kelp at high rates, although local kelp abundance was low. Most detached kelp present on the reef was retained by sea urchins. Detached seagrass, which was abundant on the reef, was not retained by sea urchins in large quantities. Experiments with tethered pieces of kelp showed that sea urchins only consumed detached fragments, and did not consume attached kelps. Comparisons of the morphology of detached fragments of kelp collected from the inshore reef to attached kelps from reefs further offshore showed that a large proportion (30–95%, varying among dates) of the fragments originated at distant reefs (≥2 km away). At the inshore reef, the sea urchinH. erythrogrammais subsidised by detached kelps, and detached kelp fragments have been transported across landscapes. Cross-habitat resource subsidies therefore link discrete reef habitats separated by kilometres of non-reef habitat.