Burrowing Behavior of a Deposit Feeding Bivalve Predicts Change in Intertidal Ecosystem State
Burrowing Behavior of a Deposit Feeding Bivalve Predicts Change in Intertidal Ecosystem State
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DOI：
10.3389/fevo.2016.00019
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发表时间：
2016-01-01
影响因子：
3
通讯作者：
Piersma, Theunis
中科院分区：
文献类型：
--
作者：
Compton, Tanya J.;Bodnar, Wanda;Piersma, Theunis
行为具有一种预测能力，作为一种传达生态变化信号的工具，这种能力往往没有得到充分利用。觅食双壳贝类Macoma balthica的洞穴行为反映了典型的食品安全权衡。选择生活在靠近沉积物表面的地方会有被捕食的风险，这是在捕食危险、食物摄取率或未来健康前景较低的情况下做出的决定。在荷兰瓦登海的部分地区，马科马的数量在20世纪90年代末下降了90%，同时进行了大规模的机械疏浚活动。在这一下降过程中，Macoma的洞穴深度变浅，并与第二年的种群减少相关，表明它预测了种群的变化。最近，Macorna发生了一系列大型招聘活动。根据食品安全的权衡，我们预计马科马现在应该生活得更深，身体状况更好。事实上，我们观察到Macorna现在生活得更深，给定年份的生活深度预测了下一年的人口增长，特别是在超过14毫米的个体中。由于大于14 mm的个体的生存深度与身体状况密切相关，体型较大的猕猴可能会生活得更深，以保护它们的生殖资产。我们的结果证实，洞穴深度预示着即将发生的种群变化，与身体状况一起，可以提供生态变化的早期预警信号。我们认为，人口复苏是由荷兰瓦登海潮间带栖息地质量的改善推动的，而不是由拟议的与气候变化相关的影响推动的。这种生态系统状态的转变被认为包括疏浚结束后沉积物表层硅藻栖息地的恢复。
Behavior has a predictive power that is often underutilized as a tool for signaling ecological change. The burrowing behavior of the deposit feeding bivalve Macoma balthica reflects a typical food-safety trade-off. The choice to live close to the sediment surface comes at a risk of predation and is a decision made when predation danger, food intake rates or future fitness prospects are low. In parts of the Dutch Wadden Sea, Macoma populations declined by 90% in the late 1990s, in parallel with large-scale mechanical cockle-dredging activities. During this decline, the burrowing depth of Macoma became shallow and was correlated with the population decline in the following year, indicating that it forecasted population change. Recently, there has been a series of large recruitment events in Macorna. According to the food-safety trade-off, we expected that Macoma should now live deeper, and have a higher body condition. Indeed, we observed that Macorna now lives deeper and that living depth in a given year forecasted population growth in the next year, especially in individuals larger than 14 mm. As living depth and body condition were strongly correlated in individuals larger than 14 mm, larger Macoma could be living deeper to protect their reproductive assets. Our results confirmed that burrowing depth signals impending population change and, together with body condition, can provide an early warning signal of ecological change. We suggest that population recovery is being driven by improved intertidal habitat quality in the Dutch Wadden Sea, rather than by the proposed climate-change related effects. This shift in ecosystem state is suggested to include the recovery of diatom habitat in the top layer of the sediment after cockle-dredging ended.