Data_Sheet_1_Time Scales of Benthic Macrofaunal Response to Pelagic Production Differ Between Major Feeding Groups.PDF

Benthic macrofauna, as an element of rich and diverse benthic communities of the shelf seas, play a key role in marine biogeochemical cycles and support a wide range of ecosystem services. To better understand how macrofauna affects mass and energy fluxes within the seabed and between the bed and the pelagic, it is fundamental to characterise their structural and dynamic response to the quantity, quality and timing of food supply. To do so, we have combined long-term time-series of pelagic productivity and macrofaunal abundance with a model of benthic food web to: (1) estimate the characteristic response time scales of major groups of benthic macrofauna to food availability, (2) relate these to carbon fluxes within sediments and across the benthic–pelagic boundary, and (3) explore the mechanisms responsible. The model was designed as a canonical representation of the benthic system, retaining the key pathways that connect benthic macrofauna to pelagic environment, but aggregating variables and groups that were not explicitly observed. Both observations and model simulations revealed pronounced differences between deposit and suspension feeders in their rate of response to phytoplankton blooms: deposit feeders showed a dampened response lagging 26–125 days behind the peak in pelagic production, while suspension feeders responded rapidly, within only 5–7 days. The model parametrisation obtained during calibration relates this to differences in feeding modes, in (trophic) proximity to primary production and in rates of ingestion and losses. Specifically, suspension feeders are predicted to act as a gateway to pelagic productivity, controlling the quantity of organic carbon reaching sediment-dwelling fauna.

海底大型无脊椎动物，作为大陆架海域丰富多样的底栖群落的重要组成部分，在海洋生物地球化学循环中发挥着关键作用，并支撑着广泛的生态系统服务。为了更好地理解大型无脊椎动物如何影响海底及海底与浮游生物之间的物质和能量通量，对其结构动态对食物供应的量、质和时机的响应进行表征是至关重要的。为此，我们结合了长期的浮游生产力及大型无脊椎动物丰度的序列数据，并使用底栖食物网模型，旨在：（1）估算底栖大型无脊椎动物主要群体对食物可利用性的特征响应时间尺度；（2）将这些时间尺度与沉积物中的碳通量以及底栖-浮游边界处的碳通量联系起来；（3）探究其背后的机制。该模型被设计为底栖系统的典范性表示，保留了将底栖大型无脊椎动物与浮游环境连接的关键途径，但对未明确观察到的变量和群体进行了汇总。观测数据和模型模拟均揭示了沉积食者和悬浮食者在响应浮游植物爆发速度上的显著差异：沉积食者表现出减弱的响应滞后，落后于浮游生产力的峰值26-125天，而悬浮食者则迅速作出反应，仅需5-7天。在模型校准过程中获得的参数化设置，将这一差异归因于摄食方式、与初级生产的营养近缘度以及摄入和损失速率的不同。具体而言，悬浮食者被预测为是连接浮游生产力的门户，控制着有机碳达到沉积生物群落数量的多少。