Lee Steven, Ford Amanda K, Mangubhai Sangeeta, Wild Christian, Ferse Sebastian C A
Leibniz Centre for Tropical Marine Research (ZMT), Bremen, Germany.
Faculty of Biology and Chemistry (FB2), University of Bremen, Bremen, Germany.
PeerJ. 2018 May 18;6:e4773. doi: 10.7717/peerj.4773. eCollection 2018.
Sea cucumbers play an important role in the recycling and remineralization of organic matter (OM) in reef sands through feeding, excretion, and bioturbation processes. Growing demand from Asian markets has driven the overexploitation of these animals globally. The implications of sea cucumber fisheries for shallow coastal ecosystems and their management remain poorly understood. To address this knowledge gap, the current study manipulated densities of within enclosures on a reef flat in Fiji, between August 2015 and February 2016, to study the effects of sea cucumber removal on sedimentary function as a biocatalytic filter system. Three treatments were investigated: (i) density (350 g m wet weight; . 15 individuals); (ii) density (60 g m; . 3 individuals); and (iii) (0 g m). Quantity of sediment reworked through ingestion by , grain size distribution, O penetration depth, and sedimentary oxygen consumption (SOC) were quantified within each treatment. Findings revealed that the natural population of at the study site can rework . 10,590 kg dry sediment 1,000 m year; more than twice the turnover rate recorded for and . There was a shift towards finer fraction grains in the treatment. In the treatment, the O penetration depth decreased by 63% following a 6 °C increase in water temperature over the course of two months, while in the treatment no such change was observed. SOC rates increased . two-fold in the treatment within the first month, and were consistently higher than in the treatment. These results suggest that the removal of sea cucumbers can reduce the capacity of sediments to buffer OM pulses, impeding the function and productivity of shallow coastal ecosystems.
海参通过摄食、排泄和生物扰动过程，在珊瑚礁砂中有机物（OM）的循环和再矿化中发挥着重要作用。亚洲市场对海参的需求不断增长，导致全球范围内对这些动物的过度捕捞。海参渔业对浅海沿岸生态系统的影响及其管理仍知之甚少。为了填补这一知识空白，本研究于2015年8月至2016年2月期间，在斐济的一个珊瑚礁坪上，对围隔内的海参密度进行了控制，以研究去除海参对作为生物催化过滤系统的沉积功能的影响。研究了三种处理方式：（i）高密度（350克/平方米湿重；约15只个体）；（ii）低密度（60克/平方米；约3只个体）；以及（iii）无海参（0克/平方米）。对每个处理方式下通过海参摄食而重新加工的沉积物数量、粒度分布、氧气渗透深度和沉积氧消耗（SOC）进行了量化。研究结果表明，研究地点的海参自然种群每年可重新加工约10,590千克干沉积物/1000平方米；这一周转率是记录的其他两种海参的两倍多。在无海参处理中，粒度向更细的颗粒转变。在低密度处理中，在两个月内水温升高6°C后，氧气渗透深度下降了63%，而在无海参处理中未观察到这种变化。在第一个月内，无海参处理中的SOC速率增加了两倍，并且一直高于低密度处理。这些结果表明，去除海参会降低沉积物缓冲OM脉冲的能力，从而阻碍浅海沿岸生态系统的功能和生产力。
