Department of Ecology and Coastal Management, Institute of Marine Sciences of Andalusia (CSIC), 11510 Puerto Real, Cádiz, Spain; Center for Functional Ecology (CEF), University of Coimbra, Portugal.
Department of Ecology and Coastal Management, Institute of Marine Sciences of Andalusia (CSIC), 11510 Puerto Real, Cádiz, Spain.
Sci Total Environ. 2018 Dec 10;644:31-36. doi: 10.1016/j.scitotenv.2018.06.336. Epub 2018 Jul 3.
Lines of evidence used in ecological risk assessment (ERA) are essentially three: chemistry, biology and ecotoxicology. Until now, the fundamental assumption made when measuring ecological risks is that organisms are forcedly exposed to stressors. However, when organisms can avoid disturbed habitats by escaping to less stressful areas, the assumption that exposure is mandatory to pose risk may not match field disturbance scenarios. A non-forced exposure approach using a linear free-choice multi-compartmented system has been proposed previously as a complementary tool to assess the effects on organisms' spatial avoidance/preference responses. Yet, the linearity of the latter system limits avoidance measurements to one spatial dimension. A novel, heterogeneous multi-habitat assay system (HeMHAS) consisting of 18 connected circular compartments (3 compartments on a vertical axis in each one of 6 zones on a longitudinal axis; a 2D system) is put forward here to be used in heterogeneous-habitat selection studies, as it makes it possible to assess the ability of organisms to detect contamination and other stressors and select more favorable habitats. In the present study, the avoidance to copper by zebrafish (Danio rerio) was tested after exposing organisms to a copper gradient in the HeMHAS and compared with that in the linear system. Avoidance occurred for all copper concentrations: 43% in the lowest (21 μg·L) to 72% in the highest (221 μg·L). Results obtained within the HeMHAS (AC: 60 μg·L) were statistically (p = 0.72) similar to avoidance of copper by D. rerio in the linear non-forced system (AC: 89 μg·L). In summary, the simulation of a copper gradient in the HeMHAS (2D system) allowed to assess the potential repellency of copper to zebrafish and to corroborate the ability of organisms to detect and avoid potentially toxic concentrations.
用于生态风险评估（ERA）的证据线本质上有三种：化学、生物学和生态毒理学。到目前为止，在测量生态风险时，基本假设是生物体被迫暴露于胁迫因素下。然而，当生物体能够通过逃往压力较小的区域来避免受干扰的栖息地时，暴露是造成风险的必要条件这一假设可能与野外干扰场景不符。之前提出了一种非强制性暴露方法，使用线性自由选择多隔室系统，作为评估对生物体空间回避/偏好反应影响的补充工具。然而，后者系统的线性限制了回避测量的空间维度。这里提出了一种新颖的、异质的多栖息地测定系统（HeMHAS），由 18 个相连的圆形隔室组成（每个垂直轴上有 3 个隔室，在 6 个纵向轴上的区域中每个有 6 个隔室；2D 系统），用于在异质栖息地选择研究中使用，因为它使生物体能够检测到污染和其他胁迫因素并选择更有利的栖息地的能力。在本研究中，在 HeMHAS 中暴露于铜梯度后，测试了斑马鱼（Danio rerio）对铜的回避行为，并将其与线性系统中的回避行为进行了比较。在所有铜浓度下都发生了回避行为：从最低（21μg·L）的 43%到最高（221μg·L）的 72%。HeMHAS 内获得的结果（AC：60μg·L）在统计学上（p=0.72）与斑马鱼在非强制线性系统中回避铜的结果（AC：89μg·L）相似。总之，在 HeMHAS（2D 系统）中模拟铜梯度允许评估铜对斑马鱼的潜在驱避性，并证实生物体检测和避免潜在毒性浓度的能力。
