Levels of submersed aquatic vegetation (SAV) are commonly assessed using a modified garden rake. However, the utility of the rake sampling method relative to methods that are typically viewed as more definitive (and expensive) such as snorkeling and coring remains a matter of debate. This study explores whether probabilities of species detections for four SAV species varied among sampling units in a rake-biomass study and, if so, whether such variation reflected variation in species abundance. Variation in detection probabilities, when unaddressed, may yield biased estimators of percent frequency of occurrence (“occupancy”) and of occurrence-habitat associations. Biomass-driven variation in detection probabilities is important because such variation may not be explainable using covariates typically measured when sampling using the rake method. This study found substantial among-unit variation in detection probabilities, with majorities of that variation on the logit or modeling scale being associated with biomass but not with the non-biomass covariates substrate type, water depth and day of study. The study closes by exploring sampling protocols and modeling methods that may yield improved SAV occupancy estimates.

通常使用改良的花园耙评估淹没水生植物（SAV）的水平。但是，相对于通常被认为更为确定（且昂贵）的方法（例如浮潜和取芯）而言，瑞克采样方法的实用性仍存在争议。本研究探讨了耙生物量研究中四个SAV物种的物种检测概率在采样单位之间是否存在差异，如果存在，这种差异是否反映了物种丰度的差异。如果未解决检测概率的变化，则可能会产生出现频率百分比（“占用率”）和出现-栖息地关联的估计值。检测概率中生物量驱动的变化非常重要，因为这种变化可能无法用使用rake方法采样时通常测得的协变量来解释。这项研究发现检测概率在单位之间存在很大差异，对数或建模尺度上的大部分差异与生物量有关，但与非生物质协变量底物类型，水深和研究天数无关。这项研究通过探索可能会提高SAV占用率估计值的采样协议和建模方法而结束。