Understanding trends in abundance is important to fisheries conservation, but techniques for estimating streamwide abundance of cryptic fishes with strong habitat–abundance relationships are not well established and need further development. We developed techniques for addressing this need using the Harlequin Darter Etheostoma histrio, a small, cryptic freshwater fish associated with submerged wood in streams. Our objectives were to (1) determine how Harlequin Darter abundance and the amount of submerged wood were related at sampled sites and (2) use this relationship to estimate Harlequin Darter abundance at unsampled sites and extrapolate Harlequin Darter abundance estimates and associated uncertainty streamwide. We conducted a mark–recapture study to estimate abundance of Harlequin Darters in 25‐m stream reaches at 24 sites in Big Escambia Creek (BEC) and 18 sites in Pine Barren Creek (PBC) (Escambia River tributaries in northwestern Florida). The number of wood pieces (submerged wood ≥1.5 m long and ≥0.25 m in circumference) in both creeks was counted and mapped using side‐scan sonar and a geographic information system. Harlequin Darter and wood data were used in a Bayesian multinomial mixture model to estimate site abundance of Harlequin Darters, to determine the relationship between wood and Harlequin Darter abundance, and to extrapolate Harlequin Darter abundance streamwide. We found a positive relationship between wood and Harlequin Darter abundance in both creeks, and there were more wood pieces in PBC than in BEC. Streamwide abundance of Harlequin Darters was greater in PBC than in BEC. The extrapolated streamwide abundance estimates were 9,369 Harlequin Darters (95% credible interval = 6,668–13,402) in PBC and 7,439 Harlequin Darters (95% credible interval = 4,493–11,226) in BEC. Our methods effectively estimated abundance of a small, cryptic fish that uses complex wood habitat. In addition, our findings may assist in the conservation of the Harlequin Darter.

中文翻译：

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利用强栖息地-丰度关系评估隐性鱼类的种群状况：以丑角突进者为例

了解丰度的趋势对渔业保护很重要，但是估算具有广泛的生境-丰度关系的隐性鱼类的溪流丰度的技术尚不完善，需要进一步发展。我们开发了使用Harlequin Darter Etheostoma histrio来解决这一需求的技术，一种淡淡的小型淡水鱼，与溪流中淹没的木材有关。我们的目标是（1）确定采样地点的Harlequin Darter丰度和淹没木材量之间的关系，以及（2）利用这种关系来估计未采样地点的Harlequin Darter丰度并推断Harlequin Darter的丰度估计值和相关的不确定性。我们进行了标记回收研究，以估计大埃斯坎比亚溪（BEC）的24个站点和派恩巴伦溪（PBC）（佛罗里达西北部的埃斯坎比亚河支流）的18个站点中25 m河段中的丑角飞镖的丰度。使用侧面扫描声纳和地理信息系统对两条小溪中的木材块数（长度≥1.5m的淹没木材，周长≥0.25m）进行计数并绘制地图。在Bayesian多项式混合模型中使用Harlequin Darter和木材数据来估计Harlequin Darters的位点丰度，确定木材与Harlequin Darter丰度之间的关系，并在整个河流范围内推断Harlequin Darter的丰度。我们发现两条小溪的木材和Harlequin Darter的丰度之间存在正相关关系，PBC中的木材比BEC中的木材多。在PBC中，Harlequin Darters在河流中的丰富度大于BEC。据推断，河床范围内的丰度估计值在PBC中为9,369丑角飞镖（95％可信区间= 6,668–13,402），在BEC中为7,439丑角飞镖（95％可信区间= 4,493–11,226）。我们的方法有效地估计了使用复杂木材栖息地的小型隐鱼的丰度。此外，