Predicted and Observed Responses of a Nonnative Channel Catfish Population Following Managed Removal to Aid the Recovery of Endangered Fishes
Predicted and Observed Responses of a Nonnative Channel Catfish Population Following Managed Removal to Aid the Recovery of Endangered Fishes
复制标题
预测和观察到的非本地斑点叉尾鮰种群在有管理的清除后的反应，以帮助濒危鱼类的恢复
DOI：
10.1002/nafm.10056
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发表时间：
2018
影响因子：
1.1
通讯作者：
N. R. Franssen
中科院分区：
文献类型：
--
作者：
C. Pennock;S. Durst;B. R. Duran;B. Hines;C. Cathcart;Jason E. Davis;Benjamin J. Schleicher;N. R. Franssen
人类对水生系统的改造和外来物种的引入日益威胁着濒危淡水鱼类的生存。作为回应，大规模的机械去除外来鱼类已实施整个部分的科罗拉多河流域，以帮助恢复濒危鱼类，但这些努力的影响可能难以量化。预测捕捞法规结果的渔业种群模型已被广泛用于防止过度捕捞商业和游戏种群。在这里，我们使用人口模型来调查特定大小的去除努力需要过度捕捞的非本地人口的渠道鲶鱼Ictalurus punctatus，从而帮助恢复濒危鱼类在圣胡安河，新墨西哥州和犹他州。用电渔具有效捕获的鱼的最小尺寸为280毫米TL，年清除率随鱼的尺寸增加而增加，从200毫米鱼的0.10到600毫米鱼的0.44不等。模型结果表明，去除率应从0.14增加到0.21-0.34的范围，以导致生长过度捕捞，并应增加到0.26-0.29的范围，以导致补充过度捕捞，最小电捕鱼尺寸限制为280毫米TL。然而，模型结果表明，与未管理的种群相比，总体种群丰度和生物量正在大幅减少。一致的是，1991年至2015年的长期监测数据表明，自2006年加强清除努力以来，癍点叉尾鮰的TL和质量有所下降，捕捞率变异性有所增加。总体而言，目前的去除率可能不会实现崩溃的非本地渠道鲶鱼人口在圣胡安河，但规模结构的减少表明，人口已作出回应，这些努力。淡水鱼类在地球仪上受到外来物种扩散的威胁（米勒等人，1989年;右旋糖酐酶和曼德拉克，2006年; Dudgeon等人，2006年; Jelks等人，2008年），入侵鱼类现在在大多数北美流域流行（Gido和Brown，1999年）。非本地物种对本地鱼类的生态和进化影响已被充分记录，并可能发生在生物组织的几个层面上（Strayer 2010; Cucherousset和奥登2011）。因此，本地鱼类可能会因与非本地物种竞争或被非本地物种捕食而数量下降（Minckley和Deacon，1968年;米尔斯等人，2004年; Strayer，2010年）。自然deparamate鱼类群落，如在美国西南部发现的那些，特别容易受到外来鱼类入侵和建立（Fitzgerald et al. 2016），这导致了该地区特有鱼类前所未有的危险（Minckley and Deacon 1968）。控制或根除有问题的外来鱼类的努力可能相对低效，因为使用常规渔业技术大幅减少种群规模的能力有限（Mueller 2005; Coggins等人，2011; Fransen等人，2014; Propst等人，2015）。尽管如此，这些机械清除的努力已经在整个科罗拉多河流域实施，是管理者必须抑制外来鱼类的少数选择之一（Tyus和Saunders 1996年，2000年;美国鱼类和野生动物局2002年）。尽管广泛且持续地使用了非本地清除措施，但这些系统中记录的成功有限（Mueller 2005），这主要是由于难以在大的空间和时间尺度上将种群变化与这些管理措施联系起来（Fransen et al. 2014; Propst et al. 2015）。旨在减少非本地物种的机械清除努力的结果差异很大（Meronek等人，1996年），通常难以衡量目标和非目标种群的反应。渔业种群模型可用于监测和评估开发的鱼类种群（Ricker 1975），通常这些模型用于预测对开发渔业的拟议捕捞法规的结果，目的是防止过度捕捞（艾伦和海托华2010; Eder等人2016）。与管理休闲或商业渔业的目标相反，外来鱼类清除计划旨在减少目标种群的规模，理想情况下，导致其崩溃，以帮助本地物种。然而，很少使用渔业种群模型来估计有目的的种群耗竭努力（Weber等人，2011年; Tsehaye等人，2013年）。自20世纪90年代末以来，一直在对圣胡安河、新墨西哥州和犹他州的外来鱼类进行机械清除，以帮助濒危鱼类（Franssen等人，2014年）。清除工作主要集中在癍点叉尾鱼和鲤鱼，后者的数量随着时间的推移而有效减少;然而，癍点叉尾鱼在系统中仍然相对丰富（Franssen等人，2014年）。由于这些清除工作既昂贵又耗时，因此有必要评估其有效性和减少目标非本地渠道鲶鱼的持续可行性。在这里，我们使用渔业人口模型和标准化监测调查的影响，旨在有利于恢复联邦保护的科罗拉多Pikeminnow Ptychocheilus lucius和Razorback吸盘Xyrauchen texanus在圣胡安河的非本地渠道鲶鱼去除努力。为了实现这一目标，我们（1）使用现场收集的数据，以量化特定大小的通道鲶鱼去除率使用标记重捕;（2）使用基于现场和文献来源的数据，以参数化人口模型，估计率的大小2彭诺克等。
Human transformation of aquatic systems and the introduction of nonnative species increasingly threaten the persistence of imperiled freshwater fishes. In response, large-scale mechanical removal of nonnative fishes has been implemented throughout parts of the Colorado River basin to aid recovery of endangered fishes, but the effects of these efforts can be difficult to quantify. Fisheries population models for predicting outcomes of harvest regulations have been widely used to prevent overfishing of commercial and game stocks. Here, we used population models to investigate size-specific removal efforts needed to overfish a nonnative population of Channel Catfish Ictalurus punctatus and thereby aid recovery of endangered fishes in the San Juan River, New Mexico and Utah. The minimum size of fish that were efficiently captured with electrofishing gear was 280 mm TL, and annual removal rates increased with fish size, ranging from 0.10 for 200-mm fish to 0.44 for 600-mm fish. Model results suggested that removal rates should be increased from 0.14 to a range of 0.21–0.34 to cause growth overfishing and should be increased to a range of 0.26–0.29 to cause recruitment overfishing at a minimum electrofishing size limit of 280 mm TL. However, model results indicated that overall population abundance and biomass are being substantially reduced compared to an unmanaged population. In concordance, long-term monitoring data from 1991 to 2015 demonstrated a decrease in Channel Catfish TL and mass as well as an increase in catch rate variability since removal efforts intensified in 2006. Overall, current rates of removal will probably not achieve collapse of the nonnative Channel Catfish population in the San Juan River, but the reduction in size structure indicates that the population has responded to these efforts. Freshwater fishes are threatened across the globe by the spread of nonnative species (Miller et al. 1989; Dextrase and Mandrak 2006; Dudgeon et al. 2006; Jelks et al. 2008), and invasive fishes are now prevalent in most North American basins (Gido and Brown 1999). Ecological and evolutionary effects of nonnative species on native fishes have been well documented and can occur at several levels of biotic organization (Strayer 2010; Cucherousset and Olden 2011). As a result, native fishes can suffer declines through competition with or predation by nonnative species (Minckley and Deacon 1968; Mills et al. 2004; Strayer 2010). Naturally depauperate fish communities, like those found in the American Southwest, are especially vulnerable to nonnative fish invasion and establishment (Fitzgerald et al. 2016), which has led to unprecedented imperilment of endemic fishes in this region (Minckley and Deacon 1968). Efforts to control or eradicate problematic nonnative fishes can be relatively inefficient because of limited ability to substantially reduce population sizes using common fisheries techniques (Mueller 2005; Coggins et al. 2011; Franssen et al. 2014; Propst et al. 2015). Nonetheless, these mechanical removal efforts have been implemented across the Colorado River basin and are among the few options managers have to suppress nonnative fishes (Tyus and Saunders 1996, 2000; USFWS 2002). Despite extensive and continued use of nonnative removal efforts, there has been limited documented success in these systems (Mueller 2005), largely due to the difficulty in linking population changes to these management actions over large spatial and temporal scales (Franssen et al. 2014; Propst et al. 2015). Outcomes of mechanical removal efforts aimed at reducing nonnative species are highly variable (Meronek et al. 1996), and it has generally been difficult to measure responses in both target and non-target populations. Fisheries population models can be used to monitor and assess exploited fish populations (Ricker 1975), and typically these models are used to predict the outcome of proposed harvest regulations on exploited fisheries, with the goal of preventing overfishing (Allen and Hightower 2010; Eder et al. 2016). Contrary to goals of managing recreational or commercial fisheries, nonnative fish removal programs seek to reduce the size of target populations and, ideally, cause their collapse to aid native species. However, the use of fisheries population models to estimate efforts of purposeful population depletions has been rare (Weber et al. 2011; Tsehaye et al. 2013). Mechanical removal of nonnative fishes in the San Juan River, New Mexico and Utah, has been ongoing since the late 1990s, with variable effort and spatial coverage, to aid endangered fishes (Franssen et al. 2014). Removal efforts have focused primarily on Channel Catfish Ictalurus punctatus and Common Carp Cyprinus carpio, with the latter being effectively reduced in number over time; however, Channel Catfish remain relatively abundant in the system (Franssen et al. 2014). Because these removal efforts are both costly and time consuming, there is a need to evaluate their effectiveness and continued feasibility of reducing targeted nonnative Channel Catfish. Here, we used fisheries population models and standardized monitoring to investigate the effect of nonnative Channel Catfish removal efforts aimed at benefiting the recovery of the federally protected Colorado Pikeminnow Ptychocheilus lucius and Razorback Sucker Xyrauchen texanus in the San Juan River. To accomplish this, we (1) used field-collected data to quantify size-specific rates of Channel Catfish removal using mark–recapture; (2) used field-based and literature-derived data to parameterize population models for estimating the rates of size2 PENNOCK ET AL.