Laurentian Great Lakes Lake Sturgeon (Acipenser fulvescens) are hosts to lamprey species, including native Silver Lamprey (Ichthyomyzon unicuspis) and invasive Sea Lamprey (Petromyzon marinus). Silver Lamprey coevolved with Lake Sturgeon and cause negligible mortality, but Sea Lamprey can negatively affect Lake Sturgeon populations. Sea Lamprey abundance in Lake Erie has been above targets set by resource managers, with the St. Clair – Detroit River System (SCDRS) suspected as a source of Sea Lamprey production into Lake Erie. This study summarizes lamprey marking on Lake Sturgeon captured during agency assessment surveys in the SCDRS since 1996 and provides insight on the potential for Sea Lamprey to negatively affect Lake Sturgeon in the SCDRS. Lamprey marks (any lamprey species) were noted on 48.2% of Lake Sturgeon (2.5 marks/fish) and 3.3% of Lake Sturgeon assumed to be susceptible to mortality by Sea Lamprey (<760 mm TL; 0.06 marks/fish). Silver Lamprey were the only lamprey species found attached to Lake Sturgeon and there was no difference between oral disc diameters of Silver Lamprey and marks measured on Lake Sturgeon in Lake St. Clair and the lower St. Clair River (p = .45). Based on logistic regression, probability of at least one lamprey mark increased with Lake Sturgeon total length and was highest in Lake St. Clair. The probability of observing at least one lamprey mark on a 760 mm Lake Sturgeon was 8.1% or less for each sampling location in the SCDRS aside from Lake St. Clair (28.1%). Results suggest that parasitism of Lake Sturgeon by Sea Lamprey in the SCDRS is rare, particularly for Lake Sturgeon <760 mm TL. Low incidence of lamprey marks on Lake Sturgeon assumed to be susceptible to mortality from Sea Lamprey parasitism and zero occurrence of Sea Lamprey being observed attached to a Lake Sturgeon suggest Sea Lamprey at their current abundance likely have little effect on the Lake Sturgeon population in the SCDRS. Caution should be taken when using mark size to assign marks to lamprey species as there is substantial overlap among species oral disc diameters, potentially inflating the perceived impact of Sea Lamprey on Lake Sturgeon in areas with native lampreys.

中文翻译：

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七鳃鳗在圣克莱尔湖鲟鱼（Acipenser fulvescens Rafinesque，1817）上的发生率 – 底特律河流系统：对海七鳃鳗（Petromyzon marinus Linnaeus，1758）的影响

劳伦大湖鲟鱼 ( Acipenser fulvescens ) 是七鳃鳗物种的宿主，包括本地银七鳃鳗 ( Ichthyomyzon unicuspis ) 和入侵海七鳃鳗( Petromyzon marinus)）。Silver Lamprey 与 Lake Sturgeon 共同进化，造成的死亡率可以忽略不计，但 Sea Lamprey 会对 Lake Sturgeon 种群产生负面影响。伊利湖的海七鳃鳗丰度一直高于资源管理者设定的目标，圣克莱尔-底特律河流系统 (SCDRS) 被怀疑是伊利湖海七鳃鳗生产的来源。本研究总结了自 1996 年以来在 SCDRS 的机构评估调查期间捕获的鲟鱼湖上的七鳃鳗标记，并提供了关于海七鳃鳗对 SCDRS 中的鲟鱼湖产生负面影响的可能性的见解。在 48.2% 的鲟鱼湖（每条鱼 2.5 条标记）和 3.3% 的鲟鱼湖上发现了七鳃鳗标记（任何七鳃鳗物种），被认为容易被海七鳃鳗杀死（<760 毫米 TL；0.06 条标记/条鱼）。磷 = .45）。基于逻辑回归，至少一个七鳃鳗标记的概率随着鲟鱼湖总长度的增加而增加，并且在圣克莱尔湖中最高。对于 SCDRS 中除圣克莱尔湖 (28.1%) 之外的每个采样位置，在 760 毫米鲟鱼湖上观察到至少一个七鳃鳗标记的概率为 8.1% 或更低。结果表明，SCDRS 中海七鳃鳗对鲟湖鲟的寄生很少见，特别是对于小于 760 毫米 TL 的鲟湖。鲟鱼湖上七鳃鳗标记的低发生率被认为容易因海七鳃鳗寄生而死亡，并且观察到附着在鲟鱼湖上的海七鳃鳗的发生率为零表明海七鳃鳗目前的丰度可能对 SCDRS 中的湖鲟种群影响不大.