The objective of the current study was to determine the extent to which planktonic sea lice (Lepeophtheirus salmonis Krøyer, 1838 and Caligus elongatus Nordmann, 1832) were present in the biofouling on open-sea net pens used for commercial rearing of Atlantic salmon (Salmo salar L.), and to assess if biofouling organisms on nets act as barriers similar to salmon lice skirts. We have examined two possible interactions of biofouling and planktonic sea lice, the first was if biofouling could function as a microhabitat for planktonic sea lice, with resuspension of sea lice during net cleaning operations. The second interaction was if biofouling may cause a retaining effect on the transport of planktonic stages out of the net pen. These interactions were investigated at different commercial salmon farms. With only one sea louse found among the biofouling on nets and cleaner fish shelters, we found no indication that sea lice utilized biofouling as a reservoir. This was further supported by the lack of impact on the proportion of samples with sea lice and the average density of sea lice in the water following the release of biofouling material during in situ net cleaning. Furthermore, the presence of biofouling had no effect on the proportion of samples with sea lice or the average density of planktonic sea lice in the net pens. The presence of a lice skirt resulted, however, in a significantly higher proportion of samples with planktonic sea lice inside the net pen in one of the two sites utilizing lice skirts. The results of our study suggested that the presence of biofouling has no influence on the average density and proportion of samples with planktonic stages of sea lice and that planktonic sea lice do not inhabit biofouling.

中文翻译：

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三文鱼围栏网和更清洁的鱼棚上的生物污垢不包含海虱的浮游阶段

本研究的目的是确定浮游海虱（Lepeophtheirus Salars Krøyer，1838 年和 Caligus elongatus Nordmann，1832 年）在用于商业养殖大西洋鲑鱼（Salmo salar L.)，并评估网上的生物污垢是否像鲑鱼虱子裙一样起到屏障的作用。我们已经研究了生物污垢和浮游海虱的两种可能相互作用，第一个是生物污垢是否可以作为浮游海虱的微生境，并在净清洁操作期间使海虱重新悬浮。第二个相互作用是生物污垢是否会对浮游阶段从网栏的运输产生保留影响。这些相互作用在不同的商业鲑鱼养殖场进行了调查。在网和更清洁的鱼棚上的生物污垢中只发现了一只海虱，我们没有发现海虱利用生物污垢作为水库的迹象。在原位网清洁过程中释放生物污垢材料后，对海虱样本的比例和水中海虱的平均密度没有影响，进一步支持了这一点。此外，生物污垢的存在对海虱样本的比例或网栏中浮游海虱的平均密度没有影响。然而，虱裙的存在导致在使用虱裙的两个地点之一中，网栏内带有浮游海虱的样本比例显着更高。