Veale LO, Hill AS, Brand AR
University of Liverpool Port Erin Marine Laboratory, IM9 6JA, Port Erin, Isle of Man, UK
J Exp Mar Biol Ecol. 2000 Dec 1;255(1):111-129. doi: 10.1016/s0022-0981(00)00295-1.
The impact of demersal fishing gears on benthic habitats and species has been the subject of much attention recently, and suggestions have been made that scavenging epifaunal species may benefit at the population level from the additional food source provided by discards. This paper investigates some aspects of this process, including the relative attractiveness to predators of different discard species, and the role of damage in scavenger attraction. A time-lapse video system with a 1000 m long cable was positioned in an area closed to fishing, adjacent to the most heavily fished scallop (Pecten maximus) ground in the Irish Sea. A variety of undamaged and damaged by-catch animals were positioned in front of the camera, and the subsequent predator aggregations investigated. Densities of scavenger species up to 200 times that of the background population were observed, and aggregations of some species persisted for up to 3 days. The most frequently recorded scavengers, and therefore presumably those species most likely to benefit from discards as a food source, were: Asterias rubens L., Astropecten irregularis (Pennant), Liocarcinus spp Stimpson, Pagurus spp Fabricius and Callionymus lyra L. Predator attraction to apparently undamaged queen scallops, Aequipecten opercularis (L.), was almost as high as to damaged A. opercularis. Of all the prey species studied, queen scallops were the most attractive to scavengers. A directional relationship was found between the ambient water current and the arrival of the starfish, Asterias rubens.
底栖捕捞渔具对底栖生境和物种的影响近来备受关注，有人提出，食腐性表栖生物物种可能会在种群层面上受益于丢弃物提供的额外食物来源。本文研究了这一过程的一些方面，包括不同丢弃物种对捕食者的相对吸引力，以及损伤在吸引食腐动物方面的作用。一个配备1000米长电缆的延时视频系统被放置在爱尔兰海一处禁止捕鱼的区域，该区域毗邻捕捞最为密集的扇贝（大扇贝）渔场。将各种未受损和受损的兼捕动物放置在摄像机前，随后对捕食者的聚集情况进行调查。观察到食腐动物物种的密度比背景种群密度高200倍，一些物种的聚集持续了长达3天。记录最频繁的食腐动物，因此大概也是最有可能从丢弃物作为食物来源中受益的物种有：红海盘车、不规则 Astropecten、Stimpson 的 Liocarcinus 属、Fabricius 的 Pagurus 属以及 L. 的 Callionymus lyra。捕食者对明显未受损的皇后扇贝（Aequipecten opercularis (L.)）的吸引力几乎与对受损的皇后扇贝的吸引力一样高。在所有研究的猎物物种中，皇后扇贝对食腐动物最具吸引力。在环境水流与海星（红海盘车）的到来之间发现了一种定向关系。
