Images from Meso- and Bathypelagic Surveys in the Gully Marine Protected Area: V: Cephalopods

During 2007–10, Canada’s Department of Fisheries and Oceans conducted a series of four midwater-trawl surveys, at meso- and bathypelagic depths, in The Gully – a very large submarine canyon incised into the Scotian Shelf, immediately east of Sable Island, the core of which has been encompassed within a Marine Protected Area since 2004. The surveys followed a fixed-station, depth-stratified design, with replicate sets both in daylight and at night. Most sampling used International Young Gadoid Pelagic Trawls (IYGPTs) –open nets with 60 m² mouth area– worked on double-oblique profiles. From the 2008 survey, the trawls were fitted with rigid (“aquarium”) codends and successfully took a number of delicate specimens in exceptional condition. Full details of the field methodologies have been presented by Kenchington et al. (2009, 2014) , while a report on the cephalopods captured is in preparation.

Anticipating that many rarely-seen species would be captured, a variety of camera systems were taken to sea on the Gully surveys and an attempt was made to capture images of every species taken, while the at-sea data-capture protocols emphasized visual recording of cephalopods – at least 38 species of which were captured. The resulting image collection has been catalogued and lightly edited (removing duplicates and unfocused or otherwise valueless images), while erring on the side of retaining any image that might prove useful in the future. Almost all of those retained are in their original formats and resolutions. The present collection includes the 402 catalogued images of cephalopods from all four surveys and a catalogue of them. Individual images are uniquely numbered (from S07001 to S07130, S08001 to S08014, S09001 to S09088 and S10001 to S10170 – the first two digits in each case indicating the survey year). There are corresponding entries in the catalogue, which presents the contents of each image (typically only a species name, though some entries have more details) and such other image-specific details as are available. Not all images can be linked to particular specimens but, for those which can be, catalogue entries include cross-references to the survey-program’s catch database, which provides further details on the specimens concerned.

All images © His Majesty the King in Right of Canada, 2022.

Amongst the named authors, the surveys were led by Trevor Kenchington, who also catalogued the images and, working with Cam Lirette, presented them here. Elizabeth Shea provided all specimen identifications, captured most of the images and assisted with their cataloguing. Other images were taken by Bill MacEachern, Kevin MacIsaac, Merlin Best or Andrew Cogswell.

2007年至2010年间，加拿大渔业与海洋部在古尔利海底峡谷（The Gully）开展了四次中层拖网调查（midwater-trawl surveys），该区域为切入斯科舍陆架的大型海底峡谷，紧邻萨布尔岛东侧，其核心区域自2004年起被纳入海洋保护区（Marine Protected Area），调查覆盖中层与深层浮游深海水深（meso- and bathypelagic depths）。

本次调查采用固定站位、深度分层的实验设计，设置昼、夜间重复采样组。多数采样作业使用国际稚鳕中层拖网（International Young Gadoid Pelagic Trawls，IYGPTs）——该网具口门面积达60平方米，采用双斜向拖曳剖面作业。2008年起，拖网加装了刚性“水族箱”式囊网（rigid “aquarium” codends），成功采集到多批状态极佳的脆弱标本。野外采样方法的完整细节已由Kenchington等人（2009、2014）发表，相关头足类（cephalopods）捕获情况的专项报告正在编制中。

考虑到本次调查可能捕获诸多罕见物种，研究团队在古尔利海底峡谷的调查中搭载了多套摄像系统，尝试为每一种捕获物种拍摄影像；同时海上数据采集规程重点对头足类进行可视化记录——本次调查共捕获至少38种头足类。所得影像集已完成编目与轻度编辑（剔除重复、失焦或无价值的影像），同时秉持“宁留勿弃”原则，保留所有未来可能具备研究价值的影像。绝大多数留存影像均保留原始格式与分辨率。

本次公开的影像集包含四次调查中采集的402张头足类影像及其编目清单。单张影像均配有唯一编号（编号范围分别为S07001至S07130、S08001至S08014、S09001至S09088及S10001至S10170，其中前两位数字代表调查年份）。编目清单中包含对应条目，每条目会说明影像内容（通常仅包含物种名称，部分条目会提供更多细节）及其他可获取的单影像专属信息。并非所有影像都能关联到具体标本，但对于可关联的标本，编目条目会附带指向调查项目捕获数据库的交叉引用，该数据库可提供相关标本的更多细节。

所有影像版权归加拿大国王陛下（以加拿大主权所有）所有，2022年。

本次调查由Trevor Kenchington牵头，他同时负责影像编目，并与Cam Lirette共同整理发布本次影像集。Elizabeth Shea完成了全部标本鉴定工作，拍摄了绝大多数影像，并协助完成编目。其余影像由Bill MacEachern、Kevin MacIsaac、Merlin Best及Andrew Cogswell拍摄。