Glass sponge grounds on the Scotian Shelf and their associated biodiversity

Emerald Basin on the Scotia Shelf off Nova Scotia, Canada, is home to a globally unique population of the glass sponge Vazella pourtalesi. Through the analysis of both in situ photographs and trawl catch data from annual multispecies bottom-trawl surveys, we examined community composition, species density, and abundance of epibenthos and fish associated with V. pourtalesi compared to locations without this sponge. Using generalized linear models and analysis of similarities, the importance of V. pourtalesi in enhancing species density and abundance of the associated epibenthic community was assessed against that of the hard substrate on which it settles. Our results indicated that the megafaunal assemblage associated with V. pourtalesi was significantly different in composition and higher in species density and abundance compared to locations without V. pourtalesi. Analysis of similarity of trawl catch data indicated that fish communities associated with the sponge grounds are significantly different from those without V. pourtalesi, although no species were found exclusively on the sponge grounds. Our study provides further evidence of the role played by sponge grounds in shaping community structure and biodiversity of associated deep-sea epibenthic and fish communities. The mechanism for biodiversity enhancement within the sponge grounds formed by V. pourtalesi is likely the combined effect of both the sponge itself and its attachment substrate, which together comprise the habitat of the sponge grounds. We also discuss the role of habitat provision between the mixed-species tetractinellid sponges of the Flemish Cap and the monospecific glass sponge grounds of Emerald Basin.
Please refer to the following citation for additional details on the data:
Hawkes N, Korabik M, Beazley L, Rapp HT, Xavier JR, Kenchington E (2019) Glass sponge grounds on the Scotian Shelf and their associated biodiversity. Mar Ecol Prog Ser 614:91-109. https://doi.org/10.3354/meps12903

加拿大新斯科舍省外斯科舍大陆架（Scotia Shelf）上的翡翠盆地（Emerald Basin），栖息着全球独有的玻璃海绵包尔提拉瓦兹海绵（Vazella pourtalesi）种群。本研究通过分析原位拍摄照片与年度多物种底拖网调查的拖网渔获数据，对比了有该海绵分布区域与无该海绵分布区域的群落组成、物种密度及表底栖生物与伴生鱼类的丰度。研究借助广义线性模型（generalized linear models）与相似性分析（analysis of similarities），评估了包尔提拉瓦兹海绵对伴生表底栖群落物种密度与丰度的提升作用，并将其与海绵所附着的硬质基底的作用进行了对比。

研究结果显示，相较于无海绵分布区域，与包尔提拉瓦兹海绵伴生的大型宏生物群落（megafaunal assemblage）在群落组成上存在显著差异，且物种密度与丰度均更高。对拖网渔获数据的相似性分析表明，尽管未发现仅栖息于海绵场的鱼类物种，但与海绵场伴生的鱼类群落与无海绵分布区域的鱼类群落存在显著差异。

本研究进一步证实了海绵场在塑造深海伴生表底栖与鱼类群落结构及生物多样性方面的关键作用。包尔提拉瓦兹海绵所形成的海绵场，其生物多样性提升机制大概率是海绵本身与其附着基底的共同效应——二者共同构成了海绵场的栖息生境。本研究还对比讨论了弗兰德斯海丘（Flemish Cap）的混合物种四放海绵群落与翡翠盆地单一种类玻璃海绵场之间的生境供给功能差异。

如需获取该数据集的更多细节，请参阅以下文献：
Hawkes N、Korabik M、Beazley L、Rapp HT、Xavier JR、Kenchington E（2019），《斯科舍大陆架的玻璃海绵场及其伴生生物多样性》，《海洋生态学进展系列（Mar Ecol Prog Ser）》第614卷，第91-109页。https://doi.org/10.3354/meps12903