Locations of green-lipped mussel attachment within macroalgal substrates on a mussel reef in New Zealand

The goal of this study was to develop and test a tool that has the potential to aid restoration practitioners in the selection of suitable natural substrates for overcoming substrate limitation at mussel reef restoration sites in New Zealand and potentially elsewhere across the globe. One of the objectives of this study was to compare the relative performance of various macroalgae species with differing morphology as attachment substrates for three size classes of juvenile green-lipped mussels or Perna canaliculus on two remnant mussel reefs. To aid an understanding of why certain morphological characteristics of macroalgae support the presence of juvenile P. canaliculus at different ontogenic stages, the location of attachment within each macroalga species was characterised for each mussel size class. This data details the presence of three different size classes of juvenile green-lipped mussels or Perna canaliculus (<10 mm, 10 - <20 mm, and 20 - <30 mm in shell length) attached to different locations within macroalgae that were sampled on two remnant intertidal mussel reefs in northeastern New Zealand (Waipu Cove and Pakiri Beach). The six possible locations of mussel attachment on different macroalgae species were; the holdfast, stipe, lower branches, lower branch nodes, upper branches, and upper branch nodes. The presence of juvenile mussels in each size class attached to each location within each macroalga species is reported binomially (i.e., present: 1, absent: 0) in the "Juvenile Mussel Presence" column. For smaller juvenile mussels <10 mm, attachments to the branches and branch nodes of macroalgae were far more common than for juveniles ≥10 mm, suggesting that juvenile mussel attachment is more likely to be influenced by the branching morphology of macroalgae earlier in juvenile development. For juveniles <10 mm SL, attachments to the upper branches and nodes of macroalgae were more common at Waipū Cove than at Pākiri Beach, where smaller juveniles were more often attached to the lower portion of macroalgae. Lastly, macroalgal holdfasts were the most common location of attachment in this study for juvenile mussels ≥10 mm, and for juveniles smaller than 10 mm, it was as common of an attachment location as the branch nodes of macroalgae. These results suggest that juvenile mussels attached to macroalgae are likely to be influenced by a macroalga’s holdfast morphology throughout all stages of development but especially in later development.本研究旨在开发并测试一款工具，有望帮助修复从业者为新西兰乃至全球其他地区的贻贝礁修复场地选择合适的天然底质，以克服底质限制问题。本研究的核心目标之一，是在两处残存的贻贝礁上，比较不同形态大型藻类（macroalgae）作为附着底质时，对三个规格组的幼年绿唇贻贝（Perna canaliculus）的相对附着效果。为阐明为何某些大型藻类的形态特征能够在不同发育阶段支持幼年P. canaliculus的存活，本研究针对每个贻贝规格组，表征了附着于各大型藻类物种的幼贻贝位置信息。本数据集详细记录了在新西兰东北部两处残存潮间带贻贝礁（怀普湾（Waipu Cove）与帕基里海滩（Pakiri Beach））采集的大型藻类上，附着的三个规格组幼年绿唇贻贝的存在情况，其壳长分级为<10 mm、10 - <20 mm以及20 - <30 mm。贻贝在不同大型藻类上的六种可能附着位置分别为：固着器（holdfast）、柄（stipe）、下部分枝、下部分枝节点、上部分枝以及上部分枝节点。"幼贻贝附着情况"列采用二项式编码记录各大型藻类物种的各附着位置上各规格组幼贻贝的附着状态，即附着记为1，未附着记为0。对于壳长<10 mm的幼年贻贝，其附着于大型藻类分枝及分枝节点的比例远高于≥10 mm的幼贻贝，这表明幼年贻贝的附着选择更易在发育早期受到大型藻类分枝形态的影响。在怀普湾，壳长<10 mm的幼贻贝更常附着于大型藻类的上部分枝及节点，而在帕基里海滩，小型幼贻贝更多附着于大型藻类的下部区域。此外，本研究中≥10 mm的幼年贻贝最常附着于大型藻类的固着器；而对于<10 mm的幼贻贝，固着器与大型藻类分枝节点的附着比例相当。上述结果表明，附着在大型藻类上的幼年贻贝，其附着选择大概率会受到大型藻类固着器形态的影响，且这种影响贯穿整个发育阶段，尤其在发育后期更为显著。