Abstract
The United Nations General Assembly has called for greater protection of the world’s deep-sea species and of features such as Vulnerable Marine Ecosystems (VMEs). Sponges are important components of VMEs and information about their spatially explicit genetic diversity can inform management decisions concerning the placement of protected areas. We employed a spatially explicit hierarchical testing framework to examine genetic variation amongst archived samples of four deep-sea sponges in the New Zealand region. For Poecillastra laminaris Sollas 1886, significant mitochondrial (COI, Cytb) and nuclear DNA (microsatellite) genetic differences were observed between provinces, amongst north-central-south regions and amongst geomorphic features. For Penares sp. no significant structure was detected (COI, 12S) across the same areas. For both Neoaulaxinia persicum Kelly, 2007 (COI, 12S) and Pleroma menoui Lévi & Lévi 1983 (COI) there was no evidence of genetic differentiation within their northern only regional distributions. Of 10 separate species-by-marker tests for isolation-by-distance and isolation-by-depth, only the isolation-by-depth test for N. persicum for COI was significant. The use of archived samples highlights how historical material may be used to support national and international management decisions. The results are discussed in the broader context of existing marine protected areas, and possible future design of spatial management measures for protecting VMEs in the New Zealand region.
Highlights
Larval dispersal and genetic connectivity are poorly understood in the deep sea, despite their importance in shaping patterns of biodiversity and biogeography, and their ability to provide insights to help guide the protection of rare and endangered species[1]
Haplotype accumulation curves failed to reach an asymptote for all markers for Penares sp., N. persicum and Pleroma menoui (Fig. S6), indicating that a better understanding of genetic diversity at different spatial scales requires more samples
The haplotype accumulation curves for c oxidase subunit I (COI) and cytochrome b (Cytb) for Poecillastra laminaris approached an asymptote despite some haplotypes still being unaccounted for (Fig. S6)
Summary
Larval dispersal and genetic connectivity are poorly understood in the deep sea, despite their importance in shaping patterns of biodiversity and biogeography, and their ability to provide insights to help guide the protection of rare and endangered species[1]. The identification of patterns of connectivity (gene flow), of regional genetic structure, and of genetic diversity hotspots is challenging in the deep sea because the high cost and logistical constraints of sampling make it difficult to acquire specimens at large spatial scales, and across a wide range of depths[1]. A limited number of studies, employing a range of genetic markers, have failed to reveal consistent patterns of genetic structuring across a range of deep-sea VME indicator taxa in the New Zealand region[12,13,14,15,16]. Whilst deep-sea genetic studies in the New Zealand region span a range of VME indicator taxa, the spatial coverage is patchy and difficult to interpret to inform general protection measures. Interpretation provided here will be added to newly published data from VME corals[16,22] and from other taxa (work in progress) to develop a multi-taxon approach to understanding spatially explicit population genetic variation within and beyond the New Zealand Exclusive Economic Zone (EEZ)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
