Patterns of Deep-sea Genetic Connectivity in the New Zealand Region: Implications for Management of Benthic Ecosystems

Patterns of genetic connectivity are increasingly considered in the design of marine protected areas in both shallow and deep water. Deep-sea communities at upper bathyal depths (<2000 m) are vulnerable to anthropogenic disturbance from fishing and potential mining operations in the New Zealand Exclusive Economic Zone (EEZ). Currently, patterns of genetic connectivity among deep-sea populations throughout New Zealand’s EEZ are not well understood. Using mitochondrial Cytochrome Oxidase I and 16S rRNA as genetic markers, this study aimed to elucidate patterns of genetic connectivity among populations of two common benthic invertebrates with contrasting life history strategies. Populations of the squat lobster Munida gracilis and the polychaete Hyalinoecia longibranchiata were sampled from continental slope, seamount, and offshore rise habitats on the Chatham Rise, Hikurangi Margin, and Challenger Plateau. For the polychaete, we found significant population structure with distinct populations on the Challenger Plateau, the Chatham Rise, and the Hikurangi Margin. Significant genetic differences were also found between slope and seamount populations on the Hikurangi Margin. There are indications of potential differentiation in populations between the northeast and southwest parts of the Chatham Rise. Patterns of genetic connectivity in Hyalinoecia longibranchiata are thought to be influenced by a number of factors including current regimes that operate on varying spatial and temporal scales to produce potential barriers to dispersal. In contrast, no significant population structure was detected across the study area for the squat lobster. The striking difference in population structure between species can be attributed to differences in life history strategies. The results of this study are discussed in the context of existing conservation areas that are intended to manage anthropogenic threats to deep-sea benthic communities in the New Zealand region.

Bors, E.K., A.A. Rowden, E.W. Maas, M. Clark, and T.M. Shank (2012) Patterns of genetic connectivity in the deep-water New Zealand region: implications for management of benthic ecosystems. PLoS One 7(11): e49474. doi:10.1371/journal.pone.0049474).