Differences in meiofauna communities with sediment depth are greater than habitat effects on the New Zealand continental margin: implications for vulnerability to anthropogenic disturbance

PeerJ. 2016 Jul 5:4:e2154. doi: 10.7717/peerj.2154. eCollection 2016.

Abstract

Studies of deep-sea benthic communities have largely focused on particular (macro) habitats in isolation, with few studies considering multiple habitats simultaneously in a comparable manner. Compared to mega-epifauna and macrofauna, much less is known about habitat-related variation in meiofaunal community attributes (abundance, diversity and community structure). Here, we investigated meiofaunal community attributes in slope, canyon, seamount, and seep habitats in two regions on the continental slope of New Zealand (Hikurangi Margin and Bay of Plenty) at four water depths (700, 1,000, 1,200 and 1,500 m). We found that patterns were not the same for each community attribute. Significant differences in abundance were consistent across regions, habitats, water and sediment depths, while diversity and community structure only differed between sediment depths. Abundance was higher in canyon and seep habitats compared with other habitats, while between sediment layer, abundance and diversity were higher at the sediment surface. Our findings suggest that meiofaunal community attributes are affected by environmental factors that operate on micro- (cm) to meso- (0.1-10 km), and regional scales (> 100 km). We also found a weak, but significant, correlation between trawling intensity and surface sediment diversity. Overall, our results indicate that variability in meiofaunal communities was greater at small scale than at habitat or regional scale. These findings provide new insights into the factors controlling meiofauna in these deep-sea habitats and their potential vulnerability to anthropogenic activities.

Keywords: Canyon; Fishing; Meiofauna; New Zealand; Seamount; Seep; Slope.

Grants and funding

This study was part of NIWA’s research project ‘Impact of resource use on vulnerable deep-sea communities’ funded by the New Zealand Ministry for Business, Innovation and Employment (CO1X0906). Voyage TAN0616 (RENEWZ) was funded by NOAA grants (NA17RJ1231 and NA05417076) and NIWA. N. Rosli received PhD research funding from the University of Otago (New Zealand), Universiti Pendidikan Sultan Idris (Malaysia), and Kementerian Pendidikan Tinggi (Malaysia). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.