Abstract

Anthropogenic perturbations and climate change are severely threatening habitats of the global ocean, especially in the Arctic region, which is affected faster than any other ecosystem. Despite its importance and prevailing threats, knowledge on changes in its micro- and nanoplanktonic diversity is still highly limited. Here, we look back almost two decades (May 1–26, 2002) in order to expand the limited but necessary baseline for comparative field observations. Using light microscopy, a total of 196 species (taxa) were observed in 46 stations across 9 transects in the Greenland Sea. Although the number of observed species per sample ranged from 12 to 68, the diversity as effective species numbers (based on Shannon index) varied from 1.0 to 8.8, leaving about 88% as rare species, which is an important factor for the resilience of an ecosystem. Interestingly, the station with the overall highest species number had among the lowest effective species numbers. During the field survey, both number of rare species and species diversity increased with decreasing latitude. In the southern part of the examined region, we observed indications of an under-ice bloom with a chlorophyll a value of 9.9 μg l−1 together with a nitrate concentration < 0.1 μM. Further, we recorded non-native species including the Pacific diatom Neodenticula seminae and the fish-kill associated diatom Leptocylindrus minimus. Our comprehensive dataset of micro- and nanoplanktonic diversity can be used for comparisons with more recent observations and continuous monitoring of this vulnerable environment—to learn from the past when looking towards the future.

Highlights

  • Ecosystems undergo dramatic changes due to climate change and anthropogenic perturbations

  • The Arctic region is negatively affected by climate change faster than any other ecosystem on Earth, and due to its early onset of climate effects, it may act as a model system for future changes of other ecosystems

  • Species number, observed species in each sample, varied between 12 and 68, which is in the upper range of the 7–12 observed by Niemi et al (2011) and 10–30 by Assmy et al (2017)

Read more

Summary

Introduction

Ecosystems undergo dramatic changes due to climate change and anthropogenic perturbations. Since the Arctic ecosystem (here defined as north of 70°) is experiencing climate change at a much higher speed compared. High diversity among and within species is important in all ecosystems, elevating resilience to environmental change (Hooper et al 2012). Due to human perturbations at the planetary scale, biodiversity is currently suffering from an increased risk of great losses (Kannan and James 2009; Steffen et al 2015). A biodiversity change can be as devastating, resulting in potential effects on ecosystem services (Dornelas et al 2014).

Methods
Results
Conclusion
Full Text
Published version (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