Journal Article

Impact of Post-Tropical Storm Arthur (2014) on benthic Arcellinida assemblage dynamics in Harvey Lake, New Brunswick, Canada

Patterson, R. Timothy, Atasiei, Dan, Wen, Anqi, Patterson, Calder W, Roe, Helen M, Nasser, Nawaf A, Galloway, Jennifer M

2022

Overview

Arcellinida (testate lobose amoebae) were examined in surface-sediment samples collected in 2015 from throughout Harvey Lake, New Brunswick, Canada to assess whether the passage of Post-Tropical Storm Arthur in 2014 impacted the distribution of taxa and assemblages. Cluster analysis and non-metric multidimensional scaling (NMDS) revealed four distinct arcellinidan assemblages: (1) Deep Water Reworking Assemblage (DWR; approximately unbiased, AU P-value = 89%); (2) Arsenic Impact Assemblage (AI; AU P-value = 92%); (3) Northern Shallow Water Assemblage A (NSWA; AU P-value = 66%); and (4) Northern Shallow Water Assemblage B (NSWB; AU P-value = 0%). Redundancy analysis (RDA) and partial-RDA results were used to identify four variables that significantly influenced the assemblage composition and explained 20.2% of the arcellinidan distributional variability: [arsenic (As), wind mixing probability (WMP), water depth and sedimentary grain size represented by the very coarse silt end member 2 (EM2) which was 40 μm]. Arsenic concentration in the sediments of Harvey Lake is an important control over the distribution of Arcellinida assemblages. Levels of sedimentary As in samples from the southern part of Harvey Lake, near As-bearing volcanic bedrock in the catchment, exceeded the Probable Effect Level (17 ppm) and Interim Sediment Quality Guideline (5.9 ppm) for this element. Shallower water (less than median water depth of 3.56 m) and highly diverse assemblages NSWA and NSWB (median SDI = 2.6) significantly correlated with wind mixing probability, while deeper water (greater than median = 6.2 m) and moderately to highly diverse assemblages DWR and AI (SDI range 2.4–2.7) associated strongly with EM2. EM2 was derived from the suspension of and redeposition of sediments when the storm water wave base was deepened during the passage of Arthur. Arcellinidans were carried into suspension along with very coarse silt grain particles during the passage of the storm and redeposited at all water depths when wave energy decreased. Water depth of sampling stations should be taken into consideration in lakes that may be periodically impacted by large storms.

• Publisher: Springer Nature B.V
• Subject: Arcellinida / Arsenic / Bedrock / Benthos / Cluster analysis / Deep water / Distribution / Grain size / Lakes / Multidimensional scaling / Probability theory / Redundancy / Scaling / Sediment / Sediment samplers / Sediment samples / Sediments / Shallow water / Silt / Storms / Stormwater / Tropical climate / Tropical depressions / Tropical storms / Water depth / Water waves / Watersheds / Wave energy / Wave power / Wind