Speed Presentation 2024 Australian Marine Sciences Association Annual Meeting combined with NZMSS

Suspended Sediment Increases Growth of Green-Lipped Mussel Spat (#470)

Brandy Biggar 1 , Jenny Hillman 1 , Andrew Jeffs 1
  1. Institute of Marine Science , University of Auckland, Auckland, New Zealand

Suspended sediment is among the greatest current threats to coastal ecology in many parts of the world. Sediment runoff into the ocean is increasing due to numerous human activities, such as population growth, agriculture, construction, and mining. Additionally, climate change is impacting local weather patterns, with many regions experiencing changes in the frequency and extent of precipitation. Extreme weather events, such as cyclones, can increase local total suspended solids (TSS) in the ocean by up to 100-fold. This rapid and severe change in turbidity can negatively affect filter-feeding bivalves, diminishing filter-feeding efficiency, preventing feeding until turbidity decreases, and/or burying them by settling particles. In New Zealand, juveniles of the green-lipped mussel (Perna canaliculus) have rudimentary structures for capturing and sorting food particles from the seston, which are prone to clogging and damage. We studied the effects of TSS concentrations on P. canaliculus juvenile (~1–2 mm in shell length) survival, growth, and condition at two time scales (5 and 30 days). Although mortality was low and not significantly related to TSS for either time, growth was positively correlated with TSS in both (p < 0.001).