A boundary current drives synchronous growth of marine fishes across tropical and temperate latitudes

• Published in: Global change biology Vol. 24; no. 5; pp. 1894 - 1903
• Main Authors: Ong, Joyce J. L., Rountrey, Adam N., Black, Bryan A., Nguyen, Hoang Minh, Coulson, Peter G., Newman, Stephen J., Wakefield, Corey B., Meeuwig, Jessica J., Meekan, Mark G.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01-05-2018
• Subjects: Animal behavior; Animals; boundary current; Capacity; Climate; Climate Change; Climate effects; Dynamics; Ecosystem; Ecosystem resilience; Ecosystems; El Nino; El Nino phenomena; El Niño‐Southern Oscillation; Entrainment; Environmental changes; Fishes - growth & development; growth chronologies; Growth patterns; History; La Nina; Marine ecosystems; Marine fish; Marine fishes; Oceans and Seas; Predictions; Southern Oscillation; Species extinction; Trophic levels; Tropical Climate; Water Movements; Western Australia; El Niño-Southern Oscillation; Western Australia; boundary current; growth chronologies; marine fishes
• ISSN: 1354-1013; 1365-2486
• DOI: 10.1111/gcb.14083

Entrainment of growth patterns of multiple species to single climatic drivers can lower ecosystem resilience and increase the risk of species extinction during stressful climatic events. However, predictions of the effects of climate change on the productivity and dynamics of marine fishes are hampered by a lack of historical data on growth patterns. We use otolith biochronologies to show that the strength of a boundary current, modulated by the El Niño‐Southern Oscillation, accounted for almost half of the shared variance in annual growth patterns of five of six species of tropical and temperate marine fishes across 23° of latitude (3000 km) in Western Australia. Stronger flow during La Niña years drove increased growth of five species, whereas weaker flow during El Niño years reduced growth. Our work is the first to link the growth patterns of multiple fishes with a single oceanographic/climate phenomenon at large spatial scales and across multiple climate zones, habitat types, trophic levels and depth ranges. Extreme La Niña and El Niño events are predicted to occur more frequently in the future and these are likely to have implications for these vulnerable ecosystems, such as a limited capacity of the marine taxa to recover from stressful climatic events.
Understanding how fish respond to climate changes is crucial for predicting future impacts. We examined the growth records of six species of marine fishes from different thermal ranges, habitats and trophic levels, along 3000 km of coastline in Western Australia. We found that five of the six species had similar growth responses to a large‐scale climate phenomenon that drove the strength of the local current. This implies that multiple species across large spatial scales will be simultaneously affected by extreme climate events, which has major consequences for the resilience of the ecosystem and its ability to recover from extreme events.