Thompson-Saud, G., Grech, A., Choukroun, S., Vásquez, S.I., Salas, C., and Ospina‐Alvarez, A. (2024) The biophysical dynamics of giant kelp, Macrocystis pyrifera: Seasonal patterns and dispersal mechanisms in the southeast Pacific. Journal of Biogeography. (In Press)

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Abstract

Aim: Dispersal and connectivity play important roles in shaping the population structure of giant kelp, Macrocystis pyrifera, across the western coast of South America. Its high potential dispersal capacity suggests the existence of metapopulations, where discrete habitat patches or groups of patches form subpopulations that interact at some level. However, the dispersal patterns of giant kelp in this region have not been quantified. This study assesses the dispersal and settlement of Macrocystis pyrifera in the southeast Pacific, specifically focusing on the impact of environmental variables and ocean currents within the Humboldt Current System.

Location: Southeast Pacific (coast of Chile and Peru).

Time Period: 1997–2008.

Major Taxa Studied: Macrocystis pyrifera (giant kelp).

Methods: Using a combination of hydrodynamic and individual-based models, we analysed kelp fragment movements over 12 years, with a particular emphasis on the effects of the El Niño-Southern Oscillation (ENSO) and seasonal changes.

Results: Our results highlight a key settlement area in the southern Chilean region. We found that shorter travel distances of kelp fragments increased the likelihood of reaching a suitable habitat, underscoring the importance of local environmental conditions. We delineated intricate northward dispersal paths for kelp fragments, which appear to be governed by the interplay of wind and ocean current dynamics. Seasonal variations, notably in autumn and winter, favour the likelihood of reaching a settlement area due to favourable winds. Furthermore, ENSO events appear to influence dispersal distances, with fragments travelling the longest distances during El Niño phases.

Main Conclusion: These findings are essential for informing kelp conservation strategies in the context of climate change, emphasizing the necessity of considering local and seasonal environmental factors alongside ENSO impacts.

Item ID:	83502
Item Type:	Article (Research - C1)
ISSN:	1365-2699
Copyright Information:	This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. © 2024 The Author(s). Journal of Biogeography published by John Wiley & Sons Ltd
Funders:	James Cook University (JCU), Australian Research Council Centre of Excellence for Coral Reef Studies (ARC CoE Coral Reef Studies)
Projects and Grants:	ARC CE140100020
Date Deposited:	03 Sep 2024 00:44
FoR Codes:	41 ENVIRONMENTAL SCIENCES > 4102 Ecological applications > 410299 Ecological applications not elsewhere classified @ 100%
SEO Codes:	18 ENVIRONMENTAL MANAGEMENT > 1802 Coastal and estuarine systems and management > 180201 Assessment and management of coastal and estuarine ecosystems @ 100%
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