MEPS 354:201-217 (2008)  -  DOI: https://doi.org/10.3354/meps07217

ABSTRACT: Isolated adult populations tend to be interconnected via the larval stage. New Zealand red rock lobster Jasus edwardsii larvae metamorphose 12 to 24 mo after hatching. Because of this long larval life, J. edwardsii provides a useful species for studying population connectivity using satellite-derived ocean currents. In this study, tracks of J. edwardsii larvae originating from different populations are simulated to build a statistical picture of larval dispersal. By adding an algorithm for larval metamorphosis, and tuning the algorithm parameters to fit observed post-metamorphosis settlement patterns, we estimate where settlement in each population originated (i.e. larval sources), and also where larvae from each population settle (i.e. larval sinks). There are likely to be 4 major geographical areas for larval dispersal around New Zealand. In the far north, both sources and sinks are non-local. Along the east coast of the North Island, because of entrainment by the Wairarapa Eddy, sources are both local and distant, whereas most sinks are local. In contrast, to the south of the South Island, most sources are local, whereas sinks are both local and distant. The Chatham Islands form a separate geographical area, with primarily non-local sources and local sinks. The results are robust to differences in the physical model, but sensitive to metamorphosis algorithm parameters. This indicates that understanding larval behaviour is the most critical aspect in determining larval connectivity.

KEY WORDS: Jasus edwardsii · Lobster · Larval dispersal · Numerical modelling · New Zealand · Phyllosoma · Settlement