Recruitment processes in Haliotis rubra (Mollusca: Gastropoda) and regional hydrodynamics in southeastern Australia imply localized dispersal of larvae

Abstract Our studies of recruitment, adult numbers, and ocean hydrodynamics suggest that recruitment of Haliotis rubra is primarily local. In three neighbouring coastal populations of Haliotis rubra in southeastern Australia where adult numbers differed significantly, recruitment was found to be correlated with the abundance of adult H. rubra counted in each population. Regional larval dispersal was examined using measurements of horizontal water velocities near the seabed and at the surface of one reef. The measurements showed that larvae entering the water column would be dispersed if they left the shelter of local reef topography. This dispersal was confirmed by numerical hydrodynamic and dispersal modelling which simulated the temporal and spatial variation of wind-driven currents near the reefs. The results from the models also demonstrated that larvae entering the water column have a low chance of returning to their parent reef and that recruitment to some reefs from an upstream population was unlikely during a typical 3–7-day pelagic period because some populations were found to be hydrodynamically isolated from their neighbours. This was confirmed by plankton surveys several days after the estimated start of spawning which revealed only one larva of H. rubra in ocean water around the reefs surveyed. The measurements and simulation models suggested that settlement of H. rubra would be most successful if the larvae remained on their parent reef. The results of additional hydrodynamic studies at the surface of one reef showed that local reef topography attenuated near-bed currents sufficiently for larvae of H. rubra to stay on the parent reef, for example, in rock crevices, for the full pelagic period. In this way, H. rubra would complete its larval life cycle near the parent.

[1]  S. Shepherd.  Studies on southern Australian abalone (genus Haliotis). I. Ecology of five sympatric species , 1973 .

[2]  R. R. Strathmann,et al.  Larval Mortality from Offshore Mixing as a Link between Precompetent and Competent Periods of Development , 1981, The American Naturalist.

[3]  Jeremy D. Prince,et al.  Experimental evidence for limited dispersal of haliotid larvae (genus Haliotis; Mollusca: Gastropoda) , 1987 .

[4]  O. Ishida,et al.  On the distribution of swimming and deposited larvae of nursery ground of abalone at the southern coast of Chiba prefecture. , 1986 .

[5]  Philip R. Sluczanowski,et al.  A Management Oriented Model of an Abalone Fishery Whose Substocks are Subject to Pulse Fishing , 1984 .

[6]  R. R. Strathmann.  The Spread of Sibling Larvae of Sedentary Marine Invertebrates , 1974, The American Naturalist.

[7]  J. Clavier,et al.  Growth of juvenile Haliotis tuberculata (Mollusca: Gastropoda) in their natural environment , 1986, Journal of the Marine Biological Association of the United Kingdom.

[8]  K. Black.  A Numerical Sediment Transport Model for Application to Natural Estuaries, Harbours and Rivers , 1987 .

[9]  S. Shepherd,et al.  Studies on southern Australian abalone (genus Haliotis). VI. Habitat preference, abundance and predators of juveniles , 1985 .

[10]  S. Pond,et al.  Introductory Dynamical Oceanography , 1983 .

[11]  S. A. Mileikovsky.  Speed of active movement of pelagic larvae of marine bottom invertebrates and their ability to regulate their vertical position , 1973 .

[12]  B. Bernstein,et al.  SELECTIVE PRESSURES AND COEVOLUTION IN A KELP CANOPY COMMUNITY IN SOUTHERN CALIFORNIA , 1979 .

[13]  Sa Shepherd,et al.  Studies on southern Australian abalone (Genus Haliotis). II. Reproduction of five species , 1974 .

[14]  G. G. Newman.  Reproduction of the South African abalone, Haliotis midae , 1967 .

[15]  D. Morse,et al.  Recruitment and metamorphosis of Haliotis larvae induced by molecules uniquely available at the surfaces of crustose red algae , 1984 .

[16]  K. Black.  Eddy formation in unsteady flows , 1987 .

[17]  C. A. Butman.  Larval settlement of soft-sediment invertebrates: the spatial scales of pattern explained by active habitat selection and the emerging rôle of hydrodynamical processes , 1987 .

[18]  K. Banse,et al.  Vertical distribution and horizontal transport of planktonic larvae of echinoderms and benthic polychaetes in an open coastal sea , 1986 .

[19]  Anson H. Hines,et al.  Abalones, Shells, and Sea Otters: Dynamics of Prey Populations in Central California , 1982 .

[20]  Mg Smith,et al.  Measuring Abundance of Juvenile Abalone, Haliotis rubra Leach (Gastropoda : Haliotidae); Comparison of a Novel Method with Two Other Methods , 1988 .

[21]  D. Morse,et al.  γ-Aminobutyric Acid, a Neurotransmitter, Induces Planktonic Abalone Larvae to Settle and Begin Metamorphosis , 1979, Science.

[22]  Jeremy D. Prince,et al.  Use of anaesthetic to standardize efficiency in sampling abalone populations (Genus Haliotis; Mollusca : Gastropoda) , 1985 .

[23]  B. Adkins,et al.  SPAWNING IN A BRITISH-COLUMBIA POPULATION OF NORTHERN ABALONE, HALIOTIS-KAMTSCHATKANA , 1980 .

[24]  T. Seki,et al.  Induced settlement of the Japanese abalone, Haliotis discus hannai, veliger by the mucous trails of the juvenile and adult abalones , 1981 .

[25]  J. Connell.  The consequences of variation in initial settlement vs. post-settlement mortality in rocky intertidal communities , 1985 .

[26]  George A. Jackson,et al.  Effect of a kelp forest on coastal currents , 1983 .

[27]  I. Hayashi,et al.  Structure and Growth of a Shore Population of the Ormer, Haliotis Tuberculata , 1980, Journal of the Marine Biological Association of the United Kingdom.

[28]  Mj Tegner,et al.  Drift-tube study of the dispersal potential of green abalone (Haliotis fulgens) larvae in the southern California Bight: implications for recovery of depleted populations , 1985 .

[29]  K. J. Sainsbury,et al.  Population dynamics and fishery management of the paua, Haliotis iris I. Population structure, growth, reproduction, and mortality , 1982 .

[30]  M. Tegner,et al.  Induction of Settling and Metamorphosis of Planktonic Molluscan ( Haliotis ) Larvae. III: Signaling by Metabolites of Intact Algae is Dependent on Contact , 1980 .