Dr. Mike Hickford

Senior Research Fellow

Phone +64 3 364 3049 or +64 21 382 877

My primary research interest is the early life history of fish. I am interested in larval dispersal and transport mechanisms and how they are influenced by nearshore hydrography. I spent 3 years with PISCO in Santa Barbara, California where I learned and helped develop a new tool for tracking the dispersal of larval fish. Otolith microchemistry uses the chemical fingerprint in the otolith (ear bone) of fish as a natural tag to help locate their natal origin (where they were born). My research to date had focussed on marine species, but I have recently switched my focus to New Zealand’s freshwater galaxiids (whitebait) because their unique life history makes them ideal candidates for tracking with otolith microchemistry.

Galaxias maculatus is one of the most widely distributed freshwater fish species in the world. It is found in New Zealand, Western Australia, Southeast Australia, Tasmania, Lord Howe Island, Chile, Argentina, Tierra del Fuego and the Falkland Islands. However, even with the very wide separations of the land masses on which they are found, G. maculatus populations throughout this wide range are almost indistinguishable genetically. It is thought that a complex life history, including a six month marine planktonic period, may enable this species to disperse widely. We are using otolith microchemistry to discern the extent of larval dispersal of G. maculatus around New Zealand. It is expected that the elemental signatures from the otoliths of demersal G. maculatus eggs, which develop in the trace element rich estuarine environment, will provide more defined source signatures than those seen in analogous work with marine reef fishes. The elemental signature from the core of the otolith of new recruits will be compared with those source signatures to determine the natal origin of individual larvae. By incorporating otolith microchemistry and coastal hydrography, we will gain a better understanding of the mechanisms and scale of dispersal of this species and begin to reveal the linkages between populations that have planktonic larvae.

Publications

Hickford, M.J.H., Schiel, D.R., (2008). Experimental gill-netting of reef fishes: species-specific responses modify capture probability across mesh sizes. J. Exp. Mar. Biol. Ecol.

Ruttenberg, B. I., S. L. Hamilton, M. J. H. Hickford, G. L. Paradis, M. S. Sheehy, J. D. Standish, O. Ben-Tzvi and R. R. Warner (2005). “Elevated levels of trace elements in cores of otoliths and their potential for use as natural tags.” Marine Ecology Progress Series 297: 273-281.

Hickford, M. J. H. & D. R. Schiel (2003). "Comparative dispersal of larvae from demersal versus pelagic spawning fishes." Marine Ecology Progress Series 252: 255-71.

Schiel, D. R. & M. J. H. Hickford (2001). "Biological structure of nearshore rocky subtidal habitats in southern New Zealand." Science for Conservation 182: 54p.

Hickford, M. J. H. & D. R. Schiel (1999). "Evaluation of the performance of light traps for sampling fish larvae in inshore temperate waters." Marine Ecology Progress Series 186: 293-302.

Hickford, M. J. H., D. R. Schiel and J. B. Jones (1997). "Catch characteristics of commercial gill-nets in a nearshore fishery in central New Zealand." New Zealand Journal of Marine and Freshwater Research 31(2): 249-59.

Hickford, M. J. H. & D. R. Schiel (1996). "Gillnetting in southern New Zealand: Duration effects of sets and entanglement modes of fish." Fishery Bulletin 94(4): 669-77.

Hickford, M. J. H. & D. R. Schiel (1995). "Catch vs count: Effects of gill-netting on reef fish populations in southern New Zealand." Journal of Experimental Marine Biology and Ecology 188: 215-32.

Presentations

Hickford, M.J.H. & Schiel, D.R.  “Attractive sinks” detract from spawning success: degraded habitats reduce egg production of whitebait in major rivers. New Zealand Marine Sciences Conference, Auckland.

Hickford, M. J. H. & D. R. Schiel (2006). Sources and sinks: loss of critical stage-specific habitats in a diadromous fish species. New Zealand Marine Sciences Conference, Nelson.

Hickford, M. J. H. (2005). Elemental fingerprinting of Galaxiid otoliths: a model system to track dispersal. Mellon Consortium Meeting, Cape Town, South Africa.

Hickford, M. J. H. & D. R. Schiel (2003). Testing the waters: determination of the natal origins of Galaxias maculatus through otolith microchemistry. 27th Annual Larval Fish Conference, Santa Cruz, California.

Hickford, M. J. H. (2003). Whitebait: where do they come from and where do they go? Rotary Club of Westport (District 9970), Westport.

Hickford, M. J. H. (2000). Fish larvae and marine reserves: do they mix? New Zealand Marine Sciences Conference, Wellington.