Richard L. Radtke
PhD University of South Carolina (Marine Science), 1978
Researcher, Hawai'i Institute of Geophysics and Planetology
School of Ocean and Earth Science and Technology
2525 Correa Road
Honolulu, Hawaii 96822 U.S.A.
phone: (808) 956-7498
FAX: (808) 956-9516
radtke@hawaii.edu
www.soest.hawaii.edu/~radtke/

Life history of fishes
The goals of our research program are to characterize the processes that affect the age, growth, recruitment and reproduction of fishes - their life history. These four areas of fish biology, ones that are the major aspects of a fish's life history, are fundamental concerns of fisheries biologists. As fisheries biologists, we must be able to accurately determine the factors that affect and shape the life history and survival of fishes in each stage of their life history. This can be accomplished by studies performed on field-caught individuals and experimentally reared individuals. Fundamental to our research program is the use of conventional statistical analyses of these aspects and the use of novel techniques that enable us to model the population structure of commercially and ecologically important species. These aspects, alone, are not a sufficient means to allow us to model the overall life history events of a selected species, thus we have combined our conventional research with specualtive research; research that allows us to visualize how environmental patterns affect the physiological patterns of fish, i.e., how temperature, food and feeding and hydrographic conditions affect migrations and behavior (feeding). We are also attempting to delimit the durations spent in each life history stage as they relate to the former conditions.

Representative publications
Radtke RL, Dempson JB, Ruzicka J. 1998. Microprobe analyses of anadromous Arctic charr, Salvelinus alpinus, otoliths to infer life history migration events. Polar Biol 19:1-8.

Radtke RL, Kinzie III RA. 1996. Evidence of a marine larval stage in endemic Hawaiian stream gobies from isolated locations. Trans Am Fish Soc 125:613-621.

Radtke RL. 1995. Forensic biological pursuits of exotic fish origins: Piranha in Hawaii. Env Biol Fish 43:393-399.

Radtke RL, Shafer DJ. 1992. Environmental sensitivity of fish otolith microchemistry. Aust J Mar Freshwater Res 43:935-951.

Radtke RL, Townsend DW, Folsom SD, Morrison MA. 1990. Strontium: calcium concentration ratios in larval herring otoliths as indicators of environmental histories. Environ Biol Fish 27:51-61.

Radtke R.L, Targett TE, Kellermann A, Bell JL, Hill KT. 1989. Antarctic fish growth: profile of Trematomus newnesi. Mar Ecol Prog Ser 57:103-117.

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