Elasmobranchs present many challenges to our traditional understanding of the population dynamics of fishes. The life histories of teleost and elasmobranch fishes differ in profound ways. Where teleosts are highly fecund, elasmobranchs are not; where teleosts have high mortality rates in the larval stage, elasmobranchs do not. These differences mean that many of the approaches that we have developed for teleosts do not serve us well when we try to understand elasmobranchs.

To develop a general framework in which to understand elasmobranch life histories we conducted a meta-analysis of published data to qunatify phyllogenetic and size-dependent trends in elasmobranch life histories (Frisk et al. 2001). Building on from this initial study, Mike Frisk has been conducting research on life history variation in three skate species from the North Atlantic. Mike has been collaborating with the NEFSC to sample skates from Cape Hatteras, NC to the Bay of Fundy.  Currently, the research is focusing on developing maturity and fecundity schedules, estimating growth rates and developing genetic markers to allow identification of juvenile stages. In the near future, Mike will be exploring the regional, population level consequences of these findings to the management and exploitation of skates in the northeast. His work is supported by a NMFS - Sea Grant Graduate Fellowship in Population Dynamics.