Shellogy: reading abalone shells to empower reef-scale management

Abstract

ABSTRACT Developing spatially explicit assessment and management techniques that engage stakeholder behaviour has been an enduring priority for fisheries targeting benthic marine invertebrates like abalone. This study describes the basis of ‘Shellogy’; a concept with the potential to empower reef-scaled management by using shell morphology to qualitatively evaluate abalone populations and their variability. The premise of shellogy is that a range of shell characteristics, previously established as distinguishing between populations with differing life history parameters, are also indicative of relative age and stage of maturation. Using the analysis of existing data, literature synthesis and illustrations, together with simulation of length frequency histograms, this study establishes from first principles that the morphometric ratios of abalone shells, along with superficial internal and external shell characteristics, change predictably with age and maturation. This study explains how recognising the connection between shell shape, and relative age and maturity, enables the appearance of shells in populations and catches, to be used to inform qualitative reef-scale assessment and facilitate stakeholder engagement with reef-scale management initiatives.