Identification of essential habitats: Including chimaeras into current shark protected areas

Abstract

1. Essential habitats are areas required to support specific functions, such as providing foraging grounds, shelter or used for reproductive purposes. For mobile aquatic species that move throughout numerous components of the seascape, identifying essential habitats within a species' broader distribution range is crucial to under-standing their ecology and provide vital information needed to underpin effective conservation and management (e.g. the implementation of protected areas). 2. In Tasmania (Australia), a number of coastal habitats have been declared shark refuge areas (SRAs), where fishing for elasmobranchs (sharks, rays and skates) is prohibited. 3. Chimaeras are relatives of elasmobranchs (class Chondrichthyes) and share traits that predispose many elasmobranch species to be vulnerable to overfishing (e.g. slow growth rates and low reproductive output). However, fishing for elephantfish Callorhinchus milii (the chimaera species found in coastal Tasmania) is still permitted in SRAs. 4. Here, a combination of acoustic tracking, catch data and reproductive information was used to determine the significance of the SRA coastal habitats for C. milii. 5. Results suggest that these areas are essential habitats for reproduction and likely important for other purposes, such as foraging. 6. Given that a key strategy in managing fish stocks is protecting areas important for reproduction, and the importance of these coastal areas of Tasmania for C. mili reproductive purposes, we recommend including C. mili in current SRAs, and decreeing these areas as chondrichthyan refuge areas.