Abstract
Marine embayments and estuaries play an important role in the ecology and life history of many fish species. Cockburn Sound is one of a relative paucity of marine embayments on the west coast of Australia. Its sheltered waters and close proximity to a capital city have resulted in anthropogenic intrusion and extensive seascape modification. This study aimed to compare the sampling efficiencies of baited videos and fish traps in determining the relative abundance and diversity of temperate demersal fish species associated with naturally occurring (seagrass, limestone outcrops and soft sediment) and modified (rockwall and dredge channel) habitats in Cockburn Sound. Baited videos sampled a greater range of species in higher total and mean abundances than fish traps. This larger amount of data collected by baited videos allowed for greater discrimination of fish assemblages between habitats. The markedly higher diversity and abundances of fish associated with seagrass and limestone outcrops, and the fact that these habitats are very limited within Cockburn Sound, suggests they play an important role in the fish ecology of this embayment. Fish assemblages associated with modified habitats comprised a subset of species in lower abundances when compared to natural habitats with similar physical characteristics. This suggests modified habitats may not have provided the necessary resource requirements (e.g. shelter and/or diet) for some species, resulting in alterations to the natural trophic structure and interspecific interactions. Baited videos provided a more efficient and non-extractive method for comparing fish assemblages and habitat associations of smaller bodied species and juveniles in a turbid environment.
Highlights
Marine embayments and estuaries provide important habitats during the life histories of many fish species [1,2,3]
Modified habitats have typically been shown to support a subset of fish species that occur in adjacent natural habitats with similar physical attributes, and in relatively higher or lower abundances depending on species-specific requirements for shelter, reproduction and diet [9]
Given Cockburn Sound is an important recruitment area for Pagrus auratus and Sillaginodes punctatus [10,32], our objective was to investigate whether baited videos or traps were the more effective method for assessing small-bodied fish assemblages to determine their composition, relative abundances and associations with four natural and two modified habitats
Summary
Marine embayments and estuaries provide important habitats during the life histories of many fish species [1,2,3]. Given the ecological importance of embayments and estuaries it is important to understand how such impacts influence their faunal assemblages. Results of studies comparing species richness, abundance and composition between natural and modified habitats (ranging from artificial reefs to piers) are inconsistent and have been shown to be influenced by the materials used in their construction and the sampling method [8]. Large habitat modifications could lead to significant changes in the ecological and/or physical (e.g. hydrodynamics) processes within these embayments and estuaries (e.g. influence spawning and recruitment processes, [10])
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
