Assessing Habitat Use by Snapper (Chrysophrys auratus) from Baited Underwater Video Data in a Coastal Marine Park.

Maria A Terres,Geoffrey R Hosack,Emma Lawrence,Michael D E Haywood,Russell C Babcock,Christopher J Fulton

doi:10.1371/journal.pone.0136799

Abstract

Baited Underwater Video (BUV) systems have become increasingly popular for assessing marine biodiversity. These systems provide video footage from which biologists can identify the individual fish species present. Here we explore the relevance of spatial dependence and marine park boundaries while estimating the distribution and habitat associations of the commercially and recreationally important snapper species Chrysophrys auratus in Moreton Bay Marine Park during a period when new Marine National Parks zoned as no-take or “green” areas (i.e., areas with no legal fishing) were introduced. BUV studies typically enforce a minimum distance among BUV sites, and then assume that observations from different sites are independent conditional on the measured covariates. In this study, we additionally incorporated the spatial dependence among BUV sites into the modelling framework. This modelling approach allowed us to test whether or not the incorporation of highly correlated environmental covariates or the geographic placement of BUV sites produced spatial dependence, which if unaccounted for could lead to model bias. We fitted Bayesian logistic models with and without spatial random effects to determine if the Marine National Park boundaries and available environmental covariates had an effect on snapper presence and habitat preference. Adding the spatial dependence component had little effect on the resulting model parameter estimates that emphasized positive association for particular coastal habitat types by snapper. Strong positive relationships between the presence of snapper and rock habitat, particularly rocky substrate composed of indurated freshwater sediments known as coffee rock, and kelp habitat reinforce the consideration of habitat availability in marine reserve design and the design of any associated monitoring programs.

Highlights

No-take marine reserves are spatial closures where all forms of extraction are banned
The result was 34 Marine National Park (MNP) Zones designated as no take areas, which we refer to as “green” zones, ranging in size from 38 to 12541 hectares designed to ensure adequate protection of each of the 16 habitat types identified within the Marine Park [42]
There is evidence in Moreton Bay that coffee rock habitats may be targeted by some fishers [51]

Summary

Introduction

No-take marine reserves are spatial closures where all forms of extraction are banned. They have been promoted as assisting in reducing over-fishing [1], conserving marine biodiversity, restoring populations of endangered species [2] and in restoring lost trophic structure [3]. Over the past few decades, marine reserves have been increasingly recognized as a key component of marine conservation strategies [4, 5]. While marine reserves are generally found to be an effective means of achieving positive conservation outcomes, their success in this regard depends on a range of interacting factors such as being no take, well enforced, old (at least 10 years), large (greater than 100km2), and isolated by deep water or sand [6], as well as containing suitable habitat types [7]. The increasing number and extent of marine reserves reinforces the need for efficiently designed monitoring and information systems that inform their management

Methods

Results

Conclusion