Detecting conservation benefits of marine reserves on remote reefs of the northern GBR
Access Status
Authors
Date
2017Type
Metadata
Show full item recordCitation
Source Title
ISSN
School
Collection
Abstract
The Great Barrier Reef Marine Park (GBRMP) is the largest network of marine reserves in the world, yet little is known of the efficacy of no-fishing zones in the relatively lightly-exploited remote parts of the system (i.e., northern regions). Here, we find that the detection of reserve effects is challenging and that heterogeneity in benthic habitat composition, specifically branching coral cover, is one of the strongest driving forces of fish assemblages. As expected, the biomass of targeted fish species was generally greater (up to 5-fold) in no-take zones than in fished zones, but we found no differences between the two forms of no-take zone: ‘no-take’ versus ‘no-entry’. Strong effects of zoning were detected in the remote Far-North inshore reefs and more central outer reefs, but surprisingly fishing effects were absent in the less remote southern locations. Moreover, the biomass of highly targeted species was nearly 2-fold greater in fished areas of the Far-North than in any reserve (no-take or no-entry) further south. Despite high spatial variability in fish biomass, our results suggest that fishing pressure is greater in southern areas and that poaching within reserves may be common. Our results also suggest that fishers ‘fish the line’ as stock sizes in exploited areas decreased near larger no-take zones. Interestingly, an analysis of zoning effects on small, non-targeted fishes appeared to suggest a top-down effect from mesopredators, but was instead explained by variability in benthic composition. Thus, we demonstrate the importance of including appropriate covariates when testing for evidence of trophic cascades and reserve successes or failures.
Related items
Showing items related by title, author, creator and subject.
-
Wenger, A.; Williamson, D.; da Silva, E.; Ceccarelli, D.; Browne, Nicola; Petus, C.; Devlin, M. (2015)Near-shore marine environments are increasingly subjected to reduced water quality, and their ability to withstand it is critical to their persistence. The potential role marine reserves may play in mitigating the effects ...
-
McLean, B.; Langlois, T.; Harvey, Euan; Shortland-Jones, H.; Stevens, R. (2015)Despite calls for networks of no-take sanctuary zones of ‘moderate size’ (10–100 km2) to meet both conservation and resource management objectives, there have been a plethora of small (1–5 km2) and very small (< 1 km2) ...
-
Moore, Cordelia; Cappo, M.; Radford, B.; Heyward, A. (2017)This paper provides a first assessment of fish communities associated with the submerged oceanic banks and shoals in north-west Australia. Until recently, little was known about these deeper and more inaccessible reefs. ...