Green zone gains for coral trout complicated by cyclone impacts and spawning behaviour
Project Leader: Dr Hugh Sweatman, AIMS
Previous MTSRF-funded research by this project demonstrated spectacular increases in coral trout abundance inside green (no-take) zones compared with similar blue-zoned (fished) reefs. However, the results of this year’s surveys were complicated by the impacts of Cyclone Hamish on survey sites on the central and southern Great Barrier Reef. This was particularly evident in the Swains and Capricorn-Bunker regions, where previously, coral trout were most abundant and the difference between fished (blue) and no-take (green) reefs was greatest. Thus, when viewed across all 28 matched pairs of reefs across five Reef regions, no consistent differences in relative numbers or relative biomass of coral trout were detectable six years after the rezoning. An additional complicating factor was the timing of the survey – reefs in the Swains and Capricorn-Bunker regions were surveyed in October and January, and there was evidence that the coral trout on some reefs were spawning. Spawning occurs around the new moon in summer months, and involves coral trout moving from their normal ranges and aggregating at particular sites on the reef, which may result in them being “missed” by standard sampling techniques.
Final project report for Year 3 (2008/2009). Includes the results of surveys of 42 transects over 26 dive sites on fifteen reefs of the Great Barrier Reef. Coral cover of the reefs surveyed has been either consistently increasing (40%) or fluctuating (44%) since the first surveys were carried out by Reef Check Australia. Results are listed by dive site, where (a) coral cover has increased; (b) coral cover has decreased; (c) coral cover has fluctuated; and (d) coral cover remains largely stable.
Reef Check Australia trains volunteers to coordinate community monitoring and reporting of the status and trends of 25 key reef tourism sites. Through regular visitation, Reef Check is able to resolve seasonal patterns and more closely observe phenomena such as outbreaks of pests and disease. Outputs from this community monitoring feeds into MTSRF Project 1.1.2. This document provides a report on several workshops convened by Reef Check in January and February of 2007 to gain dive operators' feedback on Reef Check activities and to review the current monitoring sites in light of operator knowledge.