File(s) under permanent embargo
Influence of spear guns, dive gear and observers on estimating fish flight initiation distance on coral reefs
journal contribution
posted on 2023-05-18, 18:08 authored by Januchowski-Hartley, FA, Kirsty NashKirsty Nash, Lawton, RJFish flight initiation distance (FID) is emerging as a useful metric of the response of fishes to fishing, with significant differences in FID demonstrated between fished and no-take marine reserves. However, studies investigating FID vary in methodology, and many of the potential confounding effects inherent to in-water estimation of FID have yet to be investigated. Here we examined relative effects of spear guns, dive gear, observer bias and protection status on FID estimates. Three observers estimated FID of parrotfishes in both a fished area and a no-take marine reserve, via both SCUBA and free-diving, and with and without a simulated spear gun (8 treatments). We found that FID was significantly influenced by protection status, increasing by 141 cm on average in the fished area compared to the no-take marine reserve, but not by dive type or spear gun presence. While there were some differences between observers’ mean estimate of FID, there was no evidence of observer bias, nor were there any significant differences in the precision of FID estimates between observers. Overall, management status explained almost 60% of the variation in FID estimates, while observers accounted for only 4%.
History
Publication title
Marine Ecology - Progress SeriesVolume
469Pagination
113-119ISSN
0171-8630Department/School
Institute for Marine and Antarctic StudiesPublisher
Inter-ResearchPlace of publication
Nordbunte 23, Oldendorf Luhe, Germany, D-21385Rights statement
Copyright 2012 Inter-ResearchRepository Status
- Restricted