Fig 1.
Map of the study area showing the outline of the Ningaloo Coast World Heritage Area in Western Australia, and key reef manta ray Mobula alfredi monitoring areas: Bateman Bay to the north of the Coral Bay township, waters to the western side of Cape Range National Park and the northern end of the Exmouth Gulf near Exmouth township.
Figure created using the R package ‘marmap’ [44] with bathymetric data from the ETOPO1 database [45] and the marine component of protected area bounds from The World Database on Protected Areas [46]. Major reef features were added in Adobe Photoshop, from geographically aligned Landsat-8 imagery courtesy of the U.S. Geological Survey.
Fig 2.
Images of the wounds from Days 0, 17, 33, 42 and 295 (A-E respectively) showing the fresh wound, incremental healing and near stable wounds on reef manta ray Mobula alfredi #0018.
On the right are close up images of Day 0 (i) showing severed cartilage, Day 7 (ii) (time not used in calculations) showing the start of healing, and Day 295 (iii) showing near complete healing with concave scars. The red arrows in (i) indicate the protocol for measuring each wound where the distance from the top of the wound to the mid-point between the adjacent sides at the extremity was used to indicate wound length.
Fig 3.
Wound healing rates from reef manta ray Mobula alfredi #0018.
The wound length (mm) and percentage of wound healed over time, with Day 0 representing the first observation of the animal with fresh (severed cartilage and red tissue) wounds. A negative exponential model was fit to the data (y = 15.4e-0.0149x + 0.956, pseudo-r2 = 0.96).
Fig 4.
Examples of clear predation events on reef manta rays Mobula alfredi.
Yellow arrows indicate the bite site on the fins.
Table 1.
The location and origin of scars on reef manta rays Mobula alfredi in the Ningaloo Coast World Heritage Area.
Values are proportions of the images in the total photo identification database from the 1071 individual reef manta rays as of July 2018. Values in parentheses are database proportions (805 individuals) assigned prior to injury to manta ray #0018. Descriptions of wound types in parentheses refer to the scars with undetermined causes.