E-Thesis 478 views 501 downloads
From conception to interpretation; a new angle on smart tags for reef inhabitants / LLOYD HOPKINS
Swansea University Author: LLOYD HOPKINS
DOI (Published version): 10.23889/SUthesis.59299
Abstract
Length and direction are the two parameters that define animal movement, from the scale of the limbs to whole-body animal navigation through their environment. However, although step lengths have been considered widely, the effect of angles is rarely documented. This thesis considers some of the way...
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Swansea
2022
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Wilson, Rory P. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa59299 |
| Abstract: |
Length and direction are the two parameters that define animal movement, from the scale of the limbs to whole-body animal navigation through their environment. However, although step lengths have been considered widely, the effect of angles is rarely documented. This thesis considers some of the ways in which directionality operates to define processes within marine communities, particularly reef-based inhabitants, using animal-attached technology. Rapid improvements in device power, size and utility has led to ubiquitous use of such technology in animal movement and behaviour research. Working within a setting of a proposed multi-species, mass tagging effort of a Red Sea coral reef’s inhabitants, this thesis works within the context of angles to evaluate the inherent challenges and areas of opportunities in studying both less- and more-mobile species. It begins by describing a novel system for attaching tags to the dorsal fin of elasmobranchs using a magnetic clip. The angles between the clip halves, as well as between fin and clip, determine the external forces applied to the system and, therefore, the ability of the clip to remain on the animal without causing injury. Despite significant progress in development, there is some way to go to finalise the system. In the second chapter the clip, equipped with a tri-axial accelerometer, was deployed on various captive shark species to investigate the behavioural implications of attachment. Negative reactions to attachment were most notable in whole-body roll angle, due to fleeting chafing behaviours, a reaction that would otherwise be missed by other common, non-angular, tag-derived measures. The thesis then examined the hypothesis that energy expenditure can be represented by rotational (and not necessarily dynamic) movements using invertebrates as a model. Static respirometry methods with spider conchs (Lambis truncata) showed this was valid, with important implications for our ability to quantify the energy expenditure of free-living, slow-moving animals. The next chapter found that spider conchs, despite being ostensibly relatively simplistic movers, have probabilistic movement rules, including in terms of directionality, predicted by previous movement as well as the ambient environment. Finally, gape angles of free-living giant clams (Tridacna maxima) on a Red Sea coral reef were used to infer the effect of anthropogenic noise on their behaviour, suggesting that post-tagging recovery was hindered by boat passes. |
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| Item Description: |
ORCiD identifier: https://orcid.org/0000-0001-5933-2083 |
| Keywords: |
Biologging; animal movement; animal behaviour; biology; life science; energetics; invertebrate; elasmobranchs; marine biology; tagging |
| College: |
Faculty of Science and Engineering |