Follow-up monitoring to further evaluate the effects of transdermal satellite tags on humpback whales
Abstract
Satellite tagging is an important technique for studying the spatial ecology of whales, including their critical habitats and overlap with human activities. However, all large whale satellite tags are invasive to some extent and there are on-going concerns about possible adverse effects on individuals and populations. In 2011, a designed follow-up study was initiated in the Gulf of Maine to assess the performance of consolidated transdermal tags on humpback whales (Megaptera novaeangliae) as well as their impacts on tagged individuals. The project involves well-documented deployments on well-studied individuals and intensive follow-up monitoring to evaluate the fate of the tags and the tagged animals. To date, this work has identified specific causes of early tag failure, quantified short-, medium- and longer-term effects on individuals and has prompted changes to tag design. However, the amount of follow-up coverage varies across individuals and tag designs, and there are on-going questions that require additional data and analyses. This includes the potential for consolidated transdermal tags to impact humpback whale calving rates and the degree to which a recent tag design has lessened the potential for adverse effects. We propose to conduct ten dedicated research cruises in 2020 to re-locate previously tagged whales to augment and help to maintain this long-term follow-up monitoring program. We will use a combination of mark-recapture data and progesterone-based pregnancy testing to evaluate the reproductive rates of tagged females versus a control group. We will also use systematic tag site scoring and statistical analyses to evaluate whether a new tag design has lessened the risk of individual impact. Follow-up monitoring is now recognized to be an important component of satellite tag development and evaluation. The proposed work is particularly important for determining the risk of tagging in small populations of management concern, as well as for on-going efforts to develop effective, minimally invasive satellite tag designs.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 31, 2020
- Source ID
- N000142012652
Entities
People
- Jooke Robbins
Organizations
- Center for Coastal Studies
- Office of Naval Research
- United States Navy