Defense Date

12-8-2022

Document Type

Thesis

Degree Type

Master of Science

Degree Name

Marine Science

First Advisor

David Kerstetter, Ph.D.

Second Advisor

Steven Kessel, Ph.D.

Third Advisor

Derek Burkholder, Ph.D.

Keywords

Negaprion brevirostris, lemon shark, vertical patterns, diel patterns, coastal, habitat use

Abstract

The lemon shark (Negaprion brevirostris) is a large sub-tropical species found in the western Atlantic Ocean from Virginia to Brazil, including The Bahamas and Caribbean Sea. Previous studies on habitat utilization were conducted on juveniles in The Bahamas, but little is known about vertical depth and temperature preferences of adults. Given the species’ risk to overexploitation and habitat degradation, the IUCN Red List recently listed lemon sharks as Vulnerable. Pop-up satellite archival tags (PSATs) were deployed on lemon sharks (n=7) in 2008 and 2009 off Jupiter, Florida (n=6; two females, four males) and Tiger Beach, Bahamas (n=1; one female) for programmed periods ranging from 10 days to 120 days. All PSAT tagged sharks were also fitted with acoustic tags associated with the Florida Atlantic Coast Telemetry (FACT) Network array. All sharks demonstrated similar day and night patterns across the deployment period regardless of location or sex. A male tagged in Jupiter crossed the Gulf Stream, and the tag detached near Tiger Beach while a female tagged at Tiger Beach was recorded on the acoustic array in Florida the following year– only the third and fourth documented case of a lemon shark crossing the Gulf Stream. The same sharks that crossed the Gulf Stream also periodically went to depths below 100 m with a maximum depth of 176 m. Finally, all tagged sharks were present around Jupiter in the winter months from December to May and absent from June to November. This study has demonstrated a gap in vertical habitat utilization as well as the management practices associated.

Download
Share Feedback

Share

COinS