Marine & Environmental Sciences Faculty Articles
Document Type
Article
Publication Date
2011
Publication Title
Marine and Coastal Fisheries
ISSN
1942-5120
Volume
3
Issue/No.
1
First Page
353
Last Page
365
Abstract
Pop-up satellite archival tags (PSATs) were deployed on 19 sailfish Istiophorus platypterus captured in the southern Gulf of Mexico and Florida Straits between 2005 and 2007 on commercial pelagic longline gear (n = 18) and recreational rod-and-reel gear (n = 1). The data from three tags indicated mortality events and were excluded from subsequent analyses. All PSATs were programmed to collect pressure (depth), temperature, and light-level data for 10 d at approximately 90-s intervals. These transmitted point data subsequently allowed the reconstruction of vertical movement patterns. The remaining 16 PSAT data sets indicate that sailfish are primarily associated with the upper surface waters within the top 20m (75.7% of total time during the day versus 46.7% at night) but undertake numerous short-duration vertical movements below the local mixed layer to depths of 50–150 m, presumably to feed. Analyses of 2,279 individual vertical movements among all 16 tagged sailfish indicated two distinct types (short-duration “V” and longer-duration “U” movements) similar to those reported for white marlin Kajikia albida. Sailfish also exhibited movement type differences between diel periods (having higher proportions of V movements in daytime), suggesting directed foraging at depth. Although short-duration movement to depths by these tagged fish contribute a small percentage of the total time at depth, these depths overlap with themonitored shallow-set pelagic longline gear depths actively targeting swordfish by the vessel in the local fishery. These results suggest that time-at-depth histograms alone may be insufficient to capture feeding motivations at depth and, therefore, true interaction potentials between individual sailfish and pelagic longline gear.
Additional Comments
Gulf States Marine Fisheries Commission grant #: BILLFISH-2005-009
NSUWorks Citation
David W. Kerstetter, Shannon Michael Bayse, Jenny Fenton, and John E. Graves. 2011. Sailfish Habitat Utilization and Vertical Movements in the Southern Gulf of Mexico and Florida Straits .Marine and Coastal Fisheries , (1) : 353 -365. https://nsuworks.nova.edu/occ_facarticles/564.
ORCID ID
0000-0002-4440-8767
ResearcherID
I-5396-2012
DOI
10.1080/19425120.2011.623990
Comments
©American Fisheries Society 2011