Aggregations and offshore movements as indicators of spawning activity of bonefish (Albula vulpes) in The Bahamas

• DOI: 10.1007/s00227-011-1707-6
• Publication Date: 2011-05-05T07:20:55Z
• Authors: Andy J. Danylchuk; Steven J. Cooke; Tony L. Goldberg; Cory D. Suski; Karen J. Murchie; Sascha E. Danylchuk; Aaron D. Shultz; Christopher R. Haak; Edd J. Brooks; Annabelle Oronti; Jeff B. Koppelman; David P. Philipp
• Keywords: 0106 biological sciences; 14. Life underwater; 01 natural sciences

To identify the timing and location of spawning activity for boneWsh (Albula spp.) in the Bahamian archi- pelago, we used an acoustic telemetry array spanning 44 km 2 of shallow tidal creeks, Xats, and adjacent deeper coastal waters near Cape Eleuthera. In two successive years, we surgically implanted transmitters in male and female boneWsh (n = 60) and examined their movement patterns within the array. Eight boneWsh surgically implanted with transmitters as part of an earlier study were also tracked. In 2009, the telemetry information was com- plemented with snorkeling observations, underwater video, and manual tracking of the same acoustically tagged Wsh, as well as Wsh (n = 3) gastrically implanted with continuous transmitters. During a period of 4-7 days spanning the full and new moons, primarily between October and May, boneWsh moved from their typical shallow Xats and aggre- gated at sites in close proximity to the deep water drop-oV of the Exuma Sound. Localized movements of the large schools of boneWsh (often >1,000 Wsh) at these presumptive pre-spawning aggregation sites included brief trips ( 1,000 m depth). Tagged boneWsh detected at these aggregation sites were subsequently detected back in the tidal creeks and coastal Xats shortly after new and full moons and remained at these more typical shallow sites (i.e., <2 m depth). Although we did not directly observe spawning events, we did observe ventral nudging and porpoising behaviors, which are poten- tially associated with courtship. Timing of the observed movements and possible courtship behaviors was coinci- dent with periods when gametes were well developed. Col- lectively, our study provides the Wrst objective evidence suggesting that the aggregation and seasonal migration of boneWsh to deep shelf environments during certain moon phases is for spawning.