Mar Biol DOI 10.1007/s00227-011-1707-6 ORIGINAL PAPER Aggregations and oVshore movements as indicators of spawning activity of boneWsh (Albula vulpes) in The Bahamas 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 · JeV B. Koppelman · David P. Philipp Received: 2 November 2010 / Accepted: 16 April 2011 © Springer-Verlag 2011 Abstract To identify the timing and location of spawning of the Exuma Sound. Localized movements of the large activity for boneWsh (Albula spp.) in the Bahamian archi- schools of boneWsh (often >1,000 Wsh) at these presumptive pelago, we used an acoustic telemetry array spanning pre-spawning aggregation sites included brief trips (<8 h) 44 km2 of shallow tidal creeks, Xats, and adjacent deeper just after sunset until just prior to sunrise to the abyssal wall coastal waters near Cape Eleuthera. In two successive at the edge of the Exuma Sound (i.e., >1,000 m depth). years, we surgically implanted transmitters in male and Tagged boneWsh detected at these aggregation sites were female boneWsh (n = 60) and examined their movement subsequently detected back in the tidal creeks and coastal patterns within the array. Eight boneWsh surgically Xats shortly after new and full moons and remained at these implanted with transmitters as part of an earlier study were more typical shallow sites (i.e., <2 m depth). Although we also tracked. In 2009, the telemetry information was com- did not directly observe spawning events, we did observe plemented with snorkeling observations, underwater video, ventral nudging and porpoising behaviors, which are poten- and manual tracking of the same acoustically tagged Wsh, as tially associated with courtship. Timing of the observed well as Wsh (n = 3) gastrically implanted with continuous movements and possible courtship behaviors was coinci- transmitters. During a period of 4–7 days spanning the full dent with periods when gametes were well developed. Col- and new moons, primarily between October and May, lectively, our study provides the Wrst objective evidence boneWsh moved from their typical shallow Xats and aggre- suggesting that the aggregation and seasonal migration of gated at sites in close proximity to the deep water drop-oV boneWsh to deep shelf environments during certain moon phases is for spawning. Communicated by D. Righton. A. J. Danylchuk (&) · C. R. Haak T. L. Goldberg Department of Environmental Conservation, Department of Pathobiological Sciences, School of Veterinary University of Massachusetts Amherst, 311 Holdsworth Hall, Medicine, University of Wisconsin, Madison, WI, USA 160 Holdsworth Way, Amherst, MA 01003, USA e-mail: [email protected] C. D. Suski · A. D. Shultz Department of Natural Resources and Environmental Sciences, A. J. Danylchuk · S. J. Cooke · T. L. Goldberg · C. D. Suski · University of Illinois, Urbana, IL, USA K. J. Murchie · S. E. Danylchuk · A. D. Shultz · C. R. Haak · E. J. Brooks · A. Oronti · J. B. Koppelman · D. P. Philipp E. J. Brooks Flats Ecology and Conservation Program, School of Marine Science and Engineering, Cape Eleuthera Institute, Eleuthera, The Bahamas University of Plymouth, Plymouth, UK S. J. Cooke · K. J. Murchie J. B. Koppelman · D. P. Philipp Fish Ecology and Conservation Physiology Laboratory, Illinois Natural History Survey, Institute for Natural Resource Department of Biology, Carleton University, Ottawa, ON, Canada Sustainability, Champaign, IL, USA S. J. Cooke Institute of Environmental Science, Carleton University, Ottawa, ON, Canada 123 Mar Biol Introduction coastal habitats could also negatively aVect movements to spawning sites, spawning behavior, and ultimately the sus- Fish undertake migrations to Wnd food (Choat 1982; Block tainability of Wsh stocks (Turner et al. 1999; Musick et al. et al. 2001), avoid predators (Gillian and Fraser 2001), 2000; Roberts et al. 2002; Claydon 2004). avoid unfavorable environmental conditions (Winemiller BoneWsh (Albula spp.) inhabit shallow tropical and sub- and Jepsen 1998; Albanese et al. 2004), and to reach tropical Xats worldwide (Alexander 1961), and their wari- spawning sites (McCormick et al. 1998; Fox et al. 2000; ness and speed make them one of the most prized groups of Meyer et al. 2007). The spatial and temporal scale of these marine Wshes among recreational anglers (Kaufmann migration patterns can range from daily distances of several 2000). Due to their popularity, boneWsh are the focus of a hundred meters (Domeier and Colin 1997) to annual migra- tourism-based recreational angling industry that provides tions over thousands of kilometers (Jones et al. 1984). Such substantial revenue to coastal communities (Ault et al. migration patterns in Wshes can be highly predictable and 2008; Danylchuk et al. 2008). Because boneWsh often have been correlated with a range of abiotic (Quinn et al. reside in large schools and feed mostly on benthic inverte- 1996; Sims et al. 2004) and biotic (Gross et al. 1988) envi- brates (Colton and Alevizon 1983a); this group of Wshes ronmental cues. From an evolutionary perspective, migra- may also play an integral role in the ecology of shallow tory behavior in Wshes, as well as many other animals marine Xats (Ault et al. 2008). Despite their importance, (Frank et al. 1998; Dingle and Drake 2007), is adaptive there is limited information on the life history and ecology because the energetic and life history costs of relocating, of boneWsh, especially when compared to other recreation- even over vast distances, are outweighed by the beneWts of ally angled marine species (e.g., striped bass, Morone saxa- residing in a more suitable location, even if only temporar- tilis, Rulifson and Dadswell 1995; Atlantic tarpon, ily (Huntingford 1993; Claydon 2004). Megalops atlanticus, Ault et al. 2008). Many species of marine Wsh migrate to predictable loca- One aspect of the life history of boneWsh that has proven tions and speciWc times to form aggregations for the pur- particularly diYcult to study is their reproductive ecology pose of spawning (Domeier and Colin 1997; Claydon (Ault et al. 2008). Although some published information on 2004). Transient spawning aggregations are the gathering the life history of boneWsh is now confounded by recent of reproductively active conspeciWcs at densities and/or studies indicating that a greater number of species exist numbers higher than those found in the area of the aggrega- throughout their range than was previously thought (Bowen tion during non-reproductive periods (Domeier and Colin et al. 2008), general Wndings suggest that boneWsh move 1997; Claydon 2004). A well-studied group of Wshes that from their typical Xats habitat to form pre-spawning and form transient, site-speciWc spawning aggregations are the spawning aggregations elsewhere (Johannes 1978; Johan- Serranidae, such as the red hind (Epinephelus guttatus; nes and Yeeting 2000). In Palau, local knowledge of Wshers Sadovy et al. 1994; Beats and Friedlander 1998) and indicated that Albula glossodonta form large pre-spawning Nassau grouper (Epinephelus striatus; Bolden 2000; Whay- aggregations in coastal lagoons 1–3 day prior to the full len et al. 2004). Documenting the spatial and temporal moon and then the Wsh migrate to the outer reef edge to dynamics of grouper, spawning aggregations has helped to spawn in large numbers (Johannes 1978; Johannes and characterize the biology and ecology of this important Yeeting 2000). Movement of these boneWsh was noted to group of coral reef Wshes (Whaylen et al. 2004), as well as occur in the late afternoon and early evening (i.e., 1600– highlighted the need to learn more about other marine 2200 h) concurrent with the high spring tides (Johannes and Wshes that aggregate to spawn (Sadovy and Domeier 2005). Yeeting 2000). In addition, boneWsh caught from the pre- Understanding the dynamics of spawning aggregations spawning aggregations had body cavities Wlled with also has important implications for the conservation and gonads, whereas Wshers reported boneWsh being spent once management of Wsh stocks, since Wsh that aggregate at spe- Wsh returned to the lagoon (Johannes and Yeeting 2000). ciWc times and locations can be especially vulnerable to Knowledge of these “spawning runs” by local Wshers, as intense Wshing pressure and overharvesting (Coleman et al. well as the disruption of movement corridors from shore- 1996; Domeier and Colin 1997; Roberts and Hawkins line modiWcations, are thought to have resulted in the 1999; Musick et al. 2000; Sala et al. 2001). Even non- severe depletion of local boneWsh stocks in Palau (Johannes extractive recreational catch-and-release Wsheries could and Yeeting 2000; Friedlander et al. 2008). have negative eVects on Wsh as they move to or reside at Other evidence regarding the timing and location of aggregation sites, especially if the stresses associated with spawning activity in boneWsh comes from measures for being captured and handled inXuence spawning success reproductive condition, larval dynamics, and general move- (Hutchings et al. 1999; Lowerre-Barbieri et al. 2003; Suski ment patterns. By measuring the gonadosomatic index et al. 2007). Given the site-speciWc nature of many spawn- across all moon phases for Albula glossodonta from Pal- ing aggregations, the modiWcation and destruction of myra Atoll, Friedlander et al. (2008) showed that although 123 Mar Biol males were ripe throughout the lunar cycle and throughout waters of the Exuma Sound. The substrate along the north the year, females were most reproductively active around shore of Cape Eleuthera is a mosaic of habitat types ranging full moons. In the Western Atlantic, however, seasonal from sand Xats, seagrass beds (Thallassia testidunium and trends in the allocation of energy to gonad development and Syringodium Wliforme), algal and sponge plains, exposed vitellogenisis suggest that spawning occurs in winter and calcium carbonate hard bottom, and small patch reefs, early spring (Crabtree et al. 1997; Posada et al. 2008; Mur- while the substrate between the western end of Cape Eleu- chie et al.