Tracking and mapping sun-synchronous migrations and diel space use patterns of Haemulon sciurus and Lutjanus apodus in the U.S. Virgin Islands

Abstract

The spatially explicit diel movement patterns of fish using coral reef ecosystems are not well understood, despite the widespread recognition that many common species undergo distinct migrations to utilize different resources during night and day. We used manual acoustic telemetry coupled with global positioning technology to track the detailed spatially explicit daily movements (24 h) of multiple individuals of two common Caribbean fish species, Haemulon sciurus (bluestriped grunt) and Lutjanus apodus (schoolmaster snapper). Movement pathways and day and night activity spaces were mapped and quantified in a Geographic Information System (GIS). Directional sun-synchronous migrations occurred close to astronomical sunset and sunrise. Site fidelity within day and night activity spaces was high. Nine of twelve individuals exhibited overlap of day and night activity spaces and three fish (L. apodus) exhibited complete spatial segregation. Night activity spaces (H. sciurus: 11,309±3,548 m 2 ; L. apodus: 9,950±3,120 m 2 ) were significantly larger than day activity spaces (H. sciurus: 2,778±1,979 m 2 ; L. apodus: 1,291±636 m 2 ). The distance between sequential position fixes (step lengths) was significantly greater at night than day, indicative of nocturnal foraging and day resting behavior. Integrating acoustic telemetry, GIS techniques and spatial statistics to study fish movement behavior revealed both individual variability and some broader generality in movement paths and activity spaces suggestive of complex underlying behavioral mechanisms influencing diel movements.

Ecological connectivity and niche differentiation between two closely related fish species in the mangrove-seagrass-coral reef continuum

“…A tagging study by Kaunda-Arara & Rose (2004) showed that adult L. fulviflamma swam distances up to 2 km, confirming that this species is capable of migrating between coral reefs and seagrass beds. Feeding migrations from coral reefs to adjacent seagrass beds have been documented for other snappers in the Florida Keys, USA (Luo et al 2009), and in the US Virgin Islands (Hitt et al 2011). The lack of potential food items from Mafia coral reefs in our study, however, limit our results, and further studies, tagging and following large individuals on coral reefs, are needed to confirm feeding migrations between coral reefs and seagrass beds by L. fulviflamma.…”

Do tabular corals constitute keystone structures for fishes on coral reefs?

“…The 'activity spaces' of large reef fishes that shelter (rest) during the daytime are typically smaller than at night when they forage (Nanami and Yamada 2009;Hitt et al 2011). Even so, it is likely that activity spaces of large reef fishes at rest during the daytime exceeded the areas covered by transects in this study (Nanami and Yamada 2009;Hitt et al 2011). The observed transect-level effects may, therefore, have wider implications.…”

“…The home range utilisation patterns of an individual fish may vary greatly depending upon its activity, such as resting, foraging or spawning (Pittman and McAlpine 2003). The 'activity spaces' of large reef fishes that shelter (rest) during the daytime are typically smaller than at night when they forage (Nanami and Yamada 2009;Hitt et al 2011). Even so, it is likely that activity spaces of large reef fishes at rest during the daytime exceeded the areas covered by transects in this study (Nanami and Yamada 2009;Hitt et al 2011).…”

“…A more recent study in Saba Marine Park, the Netherlands Antilles, also observed a mixed response of large reef fishes to the loss of coral cover, again with a general decline in carnivores (Noble et al 2013). It is unlikely, however, that these responses relate solely to declines in prey items because several families of carnivorous large reef fishes move off Coral Reefs the reef to feed (Nanami and Yamada 2009;Hitt et al 2011). The results of the present study may help to explain these variable results as it appears the responses of large reef fishes to the loss of tabular structure differs at the family level, with three identifiable groups: obligate, facultative and non-structure users.…”

Effect of current and daylight variations on small-pelagic fish aggregations (Selar crumenophthalmus) around a coastal fish aggregating device studied by fine-scale acoustic tracking

“…Living Resour. 26, 63-68 (2013) assessed the importance of these quantities (in particular the effect of current on the position of fish in relation to the floating object) and sun-synchronous space-use patterns have been recently identified in other species (Hitt et al 2011), so far no studies have been able to quantify their effects on fish aggregations around FADs.…”