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Red snapper Lutjanus campechanus (N ϭ 54) were tagged and tracked on 12 artificial reefs in the northeastern Gulf of Mexico. Fish were surgically implanted with ultrasonic transmitters and monitored with Vemco remote receivers and Sonotronics surface receivers from August 2000 to July 2004. Four fish were manually tracked from the surface overnight, and their positions were recorded every hour for either 9 or 16 h. The total length of fish tagged was 589 Ϯ 14 mm (mean Ϯ SE). The number of detections by the remote receivers was 290,340 Ϯ 44,696. By the end of this study, 5 fish were still being tracked, 8 fish had been lost immediately after tagging, 15 fish had been caught by fishers, and 26 fish had been lost after extended tracking. Red snapper were resident on artificial reefs for 218 Ϯ 28 d, and residence time ranged from 1 to 595 d. We estimated that most (67%) of the tagged red snapper showed long-term residence (117-595 d), 13% were resident for 8-91 d, and 20% left the tagging site soon after release (Ͻ4 d). Fish were resident on the same artificial reef over all seasons (winter, spring, summer, and fall), and no seasonal changes in proximity to the reef were detected. Red snapper left the receiver range (1.6 km) for short time periods; for example, fish 25 left the reef 285 times for 1-4 h over a 335-d period. However, all fish spent most of their time (98%) within the receiver range. We detected diel changes in proximity to the reefs (N ϭ 8), but patterns varied. In this study, red snapper showed high site fidelity over long time periods, which suggested that artificial reefs provided suitable habitat for red snapper in the northeastern Gulf of Mexico.

Red Snapper Lutjanus campechanus are generally associated with artificial reef habitats in the northern Gulf of Mexico, but whether this association results in fish production is still controversial. Information on fine‐scale habitat use patterns would be helpful in evaluating this. Little is known about the fine‐scale movement patterns of Red Snapper around artificial reefs. The present study examined fine‐scale (∼1‐m accuracy) movements of Red Snapper with the Vemco VR2W Positioning System. This system enabled continuous monitoring of tagged fish from 100 to 694 d. Locations of individual fish were recorded approximately every 10 min and totaled over 1.9 million accurate locations of Red Snapper from August 2010 through May 2012. Red Snapper showed close association with the reef structure (mean ± SD distance = 26.3 ± 35.4 m) but differential habitat use in relation to both diel and seasonal periods. Home range areas (95% kernel density estimates [KDE]) were significantly larger during day than night periods and showed the lowest area use at dawn and dusk. Monthly home ranges (95% KDE) and core areas (50% KDE) were significantly larger in spring, summer, and fall than in winter and were significantly correlated with water temperature, suggesting colder winter temperatures reduced Red Snapper movement. Home range area was significantly correlated with fish size (407–590 mm standard length), and the fish in this study showed the highest site fidelity (88% still present after >10 months) of any Red Snapper in other previous studies. Red Snapper also showed use of multiple reefs within the monitoring area, as home ranges (95% KDE) showed a second peak around other artificial reefs. The high site fidelity, long‐term use, and concentrated use of multiple artificial reefs confirm the importance of structured habitat for Red Snapper. Received September 1, 2013; accepted February 27, 2014

Residence time, site fidelity and movements for red snapper Lutjanus campechanus (Lutjanidae) were estimated from long-term telemetry monitoring (December 2005 to June 2010) at 6 sites (1 natural and 5 artificial reefs) in the northeastern Gulf of Mexico. Each site consisted of an array of 5 receivers, with 1 at the center reef site and 4 receivers placed 1100 m north, south, east and west of center (2 km radius detection area). Throughout the study, a stationary control transmitter was located 400 m south of the center receiver at each site to estimate changes in detection rates from environmental factors. These receiver arrays enabled fishery independent estimations of fishing mortality, natural mortality and emigration. Event analysis was used to estimate site fidelity and residence, based on right-censoring fishing and natural mortality. Median residence time was 542 d, ranging from 1 to 1099 d, with 72% of fish staying at least 1 yr at the site. Some fish (n = 12) showed seasonal and directed movements to other sites (up to 8 km away) and returned to original sites up to 7 mo later. Diel movements away from the structure tended to occur at night. Site fidelity and residence times of red snapper in the present study were greater than in any previous study and show the importance of artificial reefs for this species. KEY WORDS: Site fidelity · Acoustic telemetry · Seasonal movements · Red snapper · Artificial reefs Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 437: [183][184][185][186][187][188][189][190][191][192][193][194][195][196][197][198][199][200] 2011 residence times and movement patterns around natural and artificial structures.The residency of red snapper Lutjanus campechanus on natural and artificial structures has been examined by several methods, with varying results. Early studies examined the distribution of red snapper catches relative to habitat type, depth and season (Camber 1955, Moseley 1966, Bradley & Bryan 1975, and more recent studies have used mark-recapture (Beaumariage 1969, Fable 1980, Szedlmayer & Shipp 1994, Watterson et al. 1998, Patterson et al. 2001, Patterson & Cowan 2003, Diamond et al. 2007, Strelcheck et al. 2007) and ultrasonic telemetry (Szedlmayer 1997, Peabody 2004, Szedlmayer & Schroepfer 2005, Schroepfer & Szedlmayer 2006 to estimate site fidelity and movements. For the most part, these studies indicate red snapper show some affinity to both natural and artificial structures, but estimates of site fidelity and residence times seem to vary by methods (mark-recapture vs. telemetry), habitat type (e.g. small artificial reefs, oil-gas platforms and natural reefs), hurricanes, transmitter detection range, fish size and study length (Diamond et al. 2007, Gallaway et al. 2009).Recent mark-recapture studies of relatively small red snapper (mean: < 400 mm TL) off Alabama obtained different results even with similar methods (Patterson & Cowan 2003, Strelcheck et al. 2007. Patterson & Cowan (2003) estimated site fid...

Several previous studies have attempted to correlate habitat complexity and reef fish species diversity. These studies have mostly examined natural reef systems, but results differed. To examine this relation, we built 1 m 2 habitats with 20 replicates of five complexity levels from July to August 2001 in the northeastern Gulf of Mexico (n=100). In June and July 2002, we built new habitats using the 2001 design, but also added a sixth complexity level (n=120). In order of increasing complexity these included: cage, shell, cage-shell, block-shell, cage-block-shell, and shellblock-pyramid habitats. Most fish in both years were juveniles and included species common to reef structures in the northeastern Gulf of Mexico. In 2001, we identified 26 fish species, and the dominant species was red snapper, Lutjanus campechanus (41%), followed by rock sea bass, Centropristis philadelphica (23%), and sand perch, Diplectrum spp. (14%). In 2002 we identified 36 species, and the dominant species was tomtate, Haemulon aurolineatum (36%), followed by Diplectrum spp. (19%), and L. campechanus (13%). In 2001, species diversity and richness were significantly (P < 0.05) higher on more complex habitats (H¢=1.7, S=11-12) compared to less complex habitats (H¢=0.8-1.0, S=4-9). In 2002, patterns among diversity, richness and reef complexity were less apparent with only the least complex habitats shell and cage showing significantly lower values. In both years, multidimensional scaling grouped by complexity levels with cage and shell habitats showing the clearest separation from other habitat types. Also, with few exceptions (only 8%) analysis of similarities showed significant (P < 0.05) differences in fish communities across complexity levels. Although community composition varied between years, this study provided evidence to support the hypothesis that habitat complexity increased reef fish species diversity.

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