Mature sex woman Shark Bay

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Information on the spatial ecology of reef sharks is critical to understanding life-history patterns, yet gaps remain in our knowledge of how these species move and occupy space. studies have focused on offshore reefs and atolls with little information available on the movement and space use of sharks utilising reef habitats closer to shore. Cross-shelf differences in physical and biological properties of reefs can alter regional ecosystem processes resulting in different movement patterns for resident sharks.

Passive acoustic telemetry was used to examine residency, space use and depth use of 40 blacktip reef sharks, Carcharhinus melanopteruson an inshore reef in Queensland, Australia, and assess temporal or biological influences. All sharks showed strong site-attachment to inshore reefs with residency highest among adult females. Sharks exhibited a sex-based, seasonal pattern in space use Mature sex woman Shark Bay males moved more, occupied more space and explored new areas during the reproductive season, while females utilised the same amount of space throughout the year, but shifted the location of the space used.

A positive relationship was also observed between space use and size.

Mature sex woman Shark Bay

There was evidence of seasonal site fidelity and long-distance movement with the coordinated, annual migration of two adult males to the study site during the mating season. Depth use was segregated with some small sharks occupying shallower depths than Mature sex woman Shark Bay throughout the day and year, most likely as refuge from predation.

Mature sex woman Shark Bay the importance of inshore reef habitats to blacktip reef sharks and provide evidence of connectivity with offshore reefs, at least for adult males. Editor: Heather M. This is an open access article distributed under the terms of the Creative Commons Attributionwhich permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

The funders had no role in study de, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist. The link between movement and population dynamics is complex and manifests at least on a small-scale through behavioural decisions that affect reproduction and survival [ 12 ]. In addition, analysis of site fidelity and home range estimation can identify important habitats through the continued or repetitive use of specific areas by individuals restricting their movements to a region much smaller than that which they are capable of using [ 78 ].

Underpinning movement theory is the idea that the costs of establishing and maintaining a home range in terms of overall fitness should not exceed the lifetime benefits [ 79 ] related to reproductive success e. However, movement patterns e.

Mature sex woman Shark Bay

Examining how individuals of different sexes and life-history stages move and occupy space within a range of unique habitats is critical to understanding the biology and ecology of the species as a whole. Highly mobile marine species such as sharks exhibit complex movement patterns across a wide range of spatial and temporal scales. Mature sex woman Shark Bay patterns can range from small daily movements with the tide to access preferred prey [ 1011 ] to yearly seasonal migrations [ 1213 ] spanning hundreds of kilometres.

Many species have been shown to exhibit some degree of residency, site fidelity or philopatry over their lifetime [ 14 ], as Mature sex woman Shark Bay as changes in behaviour and habitat use associated with ontogeny [ 15 — 17 ] and sex [ 31819 ]. Preferential use of shallow-water habitats by juveniles, for example, has been attributed to predator avoidance strategies [ 151720 — 22 ], growth optimization [ 1523 ], foraging tactics [ 151724 ] and to avoid intraspecific competition [ 17 ].

Movement and habitat use of sharks are also known to vary between sites with different environmental, geographic and hydrodynamic properties [ 30 ]. Inshore habitats are complex heterogeneous environments ranging from soft-sediment, estuarine and seagrass habitats to highly structured fringing reef systems, which greatly influences observed movement patterns in shark species that inhabit them. To date, most studies examining the spatial ecology of reef sharks have focused primarily on offshore reefs [ 2531 ] and atolls [ 32 — 36 ], with little information available on the movement and space use of sharks occupying reef habitats closer to shore [but see 37 ].

Cross-shelf differences in physical e. In addition, the isolated and often patchy nature of atolls and offshore reefs, respectively, along with documented high site attachment of reef sharks to coral reef habitat [ 334142 ], may mean that these species have different movement potential compared to those utilising inshore reef systems where habitat is less Mature sex woman Shark Bay and adjacent to a continuous coastline [ 25 ]. Residency and movement patterns of grey reef sharks, Carcharhinus amblyrhynchosfor example, have been observed to differ between reefs with different degrees of isolation; in near continuous reef habitat on the northern Great Barrier Reef GBRAustralia, sharks exhibited low residency and large-scale movement between reefs [ 43 ], while on comparatively more isolated offshore reefs further south [ 2531 ] and elsewhere [ 3441 ] sharks were observed to be highly resident and displayed limited inter-reef movement.

Differences in movement and degree of site fidelity may reflect site-specific differences in habitat quality and resource availability [ 3144 ], indicate level of exposure to predation risk or tolerance to environmental changes [ 25 ].

Studies have shown that, for reef sharks, both the presence [ 45 ] and quality of coral reef habitat is important, with shark abundance positively correlated to the amount of coral cover [ 46 ]. However, regional declines in coral cover [ 47 ] along with deteriorating water quality associated with increasing coastal development [ 48 — 50 ] could result in some inshore shark species avoiding degraded habitats.

Proximity to shore also means that sharks utilising inshore reef habitats are more accessible to recreational and commercial fishers where they are caught as targeted species or, more commonly, as bycatch [ 4551 ]. Overfishing, including localised depletion of shark species, and habitat degradation within fished areas have been linked to ecosystem-wide changes [ 52 — 55 ]. Collectively, environmental and anthropogenic effects on inshore reef systems may result in very different movement and space use patterns for resident sharks compared to their counterparts offshore.

The purpose of this research was to investigate the movement patterns and space use of reef sharks within an inshore reef environment. We examined residency, space use and depth use patterns of the blacktip reef shark, Carcharhinus melanopteruson an inshore reef in order to determine how a species common to offshore reefs and atolls, moves and occupies space when utilising inshore reef systems. Movement metrics were analysed across time and included sex and size effects to determine if biological factors ificantly influence movement and space use of sharks.

from this study were compared to those conducted on the same or similar species within offshore reef environments to put movement of C. Examining how resident sharks utilise space within inshore reef systems will improve our knowledge of reef shark spatial ecology and help to clarify the importance of inshore reef habitats for these species [ 56 ]. Orpheus Island Mature sex woman Shark Bay depth in the bays is less than 5 m and maximum tidal range reaches 4 m with some bays becoming completely dry at lowest tide levels.

The island is surrounded by a fringing reef system with depths ranging from 8—20 m.

Mature sex woman Shark Bay

The blacktip reef shark, C. It is the third most commonly encountered shark in the GBR reef line fishery [ 59 ] and the most common reef shark caught in the commercial net fishery operating within inshore waters of the GBR [ 45 ]. High site-attachment is reported for C. Passive acoustic telemetry was used to examine the movement and space use of C. Receivers were fastened to a nylon rope with a float and anchored 2—3 m above the seabed using stainless steel chain shackled to a coral head.

Mature sex woman Shark Bay

Intertidal receivers were partially buried in the substrate with the hydrophone approximately 10 cm above the surface in order to maximise possible detection time. We assumed that once the receiver hydrophone was out of the water, the habitat was too shallow for sharks to access and thus did not bias the estimation of time spent in intertidal areas. Acoustic receivers were downloaded twice per year. A separate study run concurrently to this one, deployed receivers at Bramble Individuals were captured on multi-hook long-lines or rod and reel. Long-lines consisted of a m mainline 8 mm nylon rope with gangions 1 m of 5 mm nylon cord with 1 m wire trace and size 14 Mustad tuna circle hooks attached at 8—10 m intervals.

Lines were baited with either butterfly bream Nemipterus spp. Sharks were measured to the nearest millimetre, sexed and tagged with a rototag in the first dorsal fin for external identification. Prior to internal fitting, transmitters were coated with a mixture of paraffin and beeswax to prevent transmitter rejection [ 70 ]. Sharks were retained for approximately 10 minutes during measuring and tagging procedures. Acoustic transmitters pulsed at 69 kHz on a pseudo-random repeat rate of 50— VL— V13P-1H and 45—75 VH seconds and had an estimated battery life ofand days, respectively.

Each transmitter emitted a unique ID code specific to the individual tagged. Data from acoustic receivers were used to investigate movement patterns and space use of C. Single detections per day were classified as possible false detections and were removed before further analysis. All analyses were conducted in the R environment [ 72 ]. Residency of sharks was examined via calculation of a Residency Index which was defined by first assembling a presence history i.

Presence histories were then used to calculate the ratio of days detected within the acoustic array to days at liberty, asing each individual a value between 0—1 for low to high residency, respectively. Roaming Index values ranged from 0 no detections to 1 detected on all receivers.

Residency and roaming indices were tested for normality and transformed if required then analysed using generalised additive mixed models GAMMs to determine if there were any effects of sex and size across all tagged individuals. Space use metrics for tagged individuals were estimated using fixed kernel utilisation distributions KUDs calculated from short-term centres of activity positions COA.

COA estimates were calculated for each individual using a Mature sex woman Shark Bay R script [ 75 ] and represented the mean position of each shark over a minute time step weighted by the of detections at each receiver. COA positions were calculated prior to estimating KUDs to for the inherent spatio-temporal autocorrelation within the data structure, and for varying transmission settings among different models of acoustic transmitters used in the study [ 76 ]. It is important to note that COA estimates assume a homogenous detection probability and could not be determined when individuals utilised habitats outside of the listening range of the receiver array, making it possible that calculated metrics underestimated true space used by individuals.

Variance inflation factors were calculated using the R package car [ 80 ] to test models for multicollinearity. A subset of twenty C. Mature sex woman Shark Bay in depth use of sharks were investigated at monthly and hourly intervals, between sexes and with size in order to determine if there were any temporal or biological effects on depth use. Seasonal patterns in mean monthly depth data, and diel Mature sex woman Shark Bay in the hourly depth data, from the twenty individuals were assessed using a GAMM with individual animal ID included as random effects.

Mature sex woman Shark Bay

Fifty-nine C. Transmitters were fitted to 20 sharks tagged in December 14 female, 6 Mature sex woman Shark Bay23 sharks in December 10 female, 13 male2 in March female8 in December 3 female, 5 male and 6 in February 3 female, 3 male. Two individuals were never detected and another 17 were excluded from analyses due to limited data. Individuals detected for less than Mature sex woman Shark Bay period of maximum transmitter life either departed the monitored area permanently, died outside of the array or experienced tag failure; the timing of detection loss was random and did not appear to be coordinated among individuals Fig 2A.

Size of tagged individuals ranged from mm STL stretch total length to mm STL which is close to the minimum and maximum size reported locally for this species [ 68 ]. Only small sharks — mm STL were caught within Pioneer Bay and larger sharks — mm STL on the adjacent reef, with individuals measuring between these two size groups not encountered.

The general trend was for residency and roaming indices to increase with size. However, large females appeared to be more resident and roam less throughout the array than large males, while residency patterns among small sharks were generally similar with roaming indices of juvenile males only marginally higher than that of females. The second adult male IDmm STL was never detected outside of the array and its whereabouts for much of the monitoring period remain unknown.

Between consecutive years, times of arrival and departure fell within 1—2 weeks of each other, indicating that movements were highly coordinated. Maximum likelihood ratio tests showed best-fit models to be ificantly better than the null model. The trend was for average monthly space used by males and females to be similar for much of the year before diverging in November and December when males used nearly twice as much space as females Fig 3B and 3D. Panels include mean and standard error.

Mature sex woman Shark Bay

Female C.

Mature sex woman Shark Bay

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