The Hawaiian spinner dolphin, Stenella longirostris: Effects of tourism.

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24 and then throw their tail over their head, reentering the water tail first and slapping their dorsal surface against the water. Dolphins occasionally combine tail-over-head leaps with a spin. Tail slaps involve dolphins slapping their tail flukes against the water in either the normal or inverted position (Norris and Dohl 1980, Norris et al. 1994a). Tail slaps produce a loud noise which can be heard for several hundred meters in the air and I assume that there is a loud underwater component as well. Tail slaps which are repeated in succession produce a sound similar to a slow outboard engine and have hence been termed motorboating (Norris and Dohl 1980). Shane (1990) hypothesized that tail slaps were at least at times associated with aggression in bottlenose dolphins. In the head slap, the dolphin emerges from the water, as far as mid belly, and slaps its anterior ventral surface against the water. Backslaps are the inverse of headslaps. Dolphins exit the water as far as mid body, and slap their dorsal surface against the surface of the water (Norris and Dohl 1980). Norris et al. (1985) discovered that spinner dolphins were easily disturbed by humans in the mornings, just before they descended into rest. At times, dolphins were disturbed to such an extent that they left the bay and re-initiated morning travel along the coast. Human activity could change the activity level of a school (usually from low to high) at anytime during the day, causing dolphins to scatter, leap, aggregate, initiate evasive maneuvers, or undergo a combination of these behavioral changes (Norris et al. 1985). The frequency and type of aerial activities has been used as an index of the arousal of individual cetaceans and of schools as a whole (Herman and Tavolga 1980,
25 Norris and Dohl 1980). Increases in aerial displays may be caused by conspecifics or events outside the group (Smith and Dolphin 1993). Study Site Kealake’kua Bay is located on the leeward side of the island of Hawai'i (Figure 2). The 127.48 hectare bay is backed by an abrupt cliff formed by the scarp of the Kealake’kua fault, which follows the island contour to the north and south, frequently disappearing below a lava mantel (Wells and Norris 1994). Lava that flowed over the scarp fanned outward to form both the northern and southern limb of the bay, the deepest part of which (57 m) is located in a channel which runs between the two flows near the Ka'awaloa shoreline (Wells and Norris 1994). Kealake’kua Bay was established as a Marine Life Conservation District (MLCD) and as an underwater state park in 1969. The MLCD extends from the highwater mark seaward to a line that extends from Captain Cook Point to Manini Beach Point. A line from Cook Point to the north end of Napo'opo'o Beach divides the MLCD into subzone A to the north, and subzone B to the south (Figure 3). The anchoring of boats, fishing, and the taking or injuring of any type of marine life are all prohibited in subzone A. Fishing without the use of traps and the anchoring of boats are permitted in subzone B.
Page 1 and 2: 1 CHAPTER I INTRODUCTION Documented
Page 3 and 4: 3 avoid areas within 10 km of activ
Page 5 and 6: 5 displayed a significant reduction
Page 7 and 8: 7 a linear model, the vessel explai
Page 9 and 10: 9 decreasing their surface times (C
Page 11 and 12: 11 Hector's dolphins, Cephalorhynch
Page 13 and 14: 13 a killer whale (Herman and Tavol
Page 15 and 16: 15 The Marine Mammal Protection Act
Page 17 and 18: 17 Dearden 1993, Thompson et al. 19
Page 19 and 20: 19 dorsal surface and a white ventr
Page 21 and 22: 21 some areas consistently have mor
Page 23: 23 Aerial Behaviors Spinner dolphin
Page 27 and 28: 27 CHAPTER III OCCURRENCE AND BEHAV
Page 29 and 30: 29 Thirty-five observation days wit
Page 31 and 32: Figure 4 31
Page 33 and 34: Figure 6a,b 33
Page 35 and 36: Figure 8a 35
Page 37 and 38: 37 Most human activities that were
Page 39 and 40: Table 1 39
Page 41 and 42: 41 Discussion Norris et al. (1994 )
Page 43 and 44: 43 The correlation between number o
Page 45 and 46: 45 to perform. If the dolphins do,
Page 47 and 48: 47 times motor boats approached and
Page 49 and 50: 49 On one occasion, a swimmer obser
Page 51 and 52: Figure 11a, b 51
Page 55 and 56: 55 Figure 15. Square root of aerial
Page 57 and 58: 57 Figure 18a. Spinner dolphin surf
Page 59 and 60: 59 3.6 2 Square root of aerial acti
Page 61 and 62: 61 Figure 21a. Square root of aeria
Page 65 and 66: 65 Figure 25a. Square root of aeria
Page 71 and 72: 71 Discussion Swimmer and kayak dis
Page 73 and 74: 73 morning than in the afternoon, t
Page 75 and 76:
75 used by some boat operators resu
Page 77 and 78:
77 reduced energy levels, then incr
Page 79 and 80:
79 LITERATURE CITED Acevedo, A. 199
Page 81 and 82:
81 Cooke, J. 1991. Classification a
Page 83 and 84:
83 Gordon, J. and Moscrop, A. 1996.
Page 85 and 86:
85 Montero, R., Martin, V., Heimlic
Page 87 and 88:
87 Associates Inc., Bryan, Texas. F
Page 89 and 90:
89 Wells, R. S. and Norris, K. S. 1
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The Hawaiian spinner dolphin, Stenella longirostris: Effects of tourism.

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