Kock Alison A, Photopoulou Theoni, Durbach Ian, Mauff Katya, Meÿer Michael, Kotze Deon, Griffiths Charles L, O'Riain M Justin
1South African National Parks, Cape Research Centre, Cape Town, 8000 South Africa.
2South African Institute for Aquatic Biodiversity (SAIAB), Private Bag 1015, Grahamstown, 6140 South Africa.
Mov Ecol. 2018 May 22;6:7. doi: 10.1186/s40462-018-0125-5. eCollection 2018.
Understanding white shark () habitat use in coastal areas adjacent to large cities, is an important step when formulating potential solutions to the conservation conflict that exists between humans and large predatory sharks. In this study, we present the findings of a 2.5-year study of white shark occurrence and movement patterns adjacent to the City of Cape Town in False Bay, South Africa, with a focus on spring and summer months. Fifty-one white sharks were monitored annually at three offshore and twelve inshore sites by VR2 acoustic receivers, over 975 days from 1 May 2005 to 31 December 2007.
Occurrence patterns at inshore sites during spring and summer were analysed using a generalized additive mixed model (GAMM) with a spatial term (longitude, latitude), time of day and year included as explanatory variables for site use. We found that sharks occurred more frequently at inshore sites along the northern and northwestern shores, compared to the rest of the bay, and they transitioned most frequently between four adjacent beach sites that encompass the most popular recreational water use areas in Cape Town. There was significant diel variation, with higher shark occurrence around midday, and a peak in shark occurrence in 2005, when human-shark interactions also peaked. However, we found no effect of shark size on occurrence patterns at inshore sites.
White sharks showed the highest levels of occurrence at specific inshore sites between Muizenberg and Strandfontein beach, and thus inclusion of these sites within False Bay's marine protected area (MPA) network or recognition as Ecological or Biological Significant Areas (EBSAs) should be a future consideration. These insights into white shark habitat use at inshore sites in False Bay are important for successfully applying the principles of marine spatial planning (MSP) and for making science-based policy decisions. Furthermore, this information can be used to reduce potential shark-human conflict by incorporating it into future shark safety education campaigns.
了解大白鲨（）在大城市附近沿海地区的栖息地利用情况，是制定解决人类与大型掠食性鲨鱼之间存在的保护冲突的潜在方案的重要一步。在本研究中，我们展示了一项为期2.5年的关于南非开普敦市附近福尔斯湾大白鲨出现情况和移动模式的研究结果，重点关注春季和夏季月份。从2005年5月1日至2007年12月31日的975天里，通过VR2声学接收器每年在三个近海地点和十二个近岸地点对51条大白鲨进行监测。
使用广义相加混合模型（GAMM）分析春季和夏季近岸地点的出现模式，该模型包含空间项（经度、纬度）、一天中的时间和年份作为地点利用的解释变量。我们发现，与海湾其他区域相比，大白鲨在北部和西北海岸的近岸地点出现得更频繁，并且它们在四个相邻海滩地点之间的转换最为频繁，这些地点涵盖了开普敦最受欢迎的休闲用水区域。存在显著的昼夜变化，中午前后大白鲨出现的频率更高，并且在2005年大白鲨出现频率达到峰值，此时人鲨互动也达到峰值。然而，我们发现鲨鱼大小对近岸地点的出现模式没有影响。
大白鲨在穆伊森堡和斯特兰德方丹海滩之间的特定近岸地点出现的频率最高，因此将这些地点纳入福尔斯湾的海洋保护区（MPA）网络或认定为生态或生物重要区域（EBSAs）应是未来的一个考虑因素。这些对福尔斯湾近岸地点大白鲨栖息地利用的见解对于成功应用海洋空间规划（MSP）原则和做出基于科学的政策决策很重要。此外，这些信息可通过将其纳入未来的鲨鱼安全教育活动来减少潜在的鲨鱼与人类冲突。
