*Draft*Movement behaviours and habitat usage of West Kimberley dugongs: A community based approach

Project 0809/14: Movement behaviours and habitat usage of West Kimberley dugongs: A community based approach

Four dugong tagged in Beagle Bay 16-19 July 2009 Western Australia. Results showed a high degree of
fidelity to Beagle Bay, but one dugong travelled 500 km south.

Dugong in the West Kimberley were tagged for this study in two locations on the Dampier Peninsula. These animals showed a variety of foraging behaviours and movement patterns, in some ways similar to other populations of dugong studied throughout Australia. Dugong were observed to move over large distances (100s of kms) but also to exhibit a high level of foraging site fidelity. Foraging ranges were similar in size to other areas around Australia but appeared to be smaller within the Beagle Bay area than for other places along the Dampier Peninsula. Dugong in this area appear to travel along the sea bottom by preference and combine periods of foraging in restricted areas in between periods of migration/movement. Dugong utilised shallow water habitats (< 5metres) throughout the study area, but were observed to dive to maximum depths of approximately 20 metres. The tide and diel periods exerted a strong influence on the micro-scale patterns of habitat use, with use of the inter-tidal seagrass habitats only occurring at high waters periods during the night. These micro-scale patterns of habitat use may be influenced by avoidance of daytime predators, including traditional indigenous hunters. There was no systematic migration of animals from one area to another, however this may be due to the limited period of the deployments throughout the seasons. This study identified important foraging habitat within embayments but also along the open coastal margin of the Dampier Peninsula, suggesting that these habitats are important conservation areas for dugong. Further research to better understand the patterns of habitat use, the distribution of foraging effort and the patterns of seagrass distribution are needed to help design effective conservation programmes in this area. Studies designed to determine the seasonal migration patterns of this metapopulation of dugong are also important to understanding the links between populations of dugong throughout the north-west of WA. These data will also contribute to the development of community-led management plans for the sustainable use of dugong and the development of future research programmes to address knowledge gaps to achieve sustainable hunting outcomes. These data area also valuable in contributing to the knowledge and understanding of the likely impacts of large-scale industrial developments throughout areas identified as foraging locations for dugong in the West Kimberley.

项目0809/14：西金伯利海域儒艮的运动行为与栖息地利用：基于社区的研究方法

2009年7月16日至19日，研究人员在澳大利亚西部的比格尔湾对4头儒艮（dugong）进行了标记。结果显示，绝大多数个体对该海域具有高度的栖息地忠实性，但其中1头儒艮向南游动了500公里。

本研究在丹皮尔半岛的两处地点对西金伯利海域的儒艮进行了标记。这些个体展现出多样的觅食行为与运动模式，在某些方面与澳大利亚境内已被研究的其他儒艮种群相似。观测结果显示，儒艮既能长距离移动（可达数百公里），同时也表现出极高的觅食位点忠实性。其觅食范围的规模与澳大利亚其他海域的儒艮种群相近，但比格尔湾内的觅食范围较丹皮尔半岛其他区域更小。该区域的儒艮倾向于沿海底行进，在迁徙/移动的周期之间，穿插在受限区域内进行觅食活动。整个研究区域内，儒艮均利用水深小于5米的浅海栖息地，但观测到它们的最大下潜深度约为20米。

潮汐与昼夜周期对儒艮的微生境利用模式具有显著影响：潮间带海草栖息地的利用仅发生在夜间的涨潮时段。这种微生境利用模式可能受到躲避日间捕食者的驱动，其中包括传统的原住民猎手。研究未观测到儒艮从某一区域向另一区域进行系统性迁徙，但这一结果可能受制于研究周期在各季节中的覆盖时长有限。本研究确认了海湾内部以及丹皮尔半岛开放海岸沿线均存在重要的儒艮觅食栖息地，表明这些区域是儒艮的关键保护生境。

为了在该区域制定有效的保护方案，还需要开展进一步研究，以更好地解析栖息地利用模式、觅食活动分布以及海草床分布格局。针对该儒艮集合种群（metapopulation）的季节性迁徙模式开展研究，也有助于理解西澳大利亚州西北部儒艮种群之间的关联。本研究数据还将助力制定以社区为主导的儒艮可持续利用管理计划，以及未来为填补知识空白、实现可持续狩猎目标而开展的研究项目。此外，这些数据对于理解西金伯利海域已被认定为儒艮觅食地的区域内，大规模工业开发可能带来的潜在影响，也具有重要的参考价值。