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美国卫生研究院文献>PLoS Clinical Trials
>Local densities and habitat preference of the critically endangered spotted handfish (Brachionichthys hirsutus): Large scale field trial of GPS parameterised underwater visual census and diver attached camera
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Local densities and habitat preference of the critically endangered spotted handfish (Brachionichthys hirsutus): Large scale field trial of GPS parameterised underwater visual census and diver attached camera
The critically endangered spotted handfish (Brachionichthys hirsutus) is restricted to a limited number of locations in south-eastern Tasmania, Australia. As is often the case for rare species, conducting statistically adequate surveys for B. hirsutus can be costly and time consuming due to the low probability of encountering individuals. For the first time we used a highly efficient and rigorous Global Positioning System (GPS) parameterised underwater visual census (GUVC) to survey B. hirsutus abundance within all nine known local populations in the Derwent Estuary within one season. In addition, a benthic microhabitat assessment was conducted simultaneously using a GoPro® camera attached to diver to determine B. hirsutus microhabitat preferences. B. hirsutus local populations varied between sites, with densities ranging from 1.58 to 43.0 fishes per hectare. B. hirsutus demonstrates a strong preference for complex microhabitat features, such as depressions and ripple formations filled with biogenic substrates (e.g. shells) but avoids simple, low relief microhabitats (e.g. sand flats) and areas dominated by ephemeral, filamentous algae. Complex microhabitats may enable B. hirsutus to avoid predators, increase forage opportunities or provide higher quality spawning sites. This first wide-scale application of GUVC for B. hirsutus allowed us to survey a larger number of sites than previously possible to provide a robust reference point for future long-term monitoring.
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机译:极度濒危的斑点手鱼(Brachionichthys hirsutus)仅限于澳大利亚塔斯马尼亚州东南部的有限位置。与稀有物种通常一样,由于遇到个体的可能性低,因此对B. hirsutus进行统计上足够的调查可能既昂贵又耗时。我们首次使用一个高效且严格的全球定位系统(GPS)参数化的水下视觉普查(GUVC),在一个季节内对德文特河口所有九个已知本地种群中的嗜水芽孢杆菌进行了调查。此外,使用连接到潜水员的GoPro ® sup>相机同时进行底栖微生境评估,以确定喜多芽孢杆菌微生境偏好。 B. hirsutus本地种群在站点之间变化,密度为每公顷1.58至43.0条鱼。 B. hirsutus对复杂的微生境特征表现出强烈的偏好,例如充满生物底物(例如贝壳)的凹陷和波纹形成,但避免了简单,低起伏的微生境(例如沙地)和以短暂的丝状藻类为主的区域。复杂的微生境可能使hirsutus hirsutus能够避免掠食者,增加觅食机会或提供更高质量的产卵场所。 GUVC在hirsutus中的首次大规模应用使我们能够调查比以前更多的地点,从而为将来的长期监测提供可靠的参考点。
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