Digital video aerial surveys of seabirds and marine megafauna in the Gulf of Maine from May 2023 to January 2024

Original provider:
Biodiversity Research Institute

Dataset credits:
Biodiversity Research Institute
HiDef Aerial Surveying Limited
Bureau of Ocean Energy Management (BOEM)

Abstract:
In April 2023, the Biodiversity Research Institute (BRI) commissioned HiDef
Aerial Surveying Limited (HiDef) to conduct high-resolution digital video
aerial surveys in the Gulf of Maine. The surveys aimed to record marine
megafauna, seabirds, and human activity. The designated survey area is
approximately 5 km off the coast of Maine

A total of four surveys were conducted between May 2023 and January
2024. HiDef designed the survey using 2.5 km- and 5 km-spaced transects
across the Gulf of Maine survey area, covering approximately 6,673 km².

Surveys were undertaken using an aircraft equipped with four HiDef
cameras with a sensor package designed and calibrated to achieve a
resolution of 1.5cm Ground Sample Distance (GSD). Each camera sampled
a strip of ~ 104m width, separated from the next camera by ~ 17m, to
provide a combined sampled width of 416m within a 467m overall strip. All
four cameras were analyzed, achieving approximately 10% coverage of the
survey area during each flight.

Data analysis followed a two-stage process in which video footage was
reviewed (with a 20% random sample used for audit) and detected objects
were identified to species or species group level (again with 20% selected
at random for audit). The audit of both stages requires 90% agreement to
be achieved.

The surveys recorded a total of 7,248 birds of 33 species and 534 non-avian
animals of 12 species, in addition to two dead birds. A further 409 birds and
58 non-avian animals were recorded which were not assigned to a species.
An identification rate to species level of 94% was achieved throughout the
survey period.

原始提供方：生物多样性研究所

数据集贡献方：生物多样性研究所、HiDef航空勘测有限公司（HiDef Aerial Surveying Limited）、海洋能源管理局（Bureau of Ocean Energy Management, BOEM）

摘要：
2023年4月，生物多样性研究所（BRI）委托HiDef航空勘测有限公司（HiDef）在缅因湾开展高分辨率数字视频航空勘测。本次勘测旨在记录海洋巨型生物、海鸟及人类活动。指定勘测区域位于缅因州沿岸约5公里海域。

2023年5月至2024年1月期间共开展四次勘测。HiDef采用间隔2.5公里及5公里的测线覆盖缅因湾勘测区域，总覆盖面积约6673平方公里。

本次勘测使用搭载四台HiDef摄像机的航空器完成，摄像机配套传感器组件经设计与校准，可实现1.5厘米地面采样距离（Ground Sample Distance, GSD）。每台摄像机的采样条带宽度约104米，相邻摄像机间距约17米，最终在单次飞行467米的总条带范围内实现416米的合并采样宽度。四台摄像机均参与分析，单次飞行可覆盖勘测区域约10%的范围。

数据分析采用两阶段流程：首先审阅视频素材（抽取20%的随机样本用于审核），随后将检测到的对象识别至物种或物种类群级别（同样抽取20%的样本随机进行审核）。两阶段审核均需达到90%的一致性要求。

本次勘测共记录33种鸟类共计7248只、12种非鸟类动物共计534只，此外还记录到2只死亡鸟类。另有409只鸟类及58只非鸟类动物未被划分至具体物种。整个勘测周期内物种识别准确率达94%。