Areas of study of signal crayfish (spring 2019) — Sélune Observatory

The invasive crayfish Pacifastacus leniusculus, also known as California crayfish or Signal, has been present in the Selune basin for several years, but has been confined upstream by the dams’ reservoirs. Its potential habitat will be considerably expanded due to the renaturation of the Selune Valley. The purpose of this monitoring is to describe whether, and at what speed, the Pacifastacus colonise the downstream of the Selune as it returns to a lotic state (“current river”), and from there colonise the previously inaccessible tributaries as they flow directly into the water reservoirs. The follow-up is carried out through two annual follow-up campaigns, in spring and autumn. The presence of Pacifastacus is sought by trapping via the Ecrevisse IAE Abundance Index. The IAE is carried out on the most sensitive stations of the colonisation front and consists of laying 15 unbaited nasses for 24 hours, installed at least every 10 metres. This layer gives the locations of these stations.入侵性螯虾信号螯虾（Pacifastacus leniusculus），又名加州螯虾、Signal螯虾，已在塞吕讷（Selune）流域栖息多年，但此前受大坝水库阻隔，仅分布于上游河段。随着塞吕讷河谷的生境自然修复，该物种的潜在适宜栖息地将大幅扩张。本次监测的核心目标为：探明信号螯虾是否会随着塞吕讷河恢复为流水生境（即"current river"，天然河道），并以何种速率向中下游河段扩散；同时监测该物种是否会借助直接汇入水库的支流，入侵此前因水库阻隔无法抵达的支流区域。 本次野外监测每年开展两次调查，分别于春季和秋季进行。调查采用IAE螯虾丰度指数（Ecrevisse IAE Abundance Index）诱捕法，以确认区域内是否存在信号螯虾。该调查点位设置于种群扩散前沿的关键敏感区域，具体操作为：每至少10米布设1组无饵笼状诱捕器，每组放置15个，诱捕时长为24小时。 本数据集图层提供上述所有监测点位的空间坐标信息。