AB.H4U1 (NT)

Summary Estimated observations of the biotope AB.H4U1 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic aphotic muddy sediment dominated by meiofaunaThe HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea.Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of AB.H4U1 according to HELCOM RED LIST assessment experts:The biotope is assumed to occur throughout the Baltic Sea both in shallow coastal waters and in the deeper central parts of the sea. The distribution map indicates the area in the 100 x 100 km grid where biotope is reported to occur. The biotope may have a significantly wider distribution.(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)摘要 本数据集收录了赫尔辛基委员会（HELCOM）《生境、栖息地及生境复合体红色名录》评估工作中，从波罗的海区域获取的AB.H4U1生境的估算观测数据。 数据集说明 以小型底栖生物为优势类群的波罗的海无光带泥质沉积物：《波罗的海水下生境、栖息地及生境复合体红色名录》（2013版）是对1998年发布的海洋与海岸生境、生境复合体红色名录评估的更新优化版本。本报告的分类体系遵循国际自然保护联盟（International Union for Conservation of Nature, IUCN）提出的评估标准与原则，但针对波罗的海海域做出了部分适配调整。 赫尔辛基委员会水下生境与栖息地分类体系（HELCOM HUB）共计涵盖209类生境，其中59类被纳入红色名录。鉴于波罗的海深部海域的缺氧特性，以及波罗的海西南部海域部分生境的物种分布受盐度限制，诸多红色名录生境均集中分布于这两类区域。 赫尔辛基委员会的评估高度依赖专家研判与推演，所采用的问卷数据为估算的存在-缺失数据，而非原位实测数据，在查看本数据集的地图可视化成果时需充分考虑此前提。本数据集采用欧洲环境署（European Environment Agency, EEA）100km×100km网格进行生境制图展示。 本数据集展示了经赫尔辛基委员会红色名录评估专家估算得到的AB.H4U1生境分布范围：该生境被认为广泛分布于波罗的海的浅海近岸海域与中部深海区域。本分布地图仅标注了有观测记录的100km×100km网格单元，该生境的实际分布范围或更为广阔。 （本数据集数据为赫尔辛基委员会红色名录项目收集的专家研判结果，于2013年5月正式发布）