Standards Development

Scope

This document provides the recommendations and methods for sample collection and processing, taxonomic identification and enumeration, data processing and quality control, and specimen and data storage in the surveys of benthic macrofauna in the international seabed area.

This document applies to the survey of benthic macrofauna in the international seabed area excluding the polar oceans.

Purpose

Benthic macrofauna is one of the most diverse benthic groups in the international seabed area and an important link in the benthic food web. It plays an important role in the deep-sea material circulation and energy flow, the biogeochemical processes at the sediment-water interface, and the maintenance of the balance and stability of the ecosystem. In addition, Benthic macrofauna have strong regional distribution and weak migration ability. Some species are extremely sensitive to pollutants, while others have strong tolerance to pollutants. Therefore, Benthic macrofauna can serve as an indicator in marine pollution monitoring and ecosystem health assessment.

With the adoption of the BBNJ Agreement and people's increasing concern about environmental issues related to deep-sea mining, the protection of deep-sea biodiversity, especially benthic biodiversity, has attracted the attention of the international community. Benthos is also identified as one of the important biological groups for environmental baseline surveys and impact assessments in the "Recommendations for the guidance of contractors for the assessment of the possible environmental impacts arising from exploration for marine minerals in the Area" issued by the International Seabed Authority (ISA).

ISO 22787 issued in July 2023 provides general technical recommendations for marine biological surveys in the international seabed area, but does not cover specific technical recommendations for the survey of benthos. In 2021, three technical specifications related to deep-sea benthic biodiversity surveys have been published. Among them, ISO 23731 provides technical recommendations for studying megafauna communities based on images obtained from seabed observation platforms. The other two ISO standards involve meiofauna. Chapter 16 of ISO 23040 provides technical requirements and recommendations for field sampling, laboratory sorting, taxonomic identification, and quantification of meiofauna, while ISO 23732 provides imaging flow cytometry and environmental metagenomic analysis of meiofaunal community. Moreover, ISO 23040 also provides technical requirements and recommendations for microbenthos investigation and analysis. On benthic macrofauna, there is a technical guideline for quantitative sampling and sample processing of soft-bottom macrofauna in water quality standards (ISO 16665), but it is only applicable to intertidal zones. Therefore, currently there is no protocol for macrofauna survey in international seabed areas.

This standard will establish more specific protocols for survey techniques, sample collection and processing, data collection and quality control requirements for the benthic macrofauna in the international seabed area. It aims to standardize the methodologies used for the survey and research of benthic macrofauna in international seabed area, thereby ensuring the international comparability of the data collected by different countries, which will ultimately provide a basis for environmental investigation, impact monitoring and assessment in the international seabed area.