CMS COP15 Outcomes Relevant to ASCOBANS

The Fifteenth Meeting of the Conference of the Parties (COP15), held from 23 to 29 March 2026 in Campo Grande, Brazil brought together 105 Parties, 337 observers, including those from NGOs, IGOs, and non-Party Range States, and 54 representatives of Indigenous Peoples and local communities. The theme of the conference was “Connecting Nature to Sustain All Life” and Parties adopted of a number of Resolutions, Decisions, Action plans, and Concerted Actions addressing conservation challenges affecting migratory species. Many of these addressed cross-cutting issues pertinent to small cetacean conservation efforts.

Overexploitation and fisheries‑induced impacts

COP15 placed significant emphasis on overexploitation, recognized as a major driver of biodiversity loss in marine environments. Parties adopted amendments to the CMS resolution on bycatch, reaffirming the obligation to protect migratory species against bycatch, the goal to prohibit retention of Appendix I -listed species, and the goal to maintain at or reduce bycatch rates to sustainable levels for Appendix II -listed species (see Resolution 12.22 (Rev.COP15) and Decisions 15.26-15.29). 

Furthermore, Decisions were adopted to strengthen collaboration with IWC, CITES and other IGOs to prepare synthesis report on bycatch mitigation strategies and to provide mitigation guidance for the implementation of CMS Article III (5) that prohibits the taking of Appendix I-listed species (see Decision 15.29). This includes Decisions on Fish Aggregating Devices (FADs) to promote the sustainable and environmentally responsible design, use, and management of FADs to reduce any negative impacts on species and their environments (Decisions 15.30‑15.32).

Alongside developing effective bycatch reduction and mitigation measures, the CMS Scientific Council was requested to identify regions where reviews of relative levels of bycatch would be a priority and/or beneficial, report on the contribution of bycatch and other fisheries-related mortalities of CMS-listed cetaceans to trophic downgrading, and review the impact of maw fishers on marine mammal species, inter alia.

Marine pollution and underwater noise

Small cetaceans also face multiple, and potentially interacting, cumulative or synergistic threats from marine pollution. This includes pollution from plastics, marine debris, and chemical pollutants, such as persistent organic pollutants and toxic metals, amongst various other forms. Resolution 15.2 recognised and reaffirmed Parties’ concern for the impacts of marine pollution on migratory species. Moreover, Parties were urged to address pressing pollution threats affecting migratory species, with particular attention to vulnerable stages of the migratory cycle. 

The Scientific Council was mandated to identify species, populations, habitats and migratory stages most at risk from marine pollution and to identify global hotspots where pollution pressures overlap with critical habitats for migratory species (Decision 15.43).

COP15 also adopted decisions on anthropogenic underwater noise (see Decision 15.45‑15.47), recognizing it as an increasingly significant source of pollution affecting migratory species. ASCOBANS was specifically called upon to work with the Scientific Council, through the Joint Noise Working Group, to review sources of underwater noise of concern (Decision 15.46). This is to include an assessment of the existing guidance and knowledge available from CMS and other relevant forums in order to identify gaps in the current guidance. 

The Scientific Council were also requested to review sources of underwater noise of concern, assess existing guidance, and develop recommendations for mitigation. To support the review, the Secretariat is called upon to convene an in-person workshop to assist the Joint Noise Working Group and continue to provide updated information on the CMS website to assist Parties and stakeholders of effective mitigation measures (Decision 15.47).

Area-based and cetacean‑specific conservation measures

Relevant to area-based agreements, including ASCOBANS, COP15 urged Parties to integrate CMS-relevant area-based tools and identified sites into national conservation planning, spatial planning and reporting processes (Decisions 15.52-15.56). To do so, Parties were requested to make use of IMMAs, Ecologically or Biologically Significant Marine Areas, Key Biodiversity Areas, and to encourage RFBs to make fisheries and observer data available and/or support IMMA with their analysis. These initiatives aim to ensure that migratory species are effectively integrated into marine spatial planning and broader conservation frameworks, including in the BBNJ Agreement. 

Meanwhile, the Scientific Council have been directed to develop a report on improving the long-term effectiveness of protected areas dedicated to marine migratory species. The Scientific Council was also requested to assess how climate change affects the long‑term effectiveness of protected and conserved areas dedicated to marine migratory species and to develop recommendations to enhance their resilience (Decision 15.55).

Decisions pertaining to cetacean-specific conservation efforts were also adopted during COP15 (see ASCOBANS-relevant Decisions 15.72-15.75). Principally, Parties were encouraged to assess whether any take of Appendix I-listed cetaceans occurs within their jurisdiction. If so, Parties were urged to review and implement recommendations in UNEP/CMS/COP15/Doc.25.4.1/Annex 1 and assess the extent to which the welfare and conservation of cetaceans is impacted by climate change. This also comprises review and implementation of recommendations in UNEP/CMS/COP15/Doc.25.4.1/Annex 3.

Reducing other anthropogenic pressures

COP15 adopted Decisions 15.57-15.60 concerning vessel strikes. The Scientific Council was requested to identify additional populations and areas of at-risk CMS-listed species by mapping shipping lanes against Important Marine Mammal Areas (IMMAs), and present appropriate re-routing measures. COP15 also adopted measures for Parties to identify risk areas to implement measures to reduce collision risks for vulnerable cetacean populations and to improve reporting of incidents to relevant international databases. Further collaboration with the IUCN Commissions, the IWC and the International Maritime Organization was encouraged.

On deep-sea mining, Parties reiterated the importance of implementing CMS Resolution 14.6 Deep‑seabed mineral exploitation activities and migratory species. Decisions encouraged CMS contribution to the development of environmental impact assessment guidance by the International Seabed Authority (Decision 15.50).

COP15 also considered impacts associated with marine wildlife watching and recreational activities, promoting dissemination of existing CMS guidelines[i] and mandating further scientific assessment of cumulative disturbance effects, including from emerging technologies (Decisions 15.69-15.71).

Equally, Decisions were adopted directed to the Scientific Council, requesting a review of impacts of climate change on cetacean conservation and welfare, in collaboration with the IWC, ACCOBAMS and ASCOBANS (Decision 15.73). The review is mandated to involve investigating the impacts of mass die-offs events of cetaceans, including events linked to the presence of algal toxins, a quantification of contemporary aquatic wild meat takes, and review the priority actions in the following intersessional period. 

ASCOBANS Secretariat also delivered its progress report on activities since COP14 - the report is available here.

The Earth Negotiations Bulletin / IISD summary report on CMS COP15 is available here.