The Global Stranding Network

The Global Stranding Network (GSN) was founded in 2019 at the World Marine Mammal Conference in Barcelona in response to the call for action articulated in the Barcelona Declaration. The Declaration’s second goal emphasized the need to “enhance and strengthen international collaboration to (1) ensure consistent, high-quality response to stranded marine mammals globally, and (2) support conservation efforts for species under threat of extinction.”

The GSN’s mission is to connect people responding to marine mammal strandings world-wide and support response efforts through a community driven, “bottom-up”, approach to resource sharing, capacity building, and international collaboration. This is done by providing information on stranding response and investigations that is publicly available in a single website, and holding workshops and online webinars. The GSN aims to provide links to other online resources and national and regional stranding networks, rather than duplicate effort. Membership of the network is open to all individuals and organisations responding to strandings, with additional information available to members on the password-protected member resources section of the website.

Map showing the locations of presenters/participants to Global Stranding Cafes to date

The GSN co-hosts regular bi-monthly “Marine Mammal Case Study Cafés” in collaboration with the International Whaling Commission’s (IWC) Strandings Initiative. These “Cafés” are informal online gatherings where participants can present a brief 5-minute case study from their work, discuss cases, receive valuable insights, and connect with colleagues. The webinar series occasionally includes ‘special event’ webinars that focus on specific topics of interest. Special event webinars to date have focused on rabies in Cape fur seals, the Amazonian River dolphin unusual mortality event, and sirenians. For more information on these events, please visit the GSN’s meetings and workshops webpage or contact Andrew Brownlow (andrew.brownlow@glasgow.ac.uk) or Kristi West (kristiw@hawaii.edu).

The GSN will be co-hosting a workshop with the IWC at the upcoming Society of Marine Mammalogy Biennial Conference titled in Puerto Rico. The workshop is titled Enhancing Diagnostics and Global Collaboration. The primary objective of the workshop is to enhance the global response to marine mammal strandings by improving connectivity and coordination in diagnostic capabilities. The workshop will include a hands-on training component in disease screening for stranding responders that will be led by Dr. Wei-Cheng Yang from National Taiwan University. The workshop will be held on Saturday, October 17, 2026. To attend this workshop, please sign up on the SMM conference website.

For more information on upcoming initiatives and events, please consider joining the GSN!

A global strategy to combat cetacean and other marine megafauna bycatch in the growing trade for fish maw (swim bladders)

As previously reported (see our 2023 article: Escalating threat to marine wildlife from trade demand for croaker fish swim bladders), the IUCN Cetacean Specialist Group has a long history of engagement in efforts to save the vaquita porpoise (Phocoena sinus) from extinction due to bycatch in gillnets targeting the totoaba croaker (Totoaba macdonaldi) for its maw (swim bladder). Similar to shark fins, larger maws—particularly from croakers—are in high demand, primarily in China, as a luxury or status food and as a financial investment, while smaller maws are ground into powder for purported medicinal and cosmetic uses.

As restrictions on international trade in shark products under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) have reduced the availability of shark fins, maw is increasingly sought as an alternative. Imports of dried maws to Hong Kong alone are now valued at approximately US$280 million annually, with individual large maws fetching thousands of dollars at the point of capture. This growing “gold rush” has transformed fisheries that once treated maw as a by-product into targeted operations, with fishers often discarding the carcass and retaining only the maw. The resulting increase in fishing effort, particularly in coastal and estuarine habitats where croakers aggregate, has significantly elevated bycatch risk for already threatened small cetaceans and other marine megafauna, including sharks, rays and marine turtles, sharing these areas. Impacted small cetacean species include the Irrawaddy dolphin (Orcaella brevirostris), Indo-Pacific humpback dolphin (Sousa chinensis) and finless porpoises (Neophocaena phocaenoides) in South and Southeast Asia, as well as snubfin (Orcaella heinsoni) and humpback dolphins (Sousa sahulensis) in Papua New Guinea.

Endangered Irrawaddy dolphin caught in gillnet that catches Blackspotted croakers

Fisheries targeting maw frequently operate with limited monitoring or management, often involve illegal, unreported and unregulated (IUU) fishing, and are attracting the interest of organized criminals. These are all issues which, in addition to sustainability, must be addressed at the domestic level in each country. But multilateral environmental agreements, including the Convention on the Conservation of Migratory Species of Wild Animals (CMS) and CITES, which can regulate the take and trade of fish maw, have a vital role to play.  The CSG has been collaborating with other IUCN specialist groups and NGOs to support a wide-reaching strategy to raise awareness of the impact of the maw trade, and identify action that needs to be taken.  The CSG provides expert technical advice on this strategy, which includes targeted engagement and preparation for IGO meetings, including CITES, CMS and International Whaling Commission (IWC), where decisions can help to improve awareness, monitoring and, most importantly, mitigation of bycatch related to maw fisheries.

Most recently, the CSG contributed to a side event at the March 2026 CMS Conference of Parties.  Collaborating NGOs prepared a briefing document, and the CSG contributed to the event with a presentation on the impacts of the maw trade on cetaceans (insert photos here).  During the  meeting, CMS Parties adopted a resolution and decisions recognizing the maw trade as an emerging issue of concern and establishing collaboration with CITES and the IWC to address its impacts. This provides an important foundation for the coordinated international action that is needed, including improved trade monitoring and the development of targeted mitigation strategies to reduce bycatch of small cetaceans.

Alex cetacean presentation at side event

Alex at side event

To strengthen the evidence base for this international action, the CSG has circulated an online survey to its members to better understand the links between demand for croaker maws and fisheries that incidentally capture small cetaceans. The results will help detect bycatch hotspots, inform domestic and international conservation priorities, and identify target species that may benefit from regulation under CMS and CITES. If this approach proves useful and informative, it is hoped that a similar approach will be adopted by other IUCN Specialist Groups to support a comprehensive and coordinated response to the impacts of the global maw trade.