In early 2024, the UN released the first ever Status Report on Migratory Species, stating that 50% of the world's migratory species are in decline. While devastating, this is not surprising. Protecting migratory species is especially difficult because they are always on the move, and most conservation efforts are not. Traditional conservation models identify geographic locations with important habitat and create management plans restricting human activity to conserve them. There are also Other Effective area-based Conservation Measures (OECMs) in which conservation may not be the primary goal of the area's management, but it is a result of the stewardship of the area.
These protected areas are often important nesting, breeding, or foraging areas for highly migratory sea turtle species like leatherbacks and loggerheads, but the protections end when the turtles inevitably continue migrating. In the 2018 article “The political biogeography of migratory marine predators” by Autumn-Lynn Harrison et al., leatherbacks in the Pacific Ocean were shown to cross through the Exclusive Economic Zones (EEZ’s) of 32 countries and the high seas. So, how can we protect sea turtles throughout their ocean habitat?
MPAs
Marine Protected Areas are one of the most common tools used for ocean conservation, existing in various forms in the EEZ’s of multiple nations. They can even exist on the high seas, for example the North Atlantic Current and Evlanov Sea basin MPA, which is larger than the landmass of the United Kingdom and Germany combined. However, even within the designation “MPA” there is a wide range of management, regulations, or protections that may be present. Some MPAs have “no take” restrictions or more stringent rules regulating human activity, while others provide little more than a name.
When MPAs have consistent resources and management, they have been shown to help populations of marine species to recover. The Monterey Bay Marine Sanctuary benefits the sea otter populations that often spend the entirety of their lives within its boundaries. It also benefits the West Pacific leatherback sea turtles that come to forage on the abundant jellyfish prey in the California Current from spring to fall. Unlike otters and porpoises protected in the sanctuary, leatherbacks leave these protected waters when upwelling season ends.
Swimways
Swimways (migravías in Spanish) are aquatic migratory “highways” used by multiple marine species. This same concept is behind the flyways that many species of bird use to migrate around the globe. Though swimways are not a physical oceanographic feature like a current or sea mount, these unique marine corridors often follow underwater features and connect zones of high productivity (upwelling) to areas where reproduction takes place. The term has been used in this way since 2004 by scientists from MigraMar and other partner organizations.
Establishing that an area is used for migration by multiple species and deserving of swimway designation requires extensive research and data collection. This is usually done through animal tagging and telemetry, also called biologging. For example, Upwell Executive Director Dr. George Shillingers’ 2008 publication “Persistent Leatherback Turtle Migrations Present Opportunities for Conservation” presents data from 46 leatherbacks tagged on nesting beaches in Costa Rica that established their consistent migration towards the productive areas of upwelling around the Galapagos Islands. The article also suggests the implementation of conservation measures across nations and on the high seas to provide protection for migrating leatherbacks.
In 2018, Dr. Shillinger’s leatherback data along with data collected by many other researchers of migratory species of sharks, rays, turtles, and whales, was leveraged by MigraMar scientists and collaborators (including Upwell) to propose the “Cocos-Galapagos Swimway'' conservation area to connect the Galapagos and Cocos Islands. In 2022, Costa Rica and Ecuador expanded existing protections to create connectivity and consolidate the proposed swimway region.
“Swimways can significantly enhance existing conservation and management policies by ensuring biological connectivity between critical habitats (e.g., nursery, feeding and resting areas) of highly migratory and endangered species. Given the transboundary nature of large pelagic and endangered species, it is crucial to develop international agreements and regulations within the swimways, as well as to implement other effective management measures, such as the designation or zonation of Marine Protected Areas (MPAs), the establishment of spatial and temporal bans, the prohibition of certain fishing gear, among others.”
Dynamic Ocean Management
The ocean is an ever-changing environment; what if our conservation methods could adapt to this dynamism? Rather than demarcate a geographic area, dynamic ocean management (DOM) changes in space and time. Examples of DOM include time-closures of fisheries, and even Upwell’s own South Pacific Turtle Watch Tool (SPTW). The SPTW aims to use oceanographic conditions that are correlated with the presence of leatherbacks (sea surface temperature, time of year, chlorophyll and many more) to define where and when protection measures need to be put in place. Resource managers, fishers and other stakeholders could then use this information to anticipate and prevent fisheries interactions.
While there is further work to be done to put tools like SPTW into action, including increasing the resolution and time-scale of predictions, dynamic ocean management methods and tools offer hope as a way to allow fishers to keep their livelihoods while mitigating their impact on leatherbacks.
So, which method is the best?
The conservation methods covered here are not comprehensive, and more importantly they are not in competition. They should be seen as tools in a toolbox that can be applied alone or in conjunction to best reach our goals. In order to know which tools to use and where to use them, we need research and data to inform our decision making. Leatherbacks and many other pelagic species like beaked whales are still cryptic, meaning that we do not fully understand their lives at sea. Research through biologging and other means is critical to provide the information needed to create effective conservation strategies.
By understanding where turtles go and how they use different marine environments at various life history stages, we can advance targeted solutions to reduce threats at sea and improve protections in critical habitats. Collaborating across cultures and national jurisdictions is an essential part of reducing threats to sea turtles across vast ocean ecosystems, and we are grateful to our partners at MigraMar and other institutions as well as our supporters around the globe for making this work possible.