The International Union for Conservation Nature (IUCN) is the official advisory body on nature under the World Heritage Convention and as a result monitors the state of conservation of all natural sites on the World Heritage List. There are currently over 20 World Heritage sites that protect mangrove forests globally. IUCN has assessed the state of conservation of some of these sites which are at most risk (e.g. Belize Barrier Reef Reserve System (Belize), East Rennell (Solomon Islands), the Sundarbans (Bangladesh), and Everglades National Park (USA)), and made recommendations to the States Parties to ensure effective management of these sites. Such monitoring is ongoing and IUCN will continue to provide technical advice to the World Heritage Committee.

In addition, the IUCN World Heritage Outlook was introduced in 2014 to complement the statutory monitoring under the Convention. It recognises good conservation practice and supports the role of World Heritage sites in demonstrating excellence, whilst also identifying the actions needed to support sites that are facing threats in order to improve their conservation outlook. The IUCN World Heritage Outlook is a proactive step to overcome existing and potential knowledge gaps through a methodological approach, and it also offers an early warning system helping to identify threats and take the necessary actions. The first update was released in 2017 and IUCN will produce the third update in 2020, which will track the trends and changes to the status of natural World Heritage sites. Being a comprehensive monitoring tool applicable to all natural sites, the IUCN World Heritage Outlook includes information on the state of all World Heritage sites that protect mangroves.

In 2014, IUCN additionally produced a study on the benefits of natural World Heritage. Its main purpose is to increase awareness and understanding of the full range of direct and indirect benefits that local, national and global communities can receive from natural World Heritage sites. The online interactive tool maps the various ecosystem services provided by World Heritage sites including coastal protection and flood prevention. The study also included a number of case-studies which provided a more detailed example of each of the ecosystem services, with The Sundarbans (Bangladesh) and Sundarbans National Park (India) featured in one of the case-studies. In 2016-2018 IUCN undertook the second phase of the project to implement further research and capacity building for World Heritage site managers on recognising and quantifying benefits arising from World Heritage sites, beyond the core task of nature conservation. The outcome of this phase of the project a new guidance tools for site-level assessment of ecosystem services has now been released and is available for site managers and other practitioners.