I was thinking of how one might link marine biology to our food supply chain or services such as tourism.
Perhaps some large companies hire scientists to monitor the nearby ecosystem or maintain quality assurance vis a vis their industries.
Think of seafood organizations, they most likely care very much about marine biology and might have teams that conduct research: https://www.seafoodsource.com/news/supply-trade/the-top-10-north-american-seafood-suppliers?content%5Bb1a7c925-1ed6-4bc4-ab97-58e281440ce3%5D=9
Consider resorts (or other types of companies) with a global presence and for which marine biology is a crucial part of their brand and business model: https://www.sandsresorts.com/
Additionally, take a look at National Geographic, as they have initiatives that are linked to marine ecology. Perhaps you can contact NatGeo for recommendations or information on fellowships: https://www.nationalgeographic.com/student-expeditions/interests/marine-biology/
Since you are already thinking globally, spend time researching sectors and companies that are deeply motivated to have marine biology as a core process in their value proposition. Lastly, extend you net beyond the Atlantic Ocean; for instance, consider places like Malaysia or Indonesia for a fellowship or career opportunity if it exists, even if for a few months/years in order to gain the experience and build a professional network.
Good Luck & Stay Well,