More Mola

Last week LCTV reporter, Angela McNerney rode along on the rescue of a stranded Mola Mola (aka ocean sunfish) - and this week we continue to tell the story, exploring what lies behind the increased strandings with Mola Mola expert  Carol "Krill" Carson.

What are Mola Mola?

November 20, 2024 — WELLFLEET, MA —   Last week, LCTV Reporter Angela McNerney rode along on a Mola mola rescue, an effort to save a giant ocean sunfish. The mola mola is a gentle deep water fish who migrates through Cape Cod waters and has been stranding in growing numbers this year.

At last count, some 127 strandings has been recorded this year raising the question: Why are these massive dinner-plate shaped creatures that can reach 11 feet long and weigh as much as two and half tons, getting trapped on Cape shores?

Why are large numbers of Mola Mola stranding on Cape Cod?

This year represents the largest number of strandings ever recorded on Cape Cod and scientists are grappling with the reasons behind this spike: Why are so many of these giant fish getting caught in Cape Cod’s unique geography?

Experts like Carol "Krill" Carson, founder of the New England Coastal Wildlife Alliance, believe that Cape Cod’s shape plays a significant role in creating a barrier to their natural migration and as waters warm that migration is also shifting north. She says the Cape is a "hook within a hook within a hook," making it difficult to head for warmer waters during migration.

How does Cape geography play a role?

The "arm" of Cape Cod is distinctive in its posture. The land juts out into the sea for 60 miles and then curves up, forming a natural trap for many marine species. The peninsula creates a "hook" shape, funneling ocean currents and pulling sea creatures, including Mola molas, closer to the shore.

Molas are deep-water fish, typically accustomed to vast open ocean. Once drawn into the shallow, turbulent waters of Cape Cod Bay they find themselves trapped inside the Cape's geographical "hook," facing strong tidal shifts and sandbars. These geographic features - so different from those of the open ocean -  disorient them, impeding their ability to navigate southward to warmer waters as they normally would in the fall and winter. Once in the shallower waters they often end up stranded.

Do warming waters play a role?

Another factor contributing to the strandings may be climate change. As ocean temperatures rise, the environmental cues that Mola molas rely on to guide their seasonal migrations have altered. Marine biologists like Carol Carson suggest that the warmer waters in the fall and winter could confuse these animals, leading them to venture farther north where theyrbecome trapped in the multiple hooks on the coast of Cape Cod waters and unable to migrate south again.

Sunfish remain enigmatic, like so many deep water species. With five known species of ocean sunfish, much remains to be learned about these creatures;  changes in their migratory patterns could be an important indicator of how climate change is affecting marine life on a larger scale, said Krill.

How do the factors combine to increase Mola Mola strandings?

There is likely no single explanation for the increased strandings of Mola molas, no silver bullet of stranding strikes. However, it is clear to those who study the gentle giants that the interplay of Cape Cod’s geography, shifting ocean temperatures, and environmental factors has created a perfect storm for these unusual fish - one that this year's 127 strandings illustratees

By studying these strandings, scientists are learning more about the behavior and migration patterns of Mola molas, while also gaining insights into the broader effects of climate change on ocean ecosystems. As we continue to follow these rescue efforts and research initiatives, the hope is that science can offer solutions to help protect these remarkable animals in the years to come.