Dive Deeper
1
Presence
Right whales are in Maine waters. Here are the facts, how we know them, and why they matter.
How do we know whales are here?
Maine DMR, NMFS, and other organizations monitor right whales using aerial surveys (planes), vessel surveys, and underwater acoustic monitoring -underwater microphones that detect whale calls.
You can see this work through real-time mapping tools. Whalemap.org shows where whales have been recently detected through aerial and vessel surveys, acoustic gliders, and chance sighting reports.
The Passive Acoustic Cetacean Map allows users to explore when and where specific whale species, including right whales, have been detected using sound or passive acoustic listening technologies. Unlike WhaleMap, these data are not available in real time because recordings may be collected from these devices only every 4-6 months. Passive acoustic monitoring devices are listening for whale calls around the clock. This information is helping us better understand how right whales use the Gulf of Maine and where they may overlap with fishing activity.
Since 2022, Maine DMR has established its own right whale research program, generating Gulf of Maine-specific data that will inform future management discussion. Maine DMR Right Whale Research
Why are right whales showing up differently than before?
Ocean conditions in the Gulf of Maine have varied significantly in recent decades, reaching record warm temperatures, and then shifting back to cooler waters. Changes in water temperature affect ocean currents where whale food becomes concentrated. Right whales are kind of like us—they follow their stomachs. When food shifts, whales shift with it. That means the places and times when whales are seen may not match what fishermen remember from years past. This is why current monitoring and new data are so important.
How many right whales are there?
NMFS’s most recent right whale population was released in late 2025 and estimates there are 384 North Atlantic right whales. Less than 300 right whales existed in the early 1990’s and the population grew to 480 whales by 2011. Following a nearly 10-year decline, the right whale population, including the number of females, has increased slowly since 2020, and births now exceed deaths. There is cautious optimism that the population decline has ended. However, the population remains very small and federal laws require measures to aid the species recovery.
Why does right whale presence matter legally and practically?
The Marine Mammal Protection Act (MMPA) and the Endangered Species Act (ESA) require the federal government to reduce human-caused death and injury to right whales.
Management decisions are not based solely on documented entanglements. NMFS calculates the risk of harm from fishermen based on gear type, where gear is fished, and where whales are likely to be. That’s why recent, accurate data collected by NMFS and DMR is needed to inform the development of new management measures.
What we still don’t know
- Whale monitoring is essential, but it cannot tell us everything. Surveys don’t cover every area, every day and are limited by weather, daylight, sea conditions and whether whales are visible at the surface. Listening devices can only detect whales if they are calling within range of the equipment.
- Not all entanglements are observed. Even when an entangled whale is seen, gear markings may not be visible or recoverable, making it difficult to determine where the gear came from or identify the fishery involved. In some cases, it may also be difficult to determine the precise cause of death.
- Although right whale data will continue to improve, scientific uncertainty remains about right whale distribution patterns and how they’re changing.
- Scientific uncertainty cuts both ways. It’s a reason to be cautious, but it’s also a reason Maine-specific data matters.