Charting Whale Highways
The Science of Biologically Important Areas in Alaska's Waters
Mapping critical habitats for whale conservation in a changing ocean
Mapping Critical Habitats in a Changing Ocean
In the vast, cold waters of the Gulf of Alaska, scientists are engaged in a critical conservation effort: identifying the precise locations where whales feed, breed, migrate, and raise their young. These Biologically Important Areas (BIAs) represent crucial marine real estate for species ranging from the massive humpback to the critically endangered North Pacific right whale, of which fewer than 50 individuals remain in the eastern population2 .
As climate change rapidly transforms northern marine ecosystems and human activities like shipping, fishing, and energy exploration increase, understanding these essential habitats has never been more urgent. Through sophisticated technologies including underwater acoustic monitoring and satellite tagging, combined with traditional field observation and Indigenous knowledge, researchers are creating detailed maps that highlight areas of exceptional importance for whale conservation1 .
BIAs represent specific ocean regions and time periods when cetaceans concentrate for activities fundamental to their survival and population recovery.
What Are Biologically Important Areas?
Biologically Important Areas represent specific ocean regions and time periods when cetaceans concentrate for activities fundamental to their survival and population recovery. Scientists from the National Oceanic and Atmospheric Association (NOAA) delineate these zones using structured expert evaluation and multiple data sources1 .
Feeding Areas
Locations where whales reliably find abundant prey
Reproductive Areas
Regions used for mating, calving, and nursing
Migratory Corridors
Pathways whales travel between seasonal habitats
Small & Resident Populations
Core habitats of vulnerable small populations
The BIA identification process doesn't just draw circles on a map—each area receives scores based on intensity of use, data quality, spatiotemporal variability, boundary certainty, and overall importance. This standardized scoring allows managers to prioritize conservation efforts based on the best available science1 .
The Gulf of Alaska: A Productive but Challenging Ecosystem
The Gulf of Alaska represents one of North America's most productive marine ecosystems, characterized by a counterclockwise circulation known as the Alaska Gyre1 . This circulation pattern creates rich feeding grounds along the continental shelf and shelf break, supporting numerous fish species, marine mammals, and seabirds.
Unfortunately, this rich ecosystem is undergoing rapid changes. A historic marine heatwave from 2013-2016 dramatically altered wind patterns, ocean stratification, and food availability for large whales1 . At the same time, the region's remote location and frequent severe storms make research exceptionally challenging, measuring costs "both in terms of time and money"1 .
Gulf of Alaska BIA Locations
Interactive map showing key Biologically Important Areas
Science in Action: Tracking the Elusive North Pacific Right Whale
The Challenge of Studying an Endangered Species
Perhaps the most compelling application of BIA research involves the North Pacific right whale, one of the world's most endangered large whales. With so few individuals remaining, traditional survey methods often come up empty-handed. Scientists have therefore turned to passive acoustic monitoring to detect these elusive giants2 .
North Pacific Right Whale Population Status
Methodology: Listening for Whispers in the Deep
Hydrophone Deployment
Scientists from NOAA Fisheries and the University of Washington placed specialized underwater microphones at six strategic locations in the Aleutian Island passes and northern Gulf of Alaska2 .
Call Identification
The team programmed these hydrophones to detect two distinctive right whale vocalizations: the "upcall" (an upsweeping pattern) and the "gunshot call" (a short, broadband signal lasting less than one second)2 .
Continuous Monitoring
The acoustic moorings recorded continuously, allowing scientists to detect right whales regardless of weather conditions, daylight, or sea state.
Temporal Analysis
Researchers analyzed detection patterns across months and years to identify seasonal trends in right whale presence.
Remarkable Findings from an Acoustic Census
The results revealed critical insights about these vanishing whales:
"The greatest number of detections occurred in the whale's designated critical habitat off Kodiak, Alaska between September and November"2 .
Additionally, scientists detected right whales during winter months (December-April) throughout the study area, suggesting these areas serve as migratory corridors between northern feeding grounds and unknown southern destinations2 . This discovery represents a significant piece in the puzzle of right whale movements, about which much remains unknown.
| Location Type | Peak Detection Period | Primary Whale Activity |
|---|---|---|
| Critical Habitat off Kodiak | September-November | Feeding |
| Aleutian Island Passes | June-August | Feeding/Migration |
| Northern Gulf of Alaska | December-April | Migration |
Gulf of Alaska BIA Findings: A Regional Overview
The most recent BIA assessment identified a total of 20 Biologically Important Areas in the Gulf of Alaska region spanning six species: beluga whales, fin whales, gray whales, humpback whales, North Pacific right whales, and sperm whales1 .
BIA Distribution by Species
BIA Types in Gulf of Alaska
Perhaps most notably, the assessment identified no reproductive BIAs in the region, highlighting significant knowledge gaps about where these species breed and give birth1 . The researchers also designated five "watch list" areas—locations where preliminary evidence suggests biological importance but data remains insufficient for formal BIA designation.
The Scientist's Toolkit: Technologies Powering Whale Research
Modern whale research employs an array of sophisticated technologies that work together to reveal the hidden lives of these ocean giants.
Sonobuoys
Short-term passive acoustic monitoring that detects vocalizing species, distribution patterns, and relative abundance6 .
Satellite Tags
Tracking long-distance movements to reveal migration routes, habitat connectivity, and critical habitats.
Hydrophone Arrays
Long-term acoustic monitoring that identifies seasonal presence, human noise impacts, and communication.
Citizen Science Platforms
Collecting sighting reports to provide broad-scale distribution data and rare species sightings5 .
Environmental DNA
Detecting species from water samples to confirm species presence without visual observation.
Aerial Surveys
Photographic identification and population assessment through systematic aerial observations.
The Power of Public Participation: Citizen Science Validated
A remarkable 2025 study confirmed that citizen science observations can produce scientifically reliable data for mapping whale habitats5 . Researchers from Ocean Wise analyzed twenty years of whale sightings submitted by the public through the Ocean Wise Sightings Network.
After carefully accounting for reporting biases (such as more sightings along ferry routes), the team found that citizen science data accurately predicted known whale hotspots and closely matched results from dedicated scientific surveys5 . This validation underscores how everyday observations from coastal communities, mariners, and wildlife enthusiasts contribute meaningfully to whale conservation.
Citizen Science vs Scientific Surveys
"These sightings and detections are not just numbers; they are the bridge between people, science, and conservation"5 .
Conservation Impact: From Science to Protection
The identification of BIAs has direct, real-world applications for whale conservation.
Informing Marine Spatial Planning
BIAs help managers avoid placing high-risk activities in sensitive areas1 .
Guiding Environmental Assessments
BIAs provide crucial baseline data for evaluating potential impacts from human activities4 .
Supporting Protected Area Design
The information contributes to the identification of Important Marine Mammal Areas (IMMAs), a global conservation initiative3 .
Reducing Ship Strikes
Real-time sighting data powers alert systems that notify large vessels of whale presence5 .
As of 2025, the IMMA initiative has identified 323 Important Marine Mammal Areas worldwide, with nearly 77% containing habitat for at least one threatened marine mammal species3 .
Conclusion: The Path Forward for Whale Conservation
The scientific work to identify and map Biologically Important Areas represents a critical investment in the future of Alaska's whales. As climate change continues to reshape marine ecosystems, understanding these key habitats will only grow more important.
While significant progress has been made, important questions remain unanswered—particularly regarding winter destinations and breeding areas for many species. The combination of advanced technology, traditional scientific research, and engaged public participation creates a powerful partnership for addressing these mysteries.
As one researcher noted, these sightings and detections are "not just numbers; they are the bridge between people, science, and conservation"5 . Each identified BIA moves us closer to ensuring these ocean giants continue to thrive in the rapidly changing waters of the Gulf of Alaska.
