Protecting Whales with AI and Acoustics in Offshore Wind

This article explores how offshore wind construction vessels use integrated marine mammal protection networks to safeguard the critically endangered North Atlantic right whale. By combining underwater passive acoustic monitoring with surface-level thermal infrared artificial intelligence, these advanced systems detect approaching whales in real time, regardless of visibility or weather conditions. When a whale enters a designated safety zone, the network immediately alerts protected species observers to halt noisy pile-driving operations, preventing auditory injury and mitigating disturbance to these vulnerable marine mammals.

The Threat of Pile-Driving

Constructing offshore wind turbines requires driving massive steel foundations deep into the seabed. This process, known as pile-driving, generates intense underwater noise impulses that can travel for miles. For the North Atlantic right whale, a species with fewer than 360 individuals remaining, this noise poses a severe threat. It can cause temporary or permanent hearing loss, mask vital communication calls, and force whales to abandon critical feeding or breeding grounds. To prevent this, regulatory bodies require construction vessels to establish strict exclusion zones around pile-driving sites.

Passive Acoustic Monitoring (PAM)

Passive Acoustic Monitoring is the primary underwater defense for detecting whales that are submerged and out of sight. PAM systems utilize arrays of underwater microphones, called hydrophones, deployed via buoys, autonomous underwater gliders, or towed directly behind support vessels.

These hydrophones continuously listen to the ocean environment. Specialized software analyzes the incoming audio feeds in real time to identify the specific frequency and vocalization patterns of North Atlantic right whales, particularly their signature "upcalls." By using multiple hydrophones spaced apart, the system calculates the time difference of the sound's arrival at each sensor. This process, known as triangulation, allows the system to pinpoint the whale’s exact location and track its trajectory relative to the construction vessel.

Thermal Infrared AI

While PAM handles underwater detection, whales must eventually surface to breathe, sometimes without vocalizing. Traditional visual monitoring by human observers is ineffective at night, in dense fog, or during high seas. Thermal infrared cameras connected to artificial intelligence bridge this gap.

Mounted high on the construction vessel, stabilization gimbals keep thermal cameras steady as they scan the ocean surface in a 360-degree radius. When a whale surfaces and exhales, its blow creates a distinct heat signature against the cooler ambient temperature of the ocean water. The AI algorithms are trained on thousands of thermal video frames to instantly recognize the specific shape, temperature profile, and dissipation rate of a whale blow. This allows the AI to distinguish a surfacing whale from false positives like whitecaps, sea birds, or vessel wakes in milliseconds.

Sensor Fusion and Halting Operations

To ensure rapid action, data from the PAM arrays and thermal AI cameras are fed into a centralized software platform monitored by onboard Protected Species Observers (PSOs). This sensor fusion creates a comprehensive, real-time map of the exclusion zone around the pile-driving rig.

When either the acoustic sensors or the thermal AI detects a North Atlantic right whale approaching the exclusion perimeter, the system triggers an immediate audiovisual alarm on the vessel's bridge and at the PSO monitoring station. A PSO quickly verifies the digital data—checking the spectrogram of the acoustic call or the thermal video clip—to confirm the sighting.

Once confirmed, the Lead PSO issues a mandatory shutdown order to the pile-driving crew. The hydraulic hammers are immediately powered down, halting the acoustic impact before the whale enters the danger zone. Pile-driving operations remain suspended until the tracking network and the PSOs confirm that the whale has voluntarily left the exclusion zone and a mandatory clearance period—often 30 to 60 minutes without further detections—has safely passed.