Collisions with Ships
Ships hitting whales, dolphins and sea turtles
It’s like a hit and run death or injury to a human by a car, but in this case it’s happening to coastal wildlife.
Shipping traffic has increased along coastal United States (even as small as a jet ski), plus increasing speed of watercraft and the expanding sizes of cargo or tanker vessels often means death and injury for many slow moving whales and sea turtles who might be just resting, migrating or seeking a meal along the coast.
How do animals get struck by ships?
Large ships are unlikely to see a whale, dolphin or sea turtle. Due to the large size and speed of a ship, it may be unable to divert course even if they do see a marine mammal or sea turtle. In addition, a large ship creates something called a ‘bow null effect’ blocking the engine noise by the bow, creating a quiet zone in front of the vessel, and leaving an aquatic animal unaware of the pending hazard.
Collisions with vessels can be fatal. When a whale or sea turtle is hit by a ship or another vessel, these gentle creatures are likely to die or suffer a horrific injury. Ship collisions have been identified as a significant human cause of baleen whales (mysticete) mortality .
Whales and sea turtles are often unable to avoid ships, because many species move slowly in the water. Collisions often go unnoticed or unreported by the vessel’s captain, which means the deaths of whales and sea turtles are far higher than figures suggest. Sometimes injuries may not be life threatening right away, but a whale or sea turtle will die months or years later.
Whales slowly swimming, resting, or sleeping (logging) just below the surface of the water may be struck by speeding boats near the coast or within an estuary. Farther out in the ocean larger ships, including cargo ships and tankers, present an even greater threat of death and injury.
Whales and sea turtles spend most of their time underwater. So animals can be difficult to spot just below the surface, particularly at night or in rough ocean or choppy coastal waters.
An individual whale or sea turtle may also not see a vessel as a threat in urban waters where animals are often accustomed or familiar with boat noises around them, just like a person living on a busy city street. But life in urban waters can be deadly. Whales live in a world of sound, this is how many species of cetaceans find food and a mate, but large ships can cause a sound effect in the water called a ‘bow null’ effect. Load engine noise locate at the rear of the vessel is frequently masked or blocked by the front of the vessel. Many times a whale or sea turtle will not even hear an approaching vessel until it is too late.
Blunt trauma occurs when the vessel hull strikes a marine mammal or sea turtle straight on, resulting in bruising or broken bones or death.
Propeller strikes cause deep cuts in the tissue (or flesh) of whales and sea turtles. Sometimes this injury may result in a series of scars or death depending if main arteries or the spinal cord are cut.
Beached whales or sea turtles with large wounds from propellers, missing fins and other body parts are all evidence of a deadly encounter with a boat or ship in the water.
RIGHT WHALES: COLLISIONS ARE ONE OF THE MAIN CAUSES OF DEATH!
The North Atlantic right whale (Eubalaena glacialis) is one of the world’s most endangered large whale species, with only around 450 remaining on the planet. According to NOAA, along with entanglement in fishing lines, vessel strikes are a major threat to North Atlantic right whales. A right whale’s habitat and migration routes are close to major ports along the Atlantic seaboard and often overlap with shipping lanes, making the whales vulnerable to collisions with ships. Since the whales prefer the same coastal waters that people do, they still face a wide assortment of threats as they swim offshore, including underwater noise pollution that interrupts the normal behavior of right whales and interferes with their communication.
Northern Right Whales prefer to swim in warm coastal waters often near Boston, Charleston, Philadelphia, New York and other cities along the eastern United States. They will feed on copepods and other plankton that thrive in coastal waters. In the winter, right whale moms give birth to calves near southern states like Georgia and Florida. Then they swim north to New England and the southern coast of Canada to feed during the spring and summer months. Along the way, the whales and their young are vulnerable to collisions with ships.
The bow or front section of a boat’s hull is like a battering ram, easily smashing the bones and body of a sleeping or tired whale, sea turtle or another unsuspecting sea creature.
“Whales feed in close proximity to the entrance of the Port of New York and New Jersey, creating potentially dangerous situations for both vessels and whales. Documenting humpback whale presence and identifying the risks are crucial for both short- and long-term management,” wrote researchers at George Mason University in Virginia and Gotham Whale, a nonprofit group in New York City.
Published in the journal Marine Policy, authors Danielle M. Brown, Paul L. Sieswerda and E.C.M. Parsons report humpback whale sightings – along with strandings of dead whales – have substantially increased around the apex of the New York Bight since 2011. The team makes a case for stepping up whale monitoring in the Bight, for both conservation and the safety of mariners and whales.
Some 45% of sightings recorded by Gotham Whale were less than 3 kilometers (1.8 miles) from shore, and analysis of automatic identification system data from passing vessel traffic showed that in 2016, 95% of sightings were within 100 meters (328′) of at least one vessel transit.
Slow down! Just like vehicles around a school zone or on crowded city streets, boats and other vessels need to slow down in areas where there is a high probability of marine mammal or sea turtle activity (especially feeding areas). Research shows that boats and ships that operate at slower speeds (10kts or less) significantly reduce the risk of mortally wounding a whale if struck. Slowing down may also provide the animal with an increased reaction time to move away from the vessel. An example where this has worked well is in the St. Lawrence River estuary in Canada. Ship pilots significantly reduced their speed across the area, with 72 percent of the transits in 2014 occurring at speeds less than 13.6 miles per hour. Since 2014, there have been no or few whale strikes reported.
Better technology. Technology needs to be in place that warns a ship’s captain of a potential strike. In 2017, the Benioff Ocean Initiative, a team of marine biologists and technologists from universities and research labs around the United States, received a 1.5 million grant to develop a system that detects endangered blue whales using acoustic and thermal sensors and sends alerts to nearby boat captains. The goal is to reduce collisions between big ships and the world's largest animal in California's Santa Barbara Channel, a historical hotspot for encounters that frequently prove fatal for the whales. Additional funds need to be devoted to developing this technology on both coasts of the United States.
Better mapping. There needs to be a national strategy by the U.S. government to know exactly where marine mammals and sea turtles are most in danger, by mapping the risk of vessel strikes on a national scale. Reported strikes usually coincides with areas of heavy ship traffic and in areas of shipping traffic lanes. Hot spots can then be identified. To a certain point, this is currently being done by the International Whaling Commission (IWC) but uninfluenced and objective organizations in the United States should also be conducting this activity to make sure the data is correct.
A Warning System for Whales. In Cape Cod Bay, the US National Oceanic and Atmospheric Administration (NOAA) has established a warning system for whales in the navigation corridor to Boston. Buoys are equipped with hydrophones capable to pick up the calls of whales. If a whale is detected, a signal is sent to ships so they can slow down in a particular sector. This activity should be expanded to other waters along the east coast.
Lookouts on ships. Ship captains can also post lookouts to scan waters for nearby marine mammal or sea turtle activity. If the lookout sees a spout, tail, or breaching whale, the person can tell the captain to slow down. Some whales may dive for 20 minutes or more while searching for food. If one whale is seen, many more could be close - maybe too close to a boat and its spinning propellers and powerful steel hull.