Watch Out for Whales!
Around the world, ship and ferry strikes are causing the needless and bloody deaths of alarming numbers of whales, many of them young whales and newborn calves. The death toll is likely to rise with the expansion of global shipping, ocean cruising and fast-ferry systems.
Nearly 80,000 ships weighing more than 100 tons travel the world's oceans - each one easily capable of crushing a whale. In some waterways, vessel collisions account for the demise of between one-third to half of all whales found floating at sea, washed up on beaches, or carried into port on the bow of a ship.
Not long ago, the Queen Elizabeth II cruise ship sailed into port in Lisbon, Portugal with a 60-foot fin whale impaled on its bow. Neither the crew nor the passengers were aware that a whale had been run down until the luxury liner arrived in port. The seemingly nonchalant captain told the UK Press Association, "It is one of those things, like running over a cat."
The disturbing image of a fin whale jammed across the bow of the Celebrity cruise ship Galaxy as it cruised into Vancouver dominated the front page of the Vancouver Sun in June 1999. A blue whale was carried into Narragansett Bay in Rhode Island on the bow of a tanker in March 1998.
In the Canary Islands off northwest Africa, a new high-speed passenger ferry system instituted in 1999 has taken a major toll on pilot whales, sperm whales and dolphins. During the first three months of operation, four whales died from collisions. The impact of one collision was so strong that a ferry passenger was also killed.
Which Whales are Killed?
Ship strikes pose a serious threat to highly endangered right whales, Western Pacific gray whales and blue whales. When combined with other human-related causes of death, ship strikes could imperil the long-term survival of the more populous humpback and fin whales. This was one of the conclusions of "Collisions Between Ships and Whales," a groundbreaking report published in the January 2001 issue of Marine Mammal Science.
A key finding from the ship collision report was that the bigger and faster the vessel, the more lethal the collision. A total of 89 percent of lethal or severe injuries were inflicted by fast ferries traveling 12 to 13 knots, cargo ships traveling above 14 knots and cruise ships traveling at 20 to 22 knots. Most whales swim at 3 to 4 knots. When frightened, some whales can swim 7 to 14 knots, while a few can reach more than 26 knots.
Fast ferries have reportedly killed or injured whales in Maine, Washington state, British Columbia, Spain, New Caledonia, the Sea of Japan, the English Channel and the Mediterranean. In France and Italy, more than one in ten whale strandings was attributed to ship strikes, many from speeding ferries. Between France and Corsica, a ferry hits at least one whale per year.
Most whale-ship collisions occur in coastal waters of the continental shelf, areas with high concentrations of whales and vessels. Whales become more vulnerable in these coastal feeding, nursing, calving and mating grounds. Whales spend more time on the surface in these shallow coastal waters. Sometimes a whale sleeping on the surface gets run over by a ship.
Between 1975 and 1996, 14 percent of whales strandings along the US East Coast were attributed to vessel collision. Each year near Chesapeake Bay, nearly one-third of humpbacks found dead were killed by collisions with ships. Most of the humpback and right whales killed by ships were calves and juveniles.
As many as 50 percent of all right whale deaths are the result of ship strikes. At this rate, ship collisions could drive the 300 remaining northern right whales into extinction by 2200. Already this year, a ship has killed one of the 30 right whale calves born in the warm waters off the coast of Georgia and Florida.
Off Southern California, between 1975 and 1980, 12 collisions were reported between Eastern Pacific gray whales and ships. While this species appears to be recovering from near-extinction (it was removed from the endangered species list in 1994), increased shipping traffic could pose a future threat. A new high-speed ferry is slated to begin service between Los Angeles and San Diego in autumn 2001. These boats are equipped with an underwater hydrofoil that could prove deadly to whales and other marine mammals.
In 93 percent of ship strikes, ship operators don't see the whales, or see them too late to avoid a collision. In the majority of the remaining cases, the vessel operators saw the whales but did not attempt to avoid them. To address this problem, the National Marine Fisheries Service (NMFS) has instituted aerial surveys and a mandatory ship reporting system in critical right whale habitat off Georgia, Florida, Massachusetts and Rhode Island.
Aerial surveillance has enabled the NMFS to locate whales and warn approaching ships of their locations. The International Fund for Animal Welfare (IFAW) has installed high-tech acoustic buoys to track right whale migrations in the busy Great South Channel off the northeastern US. A ship-collision workshop organized by the IFAW and NMFS last April is expected to release a new set of recommendations requiring ships to reduce speed in right whale zones and change course to avoid springtime calving areas.
Vessel operators, ports and stranding networks should be required to report all whale collisions, so that a more complete database can be developed. Some waters should be declared seasonally or permanently off-limits to ships and ferries to prevent collisions with endangered whales. The most effective means of reducing fatal collisions would be to require that commercial vessels moving in waters frequented by whales slow to 10 knots or less.