Friday, October 26, 2007

HI Superferry: Dr. Lee Tepley on Likely Whale Strikes

POSTED: 15 OCTOBER 2007 - 7:00pm HST - The Dirty Little Secret of the Superferry
Secret of the Superferry and Six dead whales by Lee Tepley on 15 October 2007 - A recent e-mail states that Governor Lingle’s Attorney General is proposing that the Superferry be permitted to operate without restriction regardless of any existing or future laws or court decisions.In the hope that this attempt to legalize Executive Branch tyranny will not prevail, I will continue my modest effort to clarify the threats to marine life - and especially to Humpback whales - that will be caused by the Superferry.This letter will be concerned only with vessel-whale collisions. The term “Dirty Little Secret” used below refers to the fact that the Superferry will be far more dangerous to Humpbacks and other marine mammals than any other vessel in Hawaiian waters and there is no practical way to eliminate this danger.When any large vessel strikes a whale, the whale is likely to be seriously injured or killed unless the vessel is moving at a very low speed (on the order of 10 knots). As the vessel speed increases, the risk of death by collision increases rapidly. This has been demonstrated in many scientific papers - the most recent of which is called “Vessel Collisions with whales: The Probability of Lethal injury based on Vessel speed” by Vanderlaan and Taggart. A PDF copy of this paper is attached.Also, at very low vessel speeds - like 10 knots - a whale will have more time to react and get out of the vessel’s way. Sometimes the whale will react and avoid collision and sometimes it will not. Baby Humpbacks are less likely to react than adults who may have had more experience in avoiding ships. Furthermore, at very low speeds, the vessel will have more time to slow down or turn to avoid a collision; that is, if anyone on board should see the whale. Then, it will take at least 5 seconds (probably a lot more) before the Pilot can react and start to slow down or turn the ship.
If the ship is traveling slowly, this might be enough time to avoid a collision. But if the ship is traveling at high speed – say 37 knots – it would have moved at least100 yards before the pilot even reacts. And then how long would it take to slow down or turn the ship?? So a vessel moving at high speed will probably hit a whale unless it surfaces many hundreds of yards away.To summarize, low vessel speeds are obviously safer for whales than high speeds in terms of collision avoidance but when a ship-strike does occur, it is likely to be deadly at any speed above 10 knots –and will even be more deadly at higher speeds.So how does the above apply to the Superferry?If the Superferry is to travel at a low enough speed to minimize the risk of a fatal whale-strike, it would take all day to travel between islands. HSF could not possibly operate under this condition and stay in business. Therefore, it must travel fast and is inherently a serious threat to marine life. This is the “Dirty Little Secret” of the Superferry. In contrast, inter-island cruise ships can run at relatively low speeds because they have all night to travel between the islands.But the above is only part of the Superferry’s “Dirty Little Secret”. In fact, the Superferry is far more dangerous than a conventional large vessel (like a cruise ship) even when it is running at the same speed as the conventional vessel because:(1) The Superferry has two bows - as opposed to one bow for a conventional vessel. This doubles the probability of a collision with a whale.(2) The Superferry will push less water out the way than a conventional vessel and is therefore much less likely to push a whale out of the way. Instead, it will slice into the whale.So how does HSF try to cover up the Superferry’s “Dirty Little Secret”. Here are three ways:COVER-UP #1. HSF claims that it has exotic detection methods to permit the Superferry to avoid colliding with whales. It does not!! It has no way of detecting whales that suddenly surface in front of the Superferry - or maybe don’t surface at all. It’s pontoons extend down to 14 ft. Also, in rough water, observers are not likely to detect the whale’s dorsal fin which may break the surface for only a few seconds as the Superferry approaches. The likelihood of spotting a baby whale in even moderately rough seas is extremely small.COVER-UP #2. HSF has argued that there is no evidence that cruise ships traveling at 25 knots kill whales – so why worry about the Superferry. However, I demonstrated some time ago that inter-island cruise ships mostly travel at speeds much less than 25 knots – so they are much less likely to kill whales than the Superferry which will travel at 37 knots in open water. Still, large vessels do not always travel slowly and the fact that 6 dead whales (5 Humpbacks and 1 Sperm whale) have been found in Hawaiian waters in the last 3 years suggests that large vessels have been killing whales – maybe lots of whales. See my Superferry web site for details.
Go to
Then go to the page on Vessel/Whale collisions. If fast moving conventional vessels have indeed been killing whales, it follows that the Superferry will kill a lot more – partly because of it’s two bows and partly because it will travel much faster than even the largest fastest conventional vessels in Hawaiian waters. COVER-UP #3.HSF has also argued that small boats hit 6 Humpbacks last year - so, again, why worry about the Superferry. This is another way of trying to cover up the “Dirty Little Secret”. But the fact is that the 6 Humpbacks struck by small boats last year suffered only propeller cuts. They bled but, apparently, all survived. They will rarely survive when hit by a large fast vessel like the Superferry.So – in what appears to have been incredible favoritism - and which may now be turning into Executive Branch tyranny - the legislature may be pressured into permitting the Superferry to operate without restriction during the environmental assessment process and beyond. But no environmental studies can cover up the “Dirty Little Secret” of the Superferry – which is that it is inherently far more dangerous to whales and other marine mammals than any other vessel in Hawaiian waters.

1 comment:

Fabian Ritter said...

Hi there,

this is to share some information on the impact of large high speed ferries in other parts of the world.
In the Canary Islands, where I work as a cetacean biologist for more than 10 year now, HSF were introduced in 1999. Since then, the number of whales killed has increased dramatically. Primarily affected is the sperm whale, and there are now numerous findings of whales cut into halves or showing severe injuries clearly related to ship strikes. According to my colleague Manolo Carillo, who is investigating cetaceans washed ashore, there were more than 50 documented deadly ship strikes in the past 7 -8 years, and nobody knows the dark figure. This is dramatic.

Thus, although the SF operator in Hawaii appears to be much more open for discussion than the ones in the Canary Islands, we have to be extremely careful with introducing HSF in areas with known high cetacean abundance.

Fabian Ritter,