The grievous death of a 20-year-old German woman from a shark attack adds to what is described by the state director of land and natural resources as "an unprecedented spike" by the lethal predator in shallow waters off Hawaii.

The decision to launch a two-year study of the movements of sharks in Maui waters is appropriate — and could recommend more forceful action — but efforts are needed meanwhile to increase warnings.

Jana Lutteropp’s right arm was severed while she was snorkeling Aug. 14 about 50 yards off White Rock Beach on Maui and she was on life support until her death on Wednesday. The type of shark that bit Lutteropp is not known, as no one saw it.

The previous fatal shark victim was Maui surfer Willis McInnis, 57, in April 2004 off Pohaku Park in West Maui.

Following recent years that averaged three or four incidents a year, confirmed shark attacks reached 10 attacks in 2012, the highest number ever recorded.

Eight attacks already have occurred this year, including four in the last month, the most recent victim being a 16-year-old surfer who suffered leg injuries last Sunday in waters northeast of Hilo.

The prevailing theory for the increase is that more people are in the water and decades have passed since shark-culling was in practice, "so we have a great number of tiger sharks that have been born and matured since then that are now roaming our waters," said William Aila Jr., director of the Department of Land and Natural Resources.

Aila has authorized a $186,000 two-year study to examine the behavior of tiger sharks off Maui, where four of this year’s attacks have occurred.

"We are committed to furthering research efforts that will help guide effective management actions in the interest of safety," he said.

Indeed, coming up with research-based methods will be key.

The reason for the increase is difficult to explain. Hawaii Institute of Marine Biology researchers Carl Meyer and Kim Holland have pointed out that tiger sharks are constantly on the move and rarely "set up shop" at a specific spot. Some indication exists that pregnant female tiger sharks congregate around the main Hawaiian islands to give birth.

The practice of shark culling has both opponents and proponents. Critics question its overall effectiveness, noting the migratory nature of sharks; and point out that the ocean is the sharks’ — not humans’ — domain. Proponents, though, will note that culling could reduce the number of sharks appearing in near-shore waters, and fewer numbers lower the potential for encounters.

For an island state like Hawaii, and as dependent as we are on tourism and ocean recreation for tourists and residents alike, shark culling should be on the table of options given this "unprecedented spike" in attacks here since the start of 2012.

An area of Olowalu in West Maui is the only place in Hawaii with shark warning signs, which were posted after two visitors were bitten in a two-year period in the early 2000s. A resident was killed by a tiger shark in that area in 1991. Aila said the state will post warning signs in certain areas if the two-year study shows an area with a preponderance of sharks.

Meyer and Holland suggested in these pages last December that the increase in shark attacks probably reflects gradually increasing numbers of people entering in the ocean.

"Scientists believe that the number of people rather than the number of sharks is what determines attack rates," they wrote.

There is no such thing as zero risk when going into waters, but there are ways to minimize dangers. Community education plays a key role in this.

Aila says people should be vigilant and cautious, avoiding swimming by themselves a mile from shore or while injured or bleeding.

Such educational warnings need to go out routinely to visitors and residents alike.