In the News: Hawaiian monk seal sliding towards extinction in reserve
Listed as Critically Endangered by the IUCN, the Hawaiian monk seal was persecuted in the past for its meat, hide and oil, and its populations continue to decline as a result of human disturbance, low food availability and entanglement in marine debris.
The new research, published in the journal Conservation Letters, reports that the Hawaiian monk seal population in Hawaii's Papahānaumokuākea Marine National Monument is declining by about 4% a year.
In contrast, a population in the main Hawaiian Islands is increasing by 7% a year, despite fishing, development and boat activity all being permitted in the area.
Largest marine reserve
The Papahānaumokuākea Marine National Monument is one of the largest marine reserves in the world, covering an area of 362,000 square kilometres. Encompassing all of the Northwestern Hawaiian Islands, the reserve contains extensive coral reefs and includes important habitat for rare species such as the green turtle. It is also home to 85% of the Hawaiian monk seal population.
The reasons for the monk seal's decline in the reserve are unclear. According to Les Kaufman, a conservation biologist at Boston University in Massachusetts, "It's impossible to know if the reserve is actually causing or even contributing to this effect, but it's deeply disturbing that it hasn't reversed it."
Suggested causes of the decline include increased shark predation within the reserve. Fishing was banned in the area in 2006, but fishing discards prior to this may have boosted shark numbers, and these sharks could now be wreaking havoc on seal pups. Some locals have even started a shark-culling programme to control 'problem sharks'.