Dolphins Thriving in New Zealand Marine Preserve
Environmental advocacy groups have been arguing for the expansion of protected areas in the world's seas and oceans. The truth is that for centuries, man has been overexploiting the ocean's rich bounty. Advocates argue that protected reserves are vital for fish to be able to build up their numbers in order to have sustainable fishing. A new study by ecologists from New Zealand has found that not only fish thrive in these areas, but so do marine mammals. The researchers found that a marine sanctuary off the coast of Christchurch, New Zealand has led to the improved survival of one of the world's rarest dolphins, Hector's dolphins.
New Zealand is an isolated island in the middle of the South Pacific with vast expanses of marine territory. The marine preserve that was subject to investigation lays off the east coast of New Zealand’s South Island, and is known as Banks Peninsula Marine Mammal Sanctuary. It was established in 1988 to help the local dolphins from being caught in fishing nets.
Researchers have been photo-documenting the Hector's dolphins since 1986 to measure their relative success within the reserve. Over 450 individuals have been observed and many can be identified by their scars which are received from shark attacks.
The Hector's dolphin is one of the smallest dolphins in the world at only 1.4 meters in length, and only found in New Zealand. Named after Sir James Hector of Wellington, they have struggled to survive due to bottom-set gillnets, a net that is undetectable to the dolphins. When the dolphins get caught, they can’t swim to the surface to breath and eventually drown to death.
Since the marine reserve was established, the Hector's dolphin survival has increased by 5.4%. According to team member, Dr. Liz Slooten of the University of Otago, "This study provides the first empirical evidence that Marine Protected Areas are effective in protecting threatened marine mammals."
However, she warns that their population has not reached sustainable levels and is still subject to decline. Slooten argues that the size of the marine preserve is essential. If the area is too small, it will not be effective in protecting the wildlife.
Image credit: Andrewanderica