Additionally, individuals may move from one area to the next during any time period for a number of reasons, including sea otter social behavior and their reaction to the environment. Airplanes searching for sea otters have to cover more ground, usually with the same amount of time and money. Each year, animals move to new areas, increasing the amount of area and effort required to find them. It’s challenging to estimate how populations grow and spread, due to their dynamic nature. Map used with permission from the National Park Service Our approach Glacier Bay National Park, southeastern Alaska. Here they encountered vast habitat, abundant prey populations and protection from all human harvest. Sea otters first reappeared at the mouth of Glacier Bay in 1988. This new environment supported high concentrations of wildlife, including sea otter prey species-such as crabs, mollusks and sea urchins-that were able to increase in size and abundance in the absence of sea otters. After glacier retreat, a rich environment emerged. It then endured the most rapid and extensive tidewater glacier retreat in recorded history. Glacier Bay was completely covered by glacier ice until approximately 1750-about the same time sea otters vanished from the surrounding area due to over-harvest. Glacier Bay is functionally one of the largest marine protected areas in the northern hemisphere. Wildlife agencies also made an effort to aid sea otter recolonization.Įventually, sea otters began to increase in abundance and distribution, and they made their way to Glacier Bay, a tidewater glacier fjord and national park in southeastern Alaska. The International Fur Seal Treaty in 1911 protected sea otters from most human harvest. The populations at Queen Charlotte Islands and San Benito Islands went extinct by 1920.īut sea otter populations have recovered in many areas, thanks to a few changes. Historic range (gray shading) and 1911 remnant populations (red icons) of sea otters. By 1911, only a handful of small isolated populations remained. It may even help us learn what a changing climate means for many other species.Īlthough not typically viewed in the same vein as wolves, tigers and leopards, sea otters are an apex predator of the nearshore marine ecosystem-the narrow band between terrestrial and oceanic habitat.ĭuring the commercial maritime fur trade in the 18th and 19th centuries, sea otters were nearly hunted to extinction across their range in the North Pacific Ocean. Our approach-which fuses mathematics, statistics and ecology-can help us better understand the role of sea otters in marine ecosystems and the ability of apex predators to return to an ecosystem after they’ve been absent. In a recent study, our team chronicled the incredible return of sea otters to an area where they’ve been absent for at least 250 years. The sea otters in Glacier Bay, Alaska, are an exception. Rarely do the predators fully recover from human oppression, and when they do, we often lack data or tools to assess their recovery. The loss of these predators-animals at the top of the food chain-has resulted in ecological, economic and social impacts around the globe. Human beings have a long history of persecuting apex predators such as wolves, tigers and leopards.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |