New Study Reiterates Sea Otter’s Importance to Coastal Ecosystem

position1268902 New Study Reiterates Sea Otters Importance to Coastal Ecosystem A new study published in the journal Science describes how important apex predators, including sea otters, are to certain ecosystems.

The study, titled “Trophic Downgrading of Planet Earth”, explains how sea otters play an important role in promoting healthy coastal kelp ecosystems by “limiting herbivorous sea urchins” (who feed on kelp) through their rapacious diet. On average, sea otters consume 25-30% of their body weight each day.

Healthy kelp forests, the study explains, then promote robust kelp forest fish populations as well as filter-feeding mussels due to increased particulate organic carbon in coastal waters. Increased fish populations as a result of the kelp forests means birds such as gulls and bald eagles will diversify their diet to include more fish and small mammals and rely less on other birds and macroinvertebrates as part of their overall diet.

The study goes on to describe how physical properties of ecosystems, including forest cover, fire management, and water clarity, can be effected by the presence or absence of apex predators. These predators were long believed to just be “ecological passengers” with little effect on the overall function of an ecosystem. Contrary to that belief, the study finds that some apex predators can have a tremendous impact on an ecosystem by inciting “trophic cascades” like the effects sea otters have on kelp ecosystems.

The authors of the study, including long-time sea otter expert Dr. James Estes, suggest that “top-down forcing” must be assessed in any conceptual overview of an ecosystem. In other words, in addition to assessing physical processes (habitat loss, pollution, etc), resource managers should also assess the abundance of apex predators when determining management plans. Furthermore, the burden of proof should shift to show that “apex predators do not exert strong cascading effects” in an ecosystem rather than trying to prove that they do have an effect as is commonly the case today. In shifting the burden of proof, resource managers will assume apex predators play a role in maintaining an ecosystem until it is proven that they do not. This will result in a more precautionary approach to resource management plans that benefit species like the sea otter.

This study only underscores what sea otter advocates have been saying all along. In addition to their visual and economic appeal, sea otters play a very important role in maintaining a healthy coastal ecosystem full of life and abundance. If we value an ocean teeming with fish and other marine life instead of an open and barren wasteland, then saving the sea otter needs to be our top priority.

Estes, et al. “Trophic Downgrading of Planet Earth” Science 15 July 2011: 333 (6040), 301- 306. [DOI:10.1126/science.1205106]

Yampah Island Project

Recently an article was published in the Santa Cruz Sentinel about sea otter activity in the Parson’s Slough, which relates closely to one of FSO’s most recent projects.  Read below to learn further about our Yampah Island Project and to see an example of waht you can find in our up coming Spring 2011 newsletter!

In the spring 2010 edition of The Raft, we published  “Unknown Otters of Parson’s Slough.” In this article Ron Eby of the Elkhorn Slough Reserve described that among the mud flats and tidal creeks of Parson’s Slough, an area about a mile upstream in the Elkhorn Slough complex near Moss Landing, up to 20 sea otters can commonly be seen resting and foraging. Eby has also noted an unusual behavior. Some sea otters appear to be spending more time on land than is typical. FSO is most interested in this behavior, which has been thought rare for Southern Sea Otters. In October 2010 FSO entered into an agreement with the Elkhorn Slough Reserve to establish a monitoring station on Yampah Island. This region, near Parson’s Slough, will be the site of a wireless camera system that will broadcast a live feed to the Reserve’s visitor center. The live feed will also be available to sea otter researchers and FSO members.

One of our goals for this camera is to reduce the need for volunteers to observe otters on site. Video, pictures, and data captured by the monitoring station will allow sea otter researchers to better understand the behavior of our favorite critter without the potential for human disturbance. It will also provide FSO members and Elkhorn Slough visitors the chance to see exactly what the researchers are watching.

Last month, in the Yampah Island area, a Elkhorn Slough Reserve volunteer witnessed the birth of a sea otter pup.

Ron Eby, FSO’s liaison for the Yampah Island Project, reported: “This event has very seldom been observed in the wild.  The mother was hauled out on the pickleweed, then entered the water to give birth.  After giving birth she rested on her back on the mud bank while grooming her pup for the next hour or so.”

“Pictures were taken from over 100 meters away, but if the camera had been installed we might have been able to get some quality pictures and video from close range,” Eby said.

Ron Eby will install the FSO camera sometime in late spring.

To learn more about the Yampah Island project, or to become an official steward of the Yampah Island Monitoring Station, contact info@seaotters.org or visit our website at www.seaotters.org/yampah.html

yampah island1 Yampah Island Project

A female and pup are pictured on the left. With the Yampah Island Monitoring Station FSO hopes to observe sea otters at a much closer range and do so without disturbing them. Picture by Robert Scoles.

Sea Otter Bill Passes House!

Friends of the Sea Otter applauds the passage of Sea Otter Research and Recovery Bill by House!

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House Acts to Protect Marine Turtles, Sea Otters By THE ASSOCIATED PRESS
Filed at 8:24 p.m. ET

WASHINGTON (AP) — The southern sea otter and the marine turtle would get federal assistance in their struggles to survive under bills the House passed Tuesday.

The House voted 316-107 to approve $5 million a year over the next five years for research and recovery programs run by the Fish and Wildlife Service and U.S. Geological Survey for the southern sea otters along the coast of California.

In 1977, the southern sea otter was listed as threatened under the Endangered Species Act. Currently there are about 2,800 of the marine mammals along the California coast.

Under the bill, experts would study and seek to mitigate causes of high sea otter mortality, which are thought to include malnutrition, shark attacks, entanglement in fishing gear, boat strikes, shooting and proliferation of harmful algae.

”If the sea otters are dying, then something else is happening that is very keen to the coastal near-shore environment that affects the well-being of mankind,” said Rep. Sam Farr, D-Calif., sponsor of the legislation.

The marine turtle bill extends for five years a program that also provides $5 million a year to save the reptiles, which have also been endangered by the destruction of nesting habitats, poaching, entanglement in marine debris, ship strikes and pollution.

The bill, sponsored by Rep. Henry Brown, R-S.C., passed 354-72. Both bills now go to the Senate.

To Track and the Bill and its progresss, visit: http://www.govtrack.us/congress/bill.xpd?bill=h111-556