SALT LAKE CITY — Utah Division of Wildlife Resources officials are reminding the public not to feed deer or other wildlife after corn kernels were discovered in the gut of a deer that recently died of chronic wasting disease in the Moab area.
While it is not illegal to feed wildlife, there are several reasons that it is highly discouraged, including public safety concerns, the spread of chronic wasting disease among deer, elk and moose, and potential harm to wildlife from introducing foods not in their diets, particularly during winter months.
Chronic wasting disease concerns
In the past month, two mule deer have been found dead in the yards of Moab residents. Both of these deer tested positive for chronic wasting disease, a relatively rare, but fatal transmissible disease that affects the nervous systems of deer, elk and moose. It has been compared to bovine spongiform encephalopathy in cows, which is often called "Mad Cow Disease."
Infected animals develop brain lesions, become emaciated, appear listless and have droopy ears, may salivate excessively and eventually die. Infected animals ultimately lose their motor skills and eventually waste away and die from degeneration of the central nervous system. There are currently no vaccines or treatments for this disease.
CWD is highly contagious among deer. Infected animals can shed prions, which are protein-based infectious particles, in their urine, feces and saliva. Transmission may occur directly through contact with an infected animal or indirectly through environmental contamination (for example, a dead carcass can spread it to the soil). These prions are highly resistant to chemical and environmental degradation, and once the environment becomes contaminated with prions from shedding deer or infected carcasses, it can be a source of infection for years into the future.
Because the prions are shed in saliva, urine, and feces and can persist in the environment for a long time, CWD is easily transmitted in areas where a large number of deer congregate. Feeding deer can cause large groups of them to congregate into one area, increasing the chance of the disease spreading from one animal to the next.
“Because the disease is so contagious, it is essential that residents do not feed wildlife,” DWR Regional Outreach Manager Aaron Bott said. “This includes putting out corn, hay, dog food or birdseed that deer might easily access. Although it may seem like a beneficial thing to do, feeding deer actually accelerates the spread of this disease. In the most recent CWD deer fatality in Moab, biologists found corn kernels in the deer’s gut, suggesting it had been feeding on food provided by humans.”
Fortunately, the disease is not widespread throughout Utah, and is primarily found in a few counties in central and eastern Utah. The DWR takes CWD very seriously and conducts extensive monitoring each year to stay on top of the disease and its prevalence in the state. The recently updated and approved Mule Deer Management Plan includes a section on CWD that addresses ways to slow the spread of the disease in Utah.
“We want to remain as proactive as possible to slow and prevent the spread of this disease,” Bott said. “Currently, the La Sal Mountains have one of the highest concentrations of CWD in Utah, located right in Moab’s backyard. This is why it is essential that the community of Moab help us in fighting the spread of this disease by not feeding the wildlife or causing them to congregate.”
Studies have shown that humans, dogs, cats and other species are unlikely to contract CWD. However, the DWR recommends avoiding diseased deer. Any deer that looks sick (i.e., has trouble walking, drools, has drooping ears or looks emaciated) should be reported to the nearest DWR office. Learn more about CWD in Utah on the DWR website.
Other biological harm to wildlife
Introducing the wrong type of food to wildlife can harm them, especially during the winter. Deer are ruminants — mammals that acquire nutrients from plant-based food by fermenting it in a specialized stomach before digestion.
Deer have four-part stomachs, and each stomach chamber progressively breaks down woody, leafy and grassy foods into smaller particles. These stomach chambers contain microbes that are essential to digesting food. The type of microbes in deer digestive systems gradually change throughout the year and are very specific to the food that is available. During the winter, deer primarily feed on sagebrush and other woody plants. Suddenly changing a deer's diet can easily lead to the deer eating food that it cannot readily digest. In these situations, deer often die from starvation with full stomachs.
And when deer congregate to feed, it's every deer for itself. The larger deer often push the smaller deer — the fawns — aside, and they often end up receiving less food than they would have received if people had left them alone.
“This is why feeding deer and other wildlife is usually not a good idea,” DWR Big Game Coordinator Covy Jones said. “Although it sounds like an act of kindness and may sometimes help some animals get through the cold months, it can create major problems.”
The DWR does occasionally feed deer in specific emergency situations when supplemental feeding is beneficial. For example, deer herds in critical wintering areas that are caught in unusually deep and long-lasting snow might benefit from winter feeding.
When the DWR considers supplemental feeding, biologists carefully analyze whether the benefits will outweigh the disadvantages. If a decision is made by the agency to proceed, resources are allocated, special food mixtures are determined and the feeding takes place in an organized, targeted and strategic way that maximizes the benefits to the deer while minimizing the possible adverse consequences.
The DWR also feeds elk during the winter at the Hardware Ranch Wildlife Management Area to help prevent local agricultural damage from the large elk herds. However, the elk are routinely monitored and tested for disease, and the feed is specialized so as not to harm the animals.
Public safety concerns
Whenever someone feeds wildlife, those animals will frequently return to that area in search of food. These areas are often near highways and towns. Concentrating deer and other wildlife near inhabited areas can sometimes result in increased traffic accidents and other human/wildlife conflicts.
Attracting deer to your property through feeding can also attract predators, like cougars that follow deer herds. And while deer are not predators, they are still wild animals and can be aggressive.
“Help yourself and the wildlife stay safe and avoid conflicts by not feeding them,” Jones said.
Find more tips on how to avoid conflicts with wildlife on the Wild Aware Utah website.
Great Salt Lake sees record season of raw pounds of brine shrimp cysts harvested
SALT LAKE CITY — The Great Salt Lake is known for its incredibly high salinity levels that allow people to float, but many may not be aware of its multi-million dollar brine shrimp industry and how the Utah Division of Wildlife Resources manages it to help balance a unique ecosystem.
Brine shrimp are small crustaceans that inhabit salty waters around the world, both inland and on the coast. Ranging from ⅓ of an inch to a ½ inch, these shrimp are much smaller than the ones you eat.
The brine shrimp produce eggs (called cysts), which are harvested and used as food for fish and commercially grown shrimp. The brine shrimp season begins Oct. 1 and typically runs until Jan. 31 each year, except when the dates are extended or shortened for management purposes. This past season, more than 44 million raw pounds of brine shrimp cysts were harvested at the Great Salt Lake, making it the highest number of raw pounds to ever be harvested in one season. Not all of the poundage is marketable, however, as the raw pound totals include small amounts of sand and bird feathers, so it isn’t all sellable cysts. The average for the past decade has been an annual harvest of 25 million to 35 million raw pounds.
Due to the high demand for brine shrimp cysts and because of overharvesting by other commercial fisheries in other areas of the world, the DWR began managing the harvest on the Great Salt Lake in 1994. By taking an active management role, the DWR could closely regulate and monitor cyst collection so it remained sustainable.
“The companies that harvest the brine shrimp actually asked for the regulation, and have always been very compliant and responsible in making sure this valuable resource and the unique Great Salt Lake ecosystem remain in balance,” Great Salt Lake Ecosystem Program Manager John Luft said. “We greatly appreciate their cooperation and their role in helping us manage the delicate balance in this important habitat. This is one of the most successful examples of cooperation between industry and conservation.”
Each week during the harvest season, DWR biologists go out on the Great Salt Lake and pull nets at varying depths from 17 different areas to assess brine shrimp populations throughout the lake. Those samples are taken to a research lab, where the biologists count how many brine shrimp there are in each water sample, and also note the life stages of the shrimp. That helps the biologists monitor ongoing population levels so that too many cysts aren’t harvested from the lake.
“It’s a tricky balance because the adult shrimp typically freeze and die each December, while the cysts will survive and hatch in March,” Luft said. “When the cysts hatch, they survive by eating the algae in the lake, which is also what the juvenile and adult brine shrimp eat. However, if there are too many cysts that hatch, they eat all the algae and run out of food before they reach adulthood, which is when they produce more cysts. So we have to manage the harvest to fit that balance, which is about 21 cysts per liter of water. Once it reaches that threshold, we either close the harvest for the year or we extend it if enough cysts haven’t been harvested. You can overharvest them, but you can also underharvest them, which is why it’s a delicate balance that requires a lot of monitoring.”
DWR conservation officers patrol the lake by boat during the season to check permits and harvest totals of the companies gathering brine shrimp cysts. DWR officials also fly a plane over the Great Salt Lake a few times a week during the season to locate where the brine shrimp are and to do aerial patrols. The cysts collect together in the water and look like large, gold-colored oil slicks.
“That allows us to easily document where the harvest is happening on the lake, and also to research where the birds are located on the lake in relation to the cysts,” Luft said. “We do a lot of research on the relationship between the birds and brine shrimp.”
The Great Salt Lake and its associated wetlands provide an invaluable food source to around 10 million migratory birds, including about 330 different species. A variety of these birds feed on the brine shrimp, either exclusively or opportunistically, to fuel their long migrations. The Great Salt Lake gets the largest percentage of the world’s population of eared grebes feeding during their migration. Between 3 million and 5 million eared grebes have been documented using the Great Salt Lake as a stopover spot during their migration each year from September to October.
“The birds molt while they are here in the fall, which means they are flightless and completely dependent on the brine shrimp for food,” Luft said. “They will eat between 25,000 to 30,000 brine shrimp a day. Then, they migrate farther south around December, eating the brine shrimp before the shrimp freeze and die. It would be very harmful for the eared grebe populations if the brine shrimp weren’t being harvested. There would be peaks and valleys in the brine shrimp population, causing the eared grebes to starve during some of the leaner brine shrimp years. We rely on the brine shrimp industry to reduce the amount of fluctuation in the brine shrimp populations, creating a more consistent food source for the birds.”
The brine shrimp companies are required to obtain a Certificate of Registration from the DWR in order to harvest the cysts. The COR fees go toward funding research at the Great Salt Lake, and a portion of the royalty tax on the brine shrimp cyst harvest goes toward the endangered species mitigation fund.
“The Great Salt Lake brings in over $1.3 billion annually to the Utah economy,” Great Salt Lake State Park Manager Dave Shearer said. “It is one of the most important migratory stops in North America. Keeping the lake healthy is of vital importance to Utah.”
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