Saturday , November 28 2020

The Coeur d 'Alene Press – Food and Health, For Endangered Orcs, these are the hungry games



Over the past few years, the salmon of the Idaho snowflake and the Puget Sound orcs have been linked to the long battle for the fate of the four bottom dams on the Snake River and whether they should be removed to save the fish.

The orcs, especially the kits of the southern inhabitants, are in trouble and have been for some time. This summer, it is noticed when a member of the J-pod, a subgroup of Puget Sound orcas, wore his dead calf for 17 days and attracted the attention of the world's media.

The whales are facing food shortages, the noise of the pots in the loud sound of Puget, and the accumulation of pollutants in their body fat. All three are related, but what comes down to the fact that whales do not get enough food, and what they eat is mostly salmon.

This is where salmon comes from breeding in the pool of the Smye River. Whales prefer salmon and feed on different stocks up and down the western coast of the United States and Canada. For most of the year, from spring to autumn, whales chase the Chinooks that return to the rivers that pour into Puget Sound and Salish Sea, mostly in the Canadian River Fraser. But they also leave the inland waters in autumn to travel along the coast, looking for salmon and, to a lesser extent, other species before returning in the spring.

One of the stocks that whales are targeting during this period are those that come from and return to the Columbia River and its tributaries. This brings the Snake River. Orca's advocates have formed a philosophical and strategic alliance with Snaek River salmon supporters who believe they are breaking the four dams on the Lower Snak River, will significantly increase the number of salmon and steel from the Snake River Basin. They believe, as do many scientists, that the breach will improve the Snakes' salmon to restore them.

Breakthrough: How Much Impact?

So how much will the dam fail to help the whales? No one can say for sure, but there are two competing science camps in conflict over which the Snake River chinook series is more important for whales. Those who believe in the orcs are more dependent on the fall of the Cancun from the Columbia and Snake basins, with the tendency to see less potential benefit of their disruption, and the majority of the falling kinwu returning in the Colombian basin, do not come from the Snake River.

This is the country that has adopted the National Oceanic and Atmospheric Administration for Fisheries, the agency responsible for overseeing efforts to stabilize and restore whales and fish. In the fact of Skaek's whales and dams, the agency says that kinauk's fall has been fairly well over the last decade, although their returns have fallen over the last few years due to bad ocean conditions.

"Over the past decade, more adult chinook salmon returns along Bonneville Dam to the Columbia River than at any other time since the dam was completed in 1938. NOAA Fisheries found that the chinook hatchery more than offset the fish lost from dams in terms of a total number of knuckles that are available for killing whales, "the agency said in the data sheet.

The agency views Columbia's entire pool as a place that already plays its role in whaling and would like to see more improvements than other pools.

"The Columbia and the Snake rivers produce more than half of the West Coast salvo, where whales come because salmon is here, not because they are missing," said Michael Millstein, a NOAA spokesman in Portland.

Milstein said it was important to work on all the stocks that whales eat.

"They all contribute fish to the whales at different times of the year at different locations," he said. "It's not a critical river, it's about the diversity of the rivers and the stocks they produce, each with its own history of life and time."

Those who look at the spring knuckle from the Columbia Basin and the Snake, as the more important are inclined to think that the violation can play a significant role. Spring chinook are less healthy than the chinook fall, and those spawning in Columbia's larger pool are dominated by Snake River stocks. Damaging the dams would potentially help the spring to rise to a greater extent than to fall by knuckle, although it would be beneficial for both runs.

Orcas: Kinouu Specialists

One thing is for sure, southern local killing killers are salmon specialists. This makes up the bulk of their whole fish diet, and whales do not get enough to eat. To determine how to do this, NOAA scientists have tried to measure the relative importance of the various west coasts to know where to concentrate their efforts. In the list, scientists examined three factors: if a stock appeared in the whale meal; if it appears in the whale diet during the stressful winter months; and to what extent stocks overlap in time and space with whales throughout the year.

Based on this system, the collapse of chinook from the Columbia basin, including Snake River fall chinook, ranks relatively high – number 3 on the list. This is largely because the chinook fall are available to whales for much of the year. South whales living in the southern part of the country would eat the Khuunou fall during their broader West Coast plans from late autumn to about May.

Conversely, the Spring Cinema is less accessible to orcs for most of the time when whales are out of what scientists call the "outskirts". However, as the spring knuckle returns to breed in fresh water, the fish are collected or collected near the mouth of Colombia. This is a short window for whales, but some believe that due to the density of the fish at that time, it is an important source of food.

"The behavior of falling stocks is rather coastal in ocean distribution, more accessible to whales over a longer period of time, not just during migration," said Mike Ford, director of the Biological Conservation Department at Northwest Fisheries Research Center in Seattle.

"Since the spring stock, especially the Snake and Colombian interior, their distribution in the ocean does not overlap with whales at all, except for that period of several months when they return to the spawning," I said. – During this period they could be quite important for whales.

When scientists enlighten data on the power of cinematics and the health of whales, they found that during the years of good kinewave runs, whales had higher fertility rates. In fact, from 2013 to 2015 "there was a baby boom," Ford said.

Ole Shelton, a researcher at the Northwest Research Center in the Northwest NOAA Zone in Seattle, said there are more scientists who do not know then that they are doing how to exchange the specific knuckle and southern killer kits. He calls it "a very active area of ​​research".

But Shelton said the scientists know much more about the filmmaking when it comes to their distribution to the ocean than on the spring tracks.

"Fall chinook tend to be more coastal and they tend to be more southern than their spring chinook colleagues in a given area.If you look at the distribution of the falling snake from the Snake River, they tend to be a bit north of the mouth of the river , in Vancouver, Island and Central British Columbia and off the Washington coast, "he said. "The spring knuckle is much worse, but the general idea is that they are willing to move further away from the shore and further north."

Spring Wing: Measuring the Importance

Two of the three Puget Sound pods of kill whales target the spring of the Chinook when the fish scene near the mouth of the Columbia River in March when the fish is preparing to go into fresh water for breeding.

"I think it's quite reasonable that the spring spring of the Snake River tends to look like a likely bid to be important at this time of the year, and they are certainly not as important as other times of the year," said Shelton. "At this time of year – winter and spring – you will say that the spring spring of the Snake River is likely to rise considerably higher than other stocks, but if you look through the whole year, they are falling a bit. are not in the "Pigeon Sound", the Strait of Juan de Fukua and the Straits of Georgia.

The significance of the jump is unconvincing, he said.

"I can totally believe if the Snake River is springing up if there is much more that it will be healthy for the population (killer whale), and I see a scenario that is not true. you can make more stocks as you can and be successful for it, "he said.

For Sam Wasser, Professor of Conservation Biology, Ecology and Physiology at the University of Washington, there is no doubt that the Smyrna River is important and even critical of whales. Vasser studies the blood hormones found in the whales' faeces, which show, among other things, a degree of pregnancy and stress levels. His team uses a new approach to collecting whales. They followed the whales of the boats and used specially trained dogs to sniff and find stools so they could be taken out of the ocean surface with pool cleaners before they sink or distract.

He found that 69 percent of all open pregnancies in the southern population of the wrists failed, and more than 30 percent failed at the end of the term or on or soon after birth, when the risk to the mother was much higher. The stress of lack of food is probably the cause of failures, Vasser said.

He and the others measured two hormones in the whales that show stress. They found that when whales returned to the Salice Sea in the spring after eating the mouth of the Columbia River, whales showed low stress. But this has changed rapidly, most likely due to the fact that the Chinese river fader is scarce in the Salis sea until the middle of the end of August.

He said the winter when whales hunt off the coast of the United States, and Canada is a stressful time for them.

"It's a very hard time for them, it's cold, they have to regulate the heat, they do not have big salmon for adults, they climb the river mouth, they have all the fish that are harder to catch.

The next winter, the whales find a brief variety of food in the middle until the end of spring when they head to the spring witch that is linked to the Snake and Columbia rivers. The chicook stocks that push the farthest versions are usually the first ones to appear. They also tend to have a higher fat content to keep them as they push upwards. Snake River chinook predominate at the beginning of the returning spring chinook from the Columbia basin.

"The early return of the Chinook in the Columbia River is known," Wasser said, "this getaway was enormous." What the work was doing to us was very, very important to fill (the whales) of the harsh winters, and also to keep the Fraser River fridge runs tops, which is not until mid-August.

Since the Chinook, flooding to places like the Clearwater and Salmon rivers, has come so far, they have evolved to be larger and greasier than other spring.

"They have to spend around 900 miles in migration, and they have to get fat loaded too early," Wasser said. "It seems very, very important to these whales: It seems that there is a critical team that is really critical that it can do something dramatic (for) this is the Columbia River.

That's why many people see the failure of a dam as something that can help the whales. Many whale protectors see it as a potential quick fix. Vasser is not among them.

"I'm not saying they just have to break the dams," he said. "I think this is something that really deserves serious research, and so far every time you raise the issue, they say we can not go there. I think we need to investigate very seriously to see if there is a long-term solution I emphasize long-term, and there are many things we can do. "

Barker can contact [email protected] or (208) 848-2273. Follow it on Twitter @ezebarker.


Source link