ATLANTIC SALMON AND TOOLS OF NAVIGATION
Atlantic salmon do use the earth's magnetic fields as part of their navigational toolkit.
Dozens of stories this week detailed how Oregon researchers used landlocked salmon and proved the point. Now comes the hard part - determining the structure of the magnetic navigation, and the DNA basis of it.
One place to begin understanding the use of magnetic force by salmonids is in the research of Dr. Michael Walker, now retired, from the University of Aukland in New Zealand.
Thirty years ago he and graduate student researchers detailed a mechanism for Rainbow Trout. In the neighbourhood of the olfactory bulb, they found a structure that included a linear set of magnetite crystals, fused together to form an ultra-small needle, and apparently cells around it that could sense the pull and push of the ends of the needle. Is there a similar structure in Atlantic salmon? At this point, one can only say "who knows."
While the magnetic sense would be of use in the ocean and larger water bodies, more likely the Atlantic salmon's keen sense of smell is of greater benefit for salmon in freshwater in October, as these fish reach the upper sections of river. A researcher that had been working in St. Andrews measured their sensitivity to one chemical, a form of Prostaglandin, and discovered they could detect one drop of it in the equivalent of 10 Olympic-sized swimming pools.
The more we explore the Atlantic salmon's world, the more awe-inspiring is this creature capable of migrations over thousands of kilometres, with the ability to jump waterfalls, and in some cases go as long as 22 months without eating. And now all those skills are focused on making it to specific sections of river far up near the headwaters in order to produce more salmon for the years to come.
It all works like clockwork, for the most part. Fewer than five per cent of Atlantic salmon returning stray to nearby rivers instead.
So bring on the fall rains - and more of them.
Impressionistic beauties laying in a pool of the Bonaventure River before ascending further towards spawning grounds. Photo Dan Greenberg.
The counts on the Dungarvon are in for Oct. 7, and include 92 grilse and 69 large salmon, compared with 101 grilse and 126 large salmon in 2017. Salmon are coming in and hopefully with the rain in the latter part of this week, those numbers will increase.
At the Northwest Miramichi Barrier, to Oct. 7 there have been 104 grilse and 108 large salmon. In 2017 to the same date, there were 134 grilse and 120 large salmon.
Lauren Walker on the Southwest Miramichi near Doaktown with the first salmon of her fishing life. Smiling with the excitement of the moment is her brother Evan holding Lauren's rod. Photo by Tom Walker
Brock Curtis of Blackville notes this:
We are counting the days down that are left to the angling season here on the Miramichi and sadly will soon have to hang up our rods for another season. For quite a few anglers the salmon fishing has been quite good over the past two weeks, especially on the Miramichi. The tributaries are low and not as many anglers were talking of hooking into salmon while on them. I did count 50-60 salmon on one pool this past Saturday on the Dungarvon and there were probably more. On Monday they were gone. The forecast is for a good soaking of rain this week so more salmon should start moving into the tributaries.
The low water levels have kept the salmon bunched up in the larger pools creating very good fishing in some areas. With the rain in the forcast we will probably see quite a few salmon move upstream.The Fall colours continue to add to the angling experience. For salmon anglers it is hard not to want to be on the river this time of year.
The Southwest Miramichi is just about at peak colour at the moment. Nathan Wilbur/ASF
Nathan Wilbur, ASF Director of Programs for New Brunswick has some recent observations:
Fish are spread out in most pools along the Southwest Miramichi. They're rolling and jumping, and the odd one is taking softly. There are some moving fish as they get to where they want to be for spawning, which should begin in another 10 days or so once fishing season is over on the 15th. The rain on Thursday and nice weather afterwards should set things up for one last beautiful weekend of fishing with good water.
Hammond River in the Smithtown area, in southern New Brunswick. As shown by the photo taken this week, water levels are continuing to improve. Geoff Giffin/ASF
St. John River
DFO has the Sept. 30 numbers compiled, and as usual they make dismal reading. Mactaquac has had 413 grilse and 61 large salmon, compared to 317 grilse and 169 large salmon in 2017. Giving a historical perspective, the average for 1995-1999 to the same date was 4,022 grilse and 1,840 large salmon.
To Sept. 30 there were 77 grilse and 23 large salmon, compared with 2017 numbers of 51 grilse and 32 large salmon. The 1995 to 1999 average was 426 grilse and 156 large salmon.
Cains River in September - with much richer colours now on Oct. 12. Geoff Giffin/ASF
The count for Oct. 7 shows considerable numbers of grilse moving upstream, but still far below last year. There were 90 grilse and 15 large salmon to this date, compared with 157 grilse and 61 large salmon in 2017.
Northumberland Strait Rivers
Jesse Gravel, who tends to angle the western rivers of the group, says:
I never made it further east than the West River in Pictou for a couple weeks now. West from there, the Philip and Wallace have been the 'hot spots' for anglers. They're the only two rivers with somewhat decent water when compared to the other rivers and streams that still have low water. Water levels are actually looking much better than last year around this time but another good soaking is needed for all the rivers and streams.
Fishing has slowed down since the last good rain but Atlantics have made it all up and down the two rivers, and holding in the deeper pools for the most part. A good rain before the next full moon would be great! Lets hope.
The lower Wallace River has risen considerably. Photo taken this week, by Jesse Gravel
Gerry Doucet focuses on rivers in the eastern half of the group.
Fishing remains marginal along these rivers. Last weeks rains provided a raise of water allowing for some Atlantic’s to race forward and find refuge in larger deeper pools. However the rivers quickly shrank to low levels again. Primarily, the majority of salmon are still in the estuaries and tidal pools awaiting an appreciable raise of water.
Anglers eyes are closely watching the weather. Rain is in the forecast with the possibility of an extra soaking through the weekend depending on the track of Hurricane Michael which has to potential to fill all Northumberland rivers.
Lower reaches of the West River Antigonish, showing the continued low water. Photo Gerry Doucet.
Greg Lovely has some notes on the river this week:
Fall colours in the Margaree Valley are beautiful this year. But we need rain again. With the bump in water we got last week the fishing was good and many Atlantic salmon took advantage of the extra water to move far up river. Salmon were also being hooked in the nearby Middle and Baddeck rivers, spreading the fishermen, which is definitely a good thing.Etheridge Pool on the Margaree as seen on Monday, Oct. 8. The fall colours are near their maximum, and the water is coming. Photo Greg Lovely.
René Aucoin on the Margaree River on Thurs., Oct. 11, 2018. Water levels could improve, but not hopeless at the moment. Lewis Hinks/ASF
Hart Pool on the Margaree on Thurs. Oct. 11, 2018. More rain expected. Lewis Hinks/ASF
The Sept. 30 numbers are 6 grilse and 1 large salmon, compared with 29 grilse and 6 large salmon in 2017.
Morgan Falls has counted 27 grilse and 53 large salmon to Sept. 30, against 188 grilse and 25 large salmon in 2017. The 1995-1999 average was 721 grilse and 146 large salmon.
PRINCE EDWARD ISLAND
Taylor Main in Prince Edward Island notes:
The entire province was able to get some much needed rain over the past week and a half. Although we received slightly over two inches, much more is still needed for ideal conditions. At this point, the water is still higher than it ever was last fall but another foot and a half to two feet of water height would be welcome. The water is also starting to take its typical black colour over the past week. Indian Bridge Pool on the Morell River. 9 October 2018. Taylor Main photo.
It still seems like there are very few fish in yet. I have only heard of four or five fish hooked since the end of the trout season, including one earlier this week. There's no doubt that the main run hasn't started yet as fish are certainly few and far between at this point. I guess time will tell.Robbie MacIntyre casts a line on the way to the Skidoo Hole on the Morell River. Late September 2018. Taylor Main photo.
ASF Director of Programs for Newfoundland and Labrador, says:
The DFO fishway counts are out up to Sept 30th, but you will note that these counts were up to the date that each fence was removed which was before Sept 30.
Gander River is still low but water temperatures are cold. Water levels on the Lower Humber are still on the high side but temperatures remain nice and cold. Reports indicate that there was a good sign of large fish right up to the closing week-end (this past week-end). The season officially closed on Oct 7th. Kastine Coleman reports hooking and releasing two large fish on the Lower Humber on last day of the season.
Kastine Coleman of Corner Brook is seen here at Shellbird Island on The Lower Humber about to release a 40 in. and 25lb bright salmon, one of two she hooked on a trip there a few days ago. Photo Terry Byrne
The smaller salmon leaped out on a good display and helped end the 2018 season in style. Photo Terry Byrne
The final DFO count is up. Interesting numbers.
It may be that Labrador has the nicest returns this year in the North American Atlantic salmon world.
THE FINAL IMAGE
An energetic farewell on the way to the headwaters. A live release on the Kransell Pool on the Bonaventure River. Photo Dan Greenberg.