It can vary using days, but in Maine, the center of April constantly ushers within the annual smelt runs from coldwater lakes up nearby brooks and streams. As every salmon angler is aware of, these small rainbow smelts are the important thing meals supply for landlocked salmon.
Back in the Nineteen Seventies, my own family and I experienced remarkable, exciting salmon angling at a far-flung northern Maine lake. It was an angler’s banquet for 3 or four years. Then it closes down all collectively. It was like nature threw a switch and the salmon just disappeared.
What brought on the salmon famine? “Smelt crash” became on the lips of many disappointed fishermen, who sought to understand the cycle, which changed into now not specific inside the annals of salmon angling.
What reasons a smelt crash? What are the medical and organic nuances that effect smelt numbers and, for this reason, salmon survival quotes?
Greenville fisheries biologist Tim O’Brey and his staff had been running diligently to find solutions to these questions in ongoing studies at Moosehead Lake, Maine’s maximum expansive sport fishery.
Put definitely, they inventory smelt fry populations with the aid of netting them at Lily Bay Brook. From there, via “head counts,” they are capable of extrapolating the gross wide variety of smelt fry that heads lower back into the massive lake. Some years the runs have been 7 million, and a few years as excessive as nine million. Late within the summer time they behavior more populace surveys of the smelt survival fees at the lake.
O’Brey and his crew also study plankton occurrence. Plankton is the main meals supply for the smelts.
O’Brey, in his words:
“Recently, we commenced work on a brand new task that we hope will shed some mild at the biology of smell. This work isn’t always just applicable to Moosehead Lake, however, can be useful for other large lakes in Maine. The concept was to broaden a observe to offer an index of abundance for young smelt and to help recognize the herbal variant that often occurs in smelt populations. There were some studies that indicate young, newly hatched smelt can be challenge to excessive mortality if the suitable meals supply (plankton) isn’t gifted in the course of their initial two-week window after hatching and dropping out of the circulation.”
This organic dynamic and interdependence among the salmon, the smelt and the plankton explain why sport fish control is the sort of complex and fickle field.
As O’Brey explains within the following paragraph, angler agitation for extended salmon stocking on a lake is the incorrect manner to go if smelt numbers are on the margins. You would possibly call it “protective the seed corn.”
“Finally, we are hoping to combine the information from the summertime smelt tows with the plankton abundance, and the spring hatch numbers to come across any adjustments in abundance that could be associated with loss of food. If we determine that the smelt are in low abundance, we could reduce our salmon stocking to guard the increase of our game fish. Or if everything is peachy, we should boom our stocking to enhance the trap at the same time as maintaining the good increase charges.”
Maine is, certainly, lucky — not best to have a crown jewel like Moosehead Lake as a gamefish repositor, however to have seasoned, committed and informed fisheries stewards like Tim O’Brey.