Rehabilitation

 

Brook Trout Rehabilitation in the Ontario Waters of
Lake Superior, Lake Nipigon, and the Nipigon River

halfreleaselow

The Upper Great Lakes Management Unit of the MNR released the results of a 5 year study of the brook trout rehabilitation in the Nipigon basin following the 2005 regulation change. A public workshop was held in November of 2011 for approximately 50 invited guests from different branches of the MNR, DNR (USA), fishing organizations, several co-operative anglers and other special interest groups.

The following is MY interpretation of the key elements of the report. For brevity, I have narrowed the information specific to South Bay on Lake Nipigon and to the Nipigon River above the OPG Alexander dam. The entire 69 page report is available as a PDF here:

Brook Trout Rehabilitation in the Ontario Waters of
Lake Superior, Lake Nipigon, and the Nipigon River

 

Lake Nipigon and Nipigon River Angler Surveys

The OMNR periodically conducts angler surveys on the Nipigon River and at the South Bay boat launch on Lake Nipigon. These surveys provide estimates of the following fishery characteristics:

  • angler effort for all species
    • angler effort directed at brook trout
      • brook trout catch rate
        • brook trout catch
          • brook trout harvest

 

 

AnglersurveyNipr

The Nipigon River area has become increasingly popular for brook trout angling over time. The bottom graph shows harvest has dropped from 265 in '94 to only 4 kept in 2010.

 

AnglersurveyLNip

Brook trout catch rate increased after 2005 and values are approaching rehabilitation goals set for Lake Nipigon. Brook trout harvest declined dramatically beginning in 2005. (bottom graph)

 

Co-operative Brook Trout Angler Program

Since 1997, the OMNR has been working wi th a group of dedicated anglers to learn more about brook trout in Lake Superior, Lake Nipigon, and the Nipigon River. Anglers provide information by participating in a tagging program or by logging information of their fishing trips.

The Ministry of Natural Resources reports that from 1997 to 2010 a total of 1,953 brook trout were tagged, and 200 tagged brook trout were subsequently re-captured by anglers participating in the tagging program. Anglers not participating in the program reported an additional 81 tagged brook trout. The interpretation of their total result is listed below. However, to review the data on the 1258 tagged fish collected by myself and Beamer, refer to "Catch Charts"

taggedreleaseboat

Lake Nipigon and Nipigon River Angler Surveys

 

Interpretatons

  • Catch rates by co-operative anglers generally increased from 2005 to 2010, with the exception of Lake Nipigon.
  • The anglers fishing Lake Nipigon modified their behaviour, trying new locations in search of larger brook trout when catch rates increased after 2005.
  • High recapture rates reveal brook trout in these areas survive catch and release multiple times, and are highly vulnerable to angling
  • In general, brook trout grew approximately 7.5 cm (3 in) and 450g (1 lb) per year and growth reduced as fish became longer.

 

Conclusions:

  • Brook trout populations and fisheries in Lake Nipigon showed substantial change after the sport fishing regulation was modified in 2005. The estimated number of spawning brook trout in South Bay increased by 2.2 ti mes from 2003 to 2007, however estimates are 25% of management goals.
  • Brook trout catch rates improved as harvest declined.
  • the portion of the spawning population protected from angler harvest increased in South Bay from 29% to 88%
  • High recapture rates show brook trout are vulnerable to angling, but also indicates that these fish respond well to catch and release.

 

Recommendations:

Although current protective sport fishing regulations have been in place for a short period of time (five years, or approximately one brook trout generation), signs of rehabilitation are encouraging and the current restoration strategy is recommended to remain in place.

  • Refine and expand the Co-operative Brook Trout Angler Program.
  • Continue ongoing OMNR assessment of brook trout populations and fisheries in Lake Nipigon and the Nipigon River.
  • Develop research projects on: habitat use, migratory behaviour, physical requirements for streams, and a formal reasearch plan
  • Education to reduce harvest
  • Establish rehabilitation goals in consultationwith user groups

 

Catch rates for Lake Nipigon and the Jessie Lake region of the Nipigon River

Catchratescharts

Top left diagram:
The dotted line represents the management objective of an angler catch rate of 1 brook trout every 2 hours of fishing

Top right diagram:
The dotted line represents the management objective of an angler catch rate of 1 brook trout longer than 22" for every 8 hours of fishing

 

 

Lake Nipigon and Nipigon River Creel Surveys

The OMNR conducted angler (creel) surveys on the Nipigon River and at the South Bay access point of Lake Nipigon periodically from 1993 to 2010. All parties concluding their fishing trip were interviewed at the boat launch to determine fishing times and the number of each species caught, kept, and released. All harvested fish were sampled and in recent years anglers estimated lengths of all released fish.

Angler effort is reported as the length of time one rod was fishing (rod hours). Brook trout effort refers to the percent of the total effort directed at brook trout. Catch and harvest is reported in numbers of fish and catch rate is reported as the number of brook trout caught per hour fishing.

 

Angler Surveys on the Nipigon River

AnglersurveysNipigonRiver

  • The most noticeable statistic is the significant drop in Brook Trout harvest after 2005 regulation change.
  • 95% of all anglers report now perform some form of "catch and release"

Angler Surveys on Lake Nipigon (South Bay)

AnglersurveysSBay

  • The Brook Trout harvest in the South Bay area significantly reduced after 2005.

 

We must protect the "Little Guy" too, or we won't have the "Big Guys"
(suspected Eagle talon)

Littleguy

Sumary of Recommendations, Questions and Actions

  • Recommendations were made to collect more in formation on both brook trout populations (abundance, size, & distribution), and their associated sport fisheries (angler catch & harvest).
  • Concerns were raised that the Co-opprogram may not provide sufficient information, and a fishery independent survey was recommended.
  • Is migratory behaviour of coaster brook trout a genetic trait?
  • Determine if Lake Superior brook trout spawn on shoals in Ontario. This is currently unknown.
  • History has shown low success of stocking. Recommendation that stocking should not occur in Ontario.
  • Objectives for brook trout rehabilitation should be established (qualitative/quantitative values for abundance, size, distribution, age, etc.).

 

Cedarpop