Home » Research » End of Season Summary

Nature Trails/Harkness Lab - Summer 2004 - End of Season Summary

Introduction

Building upon a successful pilot season in the summer of 2003, Nature Trails, in partnership with Harkness Lab, are once again offering an opportunity for the public to participate and experience firsthand the collection of fisheries research data in Algonquin Park.

The program conducted this year by Nature Trails, under the guidance of Harkness Lab, consists of four components:

  1. Lake Opeongo temperature and dissolved oxygen profiles
  2. Sampling of the zooplankton community of Lake Opeongo
  3. Observation of the Lake Opeongo bird community
  4. Survey of small fish community in Lake Opeongo

The data collected from each of these four components represent useful trend through time information which supplement other trend through time data collected by Harkness Lab on the fish community, the fishery, and the physical environment of Lake Opeongo. The objectives of each component, progress to date this season and a summary of the data collected to date will be presented in more detail below.

1. Temperature and Dissolved Oxygen Sampling and Secchi Depth

Purpose

Thermocline depth and water transparency are two variables which are likely to be impacted by climate change. Long term monitoring of these variables will be important in interpreting the effects of climate change upon lake ecosystems.

Objectives

To obtain a dissolved oxygen and temperature profile and a secchi depth measurement from each sampling station TP1 once per week from the beginning of July until the end of August, and from the two other stations as time and weather conditions permit.

Progress

Site TP1 TP2 TP3
Week 1 x
Week 2 x
Week 3 x
Week 4 x x
Week 5 x x
Week 6 x x
Week 7 x x
Week 8 x x
Week 9 x x x
Week 10 x x
Total # Samples 57 13 1

Site TP1 was sampled a minimum of once per week and in total was visited 57 times over the course of 10 weeks. In addition profiles were obtained from sites TP2 and TP3. Figures 1 & 2 show the trends in temperature and dissolved oxygen at Site TP1 over the course of the summer.

Figure 1. Temperature profiles from Lake Opeongo for the period from July 1, 2004 to Sept. 1, 2004

Figure 2. Dissolved oxygen profiles from Lake Opeongo for the period from July 1, 2004 to Sept. 1, 2004

2. Sampling of the zooplankton community of Lake Opeongo

Purpose

The zooplankton community, one of the lower rungs of the trophic ladder in a lake ecosystem, will be one of the first communities to respond to the introduction of an invasive species such as Bythotrephes (spiny water flea, B.C.) or Zebra Mussels. The zooplankton community might also be impacted by the introduction of fish species such as northern pike, which are poised at the doorstep of Opeongo, through the impact pike might have upon planktivorous species such as lake herring.

The plankton samples collected through the Nature Trails program will become part of an archive of plankton samples collected periodically since 1960. This collection will allow us to examine the impacts of future species introductions to Lake Opeongo.

In the event that Bythotrephes is introduced to Lake Opeongo this program will also provide us with the ability to detect the introduction shortly after it occurs.

Objectives

The target will be to obtain one plankton sample from the south arm of Lake Opeongo at site TP1 once per week between the beginning of July and the end of August.

Progress

A plankton sample has been collected at the TP#1 site once weekly. The samples are preserved in alcohol and are to be stored for analysis at a later date. Bythotrephes has not been detected in any of the sample collected to date.

TP1 B.C. Present
Week 1 x No
Week 2 x No
Week 3 x No
Week 4 x No
Week 5 x No
Week 6 x No
Week 7 x No
Week 8 x No
Week 9 x No
Week 10 x No

3. Bird Observations

Purpose

One purpose of this project will be to contribute to a long term parkwide dataset of bird observations. Another purpose will be to monitor the abundance and distribution of Double Crested Cormorants, a species which has been increasing in number on Lake Opeongo over the last few years.

Objectives

To record the occurrence and behaviour (feeding, nesting etc.) of bird species on Lake Opeongo.

Progress

A total of 22 separate species were observed on Lake Opeongo by Nature Trails participants over the 10 weeks of the program. The most commonly observed species were the Common Loon, Herring Gull, Double Crested Cormorant and Osprey. When cormorants were observed, they were seen in large numbers, on average over 23 per sighting.

Figure 3 illustrates the timing of bird observations on Lake Opeongo

Species Observation Frequency Avg. Number / Observation Max Observed Min Observed
Common Loon 190 2.9 34 1
Herring Gull 129 2.3 30 1
Double Crested Cormorant 40 22.8 130 1
Osprey 17 1.3 2 1
Crow 5 1.8 5 1
Bald Eagle 3 1 1 1
Ringbill Gull 3 1 1 1
Black Duck 2 1 1 1
Great Blue Heron 2 1 1 1
Hummingbird 2 1 1 1
Kingfisher 2 1 1 1
Merganser 2 8.5 15 2
Arctic Tern 1 1 1 1
Blue Jay 1 1 1 1
Boreal Chickadee 1 1 1 1
Raven 1 1 1 1
Ruby Throated Hummingbird 1 1 1 1
Sapsucker 1 1 1 1
Tree Swallow 1 6 6 6
Turkey Vulture 1 1 1 1

Figure 3. Timing of bird observations on Lake Opeongo, 2004, larger circles indicate larger numbers observed

4. Small Fish Sampling

Purpose

Small fish surveys have not been conducted recently in Lake Opeongo. This study will update the species list of the lake and provide an opportunity to examine habitat associations of certain species.

Present species list includes:

  • Northern Redbelly Dace
  • Finescale Dace
  • Brassy Minnow
  • Golden Shiner
  • Common Shiner
  • Bluntnose Minnow
  • Fathead Minnow
  • Creek Chub
  • Pearl Dace
  • Brown Bullhead
  • Brook Stickleback
  • Iowa Darter
  • Slimy Sculpin
  • Spoonhead Sculpin
  • Pumpkinseed
  • Yellow Perch
  • Smallmouth Bass

Objectives

To fish 30 baited minnow traps in a variety of different habitats each week from the beginning of July until the end of August.

Progress

A total of 172 baited minnow traps have been fished in 86 different sites in a variety of habitats in Lake Opeongo.

Traps were set in the locations shown in Figure 4.

Of the 17 species of fish we might expect to be caught in these traps, 7 were observed this year (bold in the list above). Next season we would like to expand the range of locations trapped and the depth to see if some of the more rare species can be trapped and identified in the lake.

The species most commonly encountered in the traps is Bluntnose Minnow.

Conclusion

This has been a very successful and productive season for both Nature Trails and Harkness Lab. The data collected will become part of a long term dataset which will help us understand the effects of environmental change upon Lake Opeongo.

As important as the data collected, or perhaps even more importantly, this partnership has exposed a large number of people to the science behind monitoring our natural resources. Many of these people would never have had this opportunity without this partnership and the support of it's sponsors.

Many thanks to all and we're looking forward to an even better season next year!!

Map of Sampling Sites

Photo Credits: Rob Stimpson and Robert Taylor