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Lotic and Lentic Ecosystem Diversity 1

Measuring lotic and lentic ecosystem diversity in Lake Tamblyn and the McIntyre River to

determine water quality

Mary McDonald

0475277

BIOL–2210L-F4

Thursday 2:30

CB 3015

Barb Barnes

November 13, 2012


Abstract

The study was conducted at Lake Tamblyn and the McIntyre River located on Lakehead

University property in Thunder Bay, Ontario. The purpose of this study was to determine the

diversity and species richness of both the lentic and lotic ecosystems located on campus. Samples

of macroinvertebrates were taken from Lake Tamblyn and the McIntyre River, as well as

collecting data regarding temperatures, dissolved oxygen, pH, transparency, and rate of flow. The

samples and data were then analyzed in the lab. This study found that Lake Tamblyn had a lower

dissolved oxygen content of 7 ppm and supported a lower diversity of macroinvertebrates, having

a diversity index of 0.0963. The McIntyre River was found to have a higher dissolved oxygen

content of 132 ppm at the edge and 12.2 ppm in the centre, and it also had a higher species

diversity with a diversity index of 0.9 at the edge and 0.84 in the middle. These results suggest

that the lake has more pollutants and a poorer water quality, perhaps reaching premature

eutrophication. The river, however, has good water quality and is able to support a more diverse

population of macroinvertebrates, concluding that the lotic ecosystem is a healthier ecosystem

than the lentic ecosystem.

Key Words

Aquatic Sampling, Lake Tamblyn, McIntyre River, Lentic Ecosystem, Lotic Ecosystem,

Macroinvertebrates, Ecosystem Diversity


Introduction

Macroinvertebrates can be used to determine health and diversity of both lentic and lotic

ecosystems (Lenat, 1988). Macroinvertebrates include a variety of organisms that are classified

as grazers, shredders, gatherers, filterers, and predators; which are all critical in maintaining the

functional integrity of lentic and lotic ecosystems due to the key roles they play (Wallace &

Webster, 1996; Kagalou et al., 2006). Sampling and analyzing the presence of macroinvertebrates

can assist in assessing the health of both lentic and lotic ecosystems (Wallace & Webster, 1996).

Each group of macroinvertebrates are able to survive under differing conditions, therefore, the

presence of certain macroinvertebrates over others can suggest varying water qualities and can

assist researchers in proposing solutions. For example, shredder species are not tolerant of high

nitrogen areas; chronimids are tolerant of pollution and toxins; and Ephemeroptera, Plecoptera,

and Trichoptera (EPT) are intolerant of toxins (Deacon & Lavoie, 2010; Heino, 2000; Lenat,

1988; Kagalou et al., 2006).

Various studies pertaining to characteristics of lentic and lotic ecosystems analyze the

presence of macroinvertebrates due to the response macroinvertebrates have to changing

environmental conditions. They adjust faster than any other organism to changing environmental

conditions, allowing researchers to determine varying water conditions more efficiently (Deacon

& Lavoie, 2010; Wallace et al., 1982; Kagalou et al., 2006); however, small differences may be

reflective of the physical habitat rather than water quality (Lenat, 1988). Multiple samples should

be taken to obtain the best possible results when doing macroinvertebrate studies. In studies of

lentic ecosystems, macroinvertebrates are found to be indicators of eutrophication (Kagalou et al.,

2006), where as, in streams, they are good indicators of pollutants and toxins (Wallace &

Webster, 1996). In studies done by Heino (2000) and Kagalou et al. (2006), it was found that an


abundance of invertebrates and species richness was positively linked to the amount of vegetation

in an area.

Two studies have been conducted by Deacon & Lavoie (2005; 2010) regarding the

physical condition of the McIntyre River in test areas close to the test area used in this study. The

first study conducted by Deacon & Lavoie (2005) found that the McIntyre River had a high

species richness, which indicated a healthy ecosystem. In the second study from Deacon &

Lavoie (2010), they tested two areas of the McIntyre River. The first site was just upstream of

our test site, and the second site was downstream of our test site. From their samples, it was

concluded that the first site was unimpaired, however, it could potentially become impaired due

to the high biotic index and moderately low EPT (Deacon & Lavoie, 2010). The second site,

however, was said to be impaired possibly due to eutrophication (Deacon & Lavoie, 2010).

Deacon & Lavoie (2010) came to this conclusion due to the high percentage of worms and

chironomids, which indicate the river has been impacted by nutrient enrichment.

The aim of this study was to collect samples of organisms to determine how adaptations

of organisms reflect habitat conditions, in both lentic and lotic ecosystems. The samples could

then be analyzed to determine species diversity and its relation to habitat characteristics, as well

as in determining water quality. Chemical and physical factors were also measured to distinguish

between lentic and lotic ecosystems. Research of this nature is important as it enhances general

knowledge of the health of the ecosystem. Studies conducted in the McIntyre River and Lake

Tamblyn can also be used to determine short-term stresses, which could ultimately influence the

aquatic community of Lake Superior (Deacon & Lavoie, 2010) since the McIntyre River flows

through Lake Tamblyn and into Lake Superior.


Study Area

The study took place on Lakehead University property in Thunder Bay, Ontario, Canada.

The McIntyre River flows into the city from the north and flows through the city. It passes

through Lakehead University campus before joining the Neebing River on the east side of the

city which then flowing into Lake Superior. At Lakehead University the river flows through Lake

Tamblyn, which was constructed in the 1960s as a flood control (Braun & Tamblyn, 1987), and

is part of the McIntyre River Spillway and Fishway (Hartley, 1986). In 1988, an extension to the

McIntyre River Spillway and Fishway saw the construction of a dam adjacent to Lake Tamblyn

(LRCA, 1988). Located just outside the main building of the university, as seen in Figure 1, both

the river and lake are popular attractions for University students and community members alike.

Figure 1: Map of Lake Tamblyn and the McIntyre River at Lakehead University, modified from North Short Steelhead Association, 2012.


There are walking trails on both sides of the McIntyre River to the south of Lake Tamblyn, and

the river is a popular site for fishers. Both Lake Tamblyn and the McIntyre River are popular

locations for Lakehead University classes to have lab classes and collect samples and

observations. The lake is also a popular skating rink in the winter.

Materials and Methods

This study was conducted over two days, one day of collecting samples and one day

analyzing the samples. The first day was spent at Lake Tamblyn and the McIntyre River

collecting samples and data. At Lake Tamblyn canoes, paddles and lifejackets were used to

collect samples from the center of the lake. Three students paddled canoes to the middle of the

lake and one student took measurements, one student recorded, and one student paddled the

canoe. An Ekman Dredge was used to take samples of macroinvertebrates, as well as to measure

the depth of the water every 10 meters. Students in the canoes then took readings using a Secchi

Disk to determine the transparency of the water. A LaMotte Water Chemistry Kit and Kemmerer

bottle was then used to measure the dissolved oxygen content and the pH. Finally, a thermometer

was used to take both the ambient temperature and the water’s surface temperature. Along the

shore, some students wore hip waders and used D-nets to collect qualitative samples of

macroinvertebrates. The samples of macroinvertebrates from both the middle and edge of Lake

Tamblyn were placed in separate sorting trays and students used droppers and forceps to put

macroinvertebrates into collecting jars with some lake water. Each collecting jar was labeled with

the group number, the equipment used to collect the sample, and the location in which the sample

was taken from.

Next, students went to the McIntyre River and chose an area of the river to sample. A

transect line was chosen across the stream to take measurements in. Wearing hip waders, students


took depth measurements at every 1 metre, from bank to bank using a meter tape to measure

distance across and a meter stick to measure depth, to create a bottom profile. The students then

used a Surber Stream Bottom Sampler to take a quantitative sample of macroinvertebrates from

the middle and edge of the river. D-nets were used next to take samples from the river. Samples

were put in separate sorting trays to keep the edge Surber samples separate from center Surber

samples and D-net samples. Students used the LaMotte Water Chemistry Kits and Kemmerer

bottles to determine the dissolved oxygen content and pH of both the edge and center of the river.

The Secchi disk was used to measure transparency, velocity was calculated using a digital water

velocity device, and ambient, edge water, and center water temperatures were recorded. The

students then used forceps and droppers to place macroinvertebrates from the sorting trays into

collecting jars with some river water, labeling the jars with the group number, the equipment

used to collect the sample, and the location in which the sample was collected.

All of the samples and equipment were then taken to the laboratory. The collecting jars

were drained of any water and students poured alcohol into the jars to preserve the samples. The

samples were analyzed in the second day of the study. Using microscopes and resource materials

(Barnes, 2012) provided by the lab instructor, students were able identified the

macroinvertebrates and fill in data charts. The data charts were then analyzed to determine the

results.

Results

The study produced a variety of results regarding both Lake Tamblyn and the McIntyre

River. Our results showed that Lake Tamblyn and the McIntyre River had some differing

characteristics, as seen in Figure 2: Cross section of Lake Tamblyn and Figure 3: Cross section of


the McIntyre River. Lake Tamblyn was cooler than the McIntyre River in temperature and had a

lower dissolved oxygen content, but they had the same pH and velocity.

Figure 2: Cross section of Lake Tamblyn Temperature (ºC) Ambient - 11ºC

Surface - 8ºC Dissolved Oxygen Content

Bottom – 7 ppm

pH Bottom – 8 Transparency 125 cm Velocity (m/sec) - centre of lake

0

Figure 3: Cross section of the McIntyre River Temperature (ºC) Ambient - 11ºC

Edge - 12ºC Centre - 12ºC

Dissolved Oxygen Content

Edge – 13.2 ppm Centre – 12.2 ppm

pH Edge - 8 Centre - 8

Transparency 10 cm Velocity (m/sec) 0

Figure 4: Bottom Profile of Lake Tamblyn and Figure 5: Bottom Profile of the McIntyre River

show the differentiation of the lentic and lotic ecosystems. The lentic ecosystem has a greater

depth and the bottom contains a more muddy substrate, where as the McIntyre River was

shallower and rockier. The river contained more flat rock surface, and less organic matter.

Figure 4: Bottom Profile of Lake Tamblyn Distance (m) Depth Substrate Description (shore and centre)

0 10 cm Mud, organic matter; Small, round rocks 10 60 cm 20 110 cm 30 140 cm

40 130 cm Mud, organic matter Figure 5: Bottom Profile of the McIntyre River

Distance (m) Depth Substrate Description (every 2 metres) 0 16 cm 1 17 cm

Rocky & silty

2 16 cm 3 10 cm

Rocky & silty

4 8 cm 5 8.5 cm

Small flat rocks

6 13 cm 7 13.5 cm

Rocky (some flat)

8 13 cm 9 12 cm

Rocky (some flat)

10 20 cm 11 5.5 cm

Flat rocks & debris


Samples taken using D-nets at both Lake Tamblyn and the McIntyre River were identified

and placed in the following charts (Table 1 and Table 2) to analyze the trophic level and the

organisms tolerance to pollution.

Table 1: Organisms collected using the D-net at the edge of Lake Tamblyn Class Order Family Common Name Trophic Level Tollerance to

Pollution Chtellata Rhynochobdellida Glossiphoniidae Leech Carnivore Tolerant Insecta Hemiptera Belostromatidae Giant Water Bug Carnivore Tolerant

Malacostraca Decapoda Cambarridae Crayfish Omnivore Somewhat Tolerant

Insecta Plecoptera Pteronarcyidae Giant Stonefly Herbivore Sensitive Gastropoda Basommatophora Planorbidae Orb Snail Herbivore Tolerant

Insecta Odonata Gomphidae Dragonfly Clubtail Carnivore Somewhat

Tolerant

Malacostraca Isopoda Asellidae Aquativ Sow Bug

Detritivore / Herbivore

Somewhat Tolerant

Malacostraca Amphipoda Gammaridae Scud Omnivore Somewhat Tolerant

Insecta Hemiptera Corixidae Water Boatman Detritivore / Herbivore Tolerant

Bivalvia Veneroida Sphaeriidae Fingernail / Pill Clam Herbivore Somewhat

Tolerant

Insecta Diptera Chironomidae Bloodworm Detritivore / Herbivore Tolerant

Insecta Hemiptera Nepidae Water Scorpion Carnivore Somewhat Tolerant

Gastropoda Basommatophora Ancylidae Limpet Herbivore Tolerant

Insecta Odonata Calopterygidae Damselfly Broadwing Carnivore Somewhat

Tolerant

Clitellata Haplotaxida Lumbriculidoe Aquatic Earthworm

Detritivore / Herbivore Tolerant

Table 2: Organisms collected using the D-net in the McIntyre River

Class Order Family Common Name Trophic Level Tolerance to Pollution

Insecta Ephemeroptera Heptageniidae Flat-Headed Mayfly Herbivore Sensitive

Insecta Odonata Gomphidae Clubtail Dragonfly Carnivore Somewhat

Tolerant

Insecta Hemiptera Corixidae Water Boatmen Detritivore / Herbivore Tolerant

Insecta Diptera Chironomidae Bloodworm Detritivore / Herbivore Tolerant

Insecta Diptera Athericidae Snipefly Carnivore Sensitive Insecta Coleoptera Elmidae Riffle Beetle Herbivore Sensitive


As seen in Table 1, Lake Tamblyn contains a majority of macroinvertebrates that are either

somewhat tolerant to pollutants or highly tolerant to pollutants. Only one species, the Giant

Stonefly, is sensitive to pollutants. The table also shows that more Detritivores/Herbivores

organisms are present, followed by Carnivore organisms and the least diverse is Omnivore

species. In Table 2, which details the findings from the McIntyre River D-net samples, half of the

macroinvertebrates are sensitive and half have a tolerance for pollutants. Only one

macroinvertebrate was carnivorous.

The quantitative sampling method, the Ekman Dredge, used in Lake Tamblyn showed a

high density of bloodworms, and a low density of leeches and Pill or Fingernail Clams. Table 3

details the findings, concluding a diversity index of 0.0963, using Simpons Diversity Index.

Table 3: Organisms collected using the Ekman Dredge in centre of Lake Tamblyn Class Order Family Common

Name Trophic Level (Pi)2 Pollution Tolerance

Insecta Diptera Chironomidae Bloodworm Detritivore / Herbivore 0.9025 Tolerant

Insecta Diptera Glossiphoniidae Leech Carnivore 0.0002 Tolerant

Insecta Diptera Sphaeriidae Pill or Fingernail Clam Herbivore 0.001 Somewhat

Tolerant

Simpsons Diversity Index: D = 0.0963

Table 4 details the findings of the sample collected using the Surber Stream Bottom Sampler in

the center of the McIntyre River. Out of the eight macroinvertebrates sampled, three were

sensitive to pollutants, two were somewhat tolerant of pollutants and three were fully tolerant of

pollutants. There was a high density of Common Netspinners, while the other macroinvertebrates

had the same low densities. Overall, the diversity index was 0.84 using the Simpons Diversity

Index.


Table 4: Organisms collected using Surber Stream Bottom Sampler in center of McIntyre River Class Order Family Common

Name Trophic

Level (Pi)2 Pollution Tolerance

Clitellata Haplotaxida Lumbriculidae True Earthworm

Detritivore / Herbivore 0.01 Tolerant

Insecta Trichoptera Hydropsychidae Common Netspinner Herbivore 0.09 Somewhat

Tolerant

Malacostraca Decapoda Cambaridae Fresh Water Crayfish Omnivore 0.01 Somewhat

Tolerant Clitellata Rhynchobdellae Glossiphoniidae Leech Carnivore 0.01 Tolerant

Insecta Ephemeroptera Heptageniidae Flathead Mayfly Herbivore 0.01 Sensitive

Insecta Ephemeroptera Leptophlebiidae Prong Gill Herbivore 0.01 Sensitive

Insecta Hemiptera Corixidae Water Boatmen

Detritivore / Herbivore 0.01 Tolerant

Insecta Ephemeroptera Baetidae Small

Minnow Mayfly

Herbivore 0.01 Sensitive

Simpsons Diversity Index: D = 0.84 Table 5 shows the results found at the edge of the McIntyre River using the Surber Stream

Bottom Sampler. In total, six different macroinvertebrate species were found; three of which

were sensitive to pollutants, two of which were somewhat tolerant, and one that was fully

tolerant. The Flathead Mayfly was found in the highest density, followed by the Common

Stonefly, and then the rest of the macroinvertebrates were found in the same low density. Overall

the density for this sample site was 0.9, calculated using the Simpons Diversity Index.

Table 5: Organisms collected using Surber Stream Bottom Sampler in the edge of McIntyre River Class Order Family Common

Name Trophic

Level (Pi)2 Pollution Tolerance

Bivalvia Veneroida Sphaeriidae Pill Clam Herbivore 0.1 Somewhat Tolerant

Insecta Ephemeroptera Leptophebiidae Prong Gill Herbivore 0.1 Sensitive Ciitellata Rhynchobdellae Glossiphoniidae Leech Carnivore 0.1 Tolerant

Insecta Ephemeroptera Heptageniidae Flathead Mayfly Herbivore 0.4 Sensitive

Malacostreca Decapoda Cambaridae Freshwater Crayfish Omnivore 0.1 Somewhat

Tolerant

Insecta Plecoptera Perlidae Common Stonefly Carnivore 0.2 Sensitive

Simpsons Diversity Index: D = 0.9


Discussion

The characteristic of lentic and lotic water systems vary, as seen in the results. The lentic

ecosystem of Lake Tamblyn had a warmer temperature, a lower dissolved oxygen content and a

muddier substrate than the McIntyre River, suggesting that varying organisms and life forms

would be able to survive and thrive in each ecosystem. This is similar to the finding in the study

by Kagalou et al. (2006), which concluded that habitat conditions are closely linked to the

composition of benthic communities. Although the velocity was measured as 0 m/sec for both

ecosystems, the velocity of the McIntyre River could have been affected due to our location of

the sampling site. Since we were just past a pool area, the flow of water was just beginning. The

presence of a non-existing velocity in the river could also account for a poor sample collection

using the D-nets and Surber Stream Bottom Sampler since there was no current to carry the

organisms into the nets.

The D-net sample taken from Lake Tamblyn contained a number of different organisms,

most of which were tolerant or somewhat tolerant to pollutants. This suggests that Lake Tamblyn

has poorer quality water, which corresponds with the measurement of a low dissolved oxygen

content. Perhaps the lake has been impacted by nutrient enrichment. The study done by Deacon

& Lavoie (2010), in which a low dissolved oxygen was associated with premature eutrophication,

showed similar results to those found in Lake Tamblyn regarding water quality.

The D-net samples obtained from the McIntyre River showed different and almost

opposite results as those found in Lake Tamblyn. The McIntyre River had a less diverse finding

of species, as only six different species were identified. Along with the rocky bottom substrate,

this data correlates to findings from Heino (2000) in which an abundance and richness of

invertebrate species is directly related to the amount of vegetation. The river has little vegetation,

and a low abundance and richness of species. The D-net samples also illustrate how species that


are sensitive to pollutants survive in good quality waters, as the majority of species found in this

sample were sensitive to pollutants and the river had a higher dissolved oxygen content.

The quantitative sampling methods from Lake Tamblyn and the McIntyre River conclude

that the highest density was found in the river. This validates the conclusion that the river has

better water quality since it can support a larger diversity of species. The low density in the lake

also supports the conclusion that Lake Tamblyn had a lower dissolved oxygen content and is

impaired. The individual organisms found in these sampling methods also support the idea since

the majority of the species found in Lake Tamblyn using the Ekman Dredge were tolerant of

pollutants and able to survive in an ecosystem with a lower dissolved oxygen content. The

species found in the Surber Stream Bottom Samplers were organisms that are somewhat tolerant

of pollutants, therefore, needing better water quality to survive.

It can be concluded that lentic and lotic ecosystems have different characteristics, such as

depth, bottom substrate, and temperatures, but they are also different in the organisms they can

support. At Lakehead Univeristy, the lentic ecosystem had a greater diversity index, higher

species richness and better water quality than the lotic ecosystem. These results coincide with the

objectives of the study.

Acknowledgements

I would like to thank those who helped in making this study possible. First, I would like to thank

the ORPT Gear Depot for supplying canoes, lifejackets, paddles, and throw bags, which allowed

us to take samples on Lake Tamblyn. I would also like to thank the Biology Department for

supplying us with the rest of the equipment used. Next, I would like to thank my professor and

Teaching Assistants for the instruction, facilitation, and assistance during the study days. My

classmates are also to thank for their cooperation and teamwork in gathering and analyzing the


samples. I am grateful for the knowledge I acquired in my Ecological Literacy class that I took

last year as it assisted me in determining the pollution tolerance of the organisms. Finally, I

would like to thank my roommate, Katie McIntyre for her support and assistance in editing my

paper.

References

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