You might be surprised to learn that Canada has 879,000 lakes, far more than any other country on Earth; Russia has 201,200, USA has 102,000 and China 23,800.
Considering Canada’s vast freshwater resources, it is becoming increasingly important that we understand how our lakes respond to changes in the environment, pollution and changes that originate from human activity. In all of this lies a central imperative that we must pursue greater understandings about our freshwater lifeforms.
This might cause you to wonder what Canada and British Columbia are doing to understand and protect our lakes and the many lifeforms, including plankton, that live in our lakes.
Plankton is a term we toss around lightly; whales eat plankton, don’t they? Yes, but did you know that British Columbia has more than 19,000 lakes all of which are home to plankton. These tiny lifeforms are essential to the ecosystems in which they live and also to the planet as a whole. Plankton need to be understood for the important role they play in our global environment. Yes they are food for whales, and soon they will be farmed as food for mankind as well.
On this page we intend to narrow our focus to just Hotel Lake and begin looking at the plankton populations we can see here in Garden Bay. There is so much more to Hotel Lake than what meets-the-eye! The surface of the water, teased by sunlight, wind and rain, is a remarkable reflective shield that prevents us from seeing most of the tiny animals and plants that live below. This web page is published to introduce some of the plankton species that live in Hotel Lake in large numbers and which, for the most part, go completely unnoticed and unappreciated. The photos below, show how this was done. The large composite/slide is from Dana Halay’s presentation given to the public in Sept 2025 at Sarah Wray Hall on the south shoreside of Hotel Lake. You will see 7 types of Zooplankton identified as being in Hotel Lake.
We wish to thank UBC Professor Evgeny Pakhomov for three years of enthusiastic guidance and oversight of our volunteer efforts in Hotel Lake. We also wish to thank Doctor Florian Luskow for his early mentorship or our volunteers in the first year working with UBC
Prof. Evgeny Pakhomov
(UBC) Department of Earth, Ocean & Atmospheric Sciences, Institute for the Oceans and Fisheries and Marine Zooplankton and Micronekton Laboratory
University of British Columbia
Dr. Florian Luskow, a former postdoc at UBC and now taking up another postdoc position at Uppsala University, Campus Gotland, Sweden.
Local volunteers using plankton net
UBC Prof Evgeny Pakhomov working with students Johanna Marshall and Dana Halay
Plankton
The word “plankton” comes from the Greek word planktos which means “drifting or wandering.” Plankton are tiny organisms that live in water which are able to propel themselves and to swim very small distances but are not strong enough to swim against water currents. In oceans, plankton drift and wander mainly due to advection.
In Hotel Lake it is most likely that turbulance caused by lake turn-over or perhaps strong wind are the forces that might result in movement of the very small animals (zooplankton) and very small plants (phytoplankton) that live in Hotel Lake.
There are two types of plankton:
Zooplankton (animals) are tiny organisms that feed on other zooplankton and on bacteria, and
Phytoplankton (also known as microalgae or microscopic water plants) which are photosynthetic primary producers; they contain chlorophyll and require sunlight in order to live and grow. They are autotrophic or ‘self-feeding’, making their own food by photosynthesis or chemosynthesis. During photosynthesis, water and carbon dioxide combine to form carbohydrates (sugars) and give off oxygen.
Zooplankton and Phytoplankton are both vital food sources for fish and other aquatic life and both play roles in nutrient cycling and carbon sequestration.
The terminology of size: The size range of plankton species vary significantly:
“Macro"or macrozooplankton means they are usually bigger than 20 mm and can be observed without magnification equipment.
“Micro, Meso” or mesozooplankton means they are very small, 0.2-20 mm and cannot be seen easily unless viewed through a microscope.
All the plankton being discussed here are very small and we will generally use millimeters, using the familiar symbol “mm”. Extremely small measurements involve the use of microns also called micrometers which are 1/1000 mm which is written as "1 micron" or “1µ"
This webpage will focus initially on Zooplankton. Phytoplankton will be added further down this page, at some point in the future.
Zooplankton
Zooplankton are tiny, heterotrophic organisms that drift in the water column. Heterotrophic is an organism that cannot produce its own food but consumes nutrition and energy from other sources, mainly from other organisms. They feed on small animals and some single-celled organisms, phytoplankton (plants) and bacteria and, in turn, serve as food for larger organisms. They are considered “foundational to the food web, providing nourishment for fish, such as trout, and other larger aquatic animals”.
Plankton populations play an important role as a natural food source and also as a marker or biosentinel (an organism that is the first to respond to a pollutant or other environmental changes). As a result they have, in past years, been studied or monitored to some degree by our federal government and by the government of BC as part of evaluating water quality and ecosystem health.
In BC, Zooplankton abundance and diversity vary between lakes but are known to closely match phytoplankton abundance and diversity. For instance, in BC lakes with an abundance of green algae (phytoplankton), there was an abundance of Copepods (zooplankton).
A rough perspective of the pattern of plankton distribution across Canada as can be seen below in a chart from a 2021 paper: "Multi-scale and multi-system perspectives of zooplankton structure and function in Canadian freshwaters”, which shows plankton "species richness per lake” (a measure of the number of different species present in a particular lake) is expected to be between 3-10 species of plankton, with a “Mean: 6 species”. The real question is, what are the zooplankton species that live in Hotel Lake? We are fortunate that through our work with UBC over the past 3 years, we find ourselves able to provide some answers this question and so with thanks to UBC Professor Evgeny Pakhomov and a number of his students, we are able to produce this unique perspective of Hotel Lake for the first time.
Copepods
Copepods
Copepods are tiny crustaceans that are amongst the most abundant multi celled organisms on the planet. They are found in virtually all marine and freshwater environments where they play an important role in maintaining the ecological balance of aquatic ecosystems. We believe there are two orders of Copepods in Hotel Lake, Cyclopoid Copepods and Calanoid Copepods.
These two copepods differ in how they propel themselves while swimming or when escaping a threat. Cyclopoid Copepods use the thoracic legs for or both swimming and escape while Calanoid Copepods use the cephalic (from the head area) appendages for swimming and their thoracic legs for escape.
Cyclopoid Copepod is one of the most common freshwater copepods and, as the name suggests, has a single eye which may be either red or black. It can vary in size from 0.5 to 5 mm long. Generally speaking the female copepods are larger than male. The easiest way to tell them apart is when the female has an egg sack attached.
Copepods feed on suspended material in the water. They use a body part called a maxillae to capture food particles and move them to their mouth. Vision is carried out with a central naupliar eye. Chemical and motion sensing is performed using multiple sets of antenna.
Copepod reproduction involves the male grabbing hold of the female as they exchange genetic material for reproduction. Fertilized eggs are carried by the female in two egg sacs, one attached to her on each side. Water temperature is believed to govern when the eggs hatch and enter their free swimming larval stage. The cycle may take as little as one week or up to months or years depending on the species of copepod.
Cladocerans (Daphnia)
Cladocerans (Daphnia)
More than 100 known species of this freshwater crustacean plankton, often called “water fleas”, can be found in waterbodies around the world. They are good swimmers and are usually found in the open water but some species may frequently be seen clinging to water plants or even browsing over the bottom sediments in shallow water. They are between 1 mm to 5 mm in size. Smaller species are typically found in ponds or lakes with fish predation. The ecology of the genus Daphnia may be better known than the ecology of any other group of organisms.
Chaoborus
Chaoborus
As you saw in the video at the top of this webpage, Chaoborus, due to its size, is more visible than most other plankton in Hotel Lake. It is also of particular interest because it has both an aquatic and a brief air born period in its lifecycle.
Chaoborus are found in lakes all over the planet. They are called “glass-worms” because of their transparency. Their elongated bodies can reach up to 2 cm (0.8 in). They have two pairs of tiny but distinctive black kidney-shaped air sacks, one pair in the front and the other pair near the back of the body. They also have two small eyes at the front of their bodies.
Chaoborus spends the majority of its life in the larval stage. They move up and down the water column where their main diet consists of copepods and cladocerans. Most Chaoborus species live for one or two years. There are four instars (between moulting), followed by a brief pupal stage.
Chaoborus
The pupal stage is temperature-sensitive and typically lasts for a few days during which the larva transforms into a winged adult.
Once they emerge from the lake as flying adults, they stop eating and become completely focused on mating. Thus we may see them late in the day as they gather in huge clouds over the surface of the lake. The flying adults are sometimes called phantom midges or lake flies and they are easily mistaken for mosquitoes. However much they may look like mosquitoes, they differ primarily in that they cannot bite.
During this brief period of airborne existence, the airborne midges become an important food source for birds. After mating, the male dies but the female returns to the water to lay her eggs.
Rotifers
Rotifers
Most rotifers are microscopic, measuring 0.1–0.5 mm, though their size can range from 0.05 mm to over 2 mm. While they are generally too small to be seen with the naked eye, some larger species can be spotted, and their size is a key factor in their role as a food source for other aquatic animals
Their abundance and diversity in BC lakes are influenced by factors like temperature, food availability, and predation from larger zooplankton like copepods and Daphnia. Rotifer’s feed on organic matter, bacteria, algae, protozoa and other zooplankton. It is calculated that Rotifers are likely to constitute about 29% of the plankton in BC Lakes.
They reproduce quickly and have short life cycles of a few days to weeks. Seasonal population fluctuations may occur, with lower numbers in winter and higher populations in the spring and summer. They may live alone or in colonies. They are resilient and adaptable and have survived for more than 80 million years.
Rotifers are an important component of microbial food webs in a variety of freshwater habitats. Rotifers are a crucial link in the aquatic food web, serving as a food source for other zooplankton such as copepods, and for juvenile fish.
In littoral zones of lakes, Rotifer populations in BC lakes depend on the season and lake conditions. Their densities can be reduced by predators like certain copepods, especially during times when their food sources are also changing.
Rotifers are indicators of water quality; like other plankton, they are sensitive to changes in weather, water temperature, and nutrient availability.
Hydrachna
Hydrachna
Water Mite
For anyone swimming in Hotel Lake in the summer months and who are wearing swimming goggles, it is quite routine to encounter these tiny Hydrachna as they are bright red and highly animated in their movements.
There are more than 80 species in Hydrachna. They inhabit most fresh water aquatic habitats except Antarctica. Water mites are frequently brightly coloured, red or orange in colour, which is unusual among freshwater invertebrates. They have two deeply-seated movable, internalized eye lenses.
They can reach 2mm in size. One reference states that densities can exceed 200 mites/sq.metre.
The larvae are known to be parasitic on aquatic bugs such as Water Boatmen.
Hydrachna
Using a number of sources we can present this rough outline of the Water Mite life cycle:
A water mite’s life cycle involves four stages: egg, larva, nymph and adult. Water mites are parasitic in early life as larva and predatory in later life as nymphs and adults.
Once hatched from the egg the larvae needs to find a host to parasitize. Once found the larvae pierce the host’s tough outer layer with their chelicerae (jaws) and then feed on the host’s hemolymph/blood. Common host groups include insects with aquatic or semi-aquatic juvenile stages, including, but not limited to, true flies, dragonflies and damselflies, caddisflies and water boatman (explained below).
The larva will cling to the outside of a water boatman (explained below) until the larva is fully grown/engorged. It then detaches from the host and transforms into a predatory 8 legged nymph that can swim and hunt. Growth continues as they prey on small crustaceans or aquatic insect eggs and larvae eventually become sexually mature adults.
When the nymph is ready to become an adult, it clings to an underwater plant and changes into its adult form. After finding a mate, the female produces a jelly-like glob of eggs, which she attaches to a plant. Then she dies. The eggs are able to survive the long, hot summer. When the winter rains return, the Water Mite repeats its life cycle.
In Hotel Lake swimmers (wearing swim goggles) may encounter these underwater bright-red spider-like creatures. They routinely appear in zooplankton nets when we raise them and condense the contents for further study.
These tiny red dots may also catch your attention when they attach to dragonflies and damselflies and other substrates during their larval stage.
Studies, along with observations in sampling a wide variety of habitats in North America and elsewhere, lead to the conclusion that water mite diversity is dramatically reduced in habitats that have been degraded by chemical pollution or physical disturbance. However, inadequacies in current databases on Canadian Hydrachna (water mite) species, suggest that more data and studies are needed.
Water Boatman:
Because Water Boatman are a common sight in Canadian lakes and other freshwater bodies and also because they are involved in the life-cycle of Hydrachna-Water Mite, we offer this clarification: Water Boatman are not Plankton. They are classified as Nekton because they are organisms that can swim against a current using their long, oar-like hind legs. Water Boatmen primarily feed on algae, detritus, and other minute aquatic organisms. Water Boatmen play a key role in aquatic ecosystems as a food source for fish, especially trout and char, and are therefore important to fly-fishing.
Jellyfish
Jellyfish
Craspedacusta sowerbii
or as it is more popularly dubbed:
"Peach Blossom Jellyfish Clones”
It may come as a surprise that our invasive freshwater jellyfish in Hotel Lake are classified as plankton. Remembering that Plankton are tiny animals which are able to propel themselves and to swim very small distances but are not strong enough to swim against water currents, our jelly fish fit that description exactly. We have observed them for 3 years and filmed them underwater. What we have observed is that our Hotel Lake Jellyfish when they rise, do move constantly but only vertically up and down the water column and always very slowly. So far, we have not observed them engaged in horizontal "travel".
But yes, these jellyfish they are huge in comparison to the plankton discussed so far. While we squint to see most of the tiny plankton, like Chaoborous at 4mm, our jellyfish have been measured at 2.4cm. This is rather like elephants lumbering through a herd of rabbits. You can read more about our resident jellyfish, Craspedacusta sowerbii, by clicking here and visiting our webpage titled Jellyfish.
Where do we go from here?
While producing this website, we have benefitted greatly from the following report:
B.C. Lake Monitoring Network
Water Quality, Phytoplankton and Zooplankton Taxonomy
Summary Report for 2015-2020
The first paragraph of that report is quoted below:
"Executive Summary
The British Columbia Ministry of Environment and Climate Change Strategy (ENV) conducts spring and fall lake monitoring at select sites across the province, through a program called the B.C. Lake Monitoring Network (BCLMN). Water chemistry was the focus of lakes monitoring for decades but in 2015 the BCLMN was establish and began the collection of taxonomic samples for phytoplankton and zooplankton. However, there has only been limited analytical assessment done of the accumulated taxonomic data to date because of limited funding and ENV staff time. Larratt Aquatic Consulting (LAC) was chosen to combine the taxonomy data, analyze it alongside available water chemistry data, and interpret the results for 19 lakes across British Columbia."
This report was very helpful in allowing us to create this webpage and to hopefully increase awareness about plankton. For the past 3 years we have been involved helping UBC and BCLSS and the Ministry of Environment and Climate Change Strategy (ENV), collect data and samples. The highlighted words “limited funding” appear in the third sentence of the “Executive Summary” but this is hardly a surprise. We may be approaching a time when it will have to be the citizens who will step forward to assist governments in the harvesting and delivery of critical data, samples and local effort concerning our environment so that better decisions and outcomes may be possible in the future.
In the case of Hotel Lake we already have local volunteers trained and experienced to collect plankton samples and process and ship them for further analysis.
It would be a great step forward if the BC Lake Stewardship concept could be the foundation for rapidly expanding the citizen-scientist model. Work could then continue on the development of a larger taxonomic data bank which would allow us to better monitor and understand our changing environment. The alternative of not doing so is unthinkable.
His name is Luke Thomas Anderson and his enthusiasm is infectious,...Enjoy!
References
Zooplankton:
(followed below by Phytoplankton)
British Columbia Lakes Monitoring Program Summary Report. Prepared by Larratt Aquatic Consulting Ltd. Prepared for British Columbia Ministry of Environment and Climate Change Strategy, Self, J. and H. Larratt, 2021, This includes reports on phytoplankton and zooplankton for specific lakes. The reports often identify the dominant taxa for each lake.
The B.C. Ministry of Environment and Climate Change Strategy has published specific technical reports and keys containing extensive lists of plankton species. Freshwater Crustacean Zooplankton of British Columbia: This document provides an introduction and key for identifying freshwater calanoid copepods in the province. Assessment of a Ten Year Record of Phytoplankton and Zooplankton in six small coastal lakes in Southern British Columbia, 1984-1994, D. Christopher Parks, August 1995 PDF link, document in our library:
Multi-scale and multi-system perspectives of zooplankton structure and function in Canadian freshwaters 2021. Published by Canadian Science Publishing: https://cdnsciencepub.com/doi/10.1139/cjfas-2020-0474
UBC, A visual compendium of freshwater plankton: https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.zoology.ubc.ca/~schluter/aqua/index.html&ved=2ahUKEwi4pZvTlYGQAxW6IjQIHf13BREQFnoECBgQAQ&usg=AOvVaw1tlM3KEFVpWun9Kyuwx8D1
Study on Hydrachna: http://www.chebucto.ns.ca/ccn/info/Science/SWCS/ZOOBENTH/BENTHOS/xxi.html
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Draft only
Phytoplankton:
Cyanobacteria (blue-green algae) information: The province maintains information on cyanobacteria, particularly concerning toxic blooms. Many reports contain species lists found in B.C. lakes. PDF link: https://www2.gov.bc.ca/assets/gov/environment/air-land-water/water/waterquality/how-drinking-water-is-protected-in-bc/cyanobacteria_decision_protocol_2018.pdf
Phytoplankton reports for individual lakes: Specific lakes have their own detailed phytoplankton summary reports. Examples include:
University and Research Institutions
Various research projects and academic websites provide identification resources and species lists for freshwater plankton in B.C.
University of British Columbia (UBC) Zoology. The "aqua - freshwater plankton" resource highlights common species found in southwestern B.C. Web link: https://www.zoology.ubc.ca/~schluter/aqua/
Phytoplankton Encyclopedia Project (UBC). While focused on coastal marine species, the Earth, Ocean and Atmospheric Sciences (EOAS) department has published a key to help identify phytoplankton.
Web link: https://phytoplankton.eoas.ubc.ca/