Photo Gallery

The life cycle of a freshwater mussel begins with the male releasing sperm into the water. The eggs develop in the female's gills, so they are fertilized when the sperm enter the female when she feeds and respires (using her gills).

After a period of gestation, mature larvae are released into the water when a suitable fish host approaches. Mature larvae of the giant floater typically attach to fins and remain on the fish for weeks, or even months, in autumn/winter.

The larvae metamorphose in spring and detach from the fish to begin their life buried in the river bottom. Young mussels usually resurface when they are about two years old. Adults mature at approximately five or six years old and can live well over 10 to 15 years.

This illustration depicts the giant floater (Pyganodon grandis).

Two species of freshwater mussels are found in the Frenchman River; the giant floater (Pyganodon grandis) and the fatmucket (Lampsilis siliquoidea) are widespread across southern and central Saskatchewan.

This image shows two specimens that were collected in Grassland National Park on May 14, 2002.

The giant floater is found throughout the entire Frenchman River, and the fatmucket begins to occur below the dam at Eastend.

A study on the fish of the Frenchman River conducted in the West Block of Grasslands National Park indicated that the larvae of the giant floater are carried (hosted) by fathead minnows (Pimephales promelas), lake chub (Couesius plumbeus), brassy minnows (Hybognathus hankinsoni), brook sticklebacks (Culaea inconstans) and Iowa darters (Etheostoma exile).

So far, we do not know which fishes host the glochidia of the fatmucket mussel in the Frenchman River.

Freshwater mussels feed by filtering the water, ingesting detritus, microscopic algae, and coliform bacteria, such as those from humans and from cattle. Up to three litres of river water can be filtered by a single mussel in one hour. Accordingly, mussels are effective water filters that are worthwhile preserving—and this includes protecting the fishes that are needed for the dispersal of the mussel larvae.

A general survey aquatic invertebrates in the Frenchman River in Saskatchewan was conducted in September 2003. More than 40 000 specimens were collected at 25 locations along the river. Additional samples were collected in August 2004 at 33 sites in and near Grasslands National Park of Canada (GNP). Rock Creek was included.

These samples have shed light on the abundance and distribution of aquatic invertebrates in this watershed, especially for GNP. They also provide a valuable basis for comparison, given the potential impacts of climate change in this area and the value of aquatic-invertebrate species as indicators of ecosystem health.

Tools used by the students during fieldwork for the Frenchman River Biodiversity Project (FRBP) included digital cameras, topographical maps, water quality test kits, and an aquatic invertebrate field guide.

The guide was developed by through the FRBP, based on biological data collected from the river basin. The resources and tools that were acquired or developed through this project, including a preliminary curriculum document for ecological monitoring, were given to local schools for their use.

Researchers take water samples in the Frenchman River, Saskatchewan. On the prairies, high sulphate levels are common in ground water, and are also present in surface water. Very high sulphate levels were found at two sites along the Frenchman River, in combination with high levels of calcium, magnesium, potassium and sodium.

This combination suggests that the high levels of sulphate may be from ground water. The levels are two and three times the recommended guideline of Agriculture Canada, and, at these concentrations, can affect cattle health.

The clams in this photo are known as fingernail clams. They are classified in the genus Sphaerium, and are larger than clams in the genus Pisidium; both are commonly observed alive and dead on the bottom of the river or among detritus and accumulated debris.

The shell length reached by clams in the genus Sphaerium ranges from about 8 mm to a maximum of 15 mm.

Clams of the genus Sphaerium and Pisidium differ from other native freshwater bivalves, such as mussels, in that the adult broods its young and releases them directly as crawl-away juveniles, with no reliance on fish for dispersal (as mussels require). They are often preyed upon by fish.

These fingernail clams were collected in about 30 cm of water just above a beaver dam, in a tributary of the Frenchman River, in October 2006.

Two types of snail are shown here: the large one is a pondsnail (of the family Lymnaeidae) and the one below it is a ramshorn snail (of the family Planorbidae).

Freshwater snails eat by grazing detritus and especially the microscopic algal film that grows on the surface of aquatic plants, rocks and other substrates in rivers and lakes.

Some snail species are very sensitive to water pollution, while others are very tolerant to deterioration of water quality (for example, some tadpole snail species in the Physidae family).

Snails are gastropods, and they belong to the same phylum (Mollusca) as freshwater mussels. Gastropods are a common and important ecological component of the community of bottom animals living in the Frenchman River, Saskatchewan.

The two types of mussels found in the Frenchman River system are somewhat resilient species. They are sensitive to excessive water pollution and habitat deterioration.

Because of their dependence on fish, the mussels' sensitivity to environmental stressors, their large size and the ease of their identification, the Frenchman River Biodiversity Project proposes that freshwater mussels be used as ecological indicators of habitat quality in the Frenchman River.

Generally, the presence of a diverse and abundant fauna of freshwater mussels in a river is a very good thing because it usually means cleaner water and good fishing.

Environmental challenges that can negatively impact freshwater mussel populations (and those of other molluscs) include:
(i) damage to the riparian vegetation and to the river bank itself (such as siltation caused by excessive trampling by humans and large animals)
(ii) excessive water pollution or organic loading
(iii) loss of fish stocks and their habitat.

Grade 10 students from Eastend School and grades 9 and 10 students from Val Marie School in Saskatchewan participated in program activities of the Frenchman River Biodiversity Project as a unit in their science curricula.

Teachers prepared students by providing them with background information about the local ecology of the watershed and a review of water chemistry, and then a local FRBP representative spoke to the students about how they would be contributing to a larger project. New concepts such as "biodiversity", "stewardship", and "citizen science" were introduced. Demonstrations on the use of technical equipment, sampling procedures and safety protocols were also given.

Analysis of 2004 data from the Frenchman River Biodiversity Project compared the East and West Blocks of Grasslands National Park, Saskatchewan.

There were no East-West differences in the invertebrate communities associated with standing water, but there were differences regarding several species associated with running water. For example, aquatic mites of the genus Mideopsis were not evenly distributed among flowing water sites, while they were concentrated in East Block sites.

The water mite shown here is a species of the genus Sperchonopsis.

The analysis did find differences in water quality between the Blocks: the West Block had higher total nitrogen and phosphorus, while the East Block had higher pH and carbonates.

This illustration depicts a caddisfly larva.

The Frenchman River Biodiversity Project collected more than 1000 caddisflies and mayflies in 2003, which are associated with high-quality water.

Most of the invertebrates collected were midge larvae (in the Chironomidae family), which is to be expected in a slow-moving prairie river such as the Frenchman.