Rocky Mountain Biological Laboratory

Field TripsLife Cycles of Macroinvertebrates-- Fossils-- Riparian Vegetation

LIFE CYCLES OF MACROINVERTEBRATES

Biological monitoring, the study of biological organisms and their responses, is used to determine environmental conditions. Macroinvertebrates are organisms that are large (macro) enough to be seen with the naked eye and lack a backbone (invertebrate). They inhabit all types of running waters, from fastflowing mountain streams to slowmoving muddy rivers. Examples of aquatic macroinvertebrates include insects in their larval or nymph form, crayfish, clams, snails, and worms. Most live part or most of their life cycle attached to submerged rocks, logs, and vegetation. Aquatic macroinvertebrates are good indicators of stream quality because:

They are affected by the physical, chemical, and biological conditions of the stream. They can't escape pollution and show the effects of short- and long term pollution events. They may show the cumulative impacts of pollution. They may show the impacts from habitat loss not detected by traditional water quality assessments. They are a critical part of the stream's food web. Some are very intolerant of pollution. They are relatively easy to sample and identify.

The basic principle behind the study of macroinvertebrates is that some are more sensitive to pollution than others. Therefore, if a stream site is inhabited by organisms that can tolerate pollution and the more pollutionsensitive organisms are missing a pollution problem is likely. For example, stonefly nymphs aquatic insects that are very sensitive to most pollutants cannot survive if a stream's dissolved oxygen falls below a certain level. If a biosurvey shows that no stoneflies are present in a stream that used to support them, a hypothesis might be that dissolved oxygen has fallen to a point that keeps stoneflies from reproducing or has killed them outright.

In good quality water bodies, there may be 30 or more different types of macroinvertebrates in a small area. Their survival is directly related to water quality. As such, the life cycles of macroinvertebrates all revolve around water. From reproduction-- male mayflies form a swarm above the water and females fly into the swarm to mate. The male grabs the passing females with their elongated front legs and they mate in flight. The male then releases the female where she descends to the surface of the water to lay her eggs. All macroinvertebrates lay their eggs in water. Some species of mosquitoes lay their eggs one at a time-- and they become stuck together as rafts of a hundred or more eggs! The next stage is larvae or nymph; in this stage, the larva feeds on the streambed until it matures. The caddisfly forms a cocoon out of silk in this stage. Then, in their adult form, the macroinvertebrates swim toward the surface. The winged ones must wait a few days on the surface for their wings to dry. Adults usually live for a very short time-- only two to three weeks! They spend most of their time mating or laying eggs. Stonefly Kingdom Animalia (Animals)Phylum Arthropoda (Arthropods)Subphylum Hexapoda (Hexapods)Class Insecta (Insects)Order Plecoptera (Stoneflies)There are 3,500 species worldwide, with new species still being discovered. Stoneflies are believed to be one of the most primitive groups of Neoptera (winged insects) with close relatives identified from the Carboniferous and Lower Permian geological periods.

Mosquito Kingdom Animalia (Animals)Phylum Arthropoda (Arthropods)Subphylum Hexapoda (Hexapods)Class Insecta (Insects)Order Diptera (Flies)No Taxon ("Nematocera" (Non-Brachycera))Infraorder Culicomorpha (Mosquitoes and midges)Family Culicidae (Mosquitoes)

There are 2500 species of mosquitoes-- 150 in the United States.

MayflyKingdom Animalia (Animals)Phylum Arthropoda (Arthropods)Subphylum Hexapoda (Hexapods)Class Insecta (Insects)Order Ephemeroptera (Mayflies)

The first recorded mayfly nymphs are from the late Carboniferous period. The highest diversity of Ephemeroptera appears to have been during the Jurassic. Fossils of nine families have been found during this period. There are 2500 species known worldwide-- 630 in North America.

Caddisfly Kingdom Animalia (Animals)Phylum Arthropoda (Arthropods)Subphylum Hexapoda (Hexapods)Class Insecta (Insects)Superorder: Amphiesmenoptera-- together with Lepiodoptera, moths and butterflies, which have scales on their wings.**The amphiesmenoptera superorder probably evolved in the Jurassic Period, diverging from the extinct Necrotaulide-- which diverged from the insect order Mecoptera (Scorpionflies) somewhere between the Permian and the Triassic periods and were extinct by the Cretaceous. Caddisflies are ancient relatives of moths and butterflies! Order Trichoptera (Caddisflies)Caddisflies are small, mothlike insects, but it is in their larval stage that they prove their prowess as architects. According to North Carolina State University, all caddisfly larvae are aquatic, and some of them live within protective cases that they build from their own silk and whatever materials they find lying around, usually gravel, twigs, leaf fragments, and other debris. Caddisfly larvae will scavenge for building materials from whatever is available in their environment. Caddisflies in most temperate areas complete their life cycle in one year.

FOSSILS

Fossils are clues to the past-- they are rocks containing the preserved remains of once-living animals or plants. Fossils are formed when an animal or plant is buried in sediment. Usually, the soft part rots away, but the hardest part remains. This is why most fossils consist of bones or shells of animals; the leaves of woody parts of the plants. Fossils are found in sedimentary rocks-- rocks that are formed by the deposition of material at the earth's surface and within bodies of water-- especially limestone and shale. Do we have shale in our watershed? Yes! We are part of the Mancos Shale Formation-- 200 million years ago, Crested Butte was part of the Mancos Sea. Many fossils are of plants and animals now extinct-- like dinosaurs! Why are fossils interesting for scientists to study? They provide a valuable record of the plant and animal life and environmental conditions from millions-- even billions-- of years ago! Fossils have also been created by bogs, volcanic ash, amber and asphalt. What we'll be finding a lot of here are brachiopods-- marine animals that have hard shells on the upper and lower surfaces. There are still 300 living species of brachiopods. Brachiopods were extremely abundant during the Paleozoic Era-- 541 million to 252 million years ago. They diversified into a number of different morphologies and participated in the buildup of ancient reefs. At the end of the Paleozoic Era, they were decimated in the worst mass extinction of all time-- when 90to 95 percent of marine animals were wiped out. More on the Permian Extinction: The Paleozoic Era (from the Greek palaios, "old" and zoe, "life", meaning "ancient life") is the earliest of three geologic eras of the Phanerozoic Eon, spanning from roughly 542 to 251 million years ago (ICS, 2004). It is the longest of the Phanerozoic eras, and is subdivided into six geologic periods; from oldest to youngest they are: the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian. The Permian period is characterized by diversification of early amniotes into ancestral groups of mammals, turtles, lepidosaurs, archosaurs; world dominated by single supercontinent Pangaea surrounded by global ocean Panthalassa; Carboniferous rainforests gone; vast deserts covered western Pangea during the Permian as reptiles spread across the face of the supercontinent. The Permian–Triassic extinction event is the most significant extinction event in this plot for marine genera which produce large

numbers of fossils. 90% to 95% of marine species became extinct, as well as 70% of all land organisms. It is also the only known mass extinction of insects.

More on trilobites: Trilobites (meaning "three lobes") are a well-known fossil group of extinct marine arthopods that form the class Trilobita. Trilobites form one of the earliest known groups of arthropods. The first appearance of trilobites in the fossil record defines the Early Cambrian period (521 million years ago. Trilobites finally disappeared in the mass exctinction at the end of the Permian about 250 million years ago. The trilobites were among the most successful of all early animals, roaming the oceans for over 270 million years-- there were over 17,000 species of trilobites. All trilobites are thought to have originated in present day Siberia, with subsequent distribution and radiation from this location. Trilobites appear to have been exclusively marine organisms, since the fossilized remains of trilobites are always found in rocks containing fossils of other salt-water animals such as brachiopods, crinoids, and corals. The closest extant relatives of trilobites may be the horseshoe crabs or the cephalocarids.

RIPARIAN VEGETATION

Stream or river banks are riparian areas, and the plants that grow there are called riparian vegetation. Riparian zones, especially those in headwater stream systems such as Coal Creek, are important for wildlife habitat, stream ecology, microclimatic development, migration corridors and for protecting water quality. Also as an important landscape component, riparian zones exchange nutrients and food energy with the associated stream. Additionally, riparian zones are valuable to humans for recreation as well as the reduction of the power of floods.

Bank stabilization and water quality protection The roots of riparian trees and shrubs help hold streambanks in place, preventing erosion. Riparian vegetation also traps sediment and pollutants, helping keep the water clean.

Food chain support Salmon and trout, during the freshwater stage of their life cycle, eat mainly aquatic insects. Aquatic insects spend most of their life in water. They feed on leaves and woody material such as logs, stumps and branches that fall into the water from streambanks. Standing riparian vegetation is habitat for other insects that sometimes drop into the water, providing another food source for fish.

Thermal cover Riparian vegetation shields streams and rivers from summer and winter temperature extremes that may be very stressful, or even fatal, to fish and other aquatic life. The cover of leaves and branches brings welcome shade, ensuring that the stream temperature remains cool in the summer and moderate in the winter. Cooler, shaded streams have less algae and are able to hold more dissolved oxygen, which fish need to breathe.

COAL CREEK: The Coal Creek watershed is predominantly a subalpine spruce-fir forest with drier, primarily south facing slopes being dominated by sagebrush steppe and grasslands. The riparian zones are dominated by willows and alders with some active and abandoned beaver ponds, along with wet meadows. There are many wetland plants in the narrow riparian corridor that are not found in drier soils found upslope. As a result and is typical of most riparian areas, wildlife use of these wetlands is high which contributes to local biodiversity and high plant and animal productivity. Most of the springs in the watershed are on the south side of Coal Creek. Beaver ponds have also altered long sections of Coal Creek with the fine sediments trapped behind the ponds creating sedge (Carex spp.) meadows when the beaver ponds are ultimately abandoned.

There are also a variety of lentic (=standing water) habitats found within the Coal Creek watershed. The Mount Emmons Iron Fen is a wetland complex consisting of forested wetland, sedge fen, and a pond, all underlain by peat enriched with iron oxide (limonite). The unusual geological conditions associated with the Mount Emmons Iron Fen produce a combination of mineral rich waters and a very low pH (~3-4). This rare combination also makes for habitat of the roundleaf sundew (Drosera rotundifolia) and two unusual species of dragonfly (Leucorrhinea hudsonica and Somatochlora semicircularis). These characteristics led to the designation of 75 acres in a State of Colorado Natural Area which provides some degree of protection to this wetland complex and its associated riparian community. The outflow of this fen was altered by the construction of a ditch which diverts the outflow away from it wetlands

and into a separate drainage. Since this water drained to a slope above a road that caused slumping, this diversion was constructed to reduce road maintenance costs. More typical lentic habitats are found at the high elevation lakes of Copley Lake, Green Lake and Lily Lakes that all have associated riparian zones.

SLATE RIVER: Wetland vegetation in the Middle Slate River Valley is dominated by geyer willow, mountain willow, and beaked sedge. Other major vegetation types include submerged aquatic vegetation in beaver ponds, lakes and slow-moving streams, grass, and herb-dominated wet meadows and peatland communities at seeps and springs and on lake and pond edges. The abundant water creates unique ecosystems that provide some or all of the following functions: 1. water quality enhancement 2. fish and wildlife habitat 3. ground water recharge 4. flood water retention, detention and storage 5. shore line anchoring 6. sediment trapping 7. food chain support 8. places for active and passive human recreation

The Permian–Triassic extinction event, labeled "End P" here, is the most significant extinction event in history.

The world in the Permian period was dominated by single supercontinent Pangaea surrounded by global ocean Panthalassa; Carboniferous rainforests gone, instead vast regions of arid desert.