Water is the source of life as we know it. Its many special properties are necessary for its many purposes. Life is only possible where liquid water is present. Water covers more than 71% of the earth and makes up more than half the mass of living organisms. Not only is water necessary for our lives as humans, it is also necessary for the plants and animals we eat to grow and survive. Freshwater habitats are the source for several of these. Some communities’ drinking water comes from freshwater rivers and lakes. Many freshwater fish that we eat all the time live in these same environments, in addition to macrophytes (plants you can see with the human eye) that we enjoy looking at and eating. Many freshwater habitats also serve in recreational capacities. This blog will cover some of the physical attributes, characteristics, species, and activities that make up and shape freshwater habitats.
Some of the above information to me is information that is second nature to me because I’m a senior biology major. Other information is what i learned taking Dr. Huryn’s Freshwater Studies class (BSC 320) during the Fall 2013 semester. The picture that accompanies this blog was taken from http://www.rfleming.net/Canada.htm.
The following video is one we were shown on our field trip to the Alabama Aquatic Biodiversity Center. It’s a very abbreviated and summed up version of their efforts for preserving endangered mussel species.
The Lake Nyos region in Cameroon is home to somewhere between five and ten thousand people in the floodplain. During the summer of 1985, as much as one cubic kilometer of carbon-dioxide was suddenly released from Lake Nyos. The gas and water fountain produced by the explosion reached over 100 meters. A surface wave of 30 meters high moved across the surface of the lake. The resulting gas cloud killed people and livestock as far as 26 kilometers away from the lake. A total of 1800 people died. Lake Nyos is a meromictic lake, which is a deep lake with layers that do not mix and high concentrations of solutes that originate from groundwater that enters from the bottom of the lake. Carbon-dioxide gas from magma from nearby volcanos dissolved in the groundwater and was trapped due to stratification. Any movement of deep water could trigger a gas release of saturated water. The eruption was most likely triggered due to a landslide into the lake. Several processes have since been out into place to prevent this kind of thing from happening again in Lake Nyos. One of these, and possibly the most effective, is a degassing fountain that was installed in the lake (can be seen below). Once it was started, the degassing was spontaneous and self-sustaining.
Rivers are dammed to form impoundments for many reasons, including: transportation, hydroelectric power, water supply, flood control, and reacreation. The rivers of Alabama have been altered dramatically by dams, primarily for transportation and hydropower. This is important to freshwater studies because of its consequences for biota. The environmental effects of dams include habitat loss & modification, downstream effects—discharge pattern and temperature pattern, water chemistry, channel formation, and upstream & downstream effects on migration and dispersal of biota.
In Alabama, the Alabama Power company was originally started for its hydropower purposes. The image included in this post is an example of the turbine propellers used in dams in Alabama that generate electricity. This is one I saw on a field trip to Hold Dam located in Tuscaloosa.
There are multiple studies proving that biodiversity is better maintained in the presence of beavers. One study I looked at was conducted in Illinois, and it found that beaver ranges are larger when located in the main river as opposed to tributaries and also when further from agricultural areas. Another studied conducted in Lithuania determined that hilly, uplands had a higher beaver population and were more intensely impacted than plain landscapes, probably partially because the plains had fewer streams and were harder to transform. The plain landscapes were still inhabited by beavers. And another study done in Canada, found that beaver impacted biodiversity is higher in agricultural areas than in protected areas. Overall, beavers will seek out ideal habitats to transform into their homes, but beavers are still able to transform and thrive in non-ideal habitats because of their extraordinary ability to transform ecosystems.
Photo from Dr. Huryn’s Freshwater Studies class in the fall of 2013.
This is a link to the University of Alabama Ichthyological Collection website. During one of the field trips in Dr. Huryn’s Freshwater Studies class we visited UA’s Ichthyological Collection located on the University of Alabama campus.
There are about 173 mussel species and subspecies in Alabama, 11 of which have never been found outside of Alabama. Freshwater mussels basically do two things: filter feed and reproduce. Though they seem simple, they have a diverse anatomy. The following is just an example of some of the anatomy of freshwater mussels.
The gills are used for filter feeding. The foot is usually required when it comes to reproduction. In order to reproduce, mussels produce glochidia, which are basically juvenile mussels. These glochidia require a host fish in order to transform into an adult mussel. Sometimes these glochidia can just be released into the flowing water and attach to their host fish, but more often, the parent mussel uses its foot to attract the host fish. Below are some pictures of mussels using their foot as a lure.
Lampsilini: Villosa iris (this one is using its foot to look like a crayfish to attract its host fish which feeds on crayfish)
Mussels are a lot more complex than they seem to be and can be easily found if you’re in the right place. Bogue Chitto Creek near Marion, AL is an area that has a high mussel species richness.
Photos taken from Dr. Huryn’s Freshwater Studies class in Fall 2013.
Biodiversity for a state is determined by species diversity, levels of rarity and risk, endemism, and number of species lost to extinction. California, Hawaii, Texas, and Alabama have the highest biodiversity levels in the US. Alabama is ranked #1 for fish diversity and #1 among eastern states for species diversity. Alabama has 43% of snails species, 63% of mussels species, 23% of crayfishes species, 38% of fishes species, and 52% of turtles species of the total US and Canada species richness. This richness is partly due to climate, geology, hydrology, and drainage evolution. Climate is a key factor because our climate is relatively constant year round (it may not seem like it since we live here, but compared to other places it is). The lack of direct physical impact from habitat destroying glaciers has also played a role in our biodiversity. Alabama has a great degree of physiographic diversity. Alabama has six regions of physiographic diversity.
This picture labels five of the regions and the sixth is the line, called the Fall Line, that separates the East Gulf Coastal Plain from all the others. Continuing drain evolution, which separates species from their natural habitat and puts different species in the same environment which sometimes creates new species, is a big player in the biodiversity of Alabama.
All of these things lead to the extremely high levels of biodiversity in the state of Alabama.
Picture taken from Dr. Huryn’s Freshwater Studies class from Fall 2013.