Great Lakes Literacy, Principles Four & Five – Water makes Earth habitable
Great Lakes Literacy is an understanding of the Great Lakes’ influence on you and your influence on the Great Lakes. Principles Four & Five focus on the fundamental importance of water to all living things.
May 24, 2012 - Author: Steve Stewart, Michigan State University Extension
This article is the fifth in a series of articles discussing what Great Lakes literacy means for residents of the state of Michigan and the Great Lakes region.
The Great Lakes contain approximately 20% of Earth’s surface fresh water, and fresh water has many unique properties. Water is essential for life, and all living processes occur in an aqueous environment. Every aquatic and terrestrial organism in the Great Lakes basin requires a source of fresh water to survive.
Life in the Great Lakes ranges in size from the smallest blue-green bacteria to the largest animal that lives in the Great Lakes, the lake sturgeon. Most life in the Great Lakes exists as microorganisms. Microorganisms, such as phytoplankton and cyanobacteria, are the most important primary producers in the lakes.
The Great Lakes’ watershed supports organisms from every kingdom on Earth and Great Lakes biology provides many examples of life cycles, adaptations, and important relationships among organisms, such as symbionts, predator-prey dynamics, and energy transfer.
The Great Lakes ecosystem provides habitat for both terrestrial and aquatic species. The Great Lakes are three-dimensional, offering vast living space and diverse habitats from the shoreline and surface down through the water column to the lake floor. Great Lakes’ habitats are defined by environmental factors. As a result of interactions involving abiotic factors such as temperature, clarity, depth, oxygen, light, pressure, substrate type and circulation, life in the Great Lakes is not evenly distributed. Abiotic factors can change daily, seasonally or annually due to natural and human influences.
Ecosystem processes influence the distribution and diversity of organisms from surface to bottom and nearshore to offshore. Wetlands, including coastal marshes and freshwater estuaries, provide important and productive nursery areas for many species that rely on these habitats for protective structure, hunting grounds, migration stops and raising offspring.
Life cycles, behaviors, habitats and the abundance of organisms in the Great Lakes have all been altered, in some cases to the good and others to the bad, by intentional and unintentional introduction of non-native plant and animal species.
MSU Extension and Michigan Sea Grant offer many opportunities to learn more about the Great Lakes. Registration is currently open for our 2012 Summer Discovery Cruises, and K-12 classes are on the water this spring participating in our Great Lakes Education Program. For educators, our Teaching with Great Lakes Data professional development workshops and accompanying website offer many ways to include historical and real-time Great Lakes weather and climate data in the classroom.
This article was adapted from Great Lakes Literacy: Essential Principles and Fundamental Concepts for Great Lakes Learning (Ohio Sea Grant, 2010).