WHY BENTHIC MACROINVERTEBRATES?
Written by Dr. Checo Colon-Gaud, Associate Professor of Biology at Georgia Southern University If memory serves me right, I’ve spent most of my life around rivers and streams. Stumping across creeks and flipping rocks as a kid to fishing and paddling as I grew older. However, it wasn’t until I was in my twenties that I truly appreciated the great diversity of organisms that lived beneath the water’s surface. Little by little I became more intrigued by a particular group of creatures that appeared to rule these underwater habitats. Benthic macroinvertebrates. The word benthic (or benthos) refers to those organisms that live in the bottom substrates and macroinvertebrate are organisms that lack a backbone and usually are large enough to see with the naked eye. Well…usually. These bottom-dwelling invertebrates can be vastly abundant in freshwater systems (rivers, lakes, wetlands) and can often be dominated by immature, larval, or nymph stages of aquatic insects. Aquatic insects can be incredibly diverse in freshwater systems and they tend to be ubiquitous to almost all aquatic environments. They can also be relatively long-lived in aquatic environments, with some spending over a year of their life cycles as immature stages, whereas their terrestrial adult stages can often only last several hours to several days. This unique life history of shared aquatic and terrestrial life stages makes them important conduits of energy between the water and the land, as many adults return to the water to deposit energy-rich eggs and young that provide a food source to many fish and other aquatic consumers. Whereas those that survive to became aerial adults often become a prey source to terrestrial consumers such as birds, spiders, etc. Aquatic insects are not only taxonomically diverse, but also functionally diverse. Meaning that they can play important roles during their aquatic life stages that support essential ecosystem services such as the decomposition of organic matter and the cycling of energy and nutrients. Many of these ecosystem services can be associated with the maintenance of healthy aquatic environments and clean water. And again, let’s not forget that they are also an important food source to fish, waterfowl, and other valuable aquatic organisms. Aquatic insects and other benthic macroinvertebrates are also important indicators of ecosystem health and condition. Because of their high levels of diversity and unique adaptations to endure life in water, many benthic invertebrates are known to be sensitive to pollution and other alterations to aquatic ecosystems. The presence of high numbers (i.e., abundance) or high levels of diversity of sensitive groups of benthic invertebrates can usually be associated with ideal water quality conditions such as high dissolved oxygen content. On the other hand, freshwater systems that are mostly dominated by somewhat tolerant to highly tolerant taxa of benthic invertebrates can be often associated with alterations or impairment to the system (e.g., pollution, habitat loss, etc.). Freshwater scientists have used benthic macroinvertebrates as a tool for assessing the health of freshwater systems for decades as these can provide a more in depth look at the conditions of the system in real time. The basis for this is that the organisms that are present in the system are exposed to such conditions continuously. Benthic macroinvertebrates can teach us a lot about the systems they inhabit. Not only are they essential role players in the functioning of freshwater ecosystems, but they help sustain the organisms that we most often associate with these systems. Gaining an appreciation of benthic macroinvertebrates, as well as the diversity and function of the aquatic organisms that live underneath the water can provide a valuable way to protect and conserve these important natural resources.
0 Comments
Your comment will be posted after it is approved.
Leave a Reply. |
Details
Archives
June 2019
CategoriesSupported by the Gulf Research Program of the National Academies of Sciences, Engineering, and Medicine under the Grant Agreement: 20000G9576
|