Endangered Filter Feeder the Orangefoot Pimpleback Pearlymussel

What are they?

Mussels are filter feeders which not only are the source of food for many other species in their ecosystem, but serve a valuable role in filtering out pollutants which harm other aquatic life. North America has the greatest diversity of freshwater mussels in the world, however their stocks are being depleted and their ecosystems are being degraded. Over 70% of mussels in North America are extinct, compared to 16.5% of mammals, 14.7 % of bird species. The orangefoot pimpleback pearlymussel is indiginous to the lower Ohio River, and like the rest of its relative is on the verge of extinction. 

Why do we care?

Mussels are/have

• Bioindicators of aquatic health: the presence of diverse and reproducing populations of mussels indicate a healthy aquatic system which means good fishing, good water quality for waterfowl and other wildlife species, as well as insurance that our water is safe. Conversely, when mussel populations are at risk, it indicates problems for other fish and wildlife species, and people too.
• Ecological value: mussels are natural filters, feeding on algae, plankton, and silts, they help purify the aquatic system. Mussels are also an important food source for many species of wildlife including otters, raccoon, muskrat, herons, egrets, and some fish.
• Economic value: freshwater mussels have been and continue to be a major economic resource; first in the button industry and now in the cultured pearl industry. Mussels from North American form the nucleus of the cultured pearl industry in Asia.Education and aesthetic value: the study of mussels, their natural history, and habitat requirements provides interesting and important lessons on the interconnectedness of the aquatic system and how species adapt to their ecosystem.
• Cultural value: Mussels play an important role in the cultural history of prehistoric and recent native peoples of the Ohio and Mississippi River basins. They were used as food and the shells were used for ornamentation, tools, and as a commodity for trade. Indian shell middens (the piles of shells that native Americans have left behind) extend for miles along sites of old villages and encampments along the Mississippi and Ohio Rivers.
• Research value: Mussels have and will continue to play an important role in our aquatic ecosystems. Considering that less than 20 mussel species are found in most other countries of the world, our North American rivers and streams are more diverse with over 300 species. Mussels do not develop cancer and have additional research value which is being uncovered. The loss of any of these species will definitely have consequences on aquatic ecosystem functions.
• What caused mass extinction of relatives and endangered this species?

Sedimentation and pollution from agricultural production has allowed run off of eroding soil to enter rivers and lakes. Most species of mussels cannot survive on muddy river bottoms but instead need rock gravel or firm sand. The other main cause is the introduction of man made structures into their habitat such as hydroelectric power plants. Additionally pesticides, PCBs, and mercury contaminate their habitat and has contributed to their drastic population decline. This does not mean there is no hope; mussel populations have been revitalizing since the introduction of the clean water act, as the prohibited pollutant discharge used to be one of the main causes of mussel extinction. If we can continue to introduce regulations like the CWA, CAA, and the ESA we will be able to stop their habitat loss and contamination.

                                                   

What's being done and what can we do?
There are no recovery or habitat conservation plans, as the plight of the orangefoot pimpleback pearlymussel is shared among over 70 endangered mussel in North America. What needs to be done are community efforts to raise awareness of the fragility of our freshwater ecosystems. We can do minor behavioral adjustments to ensure the population is able to recover such as

• Conserving energy to limit the construction of hydroelectric power plants. 
• Limit or stop pesticide use. Integrated Pest Management (IPM) has been a proven pesticide free agricultural practice. 
• Control erosion by planting trees and plants to avoid/reduce runoff. 
• Remove aquatic weeds from boat trailers to reduce the spread of invasives such as the Zebra Mussel.
• Support and follow zebra mussel quarantine/inspection/decontamination programs.

References:

http://www.earthsendangered.com/profile.asp?gr=CL&sp=761

http://www.fws.gov/midwest/endangered/clams/mussels.html