Salt Marsh RestorationRole of Animals
Felicia Woods
Role of Animals
Animals are important to the processes occurring in salt marshes, and can be key indicators (or causes) of an unhealthy marsh.
Bioaccumulation of toxins can reduce populations (e.g. DDT interferes with calcium deposition)
There is an upper limit of population density that marshes can support.
Animals Common to Salt Marshes
Mollusks
Razor Clams
Ribbed Mussels
Quahogs
Soft shelled clams
Coffee bean snail
Whelks
Periwinkle…
Polycheates
Clam Worms
lugworms…
Arthropods
Fiddler Crabs
Purple Marsh crab
Burrowing shrimp
European Green Crab…
Vertebrates
Mummichog
Diamondback Terrapins
Sparrows, Shore birds, and Gulls…
Insects…
LOTS!!!
What is known in the context of salt marsh
Studies have been conducted to test the importance of animals, both vertebrates and invertebrates, in salt marsh ecosystems.
Trophic Cascades
Bottom-up
Top-Down
Importance of biodiversity
Adaptations
Behavioral and physiologicalSilliman and Bertness (2012)
Trophic Cascades
Top-Down Effect
Consumer impacts on herbivory Silliman et al study on periwinkle population density Overexploitation of top predators or keystone species But wait!!! There could be hope…
Bottom-Up Effect
Resource availability Degraded resources affect animal poplation
Biodiversity
“The most unique feature of Earth is the existence of life and the most extraordinary feature of life is its diversity” (Cardinale et al, 2012)
Healthy Marsh ecosystems support biodiversity Many shorebirds and fish depend on marsh habitats for essential
food supplies and nursery grounds,, as well as take refuge from
larger preditors.
Adaptations
“Great changes in conditions occur in the salt marsh and many organisms are not adapted to cope with such changes. “ John Teal
Physiological
Osmotic equilibrium: e.g. salt excretion glands (birds)
Temperature regulation
Closable shells
Primitive lung (fiddler crab)
Behavioral
Burrowing
Zonation (aquatic group stays near low tide zone)
Importance in Salt Marsh Restoration
Top down consumer control of herbivores
Sustainable fishing (recreational and commercial) Controlling top predator densities
Healthy population densities of key species indicate healthier system.
References
Altieri, A., Bertness, M., Coverdale, T., Herrmann, N., & Angelini, C. (2012). A trophic cascade triggers collapse of a salt-marsh ecosystem with intensive recreational fishing. Ecology, 93(6), 1402-1410.
Cardinale, B., et al (2012). Biodiversity loss and its impact on humanity. Nature, 486, 59-67.
Shumway, S. (2008). Salt Marshes. In The naturalist's guide to the Atlantic seashore: Beach ecology from the Gulf of Maine to Cape Hatteras. Guilford, Conn.: Globe Pequot Press.
Silliman, B., & Bertness, M. (2002). A trophic cascade regulates salt marsh primary production. PNAS, 99(16), 10500-10505 http://www.pnas.org/content/99/16/10500.full.pdf+html?sid=dd3ef75d-f088-4e48-9ff0-803f42b63479
Teal, J., & Teal, M. (1969). Marsh Animals. In Life and death of the salt marsh,. New York: Ballantine.
http://www.dnr.sc.gov/marine/pub/seascience/dynamic.html
http://www.esajournals.org/doi/full/10.1890/12-2150.1
http://www.motherjones.com/blue-marble/2013/04/invasive-species-crab-saving-cap-cod-salt-marshes
http://pacificoceanlife.tumblr.com/post/9565494104/the-european-green-crab-food-chain
http://saltmarshlife.com/salt-marsh/invertebrates.html
http://www.nature.com/scitable/knowledge/library/trophic-cascades-across-diverse-plant-ecosystems-80060347