Salt Marsh Restoration Role 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. DDT Now banned but an example (pg 156 shumway): Breakdown product of DDT is DDE, which is stored in fatty tissues. Calcium deposition in bird eggs

Animals Common to Salt Marshes Mollusks Arthropods Razor Clams Fiddler Crabs Ribbed Mussels Purple Marsh crab Quahogs Burrowing shrimp Soft shelled clams European Green Crab… Coffee bean snail Vertebrates Whelks Mummichog Periwinkle… Diamondback Terrapins Polycheates Sparrows, Shore birds, and Gulls… Clam Worms Insects… lugworms… 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 physiological Silliman 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 Grazers can limit primary production Silliman results: effect different in different zones (low- form reduced by 88%, tall-form reduced to mudflat)

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. http://en.m.wikipedia.org/wiki/Mummichog

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) OB: diffuse salts into or out of body… think of lugworm example below Most marine Animals can deal with differences in the concentrations of individual salts but cannot cope well with dramatic changes in the total concentrations of salts in their bodies. e.g. lugworms swell when more freshwater flows into the system from rain and slowly leaches salts of its body to reestablish equilibrium Shells: prevent desiccation

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