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