Nasturtium gambelii
Gambel’s Watercress
source: https://www.wildlife.ca.gov/Conservation/Plants/Endangered/Nasturtium-gambelii
The species Nasturtium gambelii, also know as Gambel’s Watercress, is a perennial herb native to California. It is part of the mustard family (Brassicaceae) and is identified by it small white flowers (seen in the image below) blooming between April and May and height that can reach up to 6 feet tall. As 2011 however, it is ranked number 2 on the Ventura Fish and Wildlife Service priority list (Endangered and Threatened Species Listing and Recovery Priority Guidelines, 48 FR 43098, September 21, 1983) making it a very rare and vulnerable species here in California.
Study Area
In-depth map of the areas where the watercress grows or is suspected to grow
Gambel’s Watercress’ Range
Historical range of the watercress
source: https://www.sce.com/NR/rdonlyres/EEA784AB-C8D5-41FF-BB86-B66B63757522/0/AIR06SCE06ResponseAppendixB4.pdf
More current range of the watercress
source: https://ecos.fws.gov/ecp0/profile/speciesProfile?spcode=Q38L
______________________________________________________________
Historical State of the Gambel’s Watercress
source: https://camissonia.smugmug.com/Flora-Fauna/Montana-de-Oro-State-Park/i-L56njjH/A
The Gambel’s watercress was to be found primarily in coastal regions of California spanning as far south as Orange County and up to San Luis Obispo County. Historically, the Gambel’s watercress was much more abundant; descriptions of the specie’s population included, “locally common,” “occasional, becoming scarcer,” and eventually, “rare” (U.S. Fish and Wildlife Service, 5). By 1989 there were very few plants and were concentrated in three separate populations only in San Luis Obispo County. Given the species quick depletion is was listed in 1993 as being endangered (U.S. Fish and Wildlife Service, 2). Species evolved from Gambel’s watercress were observed in 2005 but pure Gambel’s watercress is very rare when not in this hybrid form, even to the San Luis Obispo area where the last populations are concentrated. In 2008 the rare and pure form of the plant was introduced on the Refuge in San Luis Obispo in hopes of continuing the species (U.S. Fish and Wildlife Service, 6). Because these plants were not viable on their own, there has not been a population of pure Gambel’s watercress reported since 2005 (U.S. Fish and Wildlife Service, 7). Time has not treated this species well as development has encroached on the habitat, thus causing even it’s endangered listing not to be protection enough.
_______________________________________________________________
Current Human Impacts
source: http://wikivisually.com/wiki/Nasturtium_(scientific_name)
The current human impacts on Gambel’s Watercress revolve around two main issues- urbanization, non-native species and stochastic. Urbanization having the most profound effect.
Gambel’s Watercress’s prime environment is costal marshes and waterways, which due to development, are rapidly disappearing in California. Development not only contributes to the obvious habitat loss but a whole host of other impacts. This includes the eutrophication and alteration of water quality as well as increased sediment content and erosion. Water run off from human development like streets and more importantly farms, which add extra chemicals like nitrogen and phosphorus which contribute to biostimulation. This in turn affects the increase and survival of non-native species.
Human intervention and introduction of non-native species into ecosystems have also attributed to the dire state of the population of Gambel’s watercress. As the 2011 US Fish and Wildlife Report on the species reports, at some of the sites of current populations, non-native eucalyptus trees have contributed to lowering the water table and threatening the delicate ecosystem of the marshland.
Future Prospects for Gambel’s Watercress
source: https://camissonia.smugmug.com/Flora-Fauna/Montana-de-Oro-State-Park/i-4HLCSGD/
Without interference from environmentalists and preservationists, the prospects for Gambel’s Watercress remain dim at best. With its shrinking habitat, mainly caused by human factors like urbanization, Gambel’s Watercress’ habitat will never be able extend to the area it once occupied. This issue, coupled with the irreversible process of invasive regular Watercress species mixing with the Gambel’s variety, are serious cause for concern. Gambel’s Watercress no longer frequently grows as a natural species and only a few locations remain including: Vandenberg Air Force Base in northern Santa Barbara County (7). The species is at a critical point in its survival and with continual human actions such as urbanization, drilling of wells, and climate change, its future is very uncertain (U.S. Fish and Wildlife Service, 7). Species such as the eucalyptus tree are now growing in Gambel’s Watercress’ natural habitat taking up the space and resources it needs to survive. With these conditions likely to continue, the Watercress is at serious threat of extinction (5). Luckily, there is widespread recognition of the need to conserve the population of Watercress at the Air Force Base and ensure that this area remains hospitable for the Watercress. Counties like Santa Barbara are developing comprehensive plans about how to save the species: establishing new plants in other regions and habitats, removing the Eucalyptus trees, and help determine the nutrient levels necessary for Gambel’s to survive (8). Unfortunately, plans like these are being devised than more often they are being put into action, yet are the only way to safeguard the survival of a dwindling population.
_________________________________________________________________
How Can We Protect Gambel’s Watercress?
Volunteers collecting sample of Gambel’s Watercress
source: https://www.fws.gov/fieldnotes/regmap.cfm?arskey=25462
The first step to conservation of Gambel’s watercress is to protect wetlands, where they are located. To do this, we must maintain a natural water level in wetlands and protect it from being filled with rocks, dirt, etc. By protecting its habitat, we reduce the amount of human impact on the species, which is one of threats to their survival (3). Next, we can also prevent certain other species from growing in wetlands that contain Gambel’s Watercress. These species, such as cattails and willows, thrive in waters that contain lots of nutrients and nitrogen. This leads to an unfavorable habitat for the watercress and as a result decreases their numbers. We can solve this issue by monitoring plant growth and water quality in wetlands to promote more growth of the species. Lastly, we can educate landowners about their impact on wetlands and endangered plants. By telling them about the consequences of their actions and giving them alternatives, it can help create an environment and habitat the Gambel’s Watercress needs to bounce back from endangerment (2).
Population Records for Gambel’s Watercress from Different Locations
Source: U.S. Fish and Wildlife Service Ventura Fish and Wildlife Office Ventura, California September 2011 (8)
Photo Gallery
Drawing of Gambel’s Watercress
source: https://www.wildlife.ca.gov/Conservation/Plants/Endangered/Nasturtium-gambelii
Top left: Studying the species, Bottom Left: Searching for the species, Right:cutting through the extra foliage,
source: https://www.fws.gov/fieldnotes/regmap.cfm?arskey=25462
References
- California Rare & Endangered Plant Walk. San Francisco: Strybing Arboretum, 1983. Web. 1 Dec. 2016.
2. “Gambel’s Water Cress.” Gambel’s Water Cress. California Department of Fish and Wildlife, 14 Jan. 2014. Web. 01 Dec. 2016.
3. “Gambel’s Watercress – Nasturtium Gambelii – Details – Encyclopedia of Life.” Encyclopedia of Life. N.p., n.d. Web. 01 Dec. 2016.
4. Parikh, Anuja K., Nathan Gale, and Connie Rutherford. “Recovery Plan for Marsh Sandwort and Gambel’s Watercress.” SpringerReference (n.d.): n. pag. U.S. Fish and Wildlife Service, 28 Sept. 1998. Web.
5. “Results Detailed Report.” Results Detailed Report. NatureServe, n.d. Web. 01 Dec. 2016.
6. “Southwest Region.” Historically Speaking 2.1 (2000): 11. Southern California Edison. Web. 01 Dec. 2016.
7. U.S. Fish and Wildlife Service. “Species Profile for Gambel’s Watercress (Rorippa Gambellii).” Species Profile for Gambel’s Watercress (Rorippa Gambellii). N.p., n.d. Web. 01 Dec. 2016.
8. U.S. Fish and Wildlife Service. “Gambel’s watercress 5-year Review: Summary and Evaluation,” Sep. 2011. Web. 01 Dec. 2016.
Site Title 