Marine Invasives Reporting App

The goal of this project is to better track the distribution and spread of the 'Devil Weed' (Sargassum horneri) and 'Asian Kelp' Undaria pinnatifida. This site will allow you to log your observations of these non-native algae and contribute to the monitoring of them in your local waterways.

S. horneri, dubbed the ‘Devil Weed’, is an invasive algae that originates in the warm waters of Japan and Korea. While it is not certain how exactly it was introduced in our waters, possibilities include hitch-hiking on the hull of ships or embryo transport in their ballast water. It was first spotted Long Beach Harbor in 2003 and has since spread as far north as Santa Barbara, south into Baja, and is now found on many of the Channel Islands.

The 'Asian Kelp', U. pinnatifida, is a brown seaweed native to Japan that is cultured and harvested for consumption (miso soup and seaweed salad). In 2000 it was discovered growing in the Los Angeles Harbor and is now found in many California harbors and two locations on the open coast. A small population has persisted off of Catalina Island since 2001 and more recently in 2016, a no population was discovered on the north side of Anacapa Island.

There is a growing number of non-native species being introduced into the marine environment. Some have taken hold and proliferated along the California coastline, displacing native habitat and compromising the very health of near-shore ecosystems. The distribution and persistence of these non-native species along the West Coast has generated concern as it poses a potential serious threat to our native ecosystems. We therefore want to know where these non-native species are being spotted.

The value of each submission increases with the accuracy of the spatial data and also the associated observations and notes. Please include notes on the weather, habitat, other species observed at the site, and anything else you think might be relevant.

Here are some resources for you to use to help you identify the different species of sargassum and their life stages.

http://www.eeb.ucsc.edu/pacificrockyintertidal/data-products/invasive-species/SargassumIdentificationGuide_8.27.15_compressed.pdf
Put together by: Lindsay Marks, Jack Engle, Kathy Ann Miller, and Jessie Aslatt

http://www.eeb.ucsc.edu/pacificrockyintertidal/data-products/invasive-species/muticum_horneri_id.pdf
Put together by: Lindsay Marks

Los Angeles Waterkeeper is an influential force on the water and our resources, history, and experience allows us to undertake this effort. We rely on volunteers to be able to accomplish out work and your contribution to this effort directly relates to the success of this project. To find out more ways you can become involved, visit http://lawaterkeeper.org/get-involved-2/ menos ↑