Extraordinary measures are being taken to protect existing species where the Malibu Lagoon restoration will take place in the western arms and three channels of the lagoon: fish and surface invertebrates will be herded into the main channel of the lagoon. The main channel of the lagoon will not be touched.
While the water levels in the three channels are being emptied, a team of fish biologists will relocate any fish that were stranded to the main lagoon. During the entire construction process, the western arms and three channels will be isolated, using a temporary sand berm, to keep all fish and other aquatic wildlife out of the construction area. All water pumped out must go through specialized screens so that fish and aquatic wildlife cannot be sucked up into the pumps that will empty the three channels.
Bird nest surveys will be conducted one month and three days prior to construction to ensure no bird nests are within 500 feet of the construction area. Resource specialists will walk the site every day before any earthmoving takes place to ensure no small mammals, bugs, lizards or amphibians are hurt during construction.
As mentioned, this area is disturbed with an enormous amount of unnatural fill that must be removed to restore the historic wetland. Heavy equipment was used to bring in the fill and heavy equipment is what is needed to remove the fill.
The existing conditions of the lagoon are horrible. Consistently low levels of dissolved oxygen are well below the minimum recommended levels required by the Regional Water Quality Control Board. Numerous studies comparing benthic invertebrates, clams and bivalves, crustaceans (crabs) and fish have been conducted comparing Malibu Lagoon to several other tidal lagoons, and Malibu ranks very poorly.
Yes, the water quality at Surfrider Beach will not be entirely fixed, but this lagoon restoration project is just another major step in fixing a massive problem that will take many steps to fix, as recommended in the 2001 Malibu Lagoon Task Force recommendations. Legacy Park was the first major step. Now, the lagoon is the next.
The lagoon suffers from poor circulation when the beach berm is closed and poor tidal inundation and flushing during open conditions because of the existing configuration of the three channels, which are 90 degrees to the ocean tide. Additionally, the channels were dug at too high an elevation, causing a severe lag time between incoming and outgoing tides. The lagoon often recycles the same water over and over again because the tides never carry all the water in these three channels out to the ocean. As the western arms start to empty, the new tide is already coming back in, pushing the same dirty water back into the western arms.
To improve incoming and outgoing tides, and wind circulation throughout the current lagoon area, these western arm islands made of unnatural fill are being removed. The bridges and islands that connect the bridges are pinch points that cause reduced circulation throughout this particular area, in a variety of ways. The prevailing onshore winds, which come from the northwest and blow southeast, are interrupted by the bridges and islands, preventing surface waves from building up in this lagoon area. Wind circulation in this area would provide greater surface and wave action, resulting in better filtering of pathogens through the sediment during a closed condition.
The goal is a self-sustaining, functioning lagoon ecosystem. The new channels will be shallow-shaped U’s that allow water to slowly enter, and then flood over the sides onto the soils and marsh vegetation. This will provide for various levels of water and salinity in the soils, which will in turn provide for the diversity of plant materials that will feed the different types of plants and animals that live in the area.
The existing lagoon has poor plant diversity, a serious problem with non-native plants. During the 1983 attempt at restoration, improper plants were placed that are not native to the lagoon. Community volunteers will do some of the non-native and invasive plant removal, and replace them with different native habitat types that will make the area more diverse with native vegetation and critters.
Additionally, there will be harvesting of select plant materials and seeds from the site to be replanted during the restoration. There will also be plants brought in that historically did occur at Malibu Lagoon, but do not occur there presently. If you don’t address the complete array of causes, the solution will just be a Band-Aid solution that continually needs maintenance.