Amigos Town Hall Meeting ReportBolsa Chica Restoration
Two Years Later
By Dave Carlberg and Thomas Anderson
The restoration of 600 acres of Bolsa Chica wetland was essentially completed on August 24, 2006, with the opening of the ocean inlet, allowing tidal action to enter the wetland for the first time in over a century. Now, after two years, the question is being asked, Is the restoration working? The answer came on September 3 when the Amigos de Bolsa Chica sponsored a town hall meeting at the Wetlands & Wildlife Care Center in which a panel of eminent scientists reported on studies they have been conducting in the newly restored Bolsa Chica wetland over the last two years.
The first speaker was Bob Hoffman from the National Marine Fisheries Service who, as a member of the restoration steering committee, has devoted much of his career towards the project at Bolsa Chica. He gave an overview of the entire restoration project, and spoke about the need for periodic dredging of the inlet (see article on page 1 for details on this upcoming project) to keep the new embayment healthy.
Rachel Woodfield, a biologist from Merkel and Associates, described two years of biological and physical monitoring her company is under contract to carry out in the newly restored wetland. The monitoring is scheduled to occur 1, 2, 3, 5 and 10 years following the opening of the inlet.
Bird surveys were conducted every month over the past two years and total populations went as high as 10,000 on a single day. Total species counted was 136, the peak occurring in February, corresponding to the beginning of spring migration. Not surprisingly, over half of the species were shorebirds such as dowitchers and willets, with western sandpipers being the most numerous.
In surveying the fish populations in the full tidal wetland, Woodfields crew used a variety of nets to assure getting representative samples. A total of 41 species were identified, many of which were popular game fish, such as halibut, turbot, kelp bass and spotted sand bass, as well as large numbers of their prey, top smelt, grunion and anchovies. Probably the most significant observation made during the fish surveys was that juveniles were seen for all 41 species, showing that the wetland is providing a much needed nursery for our struggling local fishery.
Crabs, shrimp, mussels, oysters and scallops were found thriving, with again, juvenile forms present. Mud samples revealed a healthy population of invertebrates, which are a critical link near the bottom of the wetlands food chain. Eel grass is abundant and spreading. Cordgrass in the intertidal mudflats is showing some limited growth. In spite of shoaling near the inlet that is slightly retarding tidal flow, oxygen levels and salinity remain normal. The conclusion is that after two years, the newly restored wetland system at Bolsa Chica is healthy and developing nicely.
Ms. Woodfield was followed by Dr. Christopher Lowe from CSU Long Beach. He has been monitoring the movements of stingrays. Stingrays have been highly concentrated in Seal Beach near the San Gabriel River mouth for several decades. His team has tagged individual rays to get a better understanding of their breeding habits and movements when not at Seal Beach. Water temperature plays a large role in what they do, when they do it and where they go. The new tidal basin at Bolsa Chica appears to be the right temperature and is luring rays away from Seal Beach.
Dr. Lowes graduate student, Thomas Farrugia, reported on his and fellow graduate student Mario Espinozas efforts to measure and track the movements shovelnose guitar fish, gray smoothhound sharks and leopard sharks. Already at Bolsa Chica there are a wide range of sizes of these top predators which are known scientifically as bottom-dwelling elasmobranchs. This is another sign that the new tidal basin is meeting the goal of providing a good nursery for a variety of fish, stingrays and small sharks.
Next was Dr. Michael Horn from CSU Fullerton and his graduate student Jeannette Hendricks. They are monitoring the foraging habits and dietary makeup of terns and skimmers. There were some surprises with the habits of elegant terns, who breed in only several concentrated colonies in California and Mexico. While they are taking advantage of the newly created nesting sites, the elegant terns still prefer to fly back and forth across PCH many times a day to find fish instead of frequenting the new tidal basin. Climate change is altering the species of fish available for feeding their young. The largest part of their diet is a species of pipefish which the terns had not been known to eat in such great quantities before. Horn and Hendricks described how they were able to determine what comprised the terns diet, one method being a tern camera which gave an up close and personal effect of life in an elegant tern colony.
Kelly OReilly, Biologist with California Fish & Game closed the evening with details on the monitoring of snowy plovers and least terns. Largely through the efforts of her team, there has been an increase in the number of fledglings from both species. The details of her report can be found in "A Successful Breeding Season for California Least Terns and Western Snowy Plovers at Bolsa Chica."