2008 Annual Monitoring Report (pdf 10.9MB) - Bolsa Chica ...
2008 Annual Monitoring Report (pdf 10.9MB) - Bolsa Chica ...
2008 Annual Monitoring Report (pdf 10.9MB) - Bolsa Chica ...
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<strong>Bolsa</strong> <strong>Chica</strong> Lowlands Restoration <strong>Monitoring</strong><br />
<strong>2008</strong> <strong>Annual</strong> <strong>Report</strong><br />
Management of the California least tern and western snowy plover nesting sites is expected to be<br />
adaptive due to enhancement of the <strong>Bolsa</strong> <strong>Chica</strong> area and the creation of new nesting and foraging<br />
areas. Management recommendations for <strong>2008</strong> were made to increase reproductive success and to<br />
enhance the newly created nesting sites (Knapp and Peterson, <strong>2008</strong>) and are summarized below.<br />
There are currently at least 6 species nesting on NS1 including black skimmer, elegant tern, royal tern,<br />
Caspian tern, as well as the western snowy plover and California least tern. This high-density nesting<br />
may have some benefits but appears to be highly detrimental to least tern and snowy plover nests and<br />
chicks. This problem requires long-term management that would address overcrowding and its effect<br />
on listed species, as well as a review of monitoring methods that would minimize disruption of this<br />
large nesting colony. For the <strong>2008</strong> breeding season, roof tiles were placed on the site. This<br />
management aided in the increased survival of chicks on the site through protection from both<br />
predation and trampling. Increased cover on NS1 in the form of vegetation and debris would decrease<br />
least terns and snowy plovers chick exposure to predators, lowering predation and aiding in increased<br />
foraging areas for snowy plovers. NS2 is not used by any nesting avian species and NS3 is currently<br />
being utilized by the snowy plover. These sites need to be assessed to determine how they can be<br />
managed and for what species. Finally, there needs to be improved water management in the Seasonal<br />
Ponds. Several zones, normally utilized by the snowy plover for nesting, were not available in <strong>2008</strong><br />
due to seasonal flooding and subsequent poor drainage.<br />
Recommendations<br />
• Increase cover on NS1 in the form of vegetation and debris.<br />
• Assess sites NS2 and NS3 to determine how they can be managed and for what species.<br />
• Improve water management in the Seasonal Ponds.<br />
1.7. NON-NATIVE INVASIVE SPECIES<br />
An awareness of the importance of tracking the arrival and spread of non-native species has increased<br />
in recent years, particularly with the discovery of the invasive non-native seaweed Caulerpa taxifolia<br />
in nearby Huntington Harbour and in Agua Hedionda Lagoon in San Diego County. Early detection of<br />
some species of invasive plants and animals may allow the opportunity for quick and economical<br />
response activities. These species may include non-native seaweeds such as Caulerpa spp., Sargassum<br />
filicinum, and Undaria pinnatifida, or terrestrial weed plants such as pampas grass or Arundo, as<br />
mentioned above. However, there are other non-native species that are already proliferating in<br />
regional coastal embayments and are likely to invade the tidal areas of <strong>Bolsa</strong> <strong>Chica</strong> at some point in the<br />
future. While options to restrict these species from <strong>Bolsa</strong> <strong>Chica</strong> are limited, keeping good records on<br />
the time of arrival and the degree of spread can be helpful for understanding the threat posed by these<br />
species to <strong>Bolsa</strong> <strong>Chica</strong>, as well as for the general body of knowledge about these species.<br />
During the <strong>2008</strong> monitoring several non-native marine species were observed. At least two non-native<br />
tunicate species were captured in the restoration areas: Styela plicata and S. clava. These species are<br />
common occurrences in southern California and both have been documented to impact native species<br />
of tunicate by competing with them for space or food, or by impacting the reproductive success of the<br />
native species by consuming the planktonic larvae before they settle. Both species were first found in<br />
Merkel & Associates, Inc. 96