Help
us keep watch for the two
dozen "least wanted" invaders! Familiarize yourself
with these unwanted aliens, and help us to better protect the
rich native coastal biodiversity of central California!
If you represent a coastal organization that would be interested
in involving your members or staff in this program, contact to receive a free shipment of booklets, flyers, and
a CD providing background on aquatic invasions.
To learn which non-native aquatic species have already been recorded
from the Elkhorn Slough, Monterey Bay National Marine Sanctuary
and surrounding coastal uplands, click
here to download an Excel table summarizing these results
(.xls file, 32KB).
Download the Aquatic Invaders booklet (.pdf file, 811KB).
Keeping
watch for "least wanted" invaders
The Elkhorn Slough National Estuarine Research Reserve, in partnership
with the Elkhorn Slough Foundation and the Monterey Bay National
Marine Sanctuary, and with funding from California Sea Grant,
has recently launched an early detection program for aquatic alien
invaders. The goal of this new program is to detect new invasions
of problematic non-native aquatic organisms early enough to allow
for successful eradication.
Background
on aquatic invasions
"Alien,""non-indigenous,""non-native,"
or "introduced" species are those moved far beyond their
natural ranges by human activities. Aquatic species are transported
between bioregions by activities such as commercial shipping and
oyster culturing, and can spread within a region due to local boat
traffic and dispersal of larvae on currents. Aquatic invasions have
been extremely common in recent decades, and are continuing at a
rapid pace. Estuaries are particularly highly invaded; those with
big ports often have hundreds of non-native species established
in them. Many non-native species may have relatively minor influences
on the communities they invade. Some, however, have dramatic negative
impacts. Our early detection program focuses on such species, whose
negative effects have been demonstrated elsewhere. These non-native
species may have impacts at a variety of scales. Invaders have been
shown to cause local extinction of native competitors or prey organisms,
alteration of community composition or food webs, change in physical
habitat structure, and even alteration of energy or material flux
through whole ecosystems.
Biological invasions of marine habitats, and particularly estuaries,
are occurring at an accelerating rate. The ecological threats posed
by some alien species rival those of pollution or anthropogenic
habitat destruction, and are among the greatest resource management
challenges for estuarine ecosystems. Once widespread and abundant,
aquatic invaders are extremely difficult, if not impossible to eradicate.
However, if they are detected soon after initial establishment,
removal efforts can be successful. Such management depends on early
detection of new invasions within this window of opportunity.
What can be done about aquatic invasions? On the one hand, prevention
of further invasions is critical. Public support for regulatory
measures decreasing human transport of invasive propagules will
help prevent invasions. On the other hand, control of existing invasions
is sometimes possible. Once a non-native aquatic species has become
abundant and widespread, it is difficult or impossible to control
it. However, there is a window of opportunity soon after invasion
when eradication efforts may be successful. In order to intervene
during this early establishment phase, early detection of new invasions
is essential.
Development of an early detection program
In order to accomplish such early detection during the window of
opportunity for eradication, we have developed this new program.
We began by assessing existing non-native species composition in
the region to establish a baseline, and then chose "least wanted"
invaders for the area. From a potential pool of hundreds of known
aquatic invaders, we chose a subset of two dozen species that: 1)
are not yet present in the Monterey Bay area, 2) have a high potential
to be transported there (especially from nearby sources such as
San Francisco Bay), 3) are relatively large and easy to identify,
and 4) are likely to have a significant ecological impact if they
invade.
Each of the two dozen "least wanted" species is described
in booklets we have prepared and published. We provide information
on diagnostic features for identification, and information on habitat,
native origin, invaded areas, and ecological concerns. The booklets
also contain instructions on what to do if a putative invader is
sighted: individuals are directed to note their exact location,
collect a single voucher specimen, and immediately make an "urgent
invasive alert" to us. We will then confirm the identification
and inform the appropriate agencies (which vary by species and habitat).
We will help to coordinate interagency efforts to plan the most
appropriate response strategy, and will support rapid response efforts
to contain or eradicate the new invasion, if appropriate. The target
areas for this early detection program are Elkhorn Slough and Monterey
Bay, central California, because the coordinators of this program
are based there, because we have good baseline information for these
areas and because there are many citizens active in aquatic habitats
there. However, we welcome reports from as far south as Morro Bay
to as far north as Moss Beach.
The success of this program depends on having as many pairs of eyes
as possible on the lookout for new aliens. Toward this end, we
are attempting to provide booklets to all citizens in the Monterey
Bay area who frequent aquatic habitats and are likely to notice
alien species. By holding a training workshop and providing free
materials, we have involved about 50 regional coastal organizations
(kayaking, fishing, diving, conservation groups; harbormasters;
government agencies; aquaria; universities and research organizations)
in this effort, resulting in broad dissemination of nearly 4000
booklets to their constituents. By involving the community in this
effort to look for and report new invasions of "least wanted"
species, we are increasing the likelihood of detecting new invasions
in time to take action. Familiarize yourself with these unwanted
aliens, and help us to better protect the rich native coastal biodiversity
of central California! |
