Problem Statement:
Invasive aquatic species are a major economic and environmental threat to the living resources and habitats of the Monterey Bay National Marine Sanctuary (MBNMS) as well as the commercial and
recreational uses that dependent on these resources. Once established, invasive species are extremely difficult if not impossible to eradicate; estimated costs reflect what is required to minimize rather than eliminate damage. More...

Issue Summary:

Problem Statement:
Invasive aquatic species are a major economic and environmental threat to the living resources and habitats of the Monterey Bay National Marine Sanctuary (MBNMS) as well as the commercial and
recreational uses that dependent on these resources. Once established, invasive species are extremely difficult if not impossible to eradicate; estimated costs reflect what is required to minimize rather than eliminate damage.

Aquatic invasions have been extremely common in recent decades, and are increasing at a rapid pace. Estuaries are particularly vulnerable to invasion; and large ports, such as San Francisco Bay, can house hundreds of invasive species with significant impacts to native ecosystems. Discharge of aquatic invasive species into state and federal waters is exacting increasing costs on the environment and the economy.

Environmental Costs:
Invasive species are the number two threat to endangered and threatened species nationwide, second only to habitat destruction. Invasive species may cause local extinction of native competitors either by preying upon them directly or by outcompeting native species for prey. For example, the European green crab, now found in Elkhorn Slough, Tomales Bay, Bodega Bay and Bolinas Lagoon, Estero de San Antonio, and Estero de Americano, both preys on the young of valuable species (such as oysters and Dungeness crab) and competes with them for resources. The green crab is highly adaptable; it can tolerate a wide range of temperatures and salinities, grow quickly, produce large numbers of offspring, and are voracious predators. Marine biologists in Bodega Bay documented a 90 percent reduction in local populations of native clams and small shore crabs due to the European green crab in less than 10 years. Invasive species can also dilute native species through cross-breeding and alter community composition or food webs. Finally, they may cause changes in physical habitat structure. For example, burrows caused by the isopod Sphaeroma quoyanum, originally from New Zealand and Australia, are found in banks throughout the Elkhorn Slough, and may exacerbate the high rate of tidal erosion in the Slough.

Economic Costs:
Aquatic invasive species impact industries such as water and power utilities, commercial and recreational fishing and agriculture. Examples include the zebra mussel ($3.1 billion in nationwide costs annually, primarily to water and power plants that are trying to keep it from clogging their works), the Asian clam ($1 billion in costs annually to utilities, the fishing industry and others), and the European green crab ($44 million in costs annually to aquaculture, fishing and other industries). These costs will be ongoing, as aquatic invasive species are virtually impossible to eradicate once established.

DRAFT Outline for Action Plan:
I. Aquatic Invasive Species - Major Environmental and Economic Threats

II. Pathways of Introduction

A. Aquaculture
B. Intentional introduction
C. Aquarium trade
D. Biological control
E. Boats and ships

i. Ballast water transfer
ii. Hull, anchor and trailer fouling
iii. Entanglement (mostly aquatic plants)

F. Live bait

i. Bait species
ii. Packing material

G. Nursery industry

H. Scientific research institutions, schools and public aquariums

i. Intentional
ii. Accidental escape

I. Recreational fisheries enhancement
J. Restaurants, seafood retail and processing

III. Preventing Introduction

IV. Monitoring/Identifying Invasive Species

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