Top Wave

Invasives Watch | MIS ID Cards | Citizen's Monitoring Guide

Marine Introduced Species
Monitoring Resource Center

Salem Sound Coastwatch has organized this Resource Center as a portal to a multitude of resources that can help you learn about the aquatic animals and seaweeds that have arrived in New England from all over the globe. We hope you will learn about the problems they present and then join a group that is actively monitoring their abundance and distribution. Learn to recognize seven species that SSCW has identified as having the potential to establish themselves so you can be on the lookout for a new bioinvader, such as the Chinese mitten crab.


Prevention and early eradication of marine biological invaders are the most effective methods of managing these species.


Biological invasions have emerged as one of the leading environmental threats to our coastal and marine habitats. Marine biological invaders are species that have been moved beyond their natural geographic range by human activities. While human-mediated activities have redistributed organisms around the world for centuries, the number of species being relocated and released by transport methods or vectors continue at an unprecedented rate (Carlton 1989).

These introduced species are called by many names: non-native, nonindigenous, introduced, alien, or exotic. When an introduced species has the ability to reproduce in large numbers and to outcompete native species for food and space, they can offset the natural ecological balance. With nothing to keep nonindigenous species in check, these invaders can have damaging affects on their new environments. They can become invasive or nuisance species. More definitions


Invasive species are considered second only to human development in causing declines in the total number of species in the U.S. and worldwide, and millions of dollars are spend in control efforts (PEW_Carlton2001.pdf). You will discover from your study of introduced species that not all non-natives become invasive or destructive. However,predicting when or how an introduced species will affect its new environment can be difficult. This is why it is so important to that we work to reduce the spread of introduced species before they become invasive.


Public awareness and concern over this problem is growing. This web site provides access to important information regarding

  • How non-native species are transported around the world,
  • Why we should care,
  • What governments and their agencies are doing,
  • What are the species of concern, and
  • What you as an individual or part of a group can do about this problem.


Background: the problem, pathways, and more

Methods/Data Sharing

Additional Web Site Links

Species ID Resources


Scientific Books and Papers
MIS ID Links