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There Goes the Neighborhood: The 2003 Northeast Invasive Species Survey
By Peter Hanlon, Massachusetts Bays Program
Ceaseless drizzle, nonstop driving, questionable takeout meals ... mere nuisances when tracking down sea squirts and a particularly nasty Korean whelk.
It was a common sight at marinas between Portland, Maine, and New York Harbor during the first week of August 2003—about 20 raingear-clad scientists, armed with nets and spatulas, hanging over docks and feverishly scraping off the marine life that had collected below. The flora and fauna found were a bit odd-looking and unfamiliar, even to these trained eyes that identified many species not native to these coastal waters. These biological invaders, called marine invasive species, were exactly what the scientists were searching for, not that they were hoping to find them, of course.
Uninvited Guests that Don't Leave
The spread of invasive species is a complex international problem that has existed since the age of exploration when humans began intentionally and unintentionally transporting plants, insects, animals, and viruses from one part of the world to another. More recently, terrestrial pests such as the gypsy moth (released in the United States in the late 19th Century), and the Africanized honeybee (expanding northward from Brazil since the 1950s), have become household names. The best-known U.S. aquatic invader is the zebra mussel (Dreissena polymorpha), introduced into the Great Lakes by commercial vessels in the 1980s and now beginning to infest lakes and rivers in New England. The zebra mussel breeds prolifically, encrusting power plant and industrial water intakes and threatening the survival of more-desirable native species. The U.S. Fish and Wildlife Service estimates that the zebra mussel will have a $5 billion economic impact over the next 10 years in the Great Lakes region alone.
The spread of marine invasive species into U.S. coastal waters has accelerated in recent decades due to expanded international shipping, the growth of aquaculture, the baitfish industry, the aquarium trade, and even international Internet purchases. These different pathways, called "vectors," allow invasives to spread into local waters, presenting unique challenges for coastal managers struggling to keep up with the potential threats that can arrive from literally any point on the globe.
To help address this problem, a coalition of Massachusetts state agencies, federal government officials, consultants, and other managers (known collectively as the Massachusetts Aquatic Invasive Species Working Group) developed the Massachusetts Aquatic Invasive Species Management Plan, which was approved in December 2002. This plan designated priority species for control and management, developed a coordinated monitoring and prevention strategy, and established objectives for educating industry representatives, government employees, and the general public about the aquatic invasive species problem.
However, the question of exactly which invasive species exist within the Commonwealth coastal waters remains unanswered. In 2000, the first rapid assessment survey of invasive marine species conducted along the Massachusetts coastline found that 10 percent of the species identified were not native, including two species that had never been seen before on the East Coast. While some non-indigenous species appear benign, others can spread rapidly and cause widespread economic and ecological harm. The European green crab (Carcinus maenas) and Asian shore crab (Hemigrapsus sanguineus), for example, are invasives that prey on commercially valuable shellfish, while other species can chew up piers and pilings, damage fisheries, or cause public health problems. The 2003 survey was intended to give scientists a broader look at which exotic species are here and how far they've spread since 2000.
A Week on the Road
August 3-9, 2003—a marathon week that was a full year in the making. Funded by a grant from the U.S. Environmental Protection Agency (EPA), the seven-day survey was a mission to gather information on what species are actually present in the Northeastern U.S. waters. Jan Smith, Executive Director of the Massachusetts Bays Program (MBP), and Dr. Judy Pederson of MIT Sea Grant worked together with seven other National Estuary Programs to arrange the logistics of the rapid assessment survey. Everything was planned down to the minute as the roughly 20-member team had to visit three sites per day (often separated by long drives and occasional ferry connections), eat their meals on the road, visit laboratories for evening identification work, and find sleeping arrangements at night.
The team of scientists first gathered in New Hampshire after arriving from various universities around the country as well as from Italy, Wales, and South Africa. Each participant was an expert in a different group of species, ranging from crustaceans (hard-shelled aquatic species such as crabs and shrimp) to tunicates (sac-like animals with siphons such as sea squirts). Graduate students from local universities also participated as assistants.
The team visited permanently floating docks and piers at each site, ensuring that they examined a structurally similar habitat type at each location. The docks and piers were also likely to have a variety of marine organisms and several years of growth underneath.
During the 90-minute site visits, the scientists scraped as many organisms (both native and introduced) from the docks as they could find. The equipment used was simple—spatulas to scrape the organisms off and a net to catch them below. Sometimes the organisms were attached to ropes or buoys that were dragged up onto the dock for examination. Many of the common organisms could be identified right away and were put back in the water as a team member with a laptop recorded the identified species. For those organisms that could not be immediately recognized, a clump of the biological material was put in labeled jars in a cooler and taken back to the lab for a thorough evening investigation under a dissecting microscope, sometimes lasting for up to six hours.
Despite a workday that typically lasted from 7:00 a.m. until 11:00 p.m., the scientific crew volunteered their time largely because of their keen interest in invasive species. The team rarely found themselves alone during that rainy first week of August as numerous newspapers, local television stations, and curious onlookers visited over the course of the 20 site visits. Even the National Geographic Society joined the survey for a couple of days to film a segment for an "Explorer" television program.
Now ... The REALLY Hard Part
As successful as the survey was, it is just one of the first steps in the fight to control the spread of marine invasive species. The goal of those involved with the survey is to continue their research by repeating the process every four to five years to keep pace with potential future invaders. However, the time in between surveys will be spent on the difficult task of implementing the Massachusetts Aquatic Invasive Species Management Plan. Prevention is the focus of the plan, but if prevention fails and a harmful species is introduced, a rapid response protocol is needed to let federal, state, and local officials know what approaches they have available to prevent an emergency. A task force is currently developing this rapid response protocol, which will provide detailed pre- and post-invasion steps for officials to take in case of a harmful invasion. The Massachusetts Office of Coastal Zone Management and its partners are also working to fill in the gaps between invasive species surveys by training citizens, local officials, and others who live and work near the coast to monitor invaders.
Another key element will be education and training. Survey organizers and members of the Massachusetts Aquatic Invasive Species Working Group will continue to hold workshops for coastal scientists, managers, government agency personnel, and graduate students to give them skills necessary to identify non-native species. The Massachusetts Bays Program is also working with pet stores to educate aquarium owners on how to properly dispose of exotic fish and plants to avoid introducing potentially harmful species into the marine ecosystem.
Though Northeastern coastal waters have yet to witness an invasion as ecologically and economically destructive as that of the zebra mussel, the threat of invasives is significant since marine ecosystems are essentially borderless. Regional coordination and cooperation is necessary to effectively prevent and control future invasions of exotic marine species. Rapid assessment surveys like the one conducted in 2003 are a crucial first step in identifying the species that are here, welcome or not, and whether any of those strange-looking invaders could cause real damage to these shores.