Key Words: ballast water, west coast, education

The California Sea Grant Extension Program started the West Coast Ballast Outreach Project in February 1999. This project is funded by the National Sea Grant College Program and the Cal-Fed Bay Delta Program. Since the program's inception, various regulations that require specific ballast water management protocols, ranging from the federal to the state level, have been passed. This project has worked together with the maritime industry, regulators, and researchers over the past two years to educate the various groups on the recent developments and to coordinate management efforts along the west coast.
The West Coast Ballast Outreach Project has sponsored a series of workshops, produced a biannual newsletter, developed a web site, and produced a poster and brochure to distribute information about the latest developments in ballast water management and information on the impacts of aquatic nuisance species. The ballast water forums were held at various locations along the west coast, and were well attended by regulators and maritime industry representatives. The three volumes of the newsletter, "Ballast Exchange," included updates on the various regulatory and research programs. The web site includes information about the project, general information on ballast water and aquatic nuisance species, and links to various ballast water and aquatic nuisance species web sites. The poster and brochure, "Stop Ballast Water Invasions," contain general information about ballast water regulations and aquatic nuisances species. These documents have been widely distributed to regulators and the maritime industry.
In addition to our educational efforts, the West Coast Ballast Outreach Project has been actively involved with several working groups, the Pacific Ballast Water Group, the Pacific Ballast Water Pilot Project, and the Ballast Outreach Advisory Team. The Pacific Ballast Water Group, established in 1998, is as ad-hoc group, made up of various stakeholders, to coordinate ballast water management activities along the west coast. The Pacific Ballast Water Pilot Project, established in 2000, is working to develop ballast water treatment standards and to test various ballast water treatment systems. The Ballast Outreach Advisory Team is made up of members representing the maritime industry, regulatory agencies, and environmental groups. We have worked closely with this team throughout this project to insure that we are providing the proper educational information needed for these groups to implement and comply with the various ballast water regulations. As a result of these cooperative efforts, awareness of the impacts of aquatic nuisance species and compliance with the various new ballast water regulations has increased along the west coast.

Author to Contact: Karen Hart McDowell
California Sea Grant Extension Program/SFEP
1515 Clay Street
Suite 1400, Oakland, CA 94612
Phone: 510-622-2398
Fax: 510-622-2501
Email: kdhart@ucdavis.edu
www.ballast-outreach-ucsgep.ucdavis.edu

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Key Words: survey, detection, communication, Caulerpa taxifolia

From the first finding of 1 square meter of the tropical introduced algae Caulerpa taxifolia (Vahl) C. Agardh to the present day situation which involves 3184 hectares of the invasive alga along the French coasts, a global strategy of detection, survey and communication of the spread has been implemented.

The first step is a detection of the alga's presence. It became quickly apparent that the alga covered a large region (in 1990 a colony was found 200 km west from the first spot). Since then, the detection and assessment of the spread can no longer be carried out by scientists or other local administrations. It was thus necessary to set up a public awareness campaign with two main objectives:
- to inform proper the authorities of the presence of the alga
- to avoid disseminating the alga by way of boat anchors
To this end, frequent public awareness campaigns have been carried out since 1991. These have allowed us to detect 80% of the newly colonized zones (Cottalorda et al 1998). Each reported colonized zone is checked by scientifically-trained SCUBA divers able to recognize the alga. In order to follow the evolution of older and more extensive colonized zones, transects were performed annually using a towed video camera (Belsher 1992).

The second step is a global evaluation of the spread. Each colonized zone is very different, and depends on the lapse of time since initial settlement. All of the intermediate situations can be observed, from a single isolated and small colony of 1 square meter to a large infested zone covering 15 km of coastline and present between depths of 0 to over 50 m. Each algal colony develops quickly, which necessitates a regular monitoring of the situation. In light of the increasing difficulty in both controlling the situation and performing the surveys, a standardization of the monitoring protocol was proposed (Vaugelas et al. 1999). This standardized protocol allows the situation to be assessed based on well defined descriptive criteria that are adapted to both the nature of the colonized zone and the monitoring efforts to be undertaken. This standardization is based on three levels of invasion that correspond to three means of evaluating the surface areas and length of coastline concerned by the invasive algal spread. Using this standardization of the descriptive criteria, any changes in the situation are easily described and can be compared from one year to the next.

The last step concerns the communication of the information. From the onset of this problem, efforts have been made to group all information concerning the spread of this alga. Between 1984 and 1991, the number of colonies increased dramatically. In order to keep both the concerned authorities and sea-going persons informed, we published an annual report from 1991 to 1998 that identified all of the invaded zones. In addition, a report was drawn up for each newly discovered zone and sent to the government and local authorities. By the end of the year 2000, over 90 zones were concerned by the invasion. In order to render more accessible this information and to avoid a tedious updating of the invasion information, an Internet data bank has been created (http://www.unice.fr/LEML), which has been called COL (Caulerpa on Line). At present, all persons interested and concerned by this problem can access this data bank, in which each colonized zone is described and a overview of its spread and corresponding maps are provided.

These three steps allow a better and more efficient understanding of the evolution of Caulerpa taxifolia spread, a phenomenon that has persisted along the French Mediterranean coasts since 1984.

References
Belsher T., Youenou G., Dimeet J., Raillard J.-M., Bertrand S.and Mereau N., 1995. Eléments cartographiques de Caulerpa taxifolia en Méditerranée (Alpes-Maritimes et Monaco , 1992). Oceanol. Acta, 17 : 443-451.
Cottalorda J.M., Gravez V., Antolic B., Aranda A., Ballesteros E., Boudouresque C.-F., Cassar N., Cinelli F., Darder Ribot J. D., Orestano C.,Grau Jofre A., Jaklin A., Meinesz A., Rodriguez-Pietro C., Span A., Thibaut T., Vaujelas de J., Zavodnik N.,and Zuljevic A., 1998 Third international Workshop on Caulerpa taxifolia Boudouresque C.-F., Gravez V., Meinesz A. and Palluy edit, GIS Posidonie publ., 9-16.
Vaugelas de J., Meinesz A., Antolic B., Ballesteros E., Belsher T., Cassar N., Ceccherelli G., Cinelli F., Cottalorda J.-M., Frada-Orestano C., Grau A.m., Jaklin A., Morucci C., Relini M., Sandulli R., Span A., Tripaldi G., Van Klaveren P., Zavodnik N., Zuljevic A., 1999, Standardization proposal for the mapping of Caulerpa taxifolia expansion in the Mediterranean Sea. Oceanol. Acta, 22 85-94.

Author to contact: Prof. A. MEINESZ,
Laboratoire Environnement Marin Littoral
Université de Nice Sophia Antipolis
06108 Nice Cedex 2
France
e-mail: meinesz@unice.fr
tel: 33 4 92 07 68 46
fax: 33 4 92 07 68 49
 
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Congressional action in response to the invasion of zebra mussels and other aquatic nuisance species in the Great Lakes led to the passage of the Non-indigenous Species Control Act of 1990 and resulted in over $17 million being spent by Sea Grant on research and outreach projects. The growing wealth of information resulting from these projects is of high value as aquatic nuisance species move to other regions of the country. The work of the Sea Grant programs can help others to respond more rapidly by applying research findings to control strategies and by using the richness of the educational materials available to teach industry and resource management agencies. This is one of the few genuinely peer-reviewed sites on the web. Great care has been taken to ensure that all materials are of the highest quality and to make sure that all information is searchable and easily accessible to the end user. This site exemplifies how technology will be transferred in the future. Researchers and other users can conduct a literature search (as is done on searchable library databases) and in addition can download the entire document or product on demand. This moves the transfer of scientific technology one step further and makes application and use of scientific information quicker and easier.

The SGNIS web site contains high-quality science and has been the web presence for the National Sea Grant College Program on non-indigenous issues since 1996. All documents contained on the site, both research and outreach, have bee subjected to peer review. People who use the site can be confident that the available materials are of the highest quality. To date, the SGNIS database contains over 1100 research reports and educational items. Currently housed at the site are over 428 completed research findings, 40 ongoing research abstracts, 312 research and outreach papers in six conference proceedings, 85 issues of newsletters, a 70 slide graphic library, 53 general publications, 14 training materials and three distribution maps. Contributions to SGNIS have been made by over 100 organizations (20 of which are Sea Grant Programs) and 23 peer reviewed journals. Last year SGNIS was accessed by users in 83 countries from government, universities, and industries.

In 2000, a panel of Sea Grant outreach leaders and national office representatives were engaged to develop a seamless interface by pulling all national Sea Grant ANS web sites into a national web. Future additions to the site include: 1) adding materials for additional Aquatic Nuisance Species, 2) enhancing and expanding an interactive kids section, 3) adding appropriate gray literature to the site in topic areas where peer reviewed literature is not available.

Author to contact: Brian K. Miller, Assistant Director
Illinois-Indiana Sea Grant, Purdue University
1200 Forest Products Bldg. West Lafayette IN 47907-1200
Phone (765) 494-3586
Fax (765) 496-6026
Email: bmiller@fnr.purdue.edu
 
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Keywords: nonindigenous, fish, direct effect, reproduction, cichlid

The Rio Grande cichlid (Cichlasoma cyanoguttatum) was introduced into drainage canals in the New Orleans area in the early 1990s, and has since spread throughout the canal system south of Lake Pontchartrain. Native to northeastern Mexico and the lower Rio Grande, this cichlid can tolerate low temperature and dissolved oxygen, as well as high salinity. Although the invasive nature of the Rio Grande cichlid is well documented, and circumstantial evidence suggests it displaced native fishes in the canals, little is known about the direct effects of the cichlid on any native fishes. We compared the reproductive success of the native Cyprinodon variegatus in the presence and absence of young of the year Rio Grande cichlids. Four female and three male adult Cyprinodon were placed in 10 pools outdoors and allowed to spawn freely. Nine young of the year Rio Grande cichlids were added to half of the pools. Fish were matched for size among controls and treatments. After 6 weeks, all fish were recovered and preserved. Adult Cyprinodon and all cichlids were measured, and Cyprinodon fry were counted. A strong direct negative effect of the cichlid on reproductive success of Cyprinodon was shown. None of the 5 treatment pools yielded fry. Follow-up experiments will also be discussed.

Author to contact: June B. Mire, Ph.D.
6813 Louisville Street
New Orleans, Louisiana 70124
(504) 486-3883
Email: tucker9@bellsouth.net

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Key Words: ballast water, exchange, verification

A primary vector for the movement of aquatic organisms within and between oceans is ships' ballast water. Although there are no systems in use today that will prevent the introduction of aquatic nuisance species (ANS) with ballast water, the International Maritime Organization (IMO) established voluntary guidelines aimed at minimizing such introductions. The primary method for reducing the risk of the introduction of nonindigenous species into U.S coastal water is for ships to perform mid-ocean ballast water exchange (BWE). During exchange, a vessel replaces its original ballast water (taken on board while the vessel was in port or near to the coast) with water from the open ocean. Ballast exchange reduces ANS by 1) discharging a percentage of them into the inhospitable environment of the ocean, and in some cases, 2) by increasing the salinity level within the ballast tank to a level such that the species of freshwater or brackish water origins cannot survive.
On May 10, 1993, the U.S. Coast Guard's ballast water management regulations became effective for vessels traveling to the Great Lakes that operate beyond the Canadian or the United States exclusive economic zone (EEZ). These regulations mandate BWE as the current procedure to control the introduction of nonindigenous species. Exchange is to take place in water outside the 200 mile EEZ and in depths greater than 2000 meters.
On October 26, 1996, Congress enacted the National Invasive Species Act of 1996 (NISA) (Pub. L. 104-332), which amended and reauthorized NANPCA. NISA provides for ballast water management to prevent introductions and spread of ANS. It expands the scope of Coast Guard regulations to include all waters of the United States.
In compliance with NISA, the Coast Guard regulatory guidelines become mandatory after three years unless the maritime industry shows a high rate of compliance under a self-policing system. Therefore, the interim rule establishes a ballast management reporting provision, which will assist the Coast Guard in assessing compliance for the next two years. Salinity measurements are currently used by the US Coast Guard to verify ballast water exchange. In some cases, the presence of low salinity ballast water (< 30 ppt) is sufficient to show that the water was not exchanged in mid-ocean, however, the technique fails when the source of the ballast is a high-salinity coastal port. In these situations, it is necessary to identify more refined techniques to determine the origin of the ballast water.
To address this problem, the Smithsonian Environmental Research Center (SERC) in conjunction with the United States Coast Guard (USCG) intiated a program to investigate whether a suite of characteristics (chemical, biological, physical or a combination of these) can be used to discriminate between coastal and oceanic water and as such represent reliable indicators of exchange, regardless of the salinity of the coastal source water.
A workshop was held at SERC in August 2000 to discuss potential techniques for verifying BWE. The workshop was attended by representatives from SERC and the USCG as well as a panel of nine invited experts. The expert panel consisted of chemical and biological oceanographers who presented information upon, and evaluated a diverse range of, potential verification techniques. Of these, it was decided that DOM fluorescence, trace metals, turbidity, lignin, radium and phytoplankton as well as the "Newcastle" verification method demonstrated the most promise as verification tools and were worthy of further investigation in this context.
To provide data on the suitability of each of these techniques for verifying BWE, ballast water samples were collected from two vessels during voyages to Alaska in November and December 2000. The first vessel left out of San Francisco with ballast tanks containing low-salinity coastal water; the second left out of Los Angeles with coastal water barely distinguishable in terms of salinity from the surrounding ocean. Each vessel performed a 300% flow through exchange in one tank, while keeping the 'partner' tank as an unexchanged control. The first vessel performed an additional 100% empty refill exchange on a third tank.
Ballast water samples were collected and insitu measurements performed before and after the exchanges with mid-ocean water took place. Samples were sent to various specialist US laboratories for analysis. In this presentation, we discuss some intial results of the two ballast water exchange verification experiments, and future directions for this program.

Author to Contact: Kate Murphy
Smithsonian Environmental Research Center
647 Contees Wharf Rd, Edgewater, MD 21037
Tel: 443 482 2361
Fax: 443 482 2380

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Key Words: Asian shore crab, Hemigrapsus sanguineus, Carcinus maenas, mud crabs, population ecology

Documenting ecosystem changes resulting from the establishment of biological invaders requires an understanding of the system before, during, and after colonization of the invader. Biological invasions that are currently in progress provide the best opportunity for this type of assessment. However, such comparative data exist for few species.
The Asian shore crab Hemigrapsus sanguineus is currently becoming established along the rocky intertidal coastline of New England. First noticed in New Jersey in 1988 (McDermott 1991), the crab was well established in southern New England by 1996 (Lohrer and Whitlatch 1997, Ledesma and O'Connor in press). Currently, the species' range extends to New Hampshire (McDermott, pers. comm.), with populations along the Massachusetts coastline continuing to grow in size.
H. sanguineus occurs throughout the rocky intertidal zone, reaching maximum densities in the mid to lower intertidal zone. Resident crab species, such as green crabs (Carcinus maenas, which is also non-indigenous), mud crabs in the family Xanthidae, and rock crabs (Cancer spp.) also inhabit the lower rocky intertidal zone. The objective of the study was to determine whether populations of these crabs are affected as H. sanguineus becomes established. Specifically, I asked whether densities of other crab species tend to decrease as densities of H. sanguineus increase.
Crab populations in several localities were sampled repeatedly, usually in the spring (May to early June) and fall (September to October) to examine temporal changes in crab populations and to determine whether any changes observed were similar at different locations. Sites sampled include Bristol, Rhode Island, in Narragansett Bay, and several sites along the Massachusetts coast: Washburn Island, Falmouth, in Vineyard Sound; Bourne, near the east end of the Cape Cod Canal; Sandwich and Dennis in Cape Cod Bay; and Marshfield and Scituate on the shore south of Boston. Three to five replicate 2m2 square quadrats were randomly placed on rocky (= 75% rock cover) areas low in the intertidal zone during low tide. All crabs were removed from the quadrats, identified, counted, measured in most cases, and then returned to the sampling site. Sampling began in 1996 at Sandwich and Washburn Island, and from 1997-1999 at the other locations.
The most abundant species at the sites were xanthid crabs, C. maenas, and H. sanguineus. Cancer spp., when present, usually occurred in very low densities (< 1 crab/m2). During initial sampling in Bristol and Washburn Island, xanthids were the most abundant and H. sanguineus occurred at low densities (< 5/m2). However, within two years the dominance pattern switched, with H. sanguineus reaching densities of 30-50/m2 and xanthids falling to < 2/m2. At Sandwich and Bourne, H. sanguineus abundance increased over 2-4 years, reaching densities of 76/m2 in Sandwich and 120/m2 in Bourne by fall 2000. C. maenas densities remained low (< 10/m2). At Dennis, C. maenas was the most abundant species in fall of 1997, although its density was low (5/m2). By fall of 1998, H. sanguineus became (and remained) the most abundant species, with densities fluctuating around 15/m2. North of Cape Cod, in Marshfield and Scituate, C. maenas remained the dominant crab species. However, C. maenas densities declined in Marshfield between 1999 and 2000 whereas H. sanguineus densities increased. Sampling planned in 2001 should determine whether this trend continues.
Size-frequency distributions of C. maenas and H. sanguineus showed temporal patterns. For both species, especially C. maenas, the populations were dominated by small crabs (< 8 mm carapace width) in the fall, indicating a recent recruitment period. H. sanguineus populations also contained several small crabs in May-early June, suggesting a spring as well as late summer-fall period of recruitment.
In summary, the establishment of H. sanguineus has negatively affected the abundance of xanthid crabs, although the mechanism is unknown. H. sanguineus might be impacting C. maenas, because densities are low where H. sanguineus is abundant. However, future sampling at Scituate and Marshfield, where C. maenas currently dominates, is necessary to determine whether C. maenas densities will decline if H. sanguineus populations grow in size.

References:
Ledesma, M.E. and N.J. O'Connor. 2001. Habitat and diet of the non-native crab Hemigrapsus sanguineus in southeastern New England. Northeastern Naturalist (in press)
Lohrer, A.M. and R.B. Whitlatch. 1997. Ecological studies on the recently introduced Japanese shore crab (Hemigrapsus sanguineus) in eastern Long Island Sound. Pp. 49-60 in N. Balcom (ed.). Proceedings of the Second Northeast Conference on Nonindigenous Aquatic Nuisance Species. Connecticut Sea Grant College Program CTSG-97-02, 68 pp.
McDermott, J.J. 1991. A breeding population of the Western Pacific crab Hemigrapsus sanguineus (Crustacea: Decapoda: Grapsidae) established on the Atlantic coast of North America. Biological Bulletin 181: 195-198

Author to Contact: Nancy J. O'Connor
Department of Biology and School for Marine Science and Technology
University of Massachusetts Dartmouth
285 Old Westport Road
N. Dartmouth, MA 02747-2300, USA
Tel: 508-999-8217
Fax: 508-999-8196
Email: noconnor@umassd.edu
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Key Words: Management - Ballast Water, Sonics and Ozone

Stakeholders interested in the introduction, spread, potential impacts, and control of aquatic nuisance, nonindigenous, and invasive species require timely, reliable scientific information and fast, easy access to published research pertaining to such organisms. Since August 1990, they have been able to obtain such information from Sea Grant's Zebra Mussel Information Clearinghouse. For seven years, the Clearinghouse was "just"a zebra mussel Clearinghouse, with North America's most extensive technical library of published research, "grey literature," and other relevant documentation pertaining to all facets of the zebra mussel issue. That was then, this is now.
The Clearinghouse has undergone extensive and exciting changes since mid-1997, resulting in the name change to the "National Aquatic Nuisance Species Clearinghouse." The mission of the Clearinghouse is: to facilitate and coordinate aquatic nuisance, nonindigenous, and invasive species information sharing among researchers throughout North America and worldwide; to provide continuity to the timely dissemination of findings of aquatic nuisance, nonindigenous, and invasive species research projects; and to facilitate aquatic nuisance, nonindigenous, and invasive species prevention and control technology transfer between researchers and stakeholder audiences. The Clearinghouse serves as a major link between the research community and a wide array of university, government agency, industrial, and special interest stakeholders. The Clearinghouse also plays a high?profile role as a primary nexus for identifying completed, current, and proposed aquatic nuisance, nonindigenous, and invasive species research activities and for linking researchers with similar interests.
The Clearinghouse now addresses both marine and freshwater aquatic nuisance, nonindigenous, and invasive species throughout the Gulf of Maine, Northern Atlantic, Mid-Atlantic, Southern Atlantic, Gulf of Mexico, Central and Northern California, Pacific Northwest, and Great Lakes regions, and North American inland river and lacustrine systems. The Clearinghouse has added to its library and searchable database, including the following organisms: zebra and "quagga" mussels (Dreissena polymorpha and D. bugensis), the Amur River Corbula (Potamocorbula amurensis), the Asian clam (Corbicula fluminea), the Asian mussel (Musculista senhousia), the Atlantic green crab (Carcinus maenas), the blue mussel (Mytilus edulis), the blueback herring (Alosa aestivalis), the brown mussel (Perna perna), the Chinese mitten crab (Eriocheir sinensis), the dark false mussel (Mytilopsis leucophaeata), the Eurasian ruffe (Gymnocephalus cernuus), the "fishhook water flea" (Cercopagis pengoi), the grass carp (Ctenopharyngodon idella), the green lipped mussel (Perna viridis), gribbles (Limnoria spp.), the golden mussel (Limnoperna fortunei), the round and tube?nose gobies (Neogobius melanostomus and Proterorhinus marmoratus), the New Zealand mud snail (Potamopyrgus antipodarum), the rudd (Scardinius erythrophthalmus), shipworms (Teredo navalis), Sphaeroma quoyanum, the spiny water flea (Bythotrephes cederstroemi), the Suminoe oyster (Crassostrea ariakensis), and the veined Rapa whelk (Rapana venosa), as well as biological macrofouling, aquatic exotic organism, and invasive species policy issues.

All of the information in the Clearinghouse is accessible to any researcher, agency, industry, utility, student, or other individual or group having need of the information via electronic mail, fax, toll? or toll?free telephone, written requests, or visits to the Clearinghouse. A new, searchable electronic database of the Clearinghouse's Technical Library Bibliography is now available on the Clearinghouse's World Wide Web home page. Citations include: author(s), title, document source and date, an annotation, whether the document is a journal article or other type of publication, document length, the language in which the document is written, whether the document is available on interlibrary loan from the Clearinghouse or direct from some other source, and the copying/mailing fee if the document is available from the Clearinghouse. The database is keyword searchable (via a 170+ keyword, four level search outline). Most documents are available directly from the Clearinghouse on interlibrary loan and can be ordered on?line. The World Wide Web address for the database is: http://cce.cornell.edu/seagrant/nansc/. The web site also contains a series of detailed maps charting the range expansion of the zebra mussel and the "quagga" mussel in North America since 1989, as well as information on a number of other informational and educational materials available from the Clearinghouse and numerous "hot links" to other aquatic nuisance, nonindigenous, and invasive species web sites.
The Federal Aquatic Nuisance Species Task Force, the U.S. Army Corps of Engineers Zebra Mussel Research Program, the Great Lakes and Western Panels on Aquatic Nuisance Species, the Western Zebra Mussel Task Force, and numerous other federal, state, and international agencies and institutions have utilized the Clearinghouse as a major channel for extending information on zebra mussel, aquatic nuisance, nonindigenous, and invasive species spread, research, and policy initiatives to all interested audiences.

Author to Contact: Tom Maddox
Phone: 636-394-8161 800-960-8161
Fax: 636-394-6776
Email: tlmaddox@aol.com
Website: www.z-mussels.com

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The lack of quantitative data on environmental tolerances of early life history stages hinders estimation of both dispersal rates and establishment ranges for invading species in receptor environments. This is particularly evident in consideration of invading species with pelagic larval life history phases where the pelagic stage effects most if not all of the dispersal at the time frame of a single generation. We present salinity tolerance data for all stages of the ontogenetic larval development of the invading predatory gastropod Rapana venosa. We propose that salinity tolerance is the dominant response controlling potential dispersal (= invasion) range of the species into the estuaries of the Atlantic coast of the United States. Salinity tolerance is then examined in conjunction with temperature, which dictates both periodicity of adult egg laying and larval development rate, and extant nearshore and estuarine current data, to estimate rates of dispersal and range expansion from the current invading epicenter in the southern Chesapeake Bay. All larval stages exhibit 48 hr tolerance to salinities as low as 15 ppt with minimal mortality. Below this value survival grades to no survival at less than 10 ppt. This tolerance is greater than of the adults of the large native predatory gastropods of the genera Busycon and Busycotypus with which, we predict, Rapana will compete directly for space and prey, notably infaunal pelecypods. We predict that counter clockwise, gyre-like circulation within the Chesapeake Bay will initially distribute larvae northward along the bay side of the DelMarVa peninsula, and eventually to the lower sections of all the major subestuaries of the western shore of the bay. The discovery in summer 2000 of small (80 mm as opposed to adult specimens of >160 mm maximum dimension) Rapana at the along the northerly leg of this gyre adds weight to the predicted dispersal route. Dispersal onto and along the coastal shelf outside of the bay mouth may be influenced by both northward and southward flowing residual current depending on depth, wind conditions, and time within the known egg laying period of the invader in the southern Chesapeake Bay. Establishment over a period of decades from Cape Cod to Cape Hatteras by natural dispersal is considered a high probability. This time frame may, however, be considerably reduced by passive dispersal of larval forms in ballast water during intra-coastal maritime trade.

Author to Contact: Charles R. O'Neill, Jr.
Senior Extension Associate, New York Sea Grant
Director, National Aquatic Nuisance Species Clearinghouse
Morgan II, State University College
Brockport, NY 14420
Phone: (716) 395-2638 Fax: (716) 395-2466
E-mail: cro4@cornell.edu

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Key Words: Southwestern Atlantic, pristine areas.

The southwestern Atlantic is often regarded as a comparatively pristine confine of the World Ocean. Yet, if man-induced changes in the biodiversity tapestry of coastal seascapes are considered, a closer look at those regions could reveal a different picture could be observed. To that end, we formed an e-discussion group of Argentinean and Uruguayan scientists within which information was exchanged and screened in preparation for a working group meeting that took place concurrently with the 3rd Jornadas Argentinas de Ciencias del Mar (Puerto Madryn, Argentina, September 11-15, 2000). The objectives were: (a) To compile all the evidence about the introduction of exotics in a region of the World Ocean where marine biodiversity is very poorly documented and (b) To develop a holistic, "big picture" of how coastal seascapes of the southwestern Atlantic have changed as a result of ecologically significant invasions. The geographic domain covered by our review corresponds to the coastal zone south of the Brazil/Uruguay border (34o SL), down to the southern end of the continent and its adjacencies (54o SL).
Criteria for Inclusion: (a) species whose "exotic" status is well documented and (b) species that are reasonable candidates to the status of invasive exotics. The second group requires the specification of criteria for inclusion; five were considered: (1) Wide geographic distribution, including "cosmopolitic" species and species showing biogeographically incongruous distribution ranges, (2) Invasive potential indicated by documented exotic status in other geographic regions, (3) The species is abundant in the vicinity of presumable centers of introduction (e.g. commercial harbors), but rare in (or absent from) the rest of the region, (4) Life history suggests high long-distance dispersive potential, particularly for rafting on man-made structures, (5) In the case of species with hard parts, absence from the Quaternary fossil record, which in this region is rich and has been well documented.
Criteria for Exclusion: (a) Anadromous salmonids, as we have concentrated on benthic/littoral organisms, (b) Wood-borers, (c) Species that within the study area are exclusively associated with floating object, (d) Hydrozoa with a medusa stage, (e) Invasive species present only on the freshwater end of estuarine environments and (f) Exotics recorded for Brazil, but not from Uruguay/Argentina.
The emerging "big picture" showed that the impact of recent, human-mediated biological invasions has had, already, a significant ecological impact. Between the most important invasive species detected were: Ficopomatus enigmaticus, Limnoperna fortunei, Crassostrea gigas, Balanus glandula, and Undaria pinnatifida and one exported invasive species (Spartina densiflora)
The results are summarized in tables with: (1) 28 species for which the exotic status is well documented and which belong to the following groups: Phaeophyta 1, Polychaeta 4, Mollusca 4, Arthropoda 9, Ectoprocta 5 and Chordata 5, (2) Likely candidates to the exotic status (with 50 species) and they are: Porifera 4, Cnidaria Polychaeta 12, Mollusca 1, Arthropoda 17, Ectoprocta 4 and Chordata 1. (3) Species presumably native to the region under consideration, that have been recorded as exotic in (distant) regions and they are: Porifera 1, Mollusca 2 and Poacea 1.
There are well known cases of species that went exting in a given region, but were later re-introduced by man-mediated Three prominent cases fall in this category: Crepidula aculeata, Petricolaria (=Petricola) pholadiformis and Balanus amphitrite.
Our survey of invasions of the southwestern Atlantic by exotic species, the first of its nature for this region, had results unexpected to us at the onset of the project. Most coastal ecosystems between the La Plata River estuary (35º SL) and Golfo Nuevo (43º SL) have been already modified, or are expected to be so in the short term. Only exposed sandy beaches appear to be free from the pervasive ecological impact of biological invasion by exotic species. It is becoming increasingly difficult to establish what the pristine condition of coastal communities was. The results of the survey reveal that (1) all the four invading animal species that have already had a significant ecological impact tend to concentrate in crowded patches and have pelagic larvae and (2) there is a sharp contrast in the impact of invasive species at equivalent latitudes along the two coasts of southern South America.
Most introductions were accidental, most likely associated with fouled objects or ballast water discharges. We hope that our compilation will assist in the implementation of more proactive policies. Given that the biodiversity of the southwestern Atlantic is among the least known in the World, it is important that scientists and scientific agencies in the region understand the urgency of research on systematic and biogeography.

Author to Contact: Orensanz
Centro Nacional Patagónico, Puerto Madryn, Argentina
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Key Words: predator invasions, rapid adaptation, marine ecology, gene flow, evolution

Ecological effects of invading predatory species, such as crowding competition and displacement of native organisms have been well studied and are known to be important both economically and ecologically. Evolutionary effects of invasive predators such as causing life history changes or extinctions are less well known. Endemic prey species may not be able to evolve defenses against specialized predator and will go extinct unless they can quickly adapt. Rapid adaptation due to predators has been shown to cause changes in life history traits as quickly as 18 generations in experiments with guppies (Resnick 1997). In field experiments that have dealt with predator prey interactions, removal experiments are more common than introductions (Sih et al 1985). This work entails the addition of predatory shore crabs (Hemigrapsis nudus) to wave exposed rocky intertidal shores where they do not naturally inhabit by building shelters for them. We are in the process of developing techniques to monitor demographic and population parameters to predict whether local snail populations (Littorina sp.) will go extinct after the invasion using a model developed by Boulding and Hay (in review). These shore crabs have been found to selectively prey on thinner shelled snails, and forage mainly within 3 meters of their shelters. After adding crabs to selected field sites we can monitor the parameters needed for the model which include: prey population size, prey population growth rate, heritability of a quantitative trait under selection (shell thickness), phenotypic variance of that trait, the strength of selection by the predator, and gene flow from neighboring prey populations subject to different selection pressures. The present research focuses on development of techniques to measure the later two parameters in order to be able to manipulate the system and monitor the evolutionary changes in the prey after the additions of predators. We have found that the strength of selection is dependant on the predator size and needs to be measured separately for each invading size class in order to get an accurate idea of the intensity of selection pressure. The large crabs are less selective on shell thickness than the small crabs. Using this information we can also manipulate the selection pressure experimentally by adding large or small crabs to various sites. We have also found that the snail neighborhood size is roughly the same area as the crabs foraging range (about 3 meters). We are unsure as to whether migration from other snail populations experiencing different selection pressure is a constraint to local adaptation. Future experiments, now that all parameters are measurable, will focus on this aspect and will attempt to highlight which parameters are most important in determining whether local native populations will adapt or go extinct after the invasion of an exotic predator. This work will allow the testing of current models in predicting the evolutionary effects of invading organisms in the intertidal as well as other ecosystems subject to invasions, which are becoming more common because of human activity.

Author to contact: Deborah Pakes -University of Guelph (Graduate student)
Elizabeth Boulding -University of Guelph
Presenter/contact
Deborah Pakes
Departement of Zoology
University of Guelph
N1G 2W1
Fax: 519 -767-1656

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Key Words: Asterias, early invasion, spread, control

The establishment of the exotic northern Pacific seastar Asterias amurensis in
Tasmania attracted a great deal of publicity and significantly increased
awareness of the impact of exotic marine species throughout Australia. During
the 1990s A. amurensis became the most conspicuous organism in the Derwent
estuary and by 1995 its population was approximately 28 million (Grannum et al.
1996). Field studies in the Derwent confirmed that A. amurensis preyed on a wide
range of native fauna and that densities were as high as 24/m2. Consequently A.
amurensis was considered to have the potential to profoundly affect native
communities in southern Australia (Ross and Johnson 1998)

Asterias amurensis is native to the coasts of Japan and southeastern Russia.
During the mid 1990s A. amurensis was confined to the Derwent estuary and
hydrological modelling suggested that this limited distribution was the result
of limited larval dispersal (Bruce 1998). However the distribution of A.
amurensis in Tasmania still has not extended significantly beyond the Derwent
estuary and more recent modelling (C. Johnson, Univ Tasmania, pers comm)
suggests that most larvae are flushed from the estuary, and hence biological
factors may be limiting the spread of A. amurensis. Between 1995 and 1997 four
adult A. amurensis were collected in Port Phillip Bay and in early 1998 many
juveniles were found (Parry et al. 2000). Studies of population genetics
indicates that the Port Phillip Bay population probably came from the population
in the Derwent (Murphy and Evans 1998). These two populations are 700 km apart
and no A. amurensis have been found at intermediate locations. This distribution
pattern and the prevailing currents (Bruce 1998) suggest that natural dispersal
of larvae from the Derwent to Port Phillip Bay is very unlikely. Vessels
travelling between Hobart and Melbourne are the most likely vector, but it is
uncertain whether A. amurensis were introduced as larvae in ballast water or
adults. That the first four animals were found 10s of km apart and all were
adults spawned in at least two different years (Parry et al. 2000) suggests that
these first arrivals were transported as adults. In contrast, when juveniles
were first found in early 1998, many individuals of the same age were found in
the same region. Such a distribution pattern would be expected if these seastars
resulted from larval settlement following a successful spawning in the bay, or
possibly following the discharge of ballast water containing a high density of
A. amurensis larvae.

Most studies of exotic species do not commence until a population is well enough
established to present an economic or environmental problem. Typically this
occurs once the exotic species is well established, some years after the initial
invasion. Studies in the Derwent followed this typical pattern and did not
commence until A. amurensis had been established for approximately a decade
(Byrne et al. 1997). However the presence of A. amurensis in the Derwent and its
apparent impact there (McLoughlin and Thresher 1994) heightened awareness of the
risk of its translocation to Port Phillip Bay and resulted in the commencement
of ecological studies of A. amurensis in the Bay during the early phase of its
establishment.

Studies during the early phase of the invasion are critical to provide a
baseline against which impacts may be measured. But it appears to be less well
appreciated that some insights into means of controlling pest species may only
be evident during the early phase of an invasion. Factors that control the
distribution and abundance of pest species may change irreversibly as the pest
becomes more abundant.

This study documents changes in the distribution and population dynamics of
Asterias amurensis during the early phase of an invasion. The population of A.
amurensis in Port Phillip Bay has grown from 300,000 in 1998 to 30 million in
1999 to approximately 100 million in 2000. The mortality rate of seastars during
their first three years in Port Phillip Bay has remained very low in the main
area of infestation, but annual somatic growth has declined so that changes in
seastar diameter decreased from 15 cm/year in 1998 to 8 cm/year in 1999. In 2000
the reproductive output in the main area of the infestation is only one third of
that during 1999. Growth in the main area of infestation appears density
dependent. The distribution of A. amurensis in Port Phillip Bay has been
influenced strongly by hydrodynamic factors. Hydrodynamic models suggest that
limited larval dispersal explains the absence of A. amurensis from western Port
Phillip Bay in the period 1997-2000. However native predators may be limiting
the spread of A. amurensis into southern regions and shallow regions on the east
of the Bay.

References

Bruce, B. (1998). A summary of CSIRO studies on the larval ecology of Asterias
amurensis. Proceedings of a meeting on the biology and management of the
introduced seastar Asterias amurensis in Australian waters. C. L. Goggin (Ed).
CSIRO, Hobart, CRIMP Technical Report. 15: 36-41.

Byrne, M., M. G. Morrice, Wolf, B. (1997).
?Introduction of the northern Pacific
asteroid Asterias amurensis to Tasmania: reproduction and current distribution.?
Marine Biology 127: 673-685.

Grannum, R. K., Murfet, N. B., Ritz, D. A., Turner, E. (1996). Part 2. The
distribution and impact of the exotic seastar, Asterias amurensis (Lutken) in
Tasmania. The introduced northern Pacific seastar, Asterias amurensis (Lutken),
in Tasmania, Australian Nature Conservation Agency.

McLoughlin, R., Thresher, R. (1994). ?The north Pacific seastar, Australia's
most damaging marine pest?? Search 25: 69-71.

Murphy, N. Evans, B. (1998). Genetic origin of Australian populations of
Asterias amurensis. Proceedings of a meeting on the biology and management of
the introduced seastar Asterias amurensis in Australian waters. C. L. Goggin
(Ed). CSIRO, Hobart, CRIMP Technical Report. 15: 22-25.

Parry, G. D., Cohen, B.F., McArthur, M. A., Hickman, N. J. (2000). Asterias
amurensis incursion in Port Phillip Bay: Status at May 1999. Queenscliff, Marine
and Freshwater Resources Institute Report No: 21.

Ross, J., Johnson, C. (1998). Invasiveness and impact of the northern Pacific
seastar Asterias amurensis on natural communities in S.E. Tasmania. Proceedings
of a meeting on the biology and management of the introduced seastar Asterias
amurensis in Australian waters. CSIRO, Hobart, CRIMP Technical Report 15: 13-17.

Author to contact: Gregory D. Parry* and Brian F. Cohen
Marine and Freshwater Resources Institute
PO Box 114
Queenscliff 3225
Phone 0011 63 5258 0334 Fax 0011 63 5258 0270.
email: greg.parry@nre.vic.gov.au

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Key Words: Southwestern Atlantic, pristine areas.

Using an approach initiated on the West Coast, a Rapid Assessment Survey of marine native and non-native species in shallow water float communities of Massachusetts was conducted from August 6-11, 2000. Twenty sites from Gloucester to Fall River, Massachusetts were visited by scientists, students and participants with broad and specific taxonomic backgrounds. The Massachusetts survey was followed by a comparable one in Rhode Island the following week with many of the same scientists participating in that survey.

Although identifications are not complete for the Massachusetts study, 157 invertebrate species and 84 algal species were identified. Of the total species identified, 20 (4 plant and 16 invertebrate) species are considered to be introduced and another 25 (1 plant and 24 invertebrate) species are classified as cryptogenic. The total number of marine nonindigenous species in Massachusetts is less than the numbers observed in Puget Sound (38 marine nonindigenous species) and San Francisco Bay (>200 marine, brackish, and freshwater nonindigenous species).

Most species are found throughout the coast of Massachusetts, but a few are limited to either north or south of Cape Cod, which divides the southern Virginian and northern Boreal Provinces.

The data and information from this study are being used to develop the marine portion of the Massachusetts Aquatic Invasive Species Management Plan. As additional information is added, a more comprehensive examination of the historical and current records of introductions will provide insight into whether more species are being introduced today compared to previous decades. As the data from Rhode Island survey become available, the information will be incorporated into a regional database that also will include the Gulf of Maine.

Author to Contact: Judith Pederson
MIT Sea Grant College Program, Cambridge, MA
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Keywords: Hemigrapsus sanguineus, introduced species, diet, substrate

Hemigrapsus sanguineus, the Japanese shore crab, is native to the Western Pacific Ocean and was first observed in Long Island Sound in 1992. Since then, it has become firmly established and, in many locations, is the most common crab in the rocky intertidal zone. Based on field observations, experiments were designed to determine substrate preference and aspects of the diet of the crab. Crabs were collected from Connecticut rocky shores, sexed and measured, and grouped together in three size classes (6-12mm, 13-19mm, and 20-26mm) in the lab. Experiments were conducted to determine the influence of crab sex or size on 1) preference for cobble substrate size and 2) preference for specific size ranges of the northern rock barnacle, Semibalanus balanoides. Individual crabs from each size class were simultaneously offered three different substrate sizes (<1cm, 2 cm, and 5 cm). In the feeding experiment, crabs were allowed to feed individually on a range of sizes of barnacles for 24 hours. Results indicate that neither sex nor carapace size of the Japanese shore crab is associated with a preference for substrate size. Most crabs preferred the five cm substrate. In the feeding experiment, neither sex nor carapace size of the crabs was associated with a preference for barnacle size. Most crabs fed on all of the barnacles.

Author to contact: Scott R. Percival
Berlin Senior High School-Science Faculty
139 Patterson Way, Berlin, CT 06037
Phone: 860-828-6577 ext. 239
Fax: 860-225-8580
email: percivalsr@aol.com

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