Marine Invasions Research

Principal Investigator

Biological invasions - the establishment of species beyond their historical range - are a major force of ecological and evolutionary change. Our lab aims to understand the patterns, processes, and consequences of invasions in marine ecosystems on local to global scales.  We have laboratories and staff on both coasts of North America, on Chesapeake Bay and San Francisco Bay (Tiburon Lab).  These bays are focal points for our long-term, intensive research, which spans Pacific and Atlantic shorelines of the Americas --- from polar to tropical latitudes. 

Most marine invasions result from human-mediated species transfers, which are often associated with commercial and recreational vessels. A major component of our research examines shipping, transportation, and trade dynamics for the United States with the National Ballast Information Clearinghouse (NBIC), a joint program with the U.S. Coast Guard that is based at SERC.  NBIC tracks the status and trends of ballast water delivery and management for the Nation.

Our research encompasses a wide range of projects, exploring the ecology and management of coastal marine ecosystems.  We focus primarily on invasion dynamics but also examine species interactions of both native and non-native species. Overall, we seek to: (1) characterize patterns of marine invasion across space, time, and taxonomic groups; (2) develop a mechanistic understanding of the processes that drive observed patterns; (3) advance predictive capability about the establishment, spread, and impacts of non-native species in marine ecosystems; (4) evaluate the efficacy of management strategies to limit the establishment and impact of invaders; and (5) understand the roles of species interactions, including predator-prey and host-parasite relationships, in marine communities. 

Further details on the various dimensions of our work are available below. 

Species distributions are at the core of all ecological and evolutionary processes. Despite recognition that accelerating invasions are radically changing fundamental ecological processes, we currently lack the data for a broad scale understanding of these  patterns, emergent properties, and practical implications across both spatial and temporal scales. We are collecting quality occurrence data and using these data to understand patterns and mechanisms of invasion, and making these data publicly available for broader application by the public.

Our Projects

The impacts of introduced species pose significant challenges for conservation and restoration because they undermine a desired outcome for target species or habitats. In addition, some invasions impose significant economic costs through loss of agriculture, forestry, and fisheries products, and others, including mosquito-borne viruses and toxic algal blooms, have severe human health effects. Detailed analysis of several high-profile species invasions have highlighted the types and potential magnitude of invasion impacts that exist, however, the effect of most non-native species and the full scope of impacts from invasions remains poorly understood. To address this gap, we use a variety of approaches to characterize and test the ecological, evolutionary, and social effects of non-native species across diverse ecosystems.  This work advances understanding of how the Earth’s ecosystems function and also serve to inform resource management and conservation strategies.

Our Projects

Biological invasions provide opportunities to examine how species and ecosystems respond to new arrivals, and how species adapt to new environmental conditions. These types of “natural experiments” provide new insights into many biological processes, especially early in the colonization process, that are not possible with native communities.  We examine invasion ecology at the population, community, and ecosystem level across a diverse range of habitats and organisms, both to advance basic science and inform management and conservation strategies.

Our Projects

Managing biological invasions is a worldwide endeavor that aims to (a) prevent the human-caused spread of species, (b) control and remove unwanted species, and (c) reduce negative impacts to society and the environment. We are evaluating the efficacy and consequences of invasion management strategies and policies in coastal estuaries and marine systems.  Our work is often done in collaboration with local, state, federal and international partners and used actively to inform current management and policy decisions.

Our Projects

We study the dynamic interactions between society, trade, transport, and species in a variety of ways. These include modeling transport networks and biotic exchange, evaluating business model forecasts and their effects on trade routes and species distributions, and assessments of organism transfers across major corridors between oceans and continents.

Our Projects

Understanding how modes of human transportation affect the environment, and biological invasions in particular, is complicated and involves many components including both human and natural history. Human history because most invasions result from human-aided species transfers and invasion patterns often reflect human movements and transportation systems. Natural history because species identifications and their life history characteristics are paramount to knowing which species are non-native and how they have likely been introduced. We work to address these complexities and strive to understand the dynamics of species transport in marine systems. 

Our Projects

Balanced predation and competition are key to the health of any ecosystem. We are examining predation and competition rates in several environments including in the Rhode River near SERC where we study native species in nearshore environments and in introduced fouling communities on the Atlantic and Pacific coasts.  

Our Projects

Communities are constantly being shaped by human activities, activates that can affect hydrology, climate, chemical inputs, species richness (number of species that make up the community), as well as habitat quantity and quality. Our research focuses on how biological invasions change the marine and estuarine communities they invade and how recipient communities protect themselves from invasion. The following highlights a few of our recent projects exploring community changes resulting from nonnative species introductions.

Our Projects

We are examining the complex, dynamic interactions between parasites and their hosts, including both the evolutionary and ecological mechanisms that influence these interactions. Our research includes a wide variety of hosts (e.g., seagrasses, bivalves, crustaceans) and parasites (e.g., protists, bacteria, crustaceans).   

Ricciardi, A., T.M. Blackburn, J.T Carlton, J.T.A. Dick, P.E. Hulme, J. C. Iacarella, J.M. Jeschke, A.M. Liebhold, J.L. Lockwood, H.J. MacIsaac, P. Pysek,  D.M. Richardson, G.M. Ruiz, D. Simberloff, W.J. Sutherland, D.A. Wardle, and D.C. Aldridge. 2017. Invasion Science: A Horizon Scan of Emerging Challenges and Opportunities. Trends in Ecology & Evolution, 32 (6) , 464-474. http://dx.doi.org/10.1016/j.tree.2017.03.007 June 2017

Simkanin C., A. Cawood. 2017. Junior scientists: senior scientists as allies for equity. Nature (Correspondence). 546: 352.

Pagenkopp Lohan, K.M., R.C. Fleischer, K.J. Carney, K.K. Holzer, and G.M. Ruiz. 2017. Molecular characterisation of protistan species and communities in ships’ ballast water across three U.S. coasts. Diversity and Distributions. Online April 17, 2017. DOI: 10.1111/ddi.12550

Carney, K.J., M.S. Minton, K.K. Holzer, A.W. Miller, L.D. McCann, G.M. Ruiz. 2017. Evaluating the combined effects of ballast water management and trade dynamics on transfers of marine organisms by ships. Published March 20, 2017 https://doi.org/10.1371/journal.pone.0172468

Blakeslee, April M. H., Y. Kamakura, J. Onufrey, W. Makino, J. Urabe, S. Park, C.L. Keogh, A.W. Miller, M.S. Minton, J.T. Carlton, and O. Miura. 2017. Erratum to: Reconstructing the Invasion History of the Asian shorecrab, Hemigrapsus sanguineus (De Haan 1835) in the Western Atlantic. Marine Biology, 164 (4) , 88. http://dx.doi.org/10.1007/s00227-017-3117-x March 21, 2017


Abstracts

June 2017

Ricciardi, A., T.M. Blackburn, J.T Carlton, J.T.A. Dick, P.E. Hulme, J. C. Iacarella, J.M. Jeschke, A.M. Liebhold, J.L. Lockwood, H.J. MacIsaac, P. Pysek,  D.M. Richardson, G.M. Ruiz, D. Simberloff, W.J. Sutherland, D.A. Wardle, and D.C. Aldridge. 2017. Invasion Science: A Horizon Scan of Emerging Challenges and Opportunities. Trends in Ecology & Evolution, 32 (6) , 464-474. http://dx.doi.org/10.1016/j.tree.2017.03.007 June 2017

Abstract

We identified emerging scientific, technological, and sociopolitical issues likely to affect how biological invasions are studied and managed over the next two decades. Issues were ranked according to their probability of emergence, pervasiveness, potential impact, and novelty. Top-ranked issues include the application of genomic modification tools to control invasions, effects of Arctic globalization on invasion risk in the Northern Hemisphere, commercial use of microbes to facilitate crop production, the emergence of invasive microbial pathogens, and the fate of intercontinental trade agreements. These diverse issues suggest an expanding interdisciplinary role for invasion science in biosecurity and ecosystem management, burgeoning applications of biotechnology in alien species detection and control, and new frontiers in the microbial ecology of invasions.

Trends

  • Expanding transportation networks, technological advances, global environmental change, and geopolitical forces are transforming risks of invasion worldwide.
  • Genomic modification tools offer novel risks and potential solutions to managing invasions.
  • Rapid warming and intensified human activities in the Arctic will alter invasion patterns and risks across the Northern Hemisphere.
  • Anthropogenic stressors promote rapid evolutionary shifts that cause native and alien populations to become invasive.
  • Microbial ecology is becoming increasingly relevant to understanding and managing invasions.
     

May 2017

Simkanin C., A. Cawood. 2017. Junior scientists: senior scientists as allies for equity. Nature (Correspondence). 546: 352.

Correspndance 

 

Asking the scientific system to fix itself from the bottom up could place an unacceptable burden on junior scientists (see J. Tregoning Nature 545, 7; 2017). Moreover, their efforts are likely to make little difference without the participation of senior colleagues.

Young researchers, especially women and those from ethnic minorities, are already forced to challenge the existing culture if they are to advance professionally. They face overt and unconscious bias, barriers to recruitment and unequal pay. They receive fewer grants and citations and must work harder for recognition than those with similar qualifications (see Nature 495, 22–24; 2013).

Such inequity could be corrected with the support of peers, as Tregoning proposes. But without higher-ranking allies, the efforts of young scientists face obstacles. To bring about change, senior scientists should couple their insight, experience and enthusiasm to that of younger colleagues. This would highlight problem areas, implement policy solutions and lead to cultural reform.

April 2017

Pagenkopp Lohan, K.M., R.C. Fleischer, K.J. Carney, K.K. Holzer, and G.M. Ruiz. 2017. Molecular characterisation of protistan species and communities in ships’ ballast water across three U.S. coasts. Diversity and Distributions. Online April 17, 2017. DOI: 10.1111/ddi.125500

Abstract

Aim: We characterised protistan taxa in ships’ ballast water (BW) arriving to port systems across three U.S. coasts. Our goals were to compare (1) diversity and (2) community composition of protists in BW among and between port systems.

Location: Chesapeake Bay in Virginia (Port of Hampton Roads), Galveston Bay in Texas (Ports of Texas City, Houston and Bayport) and Prince William Sound in Alaska (Port of Valdez).

Methods: We collected 61 BW samples from 39 vessels from May to August 2013. We conducted amplicon-based high-throughput sequencing (HTS) using the hypervariable V4 domain of the small subunit (SSU) gene of the ribosomal RNA (rRNA) complex to identify protistan taxa.

Results: We detected 8,561 OTUs from protistan taxa, including 35 taxonomic groups. We found high protistan diversity in the BW entering all three port systems, with the dominant taxa belonging to the Alveolata, Rhizaria and Stramenopiles. Thirty-eight taxa were found in high relative abundance (>10,000 sequences), and some were recovered from multiple samples within and across ports, indicating both a high relative abundance and frequency of introduction events. The composition of the protistan communities entering each of the port systems appeared to vary depending on BW source, with those entering Valdez being consistently more similar to each other than those entering other port systems.

Main conclusions: This study is the most comprehensive assessment of protistan diversity in BW and has important implications for microbial biogeography and invasions. Ships’ BW is importing distinct and diverse protistan communities to U.S. coasts with high propagule pressure for some taxa, creating opportunity for invasion by novel taxa. Further, our results demonstrate the broad-scale movement of marine protists that has occurred through BW, highlighting a discrepancy between the large magnitude of introductions and limited number of known microbial invasions.

March 2017

Carney, K.J., M.S. Minton, K.K. Holzer, A.W. Miller, L.D. McCann, G.M. Ruiz. 2017. Evaluating the combined effects of ballast water management and trade dynamics on transfers of marine organisms by ships. Published March 20, 2017 https://doi.org/10.1371/journal.pone.0172468

Abstract:

Global trade by merchant ships is a leading mechanism for the unintentional transfer of marine organisms, including non-indigenous species, to bays and estuaries worldwide. To reduce the likelihood of new invasions, ships are increasingly being required to manage their ballast water (BW) prior to discharge in coastal waters. In the United States, most overseas arrivals have been required to manage BW discharge since 2004, primarily through ballast water exchange (BWE), which flushes out ballast tanks in the open ocean (>200 miles from shore). Studies have found BWE to generally reduce the abundance of organisms, and the amount of water exchanged has been estimated at 96–100%. Despite its widespread use, the overall effect of this management strategy on net propagule supply through time has not been explored. Here, temporal changes in zooplankton concentrations and the volume of BW discharged in Chesapeake Bay, U.S. were evaluated, comparing pre-management era and post-management era time periods. Chesapeake Bay is a large port system that receives extensive BW discharge, especially from bulk cargo vessels (bulkers) that export coal overseas. For bulkers arriving from overseas, mean zooplankton concentrations of total and coastal indicator taxa in BW did not decline between pre- (1993–2000) and post management (2012–2013) eras, when controlling for season and sampling method. Moreover, bulkers discharged 21 million tonnes (82% of total for Chesapeake Bay) of overseas BW in 2013, representing a 374% increase in volume when compared to 2005. The combination of BW discharge volume and zooplankton concentration data indicates that (a) net propagule supply by bulkers has increased since BWE began in Chesapeake Bay; and (b) changes in vessel behaviour and trade have contributed strongly to this outcome. Specifically, the coal-driven increase in BW discharge volume from 2005–2013, concurrent with the onset of BWE regulations, worked to counteract intended results from BW management. A long-term analysis of bulker arrivals (1994–2013) reveals a 20-year minimum in arrival numbers in 2000, just when the implementation of BWE began. This study underscores the need to consider shifts in trade patterns, in order to advance and evaluate effective management strategies for biological invasions.

Blakeslee, April M. H., Y. Kamakura, J. Onufrey, W. Makino, J. Urabe, S. Park, C.L. Keogh, A.W. Miller, M.S. Minton, J.T. Carlton, and O. Miura. 2017. Erratum to: Reconstructing the Invasion History of the Asian shorecrab, Hemigrapsus sanguineus (De Haan 1835) in the Western Atlantic. Marine Biology, 164 (4) , 88. http://dx.doi.org/10.1007/s00227-017-3117-x March 21, 2017

Abstract

Numerous marine species have been introduced via anthropogenic vectors; however, many species, including highly abundant ones, have uncertain invasion histories. Here, we include the first large-scale population genetics study of the Asian shorecrab (Hemigrapsus sanguineus) in native (east Asia) and non-native (east USA) regions to help resolve questions of source, vector, and multiple introductions. Using a barcoding gene and six microsatellite loci, we analyzed 731 cytochrome oxidase I sequences and 500 microsatellites across 51 populations over two time periods, 2001–2002 and 2013–2014. Explorations of both genetic and historical data indicated that multiple introductions to USA are probable with the greatest genetic diversity concentrating around Long Island (near New York City). Analyses of ballast water flux and genetic data suggest that introductions from Japan via shipping are the likely source and pathway of introduction to USA. In particular, we found unexchanged ballast arriving to USA (notably New York region) from sources throughout Japan, including southern and northern areas where closer genetic connections to USA were detected. Western Europe was also a prominent source of unexchanged ballast, suggesting possible trans-Atlantic transfers. Altogether, extensive biogeographic studies like this help provide integral evidence for resolving key invasion history questions, as well as a baseline understanding of a species’ probable success and prospect for further spread. In turn, while mandatory ballast water exchange in USA has greatly lessened ballast-borne invasions, our study underscores that hotspots of unexchanged ballast can remain potential sources of novel or supplemental introductions worldwide.

The original version of this article was revised: One of the author name “Yumi Kamakura” in the authorship was incorrectly published in this original version and the same is corrected here.

 

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