Marine Invasions Research

Principal Investigator

Twitter Logo
Follow us on Twitter: @SERCinvasions


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. 

Keppel, K., Ruiz, G.M., Tavar-Hernandez, M.A. 2020. Re-description of Parasabella fullo (Grube, 1878) (Polychaeta: Sabellidae) and diagnostic characteristics for detection in California. The European Zoological Journal. 87(1) (Online February 11, 2020)

Gizzi, F., Jimenez, J., Schafer, S., Castro, N., Costa, S., Lourenco, S., Jose, R., Canning-Clode, J., and Monteriro, J. 2020. Before and after a disease outbreak: Tracking a keystone species recovery from a mass mortality event. Marine Environmental Research 256(104905) (online February 8, 2020

Pagenkopp Lohan, K.M., Ruiz, G.M., and Tochin, M.E., 2020. Invasions can drive disease dynamics. In: Marine Disease Ecology. Eds: Behringer, B.C., Laffertty, K.D., and Silliman, B.R. Oxford University Press (199-126). (January 28, 2020)

Wasson, K., Fabian, R.A., Fork, S., Stanganelli, J., Mize, Z., Beheshti, K., Jeppesen, R., Jones, I.J., Zabin, C.J, Walker, S., Lummis, S.C., Emery, M., Moore, J.D., Endris, C., Jolette, D., and Byers, J.E.  2020. Multiple factors contribute to the spatially variable and dramatic decline of an invasive snail in an estuary where it was long-established and phenomenally abundant. Biol Invasions. doi:10.1007/s10530-019-02172-w  (online January 22, 2020)

Pagenkopp Lohan, K.M., DiMaria, R., Martin, D.L., Ross, C., and Ruiz, G.M. 2020. Diversity and microhabitat associations of Labyrinthula spp. in the Indian River Lagoon System. Dis Aquat Org 137:145-157. (online January 16, 2020)


February 11, 2020

Keppel, K.Ruiz, G.M.Tavar-Hernandez, M.A. 2020. Re-description of Parasabella fullo (Grube, 1878) (PolychaetaSabellidae) and diagnostic characteristics for detection in California. The European Zoological Journal. 87(1)

The original description of the fan worm Parasabella fullo (Grube, 1878) is brief and mainly focused on the color. This paper provides a redescription based on syntype material from northern Japan kept at Museum für Naturkunde of Berlin and new records in California (USA). Diagnostic characters used in redescribing the species are the shapes of inferior thoracic notochaetae, ventral thoracic shields and dorsal collar margins. Although this Japanese species was collected on vessels’ hulls in California, it is not clear if and where the species is established here, due to past difficulties in identification without well-defined characters. Nevertheless, a resident population appears to exist in the region, given the species occurrence on local recreational vessels. The redescription provides information to distinguish it from the local Californian indigenous species Parasabella pallida Moore, 1923.

February 8, 2020

Gizzi, F., Jimenez, J., Schafer, S., Castro, N., Costa, S., Lourenco, S., Jose, R., Canning-Clode, J., and Monteriro, J. 2020. Before and after a disease outbreak: Tracking a keystone species recovery from a mass mortality event. Marine Environmental Reseach 256(104905) (online February 8, 2020

Mass mortality events involving marine taxa are increasing worldwide. The long-spined sea urchin Diadema africanum is considered a keystone herbivore species in the northeastern Atlantic due to its control over the abundance and distribution of algae. After a first registered mass mortality in 2009, another event off the coasts of Madeira archipelago affected this ecologically important species in summer 2018. This study documented the 2018 D. africanum mass mortality event, and the progress of its populations on the southern coast of Madeira island. A citizen science survey was designed targeting marine stakeholders to understand the extent and intensity of the event around the archipelago. Underwater surveys on population density prior, during and after the mass mortality, permitted an evaluation of the severity and magnitude of the event as well as urchin population recovery. A preliminary assessment of causative agents of the mortality was performed. The event was reported in the principal islands of the archipelago reducing the populations up to 90%. However, a fast recovery was registered during the following months, suggesting that the reproductive success was not compromised. Microbiological analyses in symptomatic and asymptomatic individuals, during and after the event, was not conclusive. Nevertheless, the bacteria Aeromonas salmonicida, or the gram-negative bacteria, or the interaction of different types of bacteria may be responsible for the disease outbreak. Further studies are needed to assess the role of pathogens in sea urchin mass mortalities and the compound effects that sea urchins have in local habitats and ecological functioning of coastal marine ecosystems. 

Janaury 23, 2020

Pagenkopp Lohan, K.M., Ruiz, G.M., and Tochin, M.E., 2020. Invasions can drive disease dynamicsIn: Marine Disease Ecology. Eds: Behringer, B.C., Laffertty, K.D., and Silliman, B.R. Oxford University Press (199-126).

Book Chapter, no abstract available. 

January 22, 2020

Wasson, K., Fabian, R.A., Fork, S., Stanganelli, J., Mize, Z., Beheshti, K., Jeppesen, R., Jones, I.J., Zabin, C.J, Walker, S., Lummis, S.C., Emery, M., Moore, J.D., Endris, C., Jolette, D., and Byers, J.E.  2020. Multiple factors contribute to the spatially variable and dramatic decline of an invasive snail in an estuary where it was long-established and phenomenally abundant. Biol Invasions. doi:10.1007/s10530-019-02172-w  

Boom-bust dynamics of invasive species have long intrigued scientists and managers alike, but quantification of such dynamics, let alone their causes, is rare. We documented the decline of a previously prolific invasive mudsnail, Batillaria attramentaria, at Elkhorn Slough estuary in central California, USA. The mudsnail was the most abundant epibenthic invertebrate in the estuary, maintaining very high densities for many decades before declining heterogeneously throughout the estuary over the past decade, decreasing in density by three orders of magnitude at some sites. We used field and laboratory experiments to test several possible mechanisms for its demise. We show that the crab Pachygrapsus crassipes can prey heavily on Batillaria. We detected high dissolution rates of Batillaria shells, and we measured greater predation rates on tethered snails with dissolved versus intact shells. Warm water temperatures and high water levels coincided with the period of most dramatic Batillaria declines (2013–2015). Localized water impoundments appear to buffer environmental drivers of the decline because Batillaria remained abundant at sites with artificial tidal restriction, while the population crashed at one site after full tidal exchange was restored. We also investigated trematode parasite prevalence and molluscicide applications to the surrounding watershed as possible causes of mudsnail declines, but they had little explanatory power. Our findings illustrate the potential for population crashes even for long-established introduced species at pest levels of abundance, and demonstrate that such declines can exhibit spatial heterogeneity. Both of these results highlight the value of investigating population dynamics of invaders across multiple temporal and spatial scales.

January 16, 2020

Pagenkopp Lohan, K.M., DiMaria, R., Martin, D.L., Ross, C., and Ruiz, G.M. 2020Diversity and microhabitat associations of Labyrinthula spp. in the Indian River Lagoon System. Dis Aquat Org 137:145-157. 

Seagrasses create foundational habitats in coastal ecosystems. One contributing factor to their global decline is disease, primarily caused by parasites in the genus Labyrinthula. To explore the relationship between seagrass and Labyrinthula spp. diversity in coastal waters, we examined the diversity and microhabitat association of Labyrinthula spp. in 2 inlets on Florida’s Atlantic Coast, the Indian River Lagoon (IRL) and Banana River. We used amplicon-based high throughput sequencing with 2 newly designed primers to amplify Labyrinthula spp. from 5 seagrass species, water, and sediments to determine their spatial distribution and microhabitat associations. The SSU primer set identified 12 Labyrinthula zero-radius operational taxonomic units (ZOTUs), corresponding to at least 8 putative species. The ITS1 primer set identified 2 ZOTUs, corresponding to at least 2 putative species. Based on our phylogenetic analyses, which include sequences from previous studies that assigned seagrass-related pathogenicity to Labyrinthula clades, all but one of the ZOTUs that we recovered with the SSU primers were from non-pathogenic species, while the 2 ZOTUs recovered with the ITS1 primers were from pathogenic species. Some of the ZOTUs were widespread across the sampling sites and microhabitats (e.g. SSU ZOTU_10), and most were present in more than one site. Our results demonstrate that targeted metabarcoding is a useful tool for examining the relationships between seagrass and Labyrinthula diversity in coastal waters.​


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

Propagule Pressure in Marine Habitats

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).