Gregory Ruiz

Smithsonian Environmental Research Center

Vessel biofouling is the putative vector for many marine invasions. Biofouling communities are often dominated by organisms with sessile life history strategies that cannot themselves exit a transport vector, thereby requiring another means of dispersal such as reproduction, which releases mobile propagules. For many sessile organisms, reproduction...

Many factors affect an organism’s microbiome including its environment, proximity to other organisms, and physiological condition. As filter feeders, bivalves have highly plastic microbiomes that are especially influenced by the surrounding seawater, yet they also maintain a unique core set of microbes. Using 16S ribosomal RNA sequencing, we charac...

Introduction Global shipping has accelerated the spread of non-native species. Factors such as environmental filtering and interactions with local biota can affect invasion likelihood, yet their relative contribution to predicting invasion risk remains unresolved. To test how abiotic filters and an experimentally-derived measure of biotic resistanc...

Biotic interactions play a critical role in shaping patterns of global biodiversity. While several macroecological studies provide evidence for stronger predation in tropical regions compared with higher latitudes, results are variable even within the tropics, and the drivers of this variability are not well understood. We conducted two complementa...

The spread of marine non-indigenous species (NIS) is driven largely by shipping and global trade. Biofouling on vessel hulls is a major source of invasions, but many biofouling organisms are sessile (non-motile) and require reproduction, which often produces mobile, waterborne propagules (e.g., larvae) that can colonize new regions. The ability of...

Drifting marine debris has been shown to host associated biological communities and facilitate their dispersal. Little is known about how biota engage with, and are transported by, this debris. This study characterizes debris-associated communities and explores the role of plastics in transferring fishes to new geographic regions. ~ 1500 underwater...

Aim Parasites in the genus Perkinsus infect marine molluscs globally, with novel detections expanding and reshaping our knowledge of their biogeographic patterns and the factors influencing those patterns. Here, we aimed to characterize the phylogeography and genetic connectivity of Perkinsus spp. in bivalves across North and Central America, which...

Aim Human activities have introduced numerous non‐native species (NNS) worldwide. Understanding and predicting large‐scale NNS establishment patterns remain fundamental scientific challenges. Here, we evaluate if NNS composition represents a proportional subset of the total species pool available to invade (i.e. total global biodiversity), or, conv...

We show that the high seas are colonized by a diverse array of coastal species, which survive and reproduce in the open ocean, contributing strongly to its floating community composition. Analysis of rafting plastic debris in the eastern North Pacific Subtropical Gyre revealed 37 coastal invertebrate taxa, largely of Western Pacific origin, exceedi...

Sessile marine invertebrate (biofouling) communities have served as an important model in ecology for evaluating fundamental patterns and processes, including invasion dynamics, which vary at broad spatial and temporal scales. Here, we tested for differences in biofouling community development among three biogeographically distinct bays in North Am...

The introduction of nonindigenous species (NIS) threatens global ecosystems and results primarily from human transportation and trade activities. Although some NIS can disperse immediately upon arrival (for example, mobile species), actual inoculation for other (sessile) species can require a reproductive event to produce propagules that disperse a...

Recent global trade disruptions, due to blockage of the Suez Canal and cascading effects of COVID-19, have altered the movement patterns of commercial ships and may increase worldwide invasions of marine non-indigenous species. Organisms settle on the hulls and underwater surfaces of vessels and can accumulate rapidly, especially when vessels remai...

Aim The global shipping fleet, the primary means of transporting goods among countries, also serves as a major dispersal mechanism for marine invasive species. To date, researchers have primarily focussed on the role of ships in transferring marine macrofauna, often overlooking transfers of associated parasites, which can have larger impacts on naï...

Early naturalists suggested that predation intensity increases toward the tropics, affecting fundamental ecological and evolutionary processes by latitude, but empirical support is still limited. Several studies have measured consumption rates across latitude at large scales, with variable results. Moreover, how predation affects prey community com...

Early naturalists suggested that predation intensity increases toward the tropics, affecting fundamental ecological and evolutionary processes by latitude, but empirical support is still limited. Several studies have measured consumption rates across latitude at large scales, with variable results. Moreover, how predation affects prey community com...

Early naturalists suggested that predation intensity increases toward the tropics, affecting fundamental ecological and evolutionary processes by latitude, but empirical support is still limited. Several studies have measured consumption rates across latitude at large scales, with variable results. Moreover, how predation affects prey community com...

Early naturalists suggested that predation intensity increases toward the tropics, affecting fundamental ecological and evolutionary processes by latitude, but empirical support is still limited. Several studies have measured consumption rates across latitude at large scales, with variable results. Moreover, how predation affects prey community com...

Recreational boats and their marinas are important components of the hub-and-spoke model of invasion in coastal marine systems. Like most vectors, however, species transfers by boats are under-sampled and the extent of invasion among coastal bays is patchily sampled, with a bias towards larger urbanized bays with commercial port systems. We assesse...

The hydroids of Cocos Island (Isla del Coco), Costa Rica, have received scant attention and are poorly known. Only 11 species have been reported from there previously, with five of them being stylasterids. Hydroids examined here were collected during 2019 in a search for invasive species, as part of a fouling survey. Fourteen species – three anthoa...

Biological invasions are a major driver of biodiversity loss and socioeconomic burden globally. As invasion rates accelerate worldwide, understanding past invasion dynamics is essential to inform predictions of future invaders and impacts. Owing to a high diversity of pathways and current biosecurity gaps, aquatic systems near urban centres are esp...

Aims The present study is the first attempt to grasp the scale and richness of marine biological invasions in Macaronesia. We pioneered a comprehensive non‐native species (NNS), inventory in the region to determine their diversity patterns and native distribution origins. NNS were defined here as the result of both introductions and range expansion...

Submerged ship surfaces are often inhabited by diverse sessile and sedentary marine organisms, which can directly impact vessel operations and increase the likelihood of non-indigenous species (NIS) establishment and impacts. Ship in-water cleaning (IWC) systems are now being incorporated into biofouling policy, and rigorous, transparent, and predi...

Discoveries of persistent coastal species in the open ocean shift our understanding of biogeographic barriers. Floating plastic debris from pollution now supports a novel sea surface community composed of coastal and oceanic species at sea that might portend significant ecological shifts in the marine environment.

Established non-native species can have significant impacts on native biodiversity without any possibility of complete eradication. In such cases, one management approach is functional eradication, the reduction of introduced species density below levels that cause unacceptable effects on the native community. Functional eradication may be particul...

Scenario analysis has emerged as a key tool to analyze complex and uncertain future socio-ecological developments. However, currently existing global scenarios (narratives of how the world may develop) have neglected biological invasions, a major threat to biodiversity and the economy. Here, we use a novel participatory process to develop a diverse...

Adaptation across environmental gradients has been demonstrated in numerous systems with extensive dispersal, despite high gene flow and consequently low genetic structure. The speed and mechanisms by which such adaptation occurs remain poorly resolved, but are critical to understanding species spread and persistence in a changing world. Here, we i...

Established non-native species can have significant impacts on native biodiversity without any possibility of complete eradication. In such cases, one management approach is functional eradication, the reduction of introduced species density below levels that cause unacceptable effects on the native community. Functional eradication may be particul...

Biological invasions often result from transfers of organisms during trade activities. In coastal ecosystems, commercial ships are a dominant source of species transfers globally, and ships’ ballast water (BW) is a major focus of biosecurity management and policy to reduce invasions. While trade drives shipping patterns, diverse vessel types and be...

Baseline port monitoring for fouling communities is an essential tool to assess non-indigenous species (NIS) introduction and spread, but a standardized and coordinated method among Mediterranean and European countries has not yet been adopted. In this context, it is important to test monitoring protocols that allow for the collection of standardiz...

Understanding the mechanisms of spatial variation of biological invasions, across local‐to‐global scales, has been a major challenge. The importance of evolutionary history for invasion dynamics was noted by Darwin, and several studies have since considered how biodiversity of source and recipient regions can influence the probability of invasions....

The hypothesis that biotic interactions strengthen toward lower latitudes provides a framework for linking community‐scale processes with the macroecological scales that define our biosphere. Despite the importance of this hypothesis for understanding community assembly and ecosystem functioning, the extent to which interaction strength varies acro...

Phylogeography provides insights into how historical and contemporary processes influence the genetic structure and gene flow in marine organisms around the globe. In benthic marine invertebrates, a species’ reproductive strategy can strongly impact phylogeographic patterns and distribution, with some direct-developing (non-planktonic) dispersers d...

In dynamic systems, organisms are faced with variable selective forces that may impose trade-offs. In estuaries, salinity is a strong driver of organismal diversity, while parasites shape species distributions and demography. We tested for trade-offs between low-salinity stress and parasitism in an invasive castrating parasite and its mud crab host...

To verify ships' compliance with ballast water regulations, samples may be collected and tested for viable organisms. This task is completed using a sample probe, which is placed in the ballast discharge pipe through a sample port (a flanged opening). To collect representative samples, the placement of the sample port and the size of the sample pro...

By shuffling biogeographic distributions, biological invasions can both disrupt long‐standing associations between hosts and parasites and establish new ones. This creates natural experiments with which to study the ecology and evolution of host‐parasite interactions. In estuaries of the Gulf of Mexico, the white‐fingered mud crab (Rhithropanopeus...

Vessel biofouling is a major pathway for the introduction, establishment, and subsequent spread of marine non-indigenous macro-organisms. As a result, national and international regulations and guidelines have been implemented to manage the risks associated with this pathway, yet widespread enforcement and uptake are still in their infancy. By comp...

Significance Theoretical models of population dynamics have shown the counterintuitive conclusion that harvest can increase the equilibrium size of a population. These models of increases in response to mortality have been considered for fisheries harvest and removal of non-native species and can be driven by density-dependent overcompensation. Thi...

Scenario analysis has emerged as a key tool to analyze complex and uncertain future socio-ecological developments. However, current global scenarios (narratives of how the world may develop) have neglected biological invasions, a major threat to biodiversity and the economy. We used a novel participatory process to develop a diverse set of global b...

Since the discovery of Perkinsus marinus as the cause of dermo disease in Crassostrea virginica , salinity and temperature have been identified as the main environmental drivers of parasite prevalence. However, little is known about how these variables affect the movement of the parasite from host to water column. In order to elucidate how environm...

Unprecedented rates of introduction and spread of non-native species pose burgeoning challenges to biodiversity, natural resource management, regional economies, and human health. Current biosecurity efforts are failing to keep pace with globalization, revealing critical gaps in our understanding and response to invasions. Here, we identify four pr...

Since the discovery of Perkinsus marinus as the cause of dermo disease in Crassostrea virginica , salinity and temperature have been identified as the main environmental drivers of parasite prevalence. However, little is known about how these variables affect the movement of parasites from host to water column. In order to elucidate how environment...

Aim The introduction of aquatic non‐indigenous species (ANS) has become a major driver for global changes in species biogeography. We examined spatial patterns and temporal trends of ANS detections since 1965 to inform conservation policy and management. Location Global. Methods We assembled an extensive dataset of first records of detection of A...

Abstract Aim: Topographic complexity is widely accepted as a key driver of biodiversity, but at the patch-scale, complexity–biodiversity relationships may vary spatially and temporally according to the environmental stressors complexity mitigates, and the species richness and identity of potential colonists. Using a manipulative experiment, we asse...

Characterizing biodiversity conveyed in ships' ballast water (BW), a global driver of biological invasions, is critically important for understanding risks posed by this key vector and establishing baselines to evaluate changes associated with BW management. Here we employ high throughput sequence (HTS) metabarcoding of the 18S small subunit rRNA t...

Understanding the likely future impacts of biological invasions is crucial yet highly challenging given the multiple relevant environmental, socio‐economic and societal contexts and drivers. In the absence of quantitative models, methods based on expert knowledge are the best option for assessing future invasion trajectories. Here, we present an ex...

Aim Genetic structure has proven difficult to predict for marine and estuarine species with multi‐day pelagic larval durations, since many disperse far less than expected based on passive transport models. In such cases, the gap between potential and realized dispersal may result from larval behaviours that evolved to facilitate retention and settl...

Molecular-based approaches can provide timely biodiversity assessments, showing an immense potential to facilitate decision-making in marine environmental management. However, the uptake of molecular data into environmental policy remains minimal. Here, we showcase a selection of local to global scale studies applying molecular-based methodologies...

Biofouling accumulation on ships’ submerged surfaces typically occurs during stationary periods that render surfaces more susceptible to colonization than when underway. As a result, stationary periods longer than typical port residence times (hours to days), often referred to as lay-ups, can have deleterious effects on hull maintenance strategies,...

Biofouling is a long-standing challenge for ships because it can interfere with operations and increases vessel drag, fuel consumption and exhaust emissions. More recently, ship biofouling has also been recognized as a leading vector for global transfers and introductions of marine non-indigenous species. Ship in-water cleaning and capture (IWCC) s...

The International Maritime Organization and U.S. Coast Guard have implemented regulations to reduce introductions of non-indigenous species via ballast water (BW). For phytoplankton, regulations limit discharges to < 10 live/viable cells mL −1 (size: 10-50 μm), ignoring other size fractions. Additionally, challenge conditions of 100 (shipboard) and...

Invasion dynamics are influenced by both vector operation and propagule pressure. Which propagules are entrained in a vector depends on how, where, and when a vector operates, but the timing and effects of vector operations on species delivery patterns is poorly resolved. Using the live marine baitworm trade, we tested vector selectivity across 3 b...

Aim While warming temperatures are expected to facilitate the poleward movement of species previously restricted to more equatorial waters, the arrival and persistence of cold‐water species in more equatorward waters are relatively unprecedented. The native north‐east Pacific ascidian Corella inflata Huntsman, 1912, has spread southward and invaded...

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 inf...

Over half the world’s human population lives near the coast, with diverse impacts on the structure and function of coastal ecosystems, including the introduction of parasites that result from shipborne trade, aquaculture, and other human-aided dispersal. The scale of these activities has accelerated through time, expanding the potential for new int...

As plastic pollution in the environment has increased rapidly in the last half century, so too has the study of the effects of plastic on marine, aquatic and terrestrial ecosystems. From this research, a series of new terms has emerged to describe the phenomena unique to the presence of plastic-based materials in nature. In this short note, we brin...

The hypothesis that biotic interactions are stronger at lower relative to higher latitudes has a rich history, drawing from ecological and evolutionary theory. While this hypothesis suggests that stronger interactions at lower latitudes may contribute to the maintenance of contemporary patterns of diversity, there remain few standardized biogeograp...