Richard S Nemeth

• Ph.D.
• Professor at University of the Virgin Islands

Seagrass ecosystems provide essential nursery habitat to numerous coral reef fishes. Native Caribbean seagrasses Syringodium filiforme and Thalassia testudinum provide several juvenile fish species with foraging habitat and protection during this vulnerable stage of life. In 2002, an invasive seagrass Halophila stipulacea was discovered off the coa...

This study provides some of the first evidence of how a common Caribbean fish species that relies on seagrass and sand habitats interacts with an invasive seagrass. The invasive seagrass Halophila stipulacea, first documented in the Caribbean in 2002, has rapidly expanded its range, displacing native seagrasses, and overgrowing bare sand. The south...

Designing place-based management for species that reproduce in transient fish spawning aggregations (FSAs) requires knowledge of movements and space use around aggregation sites. We examined the efficacy of the Mutton Snapper Seasonal Closed Area (MSSCA) in St. Croix, United States Virgin Islands, in protecting Lutjanus analis from fishing during t...

Because they serve as the main architects of coral reefs, the distribution and abundance of stony coral species have major impacts on other associated community members. Thus, coral diseases can have significant cascading effects throughout the ecosystem. Stony coral tissue loss disease (SCTLD) is the most recent of many diseases documented to impa...

Many commercially important groupers (Epinephelidae) form fish spawning aggregations (FSA) at specific sites where the spawning stock is concentrated to spawn within a couple of months each year. The concentrated nature and short duration of these FSAs render these species susceptible to fishing pressure leading to their disappearance or decrease i...

Nassau grouper (Epinephelus striatus, Serranidae) were one of the most important fishery species in the Caribbean, but are now listed as critically endangered. Population collapse in most places occurred primarily by fishers targeting their spawning aggregation sites, where thousands of fish gathered during full moon periods from December to April....

Over 200 species of reef fish around the world form spawning aggregations to reproduce at specific times and locations. The locations of many reef fish spawning aggregations in the Caribbean have been known and fished for decades. Red Hind (Epinephelus guttatus), a species of grouper important in Caribbean fisheries, migrate to form spawning aggreg...

Tracking studies for invasive lionfish ( Pterois volitans and P. miles ) in the Western Atlantic can provide key information on habitat use to inform population control, but to date have likely underestimated home range size and movement due to constrained spatial and temporal scales. We tracked 35 acoustically tagged lionfish for >1 yr (March 2018...

Abstract Background Atlantic tarpon (Megalops atlanticus) are a highly migratory species ranging along continental and insular coastlines of the Atlantic Ocean. Due to their importance to regional recreational and sport fisheries, research has been focused on large-scale movement patterns of reproductively active adults in areas where they are of h...

Background The movement ecology of mutton snapper Lutjanus analis is poorly understood despite their ecological and economic importance in the Caribbean. Passive acoustic telemetry was used to determine home ranges of six adult L. analis , including diel patterns, in Brewers Bay, St. Thomas, US Virgin Islands. Understanding long-term space use, inc...

Background: The movement ecology of mutton snapper Lutjanus analis is poorly understood despite their ecological and economic importance in the Caribbean. Passive acoustic telemetry was used to determine home ranges of six adult L. analis, including diel patterns, in Brewers Bay, St. Thomas, US Virgin Islands. Understanding long-term space use, inc...

A transfer learning approach is proposed to classify grouper species by their courtship-associated sounds produced during spawning aggregations. Vessel sounds are also included in order to potentially identify human interaction with spawning fish. Grouper sounds recorded during spawning aggregations were first converted to time-frequency representa...

Background Atlantic tarpon (Megalops atlanticus) are highly migratory species ranging along continental and insular coastlines of the Atlantic Ocean. Despite broad geographic distribution and importance as recreational fisheries, little is known about space-use patterns of tarpon within the Eastern Caribbean. Acoustic telemetry was used to track ta...

Background Atlantic tarpon (Megalops atlanticus) are a highly migratory species ranging along continental and insular coastlines of the Atlantic Ocean. Due to their importance to regional recreational and sport fisheries, research has been focused on large-scale movement patterns of reproductively active adults in areas where they are of high econo...

Passive acoustic monitoring (PAM) is a non‐invasive technique that uses hydrophones to monitor populations and ecosystem dynamics. Although many applications of PAM have been developed in recent years, it has never been used to identify a calling marine species. The south pass of Fakarava Atoll, French Polynesia, hosts spawning events of many reef...

Fish spawning aggregations (FSAs) consist of the temporary gathering of a large number of fishes at a specific location to spawn. Monitoring of FSA is typically conducted by divers, but surveys are often restricted to a limited area and dependent upon sea conditions, thus our knowledge of FSA dynamics is extremely limited. Fisheries independent res...

Extreme weather events (e.g., cyclones, floods, droughts) are capable of changing ecosystems and altering how animals obtain resources. Understanding the behavioural responses of animals being impacted by these natural events can help initiate and ameliorate conservation or management programs. This study investigated short- and long-term space-use...

In this paper, a method is introduced for the classification of call types of red hind grouper, an important fishery resource in the Caribbean that produces sounds associated with reproductive behaviors during yearly spawning aggregations. For the undertaken task, two distinct call types of red hind are analyzed. An ensemble of stacked autoencoders...

Mesophotic coral ecosystems (MCEs) at 30–100 m depth are the dominant hard bottom habitat in the US Virgin Islands of the northeastern Caribbean Sea. Well-developed MCEs surpass the extent of shallow coral reefs by almost a factor of three. These habitats range from high coral cover structural reefs to low coral cover hard bottoms on banks, slopes,...

Queen triggerfish Balistes vetula are an ecologically and economically important species associated with coral reefs throughout the tropical Atlantic Ocean. To better understand spatial and temporal movement patterns and help determine the effectiveness of a no-take marine reserve (Buck Island Reef National Monument, BIRNM), 55 queen triggerfish we...

Fisheries independent research strives for new technology that can help remotely and unobtrusively quantify fish biomass. Some large fish species, such as groupers vocalize during reproductive behaviors. Fish sounds provide an innovative approach to assess fish presence and numbers during reproductive events. However, large datasets make the detect...

Effective fisheries management requires a detailed understanding of the life history strategies of managed species. The Queen Triggerfish Balistes vetula supports productive fisheries in the western Atlantic, including the U.S. Caribbean. We utilized a combination of fishery-dependent and fishery-independent samples to assess the size structure, se...

The reproductive characteristics, movement patterns and courtship behaviors associated with a yellowfin grouper ( Mycteroperca venenosa, Linnaeus, 1758) fish spawning aggregation (FSA) were assessed between 2004 and 2014. The FSA was located on the Grammanik Bank, a seasonally closed area on the edge of the Puerto Rico platform, south of St. Thomas...

Grouper spawning aggregations along deep reefs of the US Virgin Islands represent a large potential prey source for predators including sharks. To examine the relationship between grouper spawning aggregations and sharks, we tagged three species of groupers and three species of sharks with acoustic transmitters and monitored their movements over se...

Caribbean seagrass habitats provide food and protection for reef-associated juvenile fish. The invasive seagrass Halophila stipulacea is rapidly altering these seascapes. Since its arrival in the Caribbean in 2002, H. stipulacea has colonized and displaced native seagrasses, but the function of this invasive seagrass as a juvenile fish habitat rema...

H. stipulacea patch and nearby coral reef in perseverance bay, St. Thomas (Photo credit: L. K. Olinger). (TIF)

Understanding passive acoustic telemetry equipment limitations is critical for correctly interpreting movements of aquatic animals. Range test studies have been performed to determine what environmental factors may interfere with acoustic equipment efficiency. Many of these studies have been performed on shallow coral reef environments for a few da...

The United States Virgin Islands are comprised of two separate insular platforms separated by the deep water Anegada Passage. Although managed by the same regulations, as one fishery, several physical and spatial differences exist between the two northern shelf islands, St. Thomas and St. John, and isolated St. Croix. Based on two long-term fisheri...

Coral reef monitoring in the united states virgin islands. Includes reef visual census for fish and Diadema antillarum, benthic cover, coral health, and benthic temperature

Spawning aggregations of reef fish tend to be predictable in time and space. The extent of movement, residence time and seasonality of the aggregation can be difficult to determine, but are important for effective management. We utilized acoustic transmitters and a receiver array to track dog snapper Lutjanus jocu and Cubera snapper Lutjanus cyanop...

Understanding of species interactions within mesophotic coral ecosystems (MCEs; ~ 30–150 m) lags well behind that for shallow coral reefs. MCEs are often sites of fish spawning aggregations (FSAs) for a variety of species, including many groupers. Such reproductive fish aggregations represent temporal concentrations of potential prey that may be dr...

Deeper coral reefs experience reduced temperatures and light and are often shielded from localized anthropogenic stressors such as pollution and fishing. The deep reef refugia hypothesis posits that light-dependent stony coral species at deeper depths are buffered from thermal stress and will avoid bleaching-related mass mortalities caused by incre...

The Nassau grouper (Epinephelus striatus) has sustained large declines across its distribution, including extirpation of many of its fish spawning aggregations (FSAs). Within US Virgin Islands (USVI) waters, Nassau grouper FSAs were overfished until their disappearance in the 1970s and 1980s. In the early 2000s, however, Nassau grouper were found g...

Marine ecosystem management has traditionally been divided between fisheries management and biodiversity conservation approaches, and the merging of these disparate agendas has proven difficult. Here, we offer a pathway that can unite fishers, scientists, resource managers and conservationists towards a single vision for some areas of the ocean whe...

http://onlinelibrary.wiley.com/doi/10.1111/faf.12132/abstract

Regional abundances of Nassau grouper Epinephelus striatus and yellowfin grouper Mycteroperca venenosa have declined due to overfishing of their spawning aggregations, prompting permanent and seasonal fisheries closures in the US Virgin Islands (USVI). As both species produce sounds associated with reproductive behaviors (courtship-associated sound...

Many coral reef fish species that have long been important for food and livelihoods reproduce by gathering in large, concentrated and predictable spawning aggregations. Particularly over the last two decades, these have become the target of expanding fishing pressure. Yet we are only recently beginning to understand their value to coral reef health...

The marine managed areas (MMAs) of the U.S. Caribbean are summarized and specific data-rich cases are examined to determine their impact upon fisheries management in the region. In this region, the productivity and connectivity of benthic habitats such as mangroves, seagrass and coral reefs is essential for many species targeted by fisheries. A min...

Long-term and short-term underwater visual censuses using SCUBA, technical Nitrox, and closed circuit rebreathers (CCR) were carried out in Pohnpei, Micronesia, to define spatial and temporal dynamics within a semi-protected multi-species epinephelid (fish) spawning aggregation (FSA) of brown-marbled grouper, Epinephelus fuscoguttatus, camouflage g...

To address patterns of genetic connectivity in a mass-aggregating marine fish, we analyzed genetic variation in mitochondrial DNA (mtDNA), microsatellites, and single nucleotide polymorphisms (SNPs) for Nassau grouper (Epinephelus striatus). We expected Nassau grouper to exhibit genetic differentiation among its subpopulations due to its reproducti...

Coral reefs and associated fish populations have experienced rapid decline in the Caribbean region and marine protected areas (MPAs) have been widely implemented to address this decline. The performance of no-take MPAs (i.e., marine reserves) for protecting and rebuilding fish populations is influenced by the movement of animals within and across t...

Tiger sharks (Galeocerdo cuvier) are a wide ranging, potentially keystone predator species that display a variety of horizontal movement patterns, making use of coastal and pelagic waters. Far less, however, is known about their vertical movements and use of the water column. We used pop-up satellite archival tags with two data sampling rates (high...

Background / Purpose: Here we aimed to discover:Acoustic telemetry of reef fishes to examine spatial scale of movements.Connectivity across a Caribbean marine protected areas (MPA) network.The size of marine protected areas in the eastern Caribbean. Main conclusion: We found that:Many fishes are capable of moving beyond the boundaries of marin...

Species-specific responses to disturbance are a central consideration for predicting the composition, dynamics, and function of future communities. These responses may be predictable based on species traits that can be analyzed systematically to understand those characteristics important in determining susceptibility and potential for recovery. Scl...

Reef fish spawning aggregations are important life history events that occur at specific times and locations and represent the primary mode of reproduction for many species. This paper provides detailed descriptions of aggregation formation and mass spawning of the Bermuda chub (Kyphosus sectatrix). Spawning coloration and gamete release of K. sect...

The benthic communities of the deep insular shelf at the Hind Bank marine conservation district (MCD), an important spawning aggregation site for groupers, were studied with the Seabed autonomous underwater vehicle (AUV) at depths between 32 and 54 m. Four digital phototransects provided data on benthic species composition and abundance of the insu...

Transient fish spawning aggregations (tFSas) are critical life-history phenomena where fish migrate to specific locations at predictable times of year to reproduce en masse. In the wider Caribbean region, 37 species of fish from 10 families are now known to form tFSas. although tFSas likely occur at times and in places that maximize reproductive su...

Thirty-six microsatellite markers were isolated from an enriched genomic library of tiger grouper (Mycteroperca tigris) and characterized in 20 individuals each for yellowfin grouper (Mycteroperca venenosa), coney (Cephalopholis fulva), and red hind (Epinephelus guttatus). The microsatellites include 23 dinucleotide repeats, twelve trinucleotide re...

The Nassau grouper (Epinephelus striatus), a severely overexploited and endangered coral reef fish in the Western Atlantic, is in urgent need of conservation and management measures. We report the development and characterization of 15 polymorphic, mostly tetranucleotide microsatellite loci based on 40 Nassau grouper samples collected from two Cari...

The brown-marbled grouper, Epinephelus fuscoguttatus, is a long-lived, late-maturing protogynous species listed as Near Threatened by the IUCN. In Pohnpei, Micronesia, reproductively active brown-marbled grouper were tagged with acoustic and spaghetti-type tags at a multi-species fish spawning aggregation (FSA) site to establish patterns of movemen...

A wide diversity of species form spawning aggregations and migrate from home ranges or feeding sites to specific locations for reproduction. Because most of these species comprise large carnivorous and numerous herbivorous fishes, they play a vital role in ecosystem function and fisheries economics. Nested within the functional migration area may b...

As a result of high levels of historical commercial and recreational fishing, the Nassau grouper (Epinephelus striatus) has sustained widespread declines across its geographic distribution. Within US Virgin Islands waters, recognized spawning aggregations have declined to low levels; however, a remnant spawning aggregation historically numbering ov...

This study characterizes the flow field at a spawning site located at the shelf break of a Caribbean island for the Epinephelus guttatus (red hind grouper) in relation to this species spawning events. In order to understand the oceanographic dynamics targeted by the fishes, current measurements were profiled throughout the water column for almost a...

Many common fishes associated with Caribbean coral reef ecosystems use resources from more than 1 patch type during routine daily foraging activities. Few studies have provided direct evidence of connectivity across seascapes, and the importance of benthic seascape structure on movement behavior is poorly known. To address this knowledge gap, we co...

Twenty-seven nuclear-encoded microsatellites were isolated from an enriched genomic library of yellowfin grouper, Mycteroperca venenosa, and characterized in 24 individuals. The microsatellites include 17 dinucleotide repeats, eight trinucleotide repeats (one imperfect), one tetranucleotide repeat, and one pentanucleotide repeat. Yellowfin grouper...

This study characterizes the flow field at a spawning site located at the shelf break of a Caribbean island for the Epinephelus guttatus (red hind grouper) in relation to this species spawning events. In order to understand the oceanographic dynamics targeted by the fishes, current measurements were profiled throughout the water column for almost a...

Many common fishes associated with Caribbean coral reef ecosystems use resources from more than 1 patch type during routine daily foraging activities. Few studies have provided direct evidence of connectivity across seascapes, and the importance of benthic seascape structure on movement behavior is poorly known. To address this knowledge gap, we co...

he temporal, spatial and behavioral dynamics of a spawning aggregation of yellowfin grouper were examined using underwater visual surveys, histological analysis, and hydro-acoustic tracking. Yellowfin grouper aggregated to spawn on the Grammanik Bank, a shelf-edge coral reef, during two or three consecutive months from February through April each y...

EXTENDED ABSTRACT The Nassau grouper (Epinephelus striatus) is an important component of the reef community found throughout the western Atlantic and Caribbean (Sadovy and Eklund 1999). Once abundant, overfishing during the 1960s and 70s caused a region wide fisheries collapse (Olsen and LaPlace 1978, Sadovy and Eklund 1999, Ehrhardt and Deleveaux...

Coral reef banks may form an important component of mesophotic coral ecosystems (MCEs) in the Caribbean, but remain poorly explored relative to shallower reefs and mesophotic habitats on slopes and walls. Consequently, the processes structuring mesophotic coral reef communities are not well understood, particularly the role of disturbance. A large...

Spawning migrations are an important life-history event for many species of commercially important tropical reef fishes and decapod crustaceans. Spawning aggregations are highly predictable events in which hundreds to thousands of individuals migrate across multiple habitats to converge on specific sites for reproduction. Species that undergo spawn...

Although little fisheries data exist for red hind, Epinephelus guttatus (Linnaeus, 1758) on the Saba Bank, Netherlands Antilles, spawning aggregation characteristics from other populations can be used to assess the health of a red hind spawning population previously undocumented there. In December 2005, a spawning aggregation site for red hind was...

Both the number of coral diseases and the intensity of their outbreaks have increased in recent years. Little is known however why certain species are more susceptible to disease. This study examines coral disease prevalence and species susceptibility to disease using data collected over a four year period at 25 sites in the U.S. Virgin Islands. Tw...

Managing the effects of anthropogenic disturbance on coral reefs is highly dependant on effective strategies to assess degradation and recovery. We used five years of field data in the US Virgin Islands to investigate coral reef response to a potential gradient of stress. We found that the prevalence of old partial mortality, bleaching, and all for...

Tropical marine habitats are often energetically linked through feeding migrations by fish. A widely accepted assumption is that species of Haemulidae (grunts) undertake nocturnal feeding migrations from coral reefs to seagrass beds. This has been based on studies investigating migrations between small patch reefs and surrounding seagrass beds loca...

Both the number of coral diseases and the intensity of their outbreaks have increased in recent years. Little is known however why certain species are more susceptible to disease. This study examines coral disease prevalence and species susceptibility to disease using data collected over a four year period at 25 sites in the U.S. Virgin Islands. Tw...

Recent, global mass-mortalities of reef corals due to record warm sea temperatures have led researchers to consider global warming as one of the most significant threats to the persistence of coral reef ecosystems. The passage of a hurricane can alleviate thermal stress on coral reefs, highlighting the potential for hurricane-associated cooling to...

This study compared the spatial and temporal patterns of red hind, Epinephelus guttatus, movement and migration from annual spawning aggregations on St Thomas (STT) and St Croix (STX), United States Virgin Islands. Around STT E. guttatus migrated 6–33km from a functional spawning migration area of 500km2 and around STX E. guttatus migrated 5–18km f...

The Grammanik bank is a deep reef (35-40 m) located approximately 14 km south of St. Thomas USVI, on the southern edge of the Puerto Rico shelf. The relatively narrow 1.5 km long reef annually hosts spawning aggregations of several species of groupers, snappers and jacks. Until February of 2005, when tempo- rary seasonal protection was offered by t...