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Sarah Frias-Torres
  • Smithsonian Marine Station
    701 Seaway Drive
    Fort Pierce, Florida 34949

Sarah Frias-Torres

  • Dr. Sarah Frias-Torres is a broadly trained, fieldwork oriented marine ecologist and biological oceanographer. Her re... moreedit
This chapter discusses methodology and techniques for conducting larval studies of Syngnathidae, including the handling of specimens, throughout the world, with emphasis on Western Central North Atlantic species. Summary from the... more
This chapter discusses methodology and techniques for conducting larval studies of Syngnathidae, including the handling of specimens, throughout the world, with emphasis on Western Central North Atlantic species.

Summary from the 2-Volume Book:
The Early Life History (ELH) of marine fishes in Fishing Area 31, which includes the western central North Atlantic, Caribbean Sea and the Gulf of Mexico, has remained somewhat incomplete over the years. This certainly was not because of any lack of interest, but rather because of the lack of a comprehensive merging of studies that would provide us with a broad understanding, as well as identify any gaps in the literature.

Early Stages of Atlantic Fishes: An Identification Guide for the Western Central North Atlantic fills the void in an exceptionally thorough fashion. Coordinated by William Richards, one of the United States' most respected fishery scientists, this two-volume set is the definitive reference covering the ELH of those fishes found in that part of the Atlantic stretching from North Carolina to the equator, across the territorial waters of at least 40 countries. With contributions from more than 70 international experts, it should be of great interest to fishery scientists, marine biologists, oceanographers, and ecologists.

Over 2600 pages, this two-volume masterwork covers the eggs, larvae, and juveniles of all families known to inhabit this area. It brings together all of the published information of merit plus original research results, providing information designed to identify these ELH stages generally collected by plankton nets. Chapters in the volume are devoted to each of the 214 families. All of them include a brief synopsis of the family, early life-stage identification, meristic data tables, and significant accounts of lower taxa, with one page giving detailed information and the facing page devoted to illustrations.
This chapter discusses methodology and techniques for conducting larval studies of Melampahidae, including the handling of specimens, throughout the world, with emphasis on Western Central North Atlantic species. Summary from the... more
This chapter discusses methodology and techniques for conducting larval studies of Melampahidae, including the handling of specimens, throughout the world, with emphasis on Western Central North Atlantic species.

Summary from the 2-Volume Book:
The Early Life History (ELH) of marine fishes in Fishing Area 31, which includes the western central North Atlantic, Caribbean Sea and the Gulf of Mexico, has remained somewhat incomplete over the years. This certainly was not because of any lack of interest, but rather because of the lack of a comprehensive merging of studies that would provide us with a broad understanding, as well as identify any gaps in the literature.

Early Stages of Atlantic Fishes: An Identification Guide for the Western Central North Atlantic fills the void in an exceptionally thorough fashion. Coordinated by William Richards, one of the United States' most respected fishery scientists, this two-volume set is the definitive reference covering the ELH of those fishes found in that part of the Atlantic stretching from North Carolina to the equator, across the territorial waters of at least 40 countries. With contributions from more than 70 international experts, it should be of great interest to fishery scientists, marine biologists, oceanographers, and ecologists.

Over 2600 pages, this two-volume masterwork covers the eggs, larvae, and juveniles of all families known to inhabit this area. It brings together all of the published information of merit plus original research results, providing information designed to identify these ELH stages generally collected by plankton nets. Chapters in the volume are devoted to each of the 214 families. All of them include a brief synopsis of the family, early life-stage identification, meristic data tables, and significant accounts of lower taxa, with one page giving detailed information and the facing page devoted to illustrations.
Coral reef restoration is a subfield within the larger scientific discipline of ecological restoration (also known as restoration ecology). Ecological restoration is the process of assisting the recovery of an ecosystem that has been... more
Coral reef restoration is a subfield within the larger scientific discipline of ecological restoration (also known as restoration ecology). Ecological restoration is the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed (SER, 2018).Coral reef restoration must follow the four basic principles of planning and implementation of ecological restoration in order to increase sustainable and valuable outcomes (Suding et al. 2015):1. Restoration increases ecological integrity. Restoration initiates or accelerates recovery of degraded areas by prioritizing the complexity of biological assemblages, including species composition and representation of all functional groups, as well as the features and processes needed to sustain these biota and to support ecosystem function;2. Restoration is sustainable in the long term. Restoration aims to establish systems that are self-sustaining and resilient; thus, they must be consistent with their environmenta...
Most large pelagic fish have a migratory life history. Such nomadic lifestyle makes conservation efforts challenging, in part because international collaboration is needed to protect these species.
Rearing coral fragments in nurseries and subsequent transplantation onto a degraded reef is a common approach for coral reef restoration. However, if barnacles and other biofouling organisms are not removed prior to transplantation, fish... more
Rearing coral fragments in nurseries and subsequent transplantation onto a degraded reef is a common approach for coral reef restoration. However, if barnacles and other biofouling organisms are not removed prior to transplantation, fish will dislodge newly cemented corals when feeding on biofouling organisms. This behavior can lead to an increase in diver time due to the need to reattach the corals. Thus, cleaning nurseries to remove biofouling organisms such as algae and invertebrates is necessary prior to transplantation, and this cleaning constitutes a significant time investment in a restoration project. We tested a novel biomimicry technique of animal-assisted cleaning on nursery corals prior to transplantation at a coral reef restoration site in Seychelles, Indian Ocean. To determine whether animal-assisted cleaning was possible, preliminary visual underwater surveys were performed to quantify the fish community at the study site. Then, cleaning stations consisting of nursery...
In coral reef restoration, coral gardening involves rearing coral fragments in underwater nurseries prior to transplantation. These nurseries become fish-aggregating devices and attract biofouling. We hypothesised that: (1) the presence... more
In coral reef restoration, coral gardening involves rearing coral fragments in underwater nurseries prior to transplantation. These nurseries become fish-aggregating devices and attract biofouling. We hypothesised that: (1) the presence of corals at a nursery is critical to recruit fish assemblages and (2) the recruited fish assemblages control biofouling, reducing person-hours invested in nursery cleaning. Three midwater coral nurseries were deployed at 8 m depth for 27 months within the marine protected area of Cousin Island Special Reserve, Seychelles, Indian Ocean. Each nursery consisted of a 6 m×6 m PVC pipe frame, layered with a recycled 5.5-cm-mesh tuna net. Human cleaning effort was calculated based on daily dive logs. Nursery-associated fish assemblages and behaviour were video-recorded prior to harvesting corals after a 20-month growth period and seven months post-coral harvesting. The density (ind. m–2) of blue-yellow damselfish Pomacentrus caeruleus was 12–16 times higher when corals were present than when corals were absent at the nurseries. Fish assemblages recruited into the nurseries included three trophic levels, from herbivores to omnivores, in six families: Ephippidae, Pomacentridae, Labridae (Scarinae), Gobiidae, Siganidae and Monacanthidae. Higher abundance of large fish (total number of individuals) resulted in 2.75 times less person-hours spent in nursery cleaning. These results have important implications for cost-effective coral reef restoration.
"Book Chapter; In: William L. Kruczynski & Pamela J. Fletcher (Eds). South Florida Marine Environments: An Ecological Synthesis. University of Florida. [In Review] "
"This chapter discusses methodology and techniques for conducting larval studies of Melampahidae, including the handling of specimens, throughout the world, with emphasis on Western Central North Atlantic species. Summary from the... more
"This chapter discusses methodology and techniques for conducting larval studies of Melampahidae, including the handling of specimens, throughout the world, with emphasis on Western Central North Atlantic species. Summary from the 2-Volume Book: The Early Life History (ELH) of marine fishes in Fishing Area 31, which includes the western central North Atlantic, Caribbean Sea and the Gulf of Mexico, has remained somewhat incomplete over the years. This certainly was not because of any lack of interest, but rather because of the lack of a comprehensive merging of studies that would provide us with a broad understanding, as well as identify any gaps in the literature. Early Stages of Atlantic Fishes: An Identification Guide for the Western Central North Atlantic fills the void in an exceptionally thorough fashion. Coordinated by William Richards, one of the United States' most respected fishery scientists, this two-volume set is the definitive reference covering the ELH of those fishes found in that part of the Atlantic stretching from North Carolina to the equator, across the territorial waters of at least 40 countries. With contributions from more than 70 international experts, it should be of great interest to fishery scientists, marine biologists, oceanographers, and ecologists. Over 2600 pages, this two-volume masterwork covers the eggs, larvae, and juveniles of all families known to inhabit this area. It brings together all of the published information of merit plus original research results, providing information designed to identify these ELH stages generally collected by plankton nets. Chapters in the volume are devoted to each of the 214 families. All of them include a brief synopsis of the family, early life-stage identification, meristic data tables, and significant accounts of lower taxa, with one page giving detailed information and the facing page devoted to illustrations. "
Research Interests:
"This chapter discusses methodology and techniques for conducting larval studies of Syngnathidae, including the handling of specimens, throughout the world, with emphasis on Western Central North Atlantic species. Summary from the... more
"This chapter discusses methodology and techniques for conducting larval studies of Syngnathidae, including the handling of specimens, throughout the world, with emphasis on Western Central North Atlantic species. Summary from the 2-Volume Book: The Early Life History (ELH) of marine fishes in Fishing Area 31, which includes the western central North Atlantic, Caribbean Sea and the Gulf of Mexico, has remained somewhat incomplete over the years. This certainly was not because of any lack of interest, but rather because of the lack of a comprehensive merging of studies that would provide us with a broad understanding, as well as identify any gaps in the literature. Early Stages of Atlantic Fishes: An Identification Guide for the Western Central North Atlantic fills the void in an exceptionally thorough fashion. Coordinated by William Richards, one of the United States' most respected fishery scientists, this two-volume set is the definitive reference covering the ELH of those fishes found in that part of the Atlantic stretching from North Carolina to the equator, across the territorial waters of at least 40 countries. With contributions from more than 70 international experts, it should be of great interest to fishery scientists, marine biologists, oceanographers, and ecologists. Over 2600 pages, this two-volume masterwork covers the eggs, larvae, and juveniles of all families known to inhabit this area. It brings together all of the published information of merit plus original research results, providing information designed to identify these ELH stages generally collected by plankton nets. Chapters in the volume are devoted to each of the 214 families. All of them include a brief synopsis of the family, early life-stage identification, meristic data tables, and significant accounts of lower taxa, with one page giving detailed information and the facing page devoted to illustrations."
Research Interests:
Biogeographical analyses provide insights on how the Deepwater Horizon oil spill impacted large pelagic fishes. We georeferenced historical ichthyoplankton surveys and published literature to map the spawning and larval areas of bluefin... more
Biogeographical analyses provide insights on how the Deepwater Horizon oil spill impacted large pelagic fishes. We georeferenced historical ichthyoplankton surveys and published literature to map the spawning and larval areas of bluefin tuna, swordfish, blue marlin and whale shark sightings in the Gulf of Mexico with daily satellite-derived images detecting surface oil. The oil spill covered critical areas used by
Additional Information and Declarations can be found on page 11
"The goliath grouper (jewfish) , Epinephelus itajara, is found in tropical and subtropical waters of eastern and western Altantic ocean. The species—listed as critically endangered by the World Conservation Union has... more
"The goliath grouper (jewfish) , Epinephelus itajara, is found in tropical and subtropical waters of eastern and western Altantic ocean. The species—listed as critically endangered by the World Conservation Union has been protected through a total fishing ban in U.S. federal and state waters since 1990 and in puerto Rico and U.S. virgin Islands waters since 2004. As one of the few grouper species that shows a high affinity for mangrove-dominated areas, E. itajara typically spends its first 5–8 yrs in that nearshore habitat before migrating to adult habitats (i.e., coral reefs, rock ledges, isolated patch reefs, and artificial structures) . To date, knowledge of the movement of goliath grouper juveniles within their mangrove nursery areas is based mainly on conventional tagging studies, which provide limited insight into the fine-scale activity patterns. In the present study, we used electronic acoustic tags and stationary hydrophone receiver stations to examine the activity patterns of three tagged juveniles inhabiting the fringing red mangrove shorelines of Ten Thousand Islands, southwest Florida, U.S.A. Our primary objective was to examine the extent to which juvenile activity was associated with time of day and tidal stage. To test our ability to detect movement at fine timescales over periods of weeks to months, as well as cues for fish movement, we examined the relationship between fish presence- absence, tidal cycle, and time of day in juvenile goliath grouper. Our results provide insight into multiple habitat use by this species and are important to consider when designing and implementing population abundance surveys. "
The goliath grouper, Epinephelus itajara, is the largest grouper in the Atlantic Ocean, exceeding 2 m in total length and 400 kg. Juveniles (< 1 m TL) inhabit fringing red mangrove (Rhizophora mangle) shorelines, whereas adults inhabit... more
The goliath grouper, Epinephelus itajara, is the largest grouper in the Atlantic Ocean, exceeding 2 m in total length and 400 kg. Juveniles (< 1 m TL) inhabit fringing red mangrove (Rhizophora mangle) shorelines, whereas adults inhabit coral reefs, patch reefs, reef ledges, and artificial reefs. After reaching commercial extinction in the late 1980s, the species has been protected in U.S. state and federal waters since 1990. Underwater visual census to study distribution and abundance of juveniles are critical to evaluate population recovery and essential fish habitat but are often limited due to low visibility in mangrove shorelines. Here we present a new type of juvenile goliath grouper surveys using high-resolution dual-frequency sonar (DIDSON). DIDSON technology uses multiple narrow hydroacoustic beams (96 at 1.8 MHz and 48 at 1.0 MHz) to produce high-resolution, near-field image streams similar to that of a black-and-white video camera. It can record the shape and size of ta...
Coral reefs worldwide are degrading due to climate change, overfishing, pollution, coastal development, bleaching and diseases. In areas where natural recovery is negligible or protection through management interventions insufficient,... more
Coral reefs worldwide are degrading due to climate change, overfishing, pollution, coastal development, bleaching and diseases. In areas where natural recovery is negligible or protection through management interventions insufficient, active restoration becomes critical. The Reef Futures symposium in 2018 brought together over 400 reef restoration experts, businesses, and civil organizations, and galvanized them to save coral reefs through restoration or identify alternative solutions. The symposium highlighted that solutions and discoveries from long-term and ongoing coral reef restoration projects in Spanish-speaking countries in the Caribbean and Eastern Tropical Pacific were not well known internationally. Therefore, a meeting of scientists and practitioners working in these locations was held to compile the data on the extent of coral reef restoration efforts, advances and challenges. Here, we present unpublished data from 12 coral reef restoration case studies from five Latin ...
Corals from the northern Red Sea, in particular the Gulf of Aqaba (GoA), have exceptionally high bleaching thresholds approaching >5℃ above their maximum monthly mean (MMM) temperatures. These elevated thresholds are thought to be due... more
Corals from the northern Red Sea, in particular the Gulf of Aqaba (GoA), have exceptionally high bleaching thresholds approaching >5℃ above their maximum monthly mean (MMM) temperatures. These elevated thresholds are thought to be due to historical selection, as corals passed through the warmer Southern Red Sea during recolonization from the Arabian Sea. To test this hypothesis, we determined thermal tolerance thresholds of GoA versus central Red Sea (CRS) Stylophora pistillata corals using multi‐temperature acute thermal stress assays to determine thermal thresholds. Relative thermal thresholds of GoA and CRS corals were indeed similar and exceptionally high (~7℃ above MMM). However, absolute thermal thresholds of CRS corals were on average 3℃ above those of GoA corals. To explore the molecular underpinnings, we determined gene expression and microbiome response of the coral holobiont. Transcriptomic responses differed markedly, with a strong response to the thermal stress in GoA corals and their symbiotic algae versus a remarkably muted response in CRS colonies. Concomitant to this, coral and algal genes showed temperature‐induced expression in GoA corals, while exhibiting fixed high expression (front‐loading) in CRS corals. Bacterial community composition of GoA corals changed dramatically under heat stress, whereas CRS corals displayed stable assemblages. We interpret the response of GoA corals as that of a resilient population approaching a tipping point in contrast to a pattern of consistently elevated thermal resistance in CRS corals that cannot further attune. Such response differences suggest distinct thermal tolerance mechanisms that may affect the response of coral populations to ocean warming.
Biogeographical analyses provide insights on how the Deepwater Horizon oil spill impacted large pelagic fishes. We georeferenced historical ichthyoplankton surveys and published literature to map the spawning and larval areas of bluefin... more
Biogeographical analyses provide insights on how the Deepwater Horizon oil spill impacted large pelagic fishes. We georeferenced historical ichthyoplankton surveys and published literature to map the spawning and larval areas of bluefin tuna, swordfish, blue marlin and whale shark sightings in the Gulf of Mexico with daily satellite-derived images detecting surface oil. The oil spill covered critical areas used by
In coral reef restoration, coral gardening involves rearing coral fragments in underwater nurseries prior to transplantation. These nurseries become fish-aggregating devices and attract biofouling. We hypothesised that: (1) the presence... more
In coral reef restoration, coral gardening involves rearing coral fragments in underwater nurseries prior to
transplantation. These nurseries become fish-aggregating devices and attract biofouling. We hypothesised
that: (1) the presence of corals at a nursery is critical to recruit fish assemblages and (2) the recruited fish
assemblages control biofouling, reducing person-hours invested in nursery cleaning. Three midwater coral
nurseries were deployed at 8 m depth for 27 months within the marine protected area of Cousin Island Special
Reserve, Seychelles, Indian Ocean. Each nursery consisted of a 6 m × 6 m PVC pipe frame, layered with a recycled
5.5-cm-mesh tuna net. Human cleaning effort was calculated based on daily dive logs. Nursery-associated fish
assemblages and behaviour were video-recorded prior to harvesting corals after a 20-month growth period and
seven months post-coral harvesting. The density (ind. m–2) of blue-yellow damselfish Pomacentrus caeruleus was
12–16 times higher when corals were present than when corals were absent at the nurseries. Fish assemblages
recruited into the nurseries included three trophic levels, from herbivores to omnivores, in six families: Ephippidae,
Pomacentridae, Labridae (Scarinae), Gobiidae, Siganidae and Monacanthidae. Higher abundance of large fish (total
number of individuals) resulted in 2.75 times less person-hours spent in nursery cleaning. These results have
important implications for cost-effective coral reef restoration.
Research Interests:
Rearing coral fragments in nurseries and subsequent transplantation onto a degraded reef is a common approach for coral reef restoration. However, if barnacles and other biofouling organisms are not removed prior to transplantation, fish... more
Rearing coral fragments in nurseries and subsequent transplantation onto a degraded reef is a common approach for coral reef restoration. However, if barnacles and other biofouling organisms are not removed prior to transplantation, fish will dislodge newly cemented corals when feeding on biofouling organisms. This behavior can lead to an increase in diver time due to the need to reattach the corals. Thus, cleaning nurseries to remove biofouling organisms such as algae and invertebrates is necessary prior to transplantation, and this cleaning constitutes a significant time investment in a restoration project. We tested a novel biomimicry technique of animal-assisted cleaning on nursery corals prior to transplantation at a coral reef restoration site in Seychelles, Indian Ocean. To determine whether animal-assisted cleaning was possible, preliminary visual underwater surveys were performed to quantify the fish community at the study site. Then, cleaning stations consisting of nursery ropes carrying corals and biofouling organisms, set at 0.3 m, 2 m, 4 m, 6 m and 8 m from the seabed, were placed at both the transplantation (treatment) site and the nursery (control) site. Remote GoPro video cameras recorded fish feeding at the nursery ropes without human disturbance. A reef fish assemblage of 32 species from 4 trophic levels (18.8% herbivores, 18.8% omnivores, 59.3% secondary consumers and 3.1% carnivores) consumed 95% of the barnacles on the coral nursery ropes placed 0.3 m above the seabed. Using this cleaning station, we reduced coral dislodgement from 16% to zero. This cleaning station technique could be included as a step prior to coral transplantation worldwide on the basis of location-specific fish assemblages and during the early nursery phase of sexually produced juvenile corals.
Research Interests:
Research Interests:
Biogeographical analyses provide insights on how the Deepwater Horizon oil spill impacted large pelagic fishes. We georeferenced historical ichthyoplankton surveys and published literature to map the spawning and larval areas of bluefin... more
Biogeographical analyses provide insights on how the Deepwater Horizon oil spill impacted large pelagic fishes. We
georeferenced historical ichthyoplankton surveys and published literature to map the spawning and larval areas of
bluefin tuna, swordfish, blue marlin and whale shark sightings in the Gulf of Mexico with daily satellite-derived images
detecting surface oil. The oil spill covered critical areas used by large pelagic fishes. Surface oil was detected in 100% of
the northernmost whale shark sightings, in 32.8 % of the bluefin tuna spawning area and 38 % of the blue marlin larval
area. No surface oil was detected in the swordfish spawning and larval area. Our study likely underestimates the extend
of the oil spill due to satellite sensors detecting only the upper euphotic zone and the use of dispersants altering crude oil
density, but provides a previously unknown spatio-temporal analysis.
The Goliath Grouper (Epinephelus Itajara) is the largest of the western north Atlantic Groupers, reaching up to 450kg and over 2 meters in length. Distinguished by their short dorsal spines and broad head, they are extremely vulnerable... more
The Goliath Grouper (Epinephelus Itajara) is the largest of the western north Atlantic Groupers, reaching up to 450kg and over 2 meters in length.  Distinguished by their short dorsal spines and broad head, they are extremely vulnerable due to a combination of life history traits such as slow growth, long life (over four decades) and late sexual maturity. The population of the species declined due to both recreational and commercial fishing, which subsequently led to extinction in many places.  However since a hunting ban was introduced in 1990, the species is now fully protected and numbers are recovering in the Florida area.
The Goliath grouper Epinephelus itajara has been protected in the USA since 1990. In Florida commercial and recreational fishers consider the species a top predator of fish and lobster and advocate culling the grouper population as a... more
The Goliath grouper Epinephelus itajara has been
protected in the USA since 1990. In Florida commercial
and recreational fishers consider the species a top predator
of fish and lobster and advocate culling the grouper
population as a solution to recover declining stocks.
I examined the scientific evidence for and against culling
the Goliath grouper, using commercial landing data from
the National Marine Fisheries Service and the Florida
Fish and Wildlife Conservation Commission (1950–2010),
fisheries-independent diver-based surveys from the REEF
Environmental Education Foundation (1993–2007), and
published dietary and morphological studies. An analysis of
the commercial extinction of the Goliath grouper in Florida
indicates that its recovering population is not the cause of
declining fish and lobster stocks. The recovering Goliath
grouper population could provide ecological and socioeconomic
benefits: as top-down control on other lobster
predators, in ecotourism, and as potential biocontrol of the
invasive Indo-Pacific red lionfish Pterois volitans on Atlantic
reefs
An interview about the historical marine megafauna in Florida and the goliath groupers.
Book Chapter; In: William L. Kruczynski & Pamela J. Fletcher (Eds). South Florida Marine Environments: An Ecological Synthesis. University of Florida. [In Review]
This THEME SECTION of ESR, which contains 12 papers, focuses on the Range-wide status of the Goliath grouper. The goliath grouper Epinephelus itajara is one of the world’s largest and longest lived epinephalids. Heavily targeted by... more
This THEME SECTION of ESR, which contains 12 papers,  focuses on the Range-wide status of the Goliath grouper. The goliath grouper Epinephelus itajara is one of the world’s largest and longest lived epinephalids. Heavily targeted by artisanal and recreational fisheries throughout its broad distributional range, the global declines in abundance and extirpation of goliath grouper spawning aggregations are of growing concern. Innovative research and management approaches coupled with international collaborative efforts are needed to address this pressing conservation problem.

This ESR THEME SECTION was catalyzed by a Symposium at the 60th Annual Conference of the Gulf and Caribbean Fisheries Institute (GCFI)  In preparation for the Symposium, I compiled an electronic library of all publications available to date on Goliath grouper, including peer-review papers, reports, thesis, and other gray literature. Such electronic library is known as the "Goliath Grouper Book of Knowledge" and was distributed among the participants of the GCFI Symposium.
We tested alternative methods to diver visual censuses of juvenile goliath grouper Epinephelus itajara in turbid mangrove habitat. We used a dual-frequency identification sonar (DIDSON) acoustic camera. DIDSON generates high resolution... more
We tested alternative methods to diver visual censuses of juvenile goliath grouper  Epinephelus itajara in turbid mangrove habitat. We used a dual-frequency identification sonar (DIDSON) acoustic camera. DIDSON generates high resolution images of fish with a high-frequency multibeam sonar. The system can record the shape, size and movement of fish under low visibility conditions. A paired DIDSON–digital underwater video camera system was used to survey the mangrove shorelines of Niles Channel, in the Lower Florida Keys, USA. In high visibility conditions, the specific E. itajara DIDSON acoustic signal was obtained and used to evaluate DIDSON’s performance for E. itajara surveys in turbid conditions. Under both clear and turbid conditions DIDSON enabled the quantification and measurement of juvenile E. itajara in mangrove undercuts and submerged
dead trees that were not visible or detected using video or by a diver. DIDSON could not detect immobile juveniles, as it was unable to discern them from the substrate or the underwater structures where they rested. We demonstrate that mangrove microhabitat underwater structures do not interfere with acoustic fish signals. This study represents the first known successful application of a DIDSON acoustic camera in mangrove shorelines to achieve juvenile E. itajara detection and sizing.
Currently, there is a conflict between the need to conserve protected fish species and the need to use lethal methods to collect essential biological data, such as age, to assess their population status and recovery trends. We evaluated... more
Currently, there is a conflict between the need to conserve protected fish species and the need to use lethal methods to collect essential biological data, such as age, to assess their population status and recovery trends. We evaluated the precision and accuracy of a non-lethal ageing method for goliath grouper Epinephelus itajara, listed as critically endangered on the IUCN Red List of Threatened Species. Paired finray and otolith samples (n = 21) were collected opportunistically from fish that had died primarily from red tide or hypothermal events in Florida coastal waters. Finray ageing proved relatively precise (coefficient of variation [CV] = 4.24%), although less so than otolith ageing (CV = 1.45%). Finray ages agreed with otolith ages the majority of the time (CV = 3.15% and concordance correlation coefficient = 0.991) for E. itajarafrom 0 to 18 yr of age. Based on a test of symmetry, finray ageing was also relatively unbiased for fish up to 18 yr of age. Further evaluation of any limitations of the method will depend on obtaining more samples, especially from larger, presumably older, fish. Clearly, the non-lethal finray ageing method can be used as an alternative to using otoliths for goliath grouper at least up to 18 yr of age. Finray ageing could significantly reduce the need to sacrifice protected E. itajarato assess their population recovery.
The goliath grouper (jewfish) , Epinephelus itajara, is found in tropical and subtropical waters of eastern and western Altantic ocean. The species—listed as critically endangered by the World Conservation Union has been protected... more
The goliath grouper (jewfish) , Epinephelus itajara, is found in tropical and subtropical waters of eastern and western Altantic ocean.  The species—listed as critically endangered by the World Conservation Union has been protected through a total fishing ban in U.S. federal and state waters since 1990  and in puerto Rico and U.S. virgin Islands waters since  2004. As one of the few grouper species that shows a high affinity for mangrove-dominated areas, E. itajara typically spends its first 5–8 yrs in that nearshore habitat before migrating to adult habitats (i.e., coral reefs, rock ledges, isolated patch reefs, and artificial structures) . To date, knowledge of the movement of goliath grouper juveniles within their mangrove
nursery areas is based mainly on conventional tagging studies, which provide  limited insight into the fine-scale activity patterns. In the present study, we used electronic acoustic tags and stationary hydrophone receiver stations to examine the activity patterns of three tagged juveniles inhabiting the fringing red mangrove shorelines of Ten Thousand Islands, southwest Florida, U.S.A.  Our primary objective was to examine the extent to which juvenile activity was associated with time of day and tidal stage. To test our ability to detect movement at fine timescales over periods of weeks to months, as well as cues for fish movement, we examined the relationship between fish presence- absence, tidal cycle, and time of day in juvenile goliath grouper. Our results provide insight into multiple habitat use by this species and are important to consider when designing and implementing population abundance surveys.
This study reports the distribution, abundance and habitat use of juvenile goliath grouper Epinephelus itajaraalong fringing red mangrove Rhizophora mangleshorelines of the Florida Keys, USA. The species has been protected from fishing in... more
This study reports the distribution, abundance and habitat use of juvenile goliath grouper Epinephelus itajaraalong fringing red mangrove Rhizophora mangleshorelines of the Florida Keys, USA. The species has been protected from fishing in US waters since 1992, after reaching commercial extinction, yet juvenile habitat use remains poorly studied. The aim of this study was to evaluate the importance of underwater mangrove habitat structure and complexity in determining distribution of juvenile goliath grouper in the Florida Keys. Visual underwater surveys were used to record juvenile presence, abundanceand size. Habitat characteristics as continuous variables (depth, canopy, overhang and prop root width) and nominal variables (bottom type, sun exposure, shoreline shape and shoreline type) were also recorded. Juveniles aggregated in sites with high structural complexity, soft sediment and eroded shorelines. Well developed fringing red mangrove shorelines were the preferred juvenile goliath grouper habitat.
Download full article here at Academia.edu
Migratory habits of large pelagic fish often limit conservation efforts.Identification of sensitive sites (feeding aggregations and spawning areas), is essential for effective conservation strategies. The location of whale shark sightings... more
Migratory habits of large pelagic fish often limit conservation efforts.Identification of sensitive sites (feeding aggregations and spawning areas), is essential for effective conservation strategies. The location of whale shark sightings and spawning areas for bluefin tuna, swordfish and blue marlin in the tropical western Atlantic obtained from the literature or from unpublished data were used to create a geographic information system (GIS). The location of existing marine protected areas and high priority conservation areas was also added to the GIS. Results show that whale shark sightings and spawning sites for bluefin tuna, swordfish and blue marlin in the tropical western Atlantic are very specific. This information may help in understanding the biology of the species essential in future conservation strategies.
Most large pelagic fish have a migratory life history. Such nomadic lifestyle makes conservation efforts challenging, in part because international collaboration is needed to protect these species.
Short Communication. Download article at Academia.edu
La Sarah Frias-Torres ha dirigit el programa de repoblació de coral més extens que mai s'ha fet als oceans. El projecte d'aquesta biòloga barcelonina s'ha dut a terme a les illes Seychelles i ha permès recuperar en dos anys un total de... more
La Sarah Frias-Torres ha dirigit el programa de repoblació de coral més extens que mai s'ha fet als oceans. El projecte d'aquesta biòloga barcelonina s'ha dut a terme a les illes Seychelles i ha permès recuperar en dos anys un total de 25.000 corals.
Research Interests:
Coral bleaching caused by unusually warm waters is becoming an increasing threat to productive and important coral reef ecosystems around the world, and is expected to get even worse as the climate warms. In an attempt to help these... more
Coral bleaching caused by unusually warm waters is becoming an increasing threat to productive and important coral reef ecosystems around the world, and is expected to get even worse as the climate warms. In an attempt to help these ecosystems recover, scientists are now experimenting with restoring devastated reefs by re-planting reefs, much the way we'd re-plant a clear-cut forest in Canada. In the Seychelles in the Indian Ocean, Dr. Sarah Frias-Torres, a marine ecologist, and Chief Scientist for the Reef Rescuers Program for the NGO Nature Seychelles, and a research associate with the Smithsonian Institution, and her colleagues, have been working on the biggest reef restoration project yet attempted. Their work involves large scale farming of heat-resistant coral "seedlings" and then transplanting them onto damaged reefs. And among their innovations is recruiting fish to "weed" their coral nurseries.
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Bien que les récifs coralliens occupent moins de 0.5 % du fond des océans, ils font vivre 25 % de toutes les espèces marines. «Longitude 181 Nature» veut mettre en évidence le travail d’un de ses Centres Ambassadeur. Praslin,... more
Bien que les récifs coralliens occupent moins de 0.5 % du fond
des océans, ils font vivre 25 % de toutes les espèces marines.
«Longitude 181 Nature» veut mettre en évidence le travail
d’un de ses Centres Ambassadeur. Praslin, Seychelles, isolée dans l’Océan Indien, chaque action  entreprise est plus compliquée, car il est difficile de trouver  les matériaux nécessaires, et délicat de mettre en place une  logistique pour mener à bien les projets. [...] Les solutions ont été trouvées…
Malgré le manque de moyens, le manque de main d’œuvre
ou de logistique, la passion, et l’enthousiasme de chacun ont su
surmonter des obstacles grace aux échanges d’informations, de
savoir faire entre l’équipe de «Nature Seychelles»
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Top scientists attempt to jump-start nature in the Seychelles by restoring its devastated coral reefs. CNN International in-depth reporting showcasing Dr. Sarah Frias-Torres research on large-scale coral reef restoration.
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