Herpes virus in juvenile Pacific oysters Crassostrea gigas from Tomales Bay, California, coincides with summer mortality episodes

Pacific Crassostrea gigas and eastern C. virginica oysters were examined between June 2002 and April 2003 from 8 locations along the east, west and south USA coasts for oyster herpes virus (OsHV) infections using the A primer set in a previously developed PCR test. Only surviving Pacific oysters from a mortality event in Tomales Bay, California, USA, where annual losses of oysters have occurred each summer since 1993, were infected with a herpes-like virus in 2002. PCR examination using template amounts of both 50 and 500 ng were essential for OsHV detection. Sequence analysis indicated that the Tomales Bay OsHV was similar to that identified in France with the exception of a single base pair substitution in a 917 bp fragment of the viral genome. However, unlike the French OsHV-1, the Tomales Bay OsHV did not amplify with the primer pair of a second OsHV-1 PCR assay, suggesting that further characterization of these viruses is warranted. No evidence of Cowdry type A viral infections characteristic of herpes virus infections or other pathogens were observed in OsHV-infected oysters. Hemocytosis, diapedesis and hemocyte degeneration characterized by nuclear pycnosis and fragmentation were observed in infected oysters, which is consistent with previous observations of OsHV infections in France. Together these data suggest that OsHV may be associated with the annual summer Pacific oyster seed mortality observed in Tomales Bay, but establishment of a causal relationship warrants further investigation.     

Detection of the oyster herpesvirus in commercial bivalve in northern California, USA: conventional and quantitative PCR

The ostreid herpesvirus (OsHV-1) and related oyster herpesviruses (OsHV) are associated with world-wide mortalities of larval and juvenile bivalves. To quantify OsHV viral loads in mollusc tissues, we developed a SYBR Green quantitative PCR (qPCR) based on the A-region of the OsHV-1 genome. Reaction efficiency and precision were demonstrated using a plasmid standard curve. The analytical sensitivity is 1 copy per reaction. We collected Crassostrea gigas, C. sikamea, C. virginica, Ostrea edulis, O. lurida, Mytilus galloprovincialis, and Venerupis phillipinarum from Tomales Bay (TB), and C. gigas from Drakes Estero (DE), California, U.S.A., and initially used conventional PCR (cPCR) to test for presence of OsHV DNA. Subsequently, viral loads were quantified in selected samples of all tested bivalves except O. lurida. Copy numbers were low in each species tested but were significantly greater in C. gigas (p < 0.0001) compared to all other species, suggesting a higher level of infection. OsHV DNA was detected with cPCR and/or qPCR and confirmed by sequencing in C. gigas, C. sikamea, C. virginica, O. edulis, M. galloprovincialis, and V phillipinarum from TB and C. gigas from DE. These data indicate that multiple bivalve species may act as reservoirs for OsHV in TB. A lack of histological abnormalities in potential reservoirs requires alternative methods for their identification. Further investigation is needed to determine the host-parasite relationship for each potential reservoir, including characterization of viral loads and their relationship with infection (via in situ hybridization), assessments of mortality, and host responses.     

Biological tags for stock separation in Pacific herring Clupea harengus pallasi in California.

A survey of the parasites of Pacific herring (Clupea harengus pallasi) off northern California identified 1 species of Acanthocephala, 1 species of Cestoda, 2 species of Copepoda, 1 species and 1 family of Digenea, 3 species of Nematoda, and 3 species of Protozoa. From this survey, Lacistorhynchus dollfusi (Cestoda), Parahemiurus merus (Digenea), and Anisakis simplex, Contracaecum sp., Hysterothylacium sp. (Nematoda) were selected as potential tags. Herring were collected in Tomales, San Francisco, and Monterey bays for the following 9 yr and examined for these select parasites. The results suggest that these parasites can be used to distinguish the spawning stocks of San Francisco and Tomales bays. The distribution of the definitive hosts of the respective parasites suggests that the Tomales Bay fish are offshore during the nonbreeding season and the San Francisco Bay fish onshore. The similarity in parasitism between San Francisco Bay and the nonspawning population in Monterey Bay suggests that these 2 populations represent a single stock.     

Factors Affecting Restoration of Halodule wrightii to Galveston Bay, Texas

Experimental restoration of Halodule wrightii (shoalgrass) to its former range on Galveston Island, Texas, began in April 1994. We tested the effects of site, planting density, water depth, and fertilizer addition on survival and growth through June 1996. Temperature, salinity, light transmittance, turbidity, and sediment properties at two restoration sites, Redfish Cove and Snake Island Cove, were similar to those in naturally occurring grassbeds in nearby Christmas Bay. Halodule survival, coverage, and new shoot densities were affected by site (significantly higher at Redfish Cove than at Snake Island Cove, which eventually failed), by planting density (significantly higher when planted on 0.25-m or 0.5-m centers rather than on 1.0-m centers), and by water depth (significantly higher when planted in relatively shallow water). Propagation (spreading from transplant units) was significantly greater from 0.25-m or 0.5-m center plantings but was not consistently affected by site or water depth. Fertilizer enhanced propagation but not survival. After two years, Redfish Cove produced belowground biomass similar to that observed in Christmas Bay, but aboveground biomass remained significantly less. Snake Island Cove plant mortality in September 1995 may have been presaged by low root-rhizome carbohydrate levels observed in October 1994, but causes remain unknown. Further restoration of Halodule to Galveston Bay is possible at selected sites, but structural equivalency will take longer than two growing seasons to achieve.     

Genetic and historical evidence disagree on likely sources of the Atlantic amethyst gem clam Gemma gemma (Totten, 1834) in California

Aim Historical information about source populations of invasive species is often limited; therefore, genetic analyses are used. We compared inference about source populations from historical and genetic data for the oyster‐associated clam, Gemma gemma that invaded California from the USA Atlantic coast. Location Mid‐Atlantic (North Carolina, Maryland), Northeastern (New Jersey, New York, Massachusetts) and the California coasts (Elkhorn Slough, San Francisco Bay, Bolinas Lagoon, Tomales Bay, Bodega Harbor). Methods The documented history of transplantation of Eastern oysters to California was reviewed. Cytochrome c oxidase subunit I (COI) sequences from recent and archived clams were examined in a haplotype network. We used AMOVA to detect geographic genetic structure and a permutation test for significant reductions in diversity. Results Chesapeake Bay oysters were transplanted to New York prior to shipment to San Francisco Bay and from there to peripheral bays. Gemma in the Northeastern and Mid‐Atlantic regions were genetically differentiated. In California, populations in Bodega Harbor and Tomales Bay were genetically similar to those in the Mid‐Atlantic area while clams in San Francisco Bay, Elkhorn Slough and Bolinas Lagoon resembled populations in the Northeastern region. In California, genetic variation was not highest in San Francisco Bay despite greater magnitude of oyster plantings. Haplotypes varied over time in native and introduced populations. Main Conclusions Historical records and inferences from genetics agree that both Northeastern and Mid‐Atlantic regions were sources for Gemma in California. Only complex genetic hypotheses reconcile the strong segregation of haplotypes in California to the historical evidence of mixing in their proximate source (New York). These hypotheses include sorting of mixtures of haplotypes or selection in non‐native areas. Haplotype turnover in San Francisco and Massachusetts samples over time suggests that the sorting hypothesis is plausible. We suggest, however, that Gemma was introduced independently and recently to Tomales Bay and Bodega Harbor.     

Pilot study of the Olympia oyster Ostrea conchaphila in the San Francisco Bay estuary: description and distribution of diseases

Olympia oysters Ostrea conchaphila have declined markedly during the last century and are a focus of restoration in many embayments, including the San Francisco Bay (SFB) estuary. Oysters were collected from 17 sites in this estuary and nearby Tomales Bay in an effort to characterize diseases that may impact recovery of this species and captive rearing programs. Three diseases/disease agents including a Mikrocytos-like protist (microcell), a haplosporidian and hemic neoplasia were observed from several sites along the western margins of the SFB estuary suggesting a geographic localization of disease presence. Based on fluoresecent in situ hybridization (FISH) assays, the microcell is distinct from M. mackini and Bonamia spp. These data highlight the need for further elucidation of the haplosporidian and for careful health management of a declining species destined for captive rearing and supplementation.     

Epizootiology of Minchinia nelsoni in susceptible wild oysters in Virginia, 1959 to 1971

Twelve years after the haplosporidian parasite Minchinia nelsoni erupted causing severe epizootics of oysters in lower Chesapeake Bay, regular patterns of mortalities and disease prevalence persisted. Distribution changed with salinity and weather patterns, but in mesohaline areas (about 15–25 ‰) infective pressure remained high and relatively stable despite scarcity of oysters.Susceptible disease-free oytsers from low-salinity areas of the James River, the major seed area in Virginia, were transplanted annually to disease-prevalent areas for monitoring in trays. Mortalities were usually over 50% the first year and almost as high in the second year. Prevalences of the pathogen, called MSX, ranged from 35 to 50% in live oysters. Seasonal patterns of disease activity are depicted from 1960 through 1971, and they exhibit exceptional regularity for open-water conditions. Source and history of oysters, and timing of exposure are important variables that affect disease activity as well as size and age. The disease caused by MSX appears to be not contagious in trays.The patterns of disease and mortality obtained from susceptible wild oysters without previous exposure provided a basis for evaluating other stocks including genetic strains selected for disease resistance.     

The occurrence and behaviour of phosphate fractions in Izmir Bay, Aegean Sea

The area around Izmir Bay (Turkey) is heavily urbanized and receives, therefore, high concentrations of phosphate originating from industrial and municipal inputs. During the surveys between April 1993 and July 1994, the total phosphate concentrations were highest in the Inner Bay (6.45 M and 5.59 M in the surface and bottom water, respectively) where very dense anthropogenic pollution occurs. The total phosphate value gradually decreased towards the Outer Bay where 0.70 M and 1.18 M were found in the surface and bottom water, respectively. The distribution of dissolved inorganic, dissolved organic and particulate phosphate along the bay reflected some peculiar spatial and temporal patterns. A high percentage of dissolved organic phosphate was observed in the Outer Bay while the particulate phosphate peaked in the Middle Bay where an upwelling mechanism was observed. In the bay, the biological production was strongly correlated with the variations in the dissolved inorganic, organic and particulate phosphate. The high phosphate concentration in particles caused the particulate phosphate formed in the Inner Bay to be transported to the outer parts of the bay because of the short water residence time. On the other hand, Principal Component Analysis showed that about 35% of the variation in all variables measured were related to the total phosphate, total dissolved phosphate, dissolved inorganic phosphate and particulate phosphate together with ammonium and reactive-Fe while about 14% of the variation was related to the dissolved organic phosphate and the number of phytoplankton cells, chl-a, pH and O₂.     

Vertical Distribution of Denitrification Potential,Denitrifying Bacteria,and Benzoate Utilization in Intertidal Microbial Mat Communities

Aspects of denitrification and benzoate degradation were studied in two estuarine microbial mat communities on the California coast by measuring the depth distributions of potential denitrification rates, genetic potential for denitrification, nitrate concentration, benzoate mineralization rates, total bacterial abundance, and abundance of a denitrifying strain (TBD-8b) isolated from one of the sites. Potential denitrification was detected in microbial mat cores from both Elkhorn Slough and Tomales Bay. Maximum denitrification rates were more than two orders of magnitude higher at Elkhorn Slough (3.14 mmol N m⁻² d⁻¹) than at Tomales Bay (0.02 mmol N m⁻² d⁻¹), and at both sites, the maximum rates occurred in the 0–2 mm depth interval. Ambient pore [NO₃+NO₂] was substantially higher at Elkhorn Slough than at Tomales Bay. Incorporation and mineralization of benzoate was maximal near the mat surface at Elkhorn Slough. The areal rate of benzoate utilization was 1045 nmol C m⁻² d⁻¹, which represented utilization of 70% of the added substrate in 24 h. Total bacterial and TBD-8b abundances were greatest near the surface at both Tomales Bay and Elkhorn Slough, and TBD-8b represented less than 0.2% of the total. Genetic potential for denitrification, quantified by hybridization with a nitrite reductase gene fragment, was present below the mat surface at average levels representing presence of the gene in approximately 10% of the total cells.     

Biochemical biomarkers in gills of mangrove oyster Crassostrea rhizophorae from three Brazilian estuaries

Responses of biochemical biomarkers were evaluated in gills of immature adult mangrove oyster Crassostrea rhizophorae collected in three estuarine regions along the Brazilian coast. In each region, ten oysters were collected in one reference site (R) located far from pollution sources, and in two polluted sites (P-I and P-II sites) located in another water body with similar characteristics. P-I site is located close to recognized pollution sources while P-II site is in the same water body, but far from pollution sources. At the Paranaguá Bay (Southern Brazil), polluted sites receive domestic, harbor and phosphate fertilizer plant discharges. High lipid peroxides (LPO) content was observed in winter oysters from the P-I site. In summer, higher catalase activity was observed in these oysters. In the Piraquê region (Southeastern Brazil), polluted sites receive domestic and agricultural effluents. Lower total oxyradical scavenging capacity (TOSC) towards peroxyradicals was observed in summer oysters from both P-I and P-II sites. In the Itamaracá region (Northeastern Brazil), polluted sites receive paper mill and caustic soda and chlorine factories effluents. Increased glutathione S-transferase (GST) activity was observed in oysters from the P-I site in both summer and winter. At Paranaguá Bay (higher latitude), no seasonal differences were observed in oysters from the R site, suggesting that temperature was not an important factor influencing biomarkers levels. Lower GST activity was observed in oysters from the R site of the Itamaracá Bay (lower latitude) in winter and summer. Taken together, data obtained point to responses of biomarkers in oysters from polluted sites of the three estuarine regions analyzed, indicating the need for future monitoring of the biological effects of contaminants in these environments. They also point to the relevance to consider both season and latitude as factors influencing biomarker responses in environmental contamination monitoring programs.     

Stable carbon and nitrogen isotopes in multiple tissues of wild and captive harbor seals (Phoca vitulina) off the California coast

Stable carbon and nitrogen isotope ratios (δ¹³C and δ¹⁵N) of serum, red blood cells (RBC), muscle, and blubber were measured in captive and wild northeast Pacific harbor seals (Phoca vitulina richardii) at three coastal California sites (San Francisco Bay, Tomales Bay, and Channel Islands). Trophic discrimination factors (Δ_{Tissue‐Diet}) were calculated for captive seals and then applied in wild counterparts in each habitat to estimate trophic position and feeding behavior. Trophic discrimination factors for δ¹⁵N of serum (+3.8‰), lipid‐extracted muscle (+1.6‰), and lipid‐blubber (+6.5‰) are proposed to determine trophic position. An offset between RBC and serum of +0.3‰ for δ¹³C and ?0.6‰ for δ¹⁵N was observed, which is consistent with previous research. Specifically, weaner seals (<1 yr) had large offsets, suggesting strong trophic position shifts during this life stage. Isotopic values indicated an average trophic position of 3.6 at both San Francisco Bay and Tomales Bay and 4.2 at Channel Islands. Isotopic means were strongly dependent on age class and also suggested that mean diet composition varies considerably between all locations. Together, these data indicate that isotopic composition of blood fractions can be an effective approach to estimate trophic position and dietary behavior in wild pinnipeds.     

Quantifying Ostreid Herpesvirus (OsHV-1) Genome Copies and Expression during Transmission

Understanding the pathogenic potential of a new pathogen strain or a known pathogen in a new locale is crucial for management of disease in both wild and farmed animals. The Ostreid herpesvirus-1 (OsHV-1), a known pathogen of early-life-stage Pacific oysters, Crassostrea gigas, has been associated with mortalities of juvenile oysters in many locations around the world including Tomales Bay, California. In two trials, the California OsHV-1 strain was transmitted from infected juvenile C. gigas to naïve C. gigas larvae. Survival of control larvae was high throughout both trials (97–100%) and low among those exposed to OsHV-1. No OsHV-1-exposed larvae survived to day 9 in trial 1, while trial 2 was terminated at day 7 when survival was 36.90?±?8.66%. To assess the amount of OsHV-1 DNA present, we employed quantitative polymerase chain reaction (qPCR) assays based on the A fragment and OsHV-1 catalytic subunit of a DNA polymerase δ (DNA pol) gene. Viral genome copy numbers based on qPCR assays peaked between 3 and 5 days. To measure the presence of viable and actively transcribing virus, the DNA pol gene qPCR assay was optimized for RNA analysis after being reverse transcribed (RT-qPCR). A decline in virus gene expression was measured using RT-qPCR: relative to earlier experimental time points copy numbers were significantly lower on day 9, trial 1 (p?p?p?p?相似文献   

Relationship between biofouling and growth of the pearl oyster pinctada fucata (Gould) in Kuwait,Arabian Gulf

Results are presented from a three-year investigation of the relationship between accumulations of marine fouling organisms and growth of the pearl oyster Pinctada fucata (Gould). Estimates are provided of the diversity of the foulers, and data on certain hydrological features of the experimental site are also given.There was an inverse correlation between growth of the pearl oyster and diversity of the biofouling assemblages, whatever depth. Growth curves did not follow seasonal variations in the environmental factors very exactly. It was also observed that the polychaete, Polydora vulgaris Mohammad, preferred the oysters planted on the bottom to those suspended near the surface. Bottom oysters suffered the highest mortality, but definite evidence of a relationship between mortality and infestation by the polychaete was not apparent. Percentages of both infestation and mortality were higher among the fouled oysters than those cleaned periodically.     

High mortality of Pacific oysters in a cold winter in the North-Frisian Wadden Sea

Mortality of introduced Pacific oysters (Crassostrea gigas) was studied in the northern Wadden Sea in response to an ice winter. After a decade of mild winters, in January and February 2010, the first severe winter occurred since the Pacific oysters became dominant on former intertidal blue mussel (Mytilus edulis) beds in the North-Frisian Wadden Sea. After the ice winter, mortality of Pacific oysters on densely populated beds in the List tidal basin reached about 90%, indicating much higher losses in comparison to former mild winters. At lower densities between the islands of Amrum and Föhr, oysters were less or even not affected. Although Pacific oysters are assumed to be very tolerant to frost, the duration of cold water- and air temperatures accompanied by mechanical stress of the ice burden might have caused the high mortality in the winter 2009/2010 in formerly dense beds.     

QTL for resistance to summer mortality and OsHV‐1 load in the Pacific oyster (Crassostrea gigas)

Summer mortality is a phenomenon severely affecting the aquaculture production of the Pacific oyster (Crassostrea gigas). Although its causal factors are complex, resistance to mortality has been described as a highly heritable trait, and several pathogens including the virus Ostreid Herpes virus type 1 (OsHV‐1) have been associated with this phenomenon. A QTL analysis for survival of summer mortality and OsHV‐1 load, estimated using real‐time PCR, was performed using five F₂ full‐sib families resulting from a divergent selection experiment for resistance to summer mortality. A consensus linkage map was built using 29 SNPs and 51 microsatellite markers. Five significant QTL were identified and assigned to linkage groups V, VI, VII and IX. Analysis of single full‐sib families revealed differential QTL segregation between families. QTL for the two‐recorded traits presented very similar locations, highlighting the interest of further study of their respective genetic controls. These QTL show substantial genetic variation in resistance to summer mortality, and present new opportunities for selection for resistance to OsHV‐1.     

Ostreid Herpesvirus 1 Infection among Pacific Oyster (Crassostrea gigas) Spat: Relevance of Water Temperature to Virus Replication and Circulation Prior to the Onset of Mortality

A number of bivalve species worldwide, including the Pacific oyster, Crassostrea gigas, have been affected by mass mortality events associated with herpesviruses, resulting in significant losses. A particular herpesvirus was purified from naturally infected larval Pacific oysters, and its genome was completely sequenced. This virus has been classified as Ostreid herpesvirus 1 (OsHV-1) within the family Malacoherpesviridae. Since 2008, mass mortality outbreaks among C. gigas in Europe have been related to the detection of a variant of OsHV-1 called μVar. Additional data are necessary to better describe mortality events in relation to environmental-parameter fluctuations and OsHV-1 detection. For this purpose, a single batch of Pacific oyster spat was deployed in 4 different locations in the Marennes-Oleron area (France): an oyster pond (“claire”), a shellfish nursery, and two locations in the field. Mortality rates were recorded based on regular observation, and samples were collected to search for and quantify OsHV-1 DNA by real-time PCR. Although similar massive mortality rates were reported at the 4 sites, mortality was detected earlier in the pond and in the nursery than at both field sites. This difference may be related to earlier increases in water temperature. Mass mortality was observed among oysters a few days after increases in the number of PCR-positive oysters and viral-DNA amounts were recorded. An initial increment in the number of PCR-positive oysters was reported at both field sites during the survey in the absence of significant mortality. During this period, the water temperature was below 16°C.     

The Influence of Environmental Variables on the Distribution and Abundance of Three Elasmobranchs in Tomales Bay, California

We tested the hypothesis that temperature, salinity, and dissolved oxygen affect elasmobranch distribution and abundance in Tomales Bay, California, with monthly longline samples over a 20 month period. We used a Poisson regression under generalized least squares and found that temperature and salinity were the most important factors determining the distribution and abundance of the three most common elasmobranch species, bat ray, Myliobatis californica, leopard shark, Triakis semifasciata, and brown smoothhound shark, Mustelis henlei. Females of all three species were more abundant than males throughout the Bay, and were most abundant in the warmer, more saline inner bay. All three species apparently left Tomales Bay in late fall as water temperatures in the bay decreased to <10–12° C, and returned in early spring after temperatures increased to > 10° C. Three of 257 bat rays tagged in Tomales Bay were recaptured, all within 1km of their tagging location despite having been free for up to 583d.     

象山港熊本牡蛎幼体分布、附着及生长的空间格局

牡蛎幼体迁移与附着影响着牡蛎的空间分布、资源补充、种群维持及生态服务功能。本研究通过野外调查,监测了1个完整潮汐周期(9个潮时采样)内象山港2个试验点(采苗场和产卵场)表层、底层水体中熊本牡蛎幼体的时空动态,并开展野外附着试验,检验了熊本牡蛎在2个试验点和3个潮区(上层T、中层M和底层B)附着及生长的空间格局。结果表明: 在1个完整潮汐周期内,2个试验点表层水体中牡蛎幼体丰度均有显著的时间变化,采苗场表层水体中熊本牡蛎幼体丰度最大值(20.8±5.6 ind·L^-1)出现于高平潮时,显著高于其他8个潮时;而产卵场相反,高平潮时牡蛎幼体丰度最低(0.1±0.1 ind·L^-1);2个试验点底层水体中牡蛎幼体丰度在不同潮时之间均无显著差异。采苗场附着牡蛎总丰度、成活率和壳高在不同潮区间差异显著,牡蛎总丰度大小顺序为B>T=M,成活率和壳高的大小顺序为T>M>B,活体牡蛎丰度在潮区之间无显著差异。产卵场附着牡蛎总丰度、成活率、活体牡蛎丰度和壳高在不同潮区之间均无显著差异。表明高平潮时是熊本牡蛎附着的主要时段,产卵场和采苗场具有相似的牡蛎稚贝附着密度。     

Effects of treating seed potatoes from commercial and stem cutting stocks with benomyl, thiabendazole and 2-aminobutane on yield and disease

Potato seed tubers of six cultivars from commercial stocks and from stocks derived from stem cuttings (healthier seed) were fumigated with 2-aminobutane 2 wk after lifting or treated with benomyl or thiabendazole in January. 2-aminobutane prevented skin spot and gangrene developing on treated tubers. Experiments were planted at Rothamsted (clay with flints soil) and at Woburn (sandy loam soil) in 1973–75. Healthier seed produced more stems/plant than commercial stocks and yielded on average 8% more at Rothamsted in 1973 and 1974 and respectively 5 and 10% more at Woburn in 1973 and 1975. Seed treatments did not consistently affect stem numbers or increase yield although all treatments tended to decrease tuber size. Infection of stem bases and tubers by Polyscytalum pustulans and Rhizoctonia solani was usually less from healthier than from commercial seed and was decreased by benomyl and thiabendazole in 1973 and 1974. Infection by Helminthosporium solani of the skin around tuber eyes was greater from healthier than from commercial seed but was decreased by benomyl and thiabendazole. 2-aminobutane sometimes decreased infection of tubers by P. pustulans and R. solani but neither of stem bases nor of tubers by H. solani. Gangrene on tubers uniformly wounded at lifting was not consistently affected by seed source or seed treatment. Treating seed with benomyl or thiabendazole in 1975 decreased skin spot and black scurf in tubers stored until March 1976. These treatments also decreased silver scurf on the produce of commercial seed at Rothamsted but gangrene was not consistently affected by seed treatments.     

Ecosystem carbon stocks of mangrove forests along the Pacific and Caribbean coasts of Honduras

Among the many ecosystem services provided by mangrove ecosystems, their role in carbon (C) sequestration and storage is quite high compared to other tropical forests. Mangrove forests occupy less than 1 % of tropical forested areas but account for approximately 3 % of global carbon sequestration by tropical forests. Yet there remain many areas where little data on the size and variation of mangrove C stocks exist. To address this gap and examine the range of C stocks in mangroves at landscape scales, we quantified C stocks of Honduran mangroves along the Pacific and Caribbean coasts and the Bay Islands. We also examined differences in ecosystem C stocks due to size and structure of mangrove vegetation found in Honduras. Ecosystem C stocks ranged from 570 Mg C ha^?1 in the Pacific coast to ~1000 Mg C ha^?1 in Caribbean coast and the Bay Islands. Ecosystem C stocks on the basis of mangrove structure were 1200, 800 and 900 Mg C ha^?1, in low, medium and tall mangroves, respectively. We did not find significant differences in ecosystem C stocks on the basis of location (Pacific coast, Caribbean coast and Bay Islands) or mangrove type (low, medium and tall). Mangrove soils represented the single largest pool of total C in these ecosystems, with 87, 81 and 94 % at the Pacific coast, Caribbean coast and the Bay Islands, respectively. While there were no significant differences in total ecosystem stocks among mangrove types, there were differences in where carbon is stored. Mangrove soils among low, medium and tall mangroves contained 99, 93 and 80 % of the total ecosystem C stocks. In addition, we found a small yet significant negative correlation between vegetation C pools and pore water salinity and pH at the sampled sites. Conversion of mangroves into other land use types such as aquaculture or agriculture could result in loses of these soil C reserves due to mineralization and oxidation. Coupled with their other ecosystem services, an understanding of the size of mangrove ecosystem C stocks underscores their values in the formulation of conservation and climate change mitigation strategies in Central America.