Population attributes of Littoraria angulifera (Gastropoda: Littorinidae) in mangroves in Bahia State, northeastern Brazil

Littoraria angulifera (Lamarck, 1822) is an estuarine gastropod of tropical occurrence, which lives mainly on trunks of mangrove tree species. This study aimed to evaluate the population attributes of this species, such as abundance, space-time distribution, sex ratio and recruitment in mangroves in Bahia State, northeastern Brazil. The specimens were collected monthly throughout 2018, on trunks of the red mangrove Rhizophora mangle L. at two heights and on two horizontal levels. Specimens that were on the marine grass Spartina alterniflora Loisel were also collected. After counting, biometrics and sexing, the specimens were returned alive to the environment. The average size and weight of L. angulifera was higher (p<0.05) in places with taller and less sparse trees and the vertical distribution on the trunks showed a preference for strata close to the soil. Both results are related to shading and protection against desiccation. Females were more abundant than males, at an approximate sex ratio F: M of 1.4: 1. Recruits were observed throughout the period, showing continuous reproduction of the species with a recruitment peak in spring (September to November). The study revealed the importance of keep the mangroves intact to allow the maintenance of the natural stocks of the species.

A preliminary investigation of endophytic fungal diversity at Hope, East Coast Demerara, Guyana

Foliar endophytic fungi spend a part of their life cycle on the leaves of plants. They may demonstrate no apparent symptoms but may also cause disease at a later time in the plant’s life. Studies investigating foliar fungal endophytes of mangroves are limited. Therefore, the purpose of this study was to investigate the foliar fungal endophytes present on the leaves of three mangrove species: namely Red mangrove (Rhizophora mangle), Black mangrove (Avicennia germinans) and White mangrove (Laguncularia racemosa). The study site was an area located at Hope, East Coast Demerara, and South America, Guyana. Out of sixty (60) leaf samples that were prepared, fourteen (14) fungal isolates were identified. Most of the fungi isolated in the study were found to be Hyphomycetes (Aspergillus, Fusarium, Penicillium, Alternaria, Cladosporium and Curvularia) while the others were Zygomorphic (Mucor and Rhizopus). The ANOVA calculations for the isolates from the three mangrove species were found to not be statistically significant. R mangle was the preferred host out of the three (3) species. The findings of this study confirm that mangroves have rich endophytic diversity and demonstrate rich research and biochemical potential.

Influence of Edaphic Salinity on Leaf Morphoanatomical Functional Traits on Juvenile and Adult Trees of Red Mangrove (Rhizophora mangle): Implications with Relation to Climate Change

Rhizophora mangle L. is one of the most distributed species of neotropical mangroves. The species exhibits great phenological variability that is associated with saline concentrations of the sediment where it grows. Among the organs that are most affected by interstitial and tidal water salinity concentrations are the leaves. Since the hypersalinity generates water deficiency, it changes photosynthetic and hydraulic processes of the plant. To understand the relationship between the variation in leaf blade parameters and the water stress generated by salinity in two growth stages, morphoanatomical functional traits were quantified in leaves of juveniles and adults of R. mangle in three structurally different mangrove forests with different ranges of natural salinity (Oligohaline: 5.8–11.7 practical salinity units (PSU); Euhaline: 9.2–35.6 PSU and 23.9–47.7 PSU). We hypothesized that water stress caused by salinity generates modification in conductivity, water-storage, and photosynthetic tissues. Our results showed a greater number of morphoanatomical traits affected by salinity in juveniles compared to adults, greater variability in the traits associated with water accumulation and transport. Adults and juveniles subjected to higher values of salinity had traits more tolerant of variability in this factor, allowing superior adaptation to environments with high water deficit than individuals originating in oligohaline environments. This difference in adaptability to salinity between populations of R. mangle may imply different responses to climate change, where populations of oligohaline origin will be more susceptible to hypersalinization resulting from this phenomenon, while populations of euhaline origin could more effectively tolerate the aquatic stresses caused, allowing a prolongation of their permanence and the provision of their ecosystem services over time.

Strategies for Successful Mangrove Living Shoreline Stabilizations in Shallow Water Subtropical Estuaries

By combatting erosion and increasing habitat, mangrove living shorelines are an effective alternative to hard-armoring in tropical and subtropical areas. An experimental red mangrove living shoreline was deployed within Mosquito Lagoon, Florida, using a factorial design to test the impact of mangrove age, breakwater presence, and mangrove placement on mangrove survival within the first year of deployment. Mixed mangrove age treatments were included to identify if seedling (11-month-old) survival could be enhanced by the presence of transitional (23-month-old) and adult (35 to 47-month-old) mangroves. Environmental factors were monitored to detect possible causes of mangrove mortalities. Approximately half (50.6%) of mangroves died, and of those, 90.7% occurred within the annual high-water season, and 88.9% showed signs of flooding stress. Planting seedlings haphazardly among older mangroves did not attenuate enough wave energy to significantly increase seedling survival. Breakwaters alleviated stress through a reduction in water velocity and wave height, increasing the odds of survival by 197% and 437% when mangroves were planted in the landward and seaward rows, respectively. Compared to seedlings, deployment of adult mangroves increased survival odds by 1087%. Collectively, our results indicate that sites with a high-water season should utilize a breakwater structure and mangroves with a woody stem.

First Molecular Characterization of Colletotrichum sp. and Fusarium sp. Isolated from Mangrove in Mexico and the Antagonist Effect of Trichoderma harzianum as an Effective Biocontrol Agent

The aim of this study was to characterize potential fungal species affecting mangrove species in Mexico. The phytopathogens were identified based on morphological and molecular characteristics using internal transcribed spacer (ITS1/ITS4) primers then sequenced and compared with the other related sequences in GenBank (NCBI). Three fungal species were identified as <i>Colletotrichum queenslandicum</i> (Weir and Johnst, 2012) from black mangrove (<i>Avicennia germinans</i>); <i>Colletotrichum ti</i> (Weir and Johnst, 2012) from white mangrove (<i>Laguncularia racemosa</i>) and buttonwood mangrove (<i>Conocarpus erectus</i>); <i>Fusarium equiseti</i> (Corda) from red mangrove (<i>Rhizophora mangle</i>). In addition, <i>C. ti</i> and <i>F. equiseti</i> were identified from mango <i>Mangifera indica</i> L. sampled close by the mangrove area. This study provides first evidence of anthracnose on four mangrove species caused by <i>Colletotrichum</i> and <i>Fusarium</i> species in the “Términos” coastal lagoon in Campeche State southern Mexico. This is the first time that <i>C. queenslandicum</i> and <i>C. ti</i> are reported in Mexico. <i>F. equiseti</i> has not been reported affecting <i>M. indica</i> and <i>R. mangle</i> until the present work. Little is known regarding fungal diseases affecting mangroves in Mexico. These ecosystems are protected by Mexican laws and may be threatened by these pathogenic fungus. This is the first report of the effect of <i>Trichoderma harzianum</i> TRICHO-SIN as an effective biological control against of <i>Colletotrichum</i> and <i>Fusarium</i> species.

Diversity of mangrove fungal endophytes from selected mangrove species of coastal Kenya

Endophytes are bacteria or fungi living asymptomatically in the internal tissues of plants. They are symbiotic in nature and can be exploited for novel bioactive metabolites with applications in agriculture, medicine and industry. Mangrove fungal endophytes from the marine environment are abundant and have been recognized as sources of bioactive natural products. The study was designed to isolate, purify and identify mangrove fungal endophytes from selected common mangrove species of Gazi Bay, Tudor and Mida creek on the Kenya coast. The colonization rate and isolation rate of the mangrove fungal endophytes were determined. The studied mangrove species were Rhizophora mucronata (red mangrove), Sonneratia alba (mangrove apple), Avicennia marina (grey or white mangrove), and Ceriops tagal (spurred mangrove). Samples from twigs of these mangrove species were collected and analyzed using standard methods. Isolation of pure cultures of the endophytes was performed using Potato Dextrose Agar (PDA) incubated at 28 ± 1ºC for 5 days. The fungal isolates were identified under a light microscope based on colony morphology characteristics, type and presentation of conidiophores and conidia. A total of 18 different mangrove fungal endophytes were identified and these belonged to 5 genera. These were Aspergillus, Penicillium, Fusarium, Cephalosporium and Blastomyces, with Aspergillus being the most dominant genus. Tudor Creek recorded the highest fungal community diversity (H’ = 1.35) and Gazi Bay had the lowest diversity (H’ = 0.45). Fungal community similarity based on the identified genera was highest between Gazi Bay and Mida Creek (0.80) and lowest between Tudor Creek and Mida Creek (0.57). The selected mangrove species recorded a colonization rate of endophytic fungi of between 38.9 – 94.4 % with the highest habitation being associated with S. alba and C. tagal. There were differences and similarities in the colonization rate within mangrove species across study sites. Findings of this study have confirmed that the selected mangrove species exhibit high diversity of fungal endophytes with host recurrence and spatial heterogeneity.

From Mangrove to Fork: Metal Presence in the Guayas Estuary (Ecuador) and Commercial Mangrove Crabs

Mangrove wetlands provide essential ecosystem services such as coastal protection and fisheries. Metal pollution due to industrial and agricultural activities represents an issue of growing concern for the Guayas River Basin and related mangroves in Ecuador. Fisheries and the related human consumption of mangrove crabs are in need of scientific support. In order to protect human health and aid river management, we analyzed several elements in the Guayas Estuary. Zn, Cu, Ni, Cr, As, Pb, Cd, and Hg accumulation were assessed in different compartments of the commercial red mangrove crab Ucides occidentalis (hepatopancreas, carapax, and white meat) and the environment (sediment, leaves, and water), sampled at fifteen sites over five stations. Consistent spatial distribution of metals in the Guayas estuary was found. Nickel levels in the sediment warn for ecological caution. The presence of As in the crabs generated potential concerns on the consumers’ health, and a maximum intake of eight crabs per month for adults is advised. The research outcomes are of global importance for at least nine Sustainable Development Goals (SDGs). The results presented can support raising awareness about the ongoing contamination of food and their related ecosystems and the corresponding consequences for environmental and human health worldwide.

Rhizophora mangle (red mangrove).

A datasheet on Rhizophora mangle covering, as an economically important tree, its taxonomy, importance, silviculture, distribution, biology and ecology, uses, products and pests.