Physiological responses of scleractinian corals in marginal habitat

Polapa FS, Werorilangi S, Ali SM, Jompa J. 2021. Physiological responses of scleractinian corals in marginal habitat. Biodiversitas 22: 4011-4018. This study aims to analyze physiological differences in corals in marginal habitats. Under different conditions, the production/respiration (P/R) ratio and photobiology of various coral genera were compared. Samples were taken from three coral reef zones representing typical reef habitats and from the mangrove ecosystem as a marginal habitat. Surveys revealed two coral genera surviving in extreme conditions (marginal habitat). The P/R ratio measurements indicated that corals living in the mangrove ecosystem tend to be heterotrophic. This was supported by observations of colonies with tentacles extended from the corallites. Furthermore, Porites living in the mangrove habitat consume more O2 directly than saving it for other purposes, such as growth. The genus Dipsastraea exhibited elevated zooxanthellae density in the mangrove ecosystem, whereas Porites exhibited similar densities in both ecosystems.

Fungal succession on the decomposition of three plant species from a Brazilian mangrove

Leaf decomposition is the primary process in release nutrients in the dynamic mangrove habitat, supporting the ecosystem food webs. On most environments, fungi are an essential part of this process. However, due to the peculiarities of mangrove forests, this group is currently neglected. Thus, this study tests the hypothesis that fungal community display an specific succession pattern in different mangrove species. A molecular approach was employed to investigate the dynamics of the fungal community during the decomposition of three common plant species (Rhizophora mangle, Laguncularia racemosa, and Avicennia schaueriana) from the mangrove habitat located at the southeast of Brazil. Plant material was the primary driver of fungi communities but time also was marginally significant for the process, and evident changes in the fungal community during the decomposition process were observed. The five most abundant classes common to all the three plant species were Saccharomycetes, Sordariomycetes, Tremellomycetes, Eurotiomycetes, and Dothideomycetes, all belonging to the Phylum Ascomycota. Microbotryomycetes class were shared only by A. schaueriana and L. racemosa, while Agaricomycetes class were shared by L. racemosa and R. mangle. The class Glomeromycetes were shared by A. schaueriana and R. mangle. The analysis of the core microbiome showed that Saccharomycetes was the most abundant class. In the variable community, Sordariomycetes was the most abundant one, mainly in the Laguncularia racemosa plant. The results presented in this work shows a specialization of the fungal community regarding plant material during mangrove litter decomposition.

Mangrove Health Assessment and Genetic Diversity of Associated Sesarmid Crab Parasesarma Persicum in Nayband National Park, Iran

Mangrove forests as one of the most important coastal ecosystems provide important ecological and economic performance to the world, have been threatened by developmental human activities and subsequent land use changes. The present study aims to assess mangrove ecosystem health in Nayband Marine National Park, Iran using Mangrove Quality Index (MQI), in addition to analyse the effect of mangrove habitat quality on the genetic diversity of Parasesarma persicum the associated mangrove crab by amplified fragment length polymorphism (AFLP). Four stations were studied for mangrove quality index analysis as well as genetic analysis. The results of MQI survey based on hydrology, water, soil, biota criteria indicated moderate to low habitat quality of mangroves in the study area. Station 4 in the southern Nayband gulf showed highest impact by human activities and MQI of 0.7, indicating serious habitat alteration in this area. Station 2 in the northern part of Nayband gulf showed a moderate mangrove quality (MQI = 0.5). Based on the results of the AFLP genetic assessment, the estimated heterozygosity(He) of crabs was between 0.29 to 0.32 with a mean of 0.30. The highest genetic diversity was found at station 2, however, no complete population differentiation was observed between 4 stations. The analysis revealed a significant correlation between mangrove habitat alteration and heterozygosity reduction (P<0.05). Based on the results of the present study, mangrove habitat destruction due to anthropogenic activities may directly reduce the genetic diversity of associated species of this ecosystem.

Threatened Mangroves in the Anthropocene: Habitat Fragmentation in Urban Coastalscapes of Pelliciera spp. (Tetrameristaceae) in Northern South America

Mangroves are fragmented habitats thriving in human-dominated coastalscapes worldwide. They provide refuge to threatened plant species, such as the Neotropical Piñuelo Mangrove (formerly the monotypic Pelliciera genus, recently split into two species: P. rhizophorae and P. benthamii). However, little is known about the relationship between urbanization and the spatial configuration of mangrove habitat and how it would drive ecological and evolutionary changes in the small populations of Pelliciera spp. We used open data (e.g., land cover, mangrove cover) for 107 locations of Pelliciera spp. in Colombia (extant populations) to assess coastalscape structure and urbanization. We described coastalscape composition dynamics (for 2000 and 2010) and mangrove habitat configuration along a human-domination gradient, using landscape metrics. We computed an urban index to compare urbanization intensity among the study areas along the Caribbean coast and compared coastalscape structure and mangrove spatial metrics between basins (Caribbean and Pacific). The proportion of artificial surfaces was greater in the Caribbean than in the Pacific, but no temporal difference was found. The Caribbean basin exhibited a greater Urban Index, particularly in Cartagena and Urabá. Mangrove fragmentation was also greater in the Caribbean and it was influenced by the degree of urbanization. Mangrove area and core area were smaller in the Caribbean than in the Pacific, while cohesion was significantly lower in Cartagena than in other urban areas of the Caribbean. We propose a conceptual eco-evolutionary framework for linking mangrove patch reduction and isolation to demographic variables of Pelliciera spp. Edge effects are expected to affect birth and mortality rates in small patches. Small patches and small effective populations are expected to be more sensitive to novel biotic interactions, extreme weather, and gradual climate change. Isolation will also influence both emigration and immigration rates of propagules. We propose: (1) Assessing the conservation status of the two species, (2) setting monitoring programs of their populations of Pelliciera spp. and their surrounding coastalscapes (particularly in the Caribbean, (3) declaring protected areas, in wild and urban settings, to reduce mangrove fragmentation and urbanization.

Niger Delta Remediation – Complex Balancing among the Local Community, Government Agencies, NGOs, Cleanup Contractors, and the Petroleum Industry; An Example from Bodo Ogoniland, Nigeria.

ABSTRACT Oil-related damage to productive mangrove habitat is prevalent in most areas of the Niger Delta where oil operations (drilling, pipelines and oil export) are present. The remediation and restoration of these areas is one of the most intractable problems confronting the oil industry and government today. The formation of the Bodo Mediation Initiative (BMI) with a partnership between the various parties has been mostly successful to date and offers a path forward to other parts of the Delta. Ogoniland, where Bodo is located, has a long history of agitations against the oil industry as a result of dwindling livelihoods and deteriorating public health largely perceived to be caused by the degradation in environmental quality due to oil spills. In 2008, two large oil spills occurred from operational breaks in the Trans Niger Pipeline and subsequently ~1000 ha of mangroves were directly killed by the spills. From 2009 onward, spills from illegal activities (oil theft, transport and refining) became common, inhibiting potential mangrove recovery further affecting the livelihood of many Bodo residents. The BMI was formed in 2013 under the auspices of the Dutch Ambassador to Nigeria with a focus on building trust between the pipeline operating oil company and the local community, in order to initiate cleanup and restoration of the damaged mangrove habitat around Bodo. The mediation process of the BMI was fraught with difficulties due to internal community squabbles arising largely from a misperception regarding the attendant benefits to the community. After a series of delays and mediation efforts, cleanup began in 2017 and continues until present (2019) with planned continuance to 2020. While the Project has obtained many successes, the inability to prevent continuing oil theft and illegal refining is a notable failure, causing continued spillages to the area and setbacks to the cleanup and restoration program being undertaken.

Fish Community in Different Mangrove Habitat in Banyuurip Ujung Pangkah – Gresik Regency

Mangroves are an important habitat for fish communities, as spawning, growing and foraging areas. This study aims to compare the species composition, presence frequency and structure of fish communities in different mangrove habitats. The research was conducted at Banyuurip Mangrove Center, Ujung Pangkah District, Gresik Regency, East Java, during July-August 2020. Determination of purposive sampling locations based on physical differences in mangrove habitats. Systematic sampling method was used to estimate the number of mangrove species using belt transects. Fish sample collection uses basic gill nets that are placed at high tide in each mangrove habitat. The results showed that the total number of individual mangrove vegetation was 505 from 12 species, the number of species and individual mangrove vegetation differed between habitats, and the highest was found in coastal mangrove habitats. The number of fish was found as many as 181 individuals from 11 species, 10 families and 5 orders. The number and composition of species, families and fish orders differ between mangrove habitats, with the highest number in coastal mangrove habitats. Mozambique tilapia (Oreochromis mossambicus) dominate the estuary mangrove habitat and giant trevally (Caranx sexfasciatus) dominate the coastal mangrove habitat. There are variations in the structure of fish communities between mangrove habitats, the dominance index value of the fish community in the estuary mangrove habitat is higher and in the medium category, while the coastal mangrove habitat is in the low category. On the other hand, the diversity index value of the fish community in the coastal mangrove habitat is in the high category and the estuary mangrove habitat is in the low category.

Composition and Density of Gastropode in Mangrove Habitat of Banyuurip, Ujung Pangkah - Gresik

Gastropods are one of the biota that live in association with mangrove habitat. This study aims to compare the species composition and structure of the gastropod community in different mangrove habitats. This research was conducted in Banyuurip Mangrove Center (BMC), Ujung Pangkah-Gresik during July-August 2020. Determination of the observation station purposively based on physical differences in mangrove habitat. Estimation of mangrove and gastrode density by systematic sampling method using belt transects. There were 12 mangrove species with the highest number of species in the coastal mangrove habitat, with the highest species composition and density of Avicennia marina. The highest mangrove density was found in coastal mangrove habitats for all criteria. The number of gastropods found were 2,171 specimens belonging to 15 species, 5 families and 5 orders. The highest number of species, families and orders in coastal mangrove habitat were 1,191 specimens, 11 species from 5 families and 5 orders, the lowest was in estuarine mangrove habitat as many as 980 specimens from 9 species, 2 families and 2 orders. Densities of gastropods differ between mangrove habitats, with the highest density in coastal mangrove habitats and the lowest in estuarine mangrove habitats. The composition and density of the highest gastropods species in the estuary mangrove habitat is Cassidula aurisfelis and in the coastal mangrove habitat is Pirenella cingulata. The importance of conservation and rehabilitation efforts for mangroves that have been degraded to support the gastropods associated in it.